ANTHROPIC_API_KEYAuthentication | — Documented | Primary API key for Claude API |
ANTHROPIC_AUTH_TOKENAuthentication | — Documented | Alternative bearer token; takes priority over API key |
ANTHROPIC_AWS_API_KEYCloud providers | — Documented | — |
ANTHROPIC_AWS_BASE_URLCloud providers | — Documented | — |
ANTHROPIC_AWS_WORKSPACE_IDCloud providers | — Documented | — |
ANTHROPIC_BASE_URLNetwork and proxy | — Documented | Custom endpoint for Anthropic services |
ANTHROPIC_BEDROCK_BASE_URLCloud providers | — Documented | Alternative Bedrock endpoint (alias) |
ANTHROPIC_BEDROCK_MANTLE_BASE_URLCloud providers | — Documented | — |
ANTHROPIC_BEDROCK_REGION_PREFIXCloud providers | — Documented | — |
ANTHROPIC_BEDROCK_SERVICE_TIERCloud providers | — Documented | — |
ANTHROPIC_BETASOther | — Documented | Comma-separated beta feature headers |
ANTHROPIC_CUSTOM_HEADERSOther | — Documented | Custom HTTP headers (newline-separated Key: Value) |
ANTHROPIC_CUSTOM_MODEL_OPTIONModels and thinking | — Documented | — |
ANTHROPIC_CUSTOM_MODEL_OPTION_DESCRIPTIONModels and thinking | — Documented | — |
ANTHROPIC_CUSTOM_MODEL_OPTION_NAMEModels and thinking | — Documented | — |
ANTHROPIC_CUSTOM_MODEL_OPTION_SUPPORTED_CAPABILITIESModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_FABLE_MODELModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTIONModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_FABLE_MODEL_NAMEModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIESModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_HAIKU_MODELModels and thinking | — Documented | Override Haiku model ID |
ANTHROPIC_DEFAULT_HAIKU_MODEL_DESCRIPTIONModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_HAIKU_MODEL_NAMEModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIESModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_MODELModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_OPUS_MODELModels and thinking | — Documented | Override Opus model ID |
ANTHROPIC_DEFAULT_OPUS_MODEL_DESCRIPTIONModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_OPUS_MODEL_NAMEModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_OPUS_MODEL_SUPPORTED_CAPABILITIESModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_SONNET_MODELModels and thinking | — Documented | Override Sonnet model ID |
ANTHROPIC_DEFAULT_SONNET_MODEL_DESCRIPTIONModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_SONNET_MODEL_NAMEModels and thinking | — Documented | — |
ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIESModels and thinking | — Documented | — |
ANTHROPIC_FEDERATION_RULE_IDOther | — Documented | — |
ANTHROPIC_FOUNDRY_API_KEYCloud providers | — Documented | Foundry API key |
ANTHROPIC_FOUNDRY_AUTH_TOKENCloud providers | — Documented | — |
ANTHROPIC_FOUNDRY_BASE_URLCloud providers | — Documented | Custom Foundry endpoint |
ANTHROPIC_FOUNDRY_RESOURCECloud providers | — Documented | Foundry resource name |
ANTHROPIC_LOGDebugging | — | SDK internal logging level |
ANTHROPIC_MODELModels and thinking | — Documented | Override the default Claude model |
ANTHROPIC_ORGANIZATION_IDOther | — Documented | — |
ANTHROPIC_PROFILEDebugging | — Documented | — |
ANTHROPIC_SMALL_FAST_MODELModels and thinking | — Documented | Override small/fast model for quick operations |
ANTHROPIC_SMALL_FAST_MODEL_AWS_REGIONCloud providers | — Documented | AWS region for small fast model on Bedrock |
ANTHROPIC_VERTEX_BASE_URLCloud providers | — Documented | — |
ANTHROPIC_VERTEX_PROJECT_IDCloud providers | — Documented | Google Cloud project ID |
ANTHROPIC_WORKSPACE_IDOther | — Documented | — |
API_FORCE_IDLE_TIMEOUTNetwork and proxy | — Documented | — |
API_TIMEOUT_MSNetwork and proxy | — Documented | Request timeout in milliseconds |
AWS_BEARER_TOKEN_BEDROCKCloud providers | — Documented | Bearer token for Bedrock authentication |
BASH_DEFAULT_TIMEOUT_MSNetwork and proxy | — Documented | — |
BASH_MAX_OUTPUT_LENGTHShell and tools | — Documented | Max bash output character length |
BASH_MAX_TIMEOUT_MSNetwork and proxy | — Documented | — |
BETA_TRACING_ENDPOINTOther | — Documented | Custom endpoint for beta tracing |
CCR_FORCE_BUNDLEFeature toggles | — Documented | — |
CLAUDECODEOther | — Documented | Set to 1 in child shell processes (auto-set) |
CLAUDE_AFK_COUNTDOWN_MSOther | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_AFK_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_AFTER_LAST_COMPACTContext and compaction | Present since v2.1.69 or earlier | Request only conversation logs after last compaction |
CLAUDE_AGENTAgents and subagents | Added between v2.1.118 and v2.1.123 | Short-form identifier for the current agent, used in inter-agent messaging and log attribution. |
CLAUDE_AGENTS_AUTO_RELAUNCHED_ATAgents and subagents | Added between v2.1.118 and v2.1.123 | Timestamp set when the agent fleet was automatically relaunched after a crash. Downstream consumers can detect state that predates the relaunch and invalidate… |
CLAUDE_AGENTS_SELECTAgents and subagents | Added between v2.1.118 and v2.1.123 | Selects which agents from a fleet configuration are active for this session or job. Analogous to a feature flag for agents: target a specific agent variant… |
CLAUDE_AGENT_SDK_CLIENT_APPAgents and subagents | Present since v2.1.69 or earlier | Client application name |
CLAUDE_AGENT_SDK_DISABLE_BUILTIN_AGENTSAgents and subagents | Present since v2.1.69 or earlier Documented | Disable built-in agent types |
CLAUDE_AGENT_SDK_DISABLE_MCP_MANIFESTSAgents and subagents | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_AGENT_SDK_MCP_NO_PREFIXAgents and subagents | Present since v2.1.69 or earlier Documented | Don't prefix MCP tool names with server name |
CLAUDE_AGENT_SDK_VERSIONAgents and subagents | Present since v2.1.69 or earlier | Agent SDK version sent in User-Agent header |
CLAUDE_AI_AUTHORIZE_URLAuthentication | Present since v2.1.69 or earlier | Authorization URL endpoint |
CLAUDE_AI_HOSTOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_AI_IMPORT_SHAPEOther | Removed between v2.1.252 and v2.1.266 | — |
CLAUDE_AI_INFERENCE_SCOPEOther | Present since v2.1.69 or earlier | — |
CLAUDE_AI_OAUTH_SCOPESAuthentication | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_AI_ORIGINOther | Added in v2.1.84 | Overrides the base URL for Claude AI authentication endpoints. This complements the existing CLAUDE_CODE_API_BASE_URL (which controls the inference endpoint)… |
CLAUDE_AI_PLUGINS_SCOPEPlugins and skills | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_AI_PROFILE_SCOPEDebugging | Present since v2.1.69 or earlier | — |
CLAUDE_AI_PROJECTS_READ_SCOPEOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_AI_PROJECTS_WRITE_SCOPEOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_API_SKILL_DESCRIPTIONPlugins and skills | Removed between v2.1.247 and v2.1.252 | Registration hook for the built-in "claude-api" skill that bundles Anthropic SDK docs (Python, TypeScript, Java, Go, Ruby, PHP, C#, curl) plus shared… |
CLAUDE_ARTIFACT_HOST_GRANTOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_ASYNC_AGENT_STALL_TIMEOUT_MSNetwork and proxy | Added between v2.1.108 and v2.1.114 Documented | Default 600,000ms (10 minutes). Directly backs v2.1.113's "subagents that stall mid-stream now fail with a clear error after 10 minutes" changelog bullet. Tune… |
CLAUDE_AUTOCOMPACT_PCT_OVERRIDEContext and compaction | Present since v2.1.69 or earlier Documented | Set when auto-compaction triggers (percentage threshold) |
CLAUDE_AUTO_BACKGROUND_TASKSSessions | Present since v2.1.69 or earlier Documented | Enable automatic background task execution |
CLAUDE_AX_ANNOUNCEMENT_HOLD_MSTerminal and UI | Added in v2.1.288 | — |
CLAUDE_AX_PREPARK_MSTerminal and UI | Added between v2.1.229 and v2.1.234 Documented | — |
CLAUDE_AX_REWRITE_HELD_ANNOUNCEMENTTerminal and UI | Added in v2.1.288 | — |
CLAUDE_AX_SCREEN_READERTerminal and UI | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_AX_STARTUP_QUIET_MSTerminal and UI | Added between v2.1.215 and v2.1.217 Documented | Startup quiet window (milliseconds) for screen-reader mode. First shipped v2.1.217; the changelog names the fix but not the knob. |
CLAUDE_BASEOther | Added in v2.1.92 | Likely overrides the base URL or base configuration path for Claude Code. This is a compact alternative to the more specific CLAUDE_CODE_API_BASE_URL —… |
CLAUDE_BASH_MAINTAIN_PROJECT_WORKING_DIRShell and tools | Present since v2.1.69 or earlier Documented | Maintain consistent working directory across commands |
CLAUDE_BASH_NO_LOGINShell and tools | — | Replaced by CLAUDE_CODE_SHELL_PREFIX |
CLAUDE_BG_AUTH_SNAPSHOT_PATHAuthentication | Added between v2.1.138 and v2.1.143 | Path for snapshotting background session auth credentials to disk. Fixes the failure mode where a background session lost auth mid-run and corrupted its state… |
CLAUDE_BG_AUTO_MEMORY_OFFMemory and CLAUDE.md | Added in v2.1.285 | — |
CLAUDE_BG_BACKENDSessions | Added between v2.1.108 and v2.1.114 | Set to "daemon" to route background work through a daemon backend. The code path is wrapped around EIO/EPIPE handling — pipe/socket IPC with graceful… |
CLAUDE_BG_CLAIM_AUTHAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BG_DISPATCHER_RATE_LIMIT_TIERSessions | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_BG_DISPATCHER_SUBSCRIPTION_TYPESessions | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_BG_ISOLATIONSessions | Added between v2.1.118 and v2.1.123 | Isolation mode for background agent processes — controls how separated the daemon's process space is from the foreground session. Values likely span a… |
CLAUDE_BG_MEMORY_TOGGLED_OFFMemory and CLAUDE.md | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BG_POST_CLEAR_RESPAWNSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BG_PTY_AUTHAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BG_RENDEZVOUS_SOCKSessions | Added between v2.1.118 and v2.1.123 | Socket path for the IPC channel between a foreground Claude session and the background daemon. The daemon starts independently and listens; the foreground… |
CLAUDE_BG_RV_AUTHAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BG_SESSION_PERMISSION_RULESPermissions and sandbox | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BG_SOCKET_TOKENS_PATHAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BG_SOURCESessions | Added between v2.1.118 and v2.1.123 | Tags where a background job originated: CLI, SDK, Remote Control, another agent. Present on the daemon side so it can route, prioritize, or attribute work… |
CLAUDE_BG_STARTUP_WEDGE_MSSessions | Added between v2.1.128 and v2.1.138 | Startup jitter for background sessions. When you spawn many agents simultaneously, they can race for the same auth or daemon connections. This introduces a… |
CLAUDE_BG_TCC_DISCLAIMEDSessions | Added between v2.1.138 and v2.1.143 | macOS TCC (Transparency, Consent, and Control) permission disclaimer state for background sessions. Background agents without a controlling terminal need… |
CLAUDE_BG_WORKSPACE_TRUSTEDSessions | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_BRIDGE_BASE_URLNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BRIDGE_OAUTH_TOKENAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BRIDGE_REATTACH_GROUPINGSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BRIDGE_REATTACH_NO_BACKFILLSessions | Added between v2.1.224 and v2.1.227 | — |
CLAUDE_BRIDGE_REATTACH_OUTBOUND_ONLYSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BRIDGE_REATTACH_OWNER_ACCTSessions | Added between v2.1.224 and v2.1.227 | — |
CLAUDE_BRIDGE_REATTACH_OWNER_ORGSessions | Removed between v2.1.245 and v2.1.247 | — |
CLAUDE_BRIDGE_REATTACH_SEQSessions | Added in v2.1.118 | Sequence number for the bridge reconnection protocol. At-least-once delivery semantics: the daemon replays events the bridge missed since this sequence point.… |
CLAUDE_BRIDGE_REATTACH_SESSIONSessions | Added in v2.1.118 | Session identity used during bridge reconnection. Pairs with CLAUDE_BRIDGE_REATTACH_SEQ — the bridge presents both to resume exactly where it disconnected. |
CLAUDE_BRIDGE_SESSION_INGRESS_URLNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_BRIDGE_USE_CCR_V2Sessions | Removed between v2.1.143 and v2.1.212 | Toggle for CCR v2 bridge protocol — companion to the existing CLAUDE_CODE_USE_CCR_V2 introduced in v2.1.69. Suggests the bridge layer (IDE extensions, remote… |
CLAUDE_BYTE_STREAM_IDLE_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CHROME_CLASSIFIER_FLOOROther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CHROME_PAIRED_DEVICE_IDOther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CHROME_PERMISSION_MODEPermissions and sandbox | Present since v2.1.69 or earlier | Permission mode for Claude for Chrome |
CLAUDE_CHROME_TAB_GROUP_KEYOther | Added in v2.1.286 | — |
CLAUDE_CLIENT_PRESENCE_FILEOther | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_3P_PROBE_WROTE_OPUS_DEFAULTModels and thinking | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_3P_PROBE_WROTE_SONNET_DEFAULTModels and thinking | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_3P_SEEDED_OPUS_DEFAULTModels and thinking | Added in v2.1.285 | — |
CLAUDE_CODE_ACCESSIBILITYTerminal and UI | Present since v2.1.69 or earlier Documented | Enable accessibility mode; disables cursor hiding |
CLAUDE_CODE_ACCOUNT_TAGGED_IDOther | Added between v2.1.77 and v2.1.79 | Stores a tagged or decorated account identifier, distinct from the existing CLAUDE_CODE_ACCOUNT_UUID. While the UUID is a raw unique identifier, a "tagged" ID… |
CLAUDE_CODE_ACCOUNT_UUIDOther | Present since v2.1.69 or earlier | Pre-configured account UUID |
CLAUDE_CODE_ACCOUNT_UUIDIOther | Removed between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_ACTIONOther | Present since v2.1.69 or earlier | Indicates running as GitHub Action |
CLAUDE_CODE_ACT_DONT_REDERIVEOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_ADDITIONAL_DIRECTORIES_CLAUDE_MDMemory and CLAUDE.md | Present since v2.1.69 or earlier Documented | Additional directories to scan for CLAUDE.md files (colon-separated) |
CLAUDE_CODE_ADDITIONAL_PROTECTIONOther | Present since v2.1.69 or earlier | Add additional protection header to API requests |
CLAUDE_CODE_ADOPT_UNDERIVABLE_PARKED_PERMISSIONPermissions and sandbox | Added in v2.1.238 | — |
CLAUDE_CODE_AGENTAgents and subagents | Added between v2.1.118 and v2.1.123 | Full agent descriptor passed into a spawned agent process — likely the agent's frontmatter (tools, allowed/disallowed lists, system prompt path) so the child… |
CLAUDE_CODE_AGENT_COST_STEERAgents and subagents | Removed between v2.1.138 and v2.1.143 | Controls cost-aware behavior for subagent delegation. As Claude Code's multi-agent architecture matures — named subagents now appear in @ mention typeahead[1]… |
CLAUDE_CODE_AGENT_LIST_IN_MESSAGESAgents and subagents | Removed between v2.1.143 and v2.1.212 | An early agent-listing toggle, made obsolete by the Agent View and coordinator surfaces that now own how agents are shown. |
CLAUDE_CODE_AGENT_PROXY_GH_SHIMNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_AGENT_PROXY_GIT_CONFIGNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_AGENT_PROXY_GIT_HOSTSNetwork and proxy | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_AGENT_RULE_DISABLEDAgents and subagents | Present since v2.1.69 or earlier | Disable agent rules |
CLAUDE_CODE_AGENT_SWARMSAgents and subagents | — | Replaced by CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS |
CLAUDE_CODE_AGENT_VIEW_RELAUNCHAgents and subagents | Added between v2.1.138 and v2.1.143 | Force-relaunches the Agent View UI component when it gets into a bad state. The Agent View is a separate surface from the main session; this is its dedicated… |
CLAUDE_CODE_ALDER_WICKETOther | Removed in v2.1.218 | — |
CLAUDE_CODE_ALTGR_AS_TEXTOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_ALT_SCREEN_FULL_REPAINTTerminal and UI | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_ALWAYS_ENABLE_EFFORTModels and thinking | Added in v2.1.70 Documented | Force-enable reasoning effort level regardless of other settings. Useful for ensuring CLAUDE_CODE_EFFORT_LEVEL always takes effect, even in contexts where it… |
CLAUDE_CODE_AMBER_ASTROLABEOther | Added between v2.1.215 and v2.1.217 | — |
CLAUDE_CODE_API_BASE_URLNetwork and proxy | Present since v2.1.69 or earlier | Custom Claude Code API base URL for proxies |
CLAUDE_CODE_API_KEY_FILE_DESCRIPTORAuthentication | Present since v2.1.69 or earlier | File descriptor to read API key from |
CLAUDE_CODE_API_KEY_HELPER_TTL_MSAuthentication | Present since v2.1.69 or earlier Documented | Cache TTL for API key helper |
CLAUDE_CODE_APPEND_PROMPT_HEADOther | Added in v2.1.284 | — |
CLAUDE_CODE_ARG_KEY_SHAPEOther | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_ARTIFACTOther | Removed in v2.1.292 | Turns on Artifacts, with companions for its API endpoint, direct upload, and MCP exposure. Claude Code can produce a first-class artifact now — and share it… |
CLAUDE_CODE_ARTIFACTS_API_BASE_URLNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_ARTIFACTS_API_TOKENAuthentication | Added between v2.1.219 and v2.1.221 | — |
CLAUDE_CODE_ARTIFACT_ASSETSOther | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_ARTIFACT_ASSET_BASE_URLNetwork and proxy | Added between v2.1.219 and v2.1.221 | — |
CLAUDE_CODE_ARTIFACT_AUTO_OPENOther | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_ARTIFACT_COMMENTSOther | Added between v2.1.219 and v2.1.221 Documented | — |
CLAUDE_CODE_ARTIFACT_COMMENTS_AUTOREACTOther | Added between v2.1.219 and v2.1.221 Documented | — |
CLAUDE_CODE_ARTIFACT_COMMENT_FAST_ACKOther | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_ARTIFACT_COMMENT_FAST_ACK_FIXEDOther | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_ARTIFACT_COMMENT_RESPONDEROther | Added between v2.1.224 and v2.1.227 | — |
CLAUDE_CODE_ARTIFACT_DBOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_CODE_ARTIFACT_DB_STR_REPLACEOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_ARTIFACT_DELETEOther | Added between v2.1.238 and v2.1.241 | Enables the delete-Artifact path (owner-only, requires confirmation, blocked in plan mode). The gate refuses in remote sessions and otherwise falls back to the… |
CLAUDE_CODE_ARTIFACT_DIRECT_UPLOADOther | Removed between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_ARTIFACT_FDOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_ARTIFACT_FIVE_CLASS_ASKSOther | Removed in v2.1.293 | — |
CLAUDE_CODE_ARTIFACT_FRESH_READOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_ARTIFACT_HOTOther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_ARTIFACT_INHERITED_TYPE_GRANTOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_ARTIFACT_LIVE_BASE_URLNetwork and proxy | Added between v2.1.219 and v2.1.221 | — |
CLAUDE_CODE_ARTIFACT_MCPMCP | Removed in v2.1.293 | — |
CLAUDE_CODE_ARTIFACT_MULTI_FILEOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_ARTIFACT_OPENING_PREFETCHOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_ARTIFACT_OPEN_ACTIONOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_ARTIFACT_PATH_PINOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_ARTIFACT_PINOther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_ARTIFACT_PRESENCEOther | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_ARTIFACT_PREVIEWOther | Removed in v2.1.292 | — |
CLAUDE_CODE_ARTIFACT_PREVIEW_EMULATOROther | Added in v2.1.292 | Pins the artifact-preview emulator on (true) or off (false); left unset, a feature flag decides. When on, the emulator checks its skill's files first and stays… |
CLAUDE_CODE_ARTIFACT_QUICKSTARTOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_ARTIFACT_REPLOther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_ARTIFACT_ROOMOther | Added in v2.1.238 | — |
CLAUDE_CODE_ARTIFACT_SHAREOther | Added in v2.1.286 | — |
CLAUDE_CODE_ARTIFACT_START_KITOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_ARTIFACT_SYNC_BASE_URLNetwork and proxy | Added in v2.1.238 | — |
CLAUDE_CODE_ARTIFACT_TEXT_VARIANTOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_ARTIFACT_TOOLSETShell and tools | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_ARTIFACT_TYPESOther | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_ARTIFACT_TYPE_CATALOGDebugging | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_ARTIFACT_TYPE_CLOUD_CREATEOther | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_ARTIFACT_VERIFYOther | Added in v2.1.238 | — |
CLAUDE_CODE_ARTIFACT_VERSIONSOther | Added in v2.1.292 | When set, the session can list and read an artifact's earlier versions; without it, a session reports that an artifact's earlier versions are not available.… |
CLAUDE_CODE_ARTIFACT_VIEWER_BASE_URLNetwork and proxy | Added in v2.1.229 | — |
CLAUDE_CODE_ATTRIBUTION_ANNOUNCEMENTOther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_ATTRIBUTION_HEADEROther | Present since v2.1.69 or earlier Documented | API billing header in system prompt |
CLAUDE_CODE_ATTRIBUTION_STATUS_TIMEOUT_MSNetwork and proxy | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_AUTH_FAIL_EXIT_MSAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_AUTO_BACKGROUND_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_AUTO_BACKGROUND_WORKER_CHECKIN_SECONDSSessions | Removed between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_AUTO_COMPACT_WINDOWContext and compaction | Added between v2.1.77 and v2.1.79 Documented | Controls the token window threshold at which automatic context compaction kicks in. Works alongside the existing CLAUDE_AUTOCOMPACT_PCT_OVERRIDE variable but… |
CLAUDE_CODE_AUTO_CONNECT_IDENetwork and proxy | Present since v2.1.69 or earlier Documented | Auto-connect to IDE on startup |
CLAUDE_CODE_AUTO_MODE_ARTIFACT_CONSENT_RULEPermissions and sandbox | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_AUTO_MODE_CANDIDATE_WORDINGPermissions and sandbox | Removed in v2.1.286 | — |
CLAUDE_CODE_AUTO_MODE_CLASSIFIER_OVERLAPPermissions and sandbox | Removed in v2.1.294 | — |
CLAUDE_CODE_AUTO_MODE_CLASSIFIER_QUEUEPermissions and sandbox | Removed between v2.1.219 and v2.1.221 | — |
CLAUDE_CODE_AUTO_MODE_CLASSIFY_ASK_USER_QUESTIONPermissions and sandbox | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_CODE_AUTO_MODE_CLASSIFY_EDITSPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Turns the classification pass on: every edit runs through the classifier before it touches disk. Every change leaves a recorded decision you can inspect, which… |
CLAUDE_CODE_AUTO_MODE_EDIT_REMOVALPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Governs whether Auto mode may delete content as part of an edit. Deletions are the riskiest edit class, so they get their own policy. |
CLAUDE_CODE_AUTO_MODE_EDIT_REMOVAL_CAPPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Caps how much a single autonomous edit can remove before it's held for a human. A direct answer to the runaway-refactor failure where an agent "simplifies" by… |
CLAUDE_CODE_AUTO_MODE_EXTERNAL_PERMISSIONSPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Hands permission decisions to an external policy engine instead of the built-in prompt. This is the hook an enterprise needs to enforce its own approval rules… |
CLAUDE_CODE_AUTO_MODE_GIT_STATUSPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Feeds the working tree's git status into the classifier's context. An edit means something different in a clean repo than in one with forty dirty files. |
CLAUDE_CODE_AUTO_MODE_GIT_STATUS_LIMITPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Bounds how much of that status is included, so the classifier prompt doesn't balloon in large or messy repos. Cost and latency control for the gate. |
CLAUDE_CODE_AUTO_MODE_GIT_STATUS_UPLOADSPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Controls whether git-status context is uploaded to the classification service. A data-governance knob — some orgs don't want file paths and change sets leaving… |
CLAUDE_CODE_AUTO_MODE_HEARTH_MEMBER_RELAY_ROWSPermissions and sandbox | Added in v2.1.286 | — |
CLAUDE_CODE_AUTO_MODE_MODELModels and thinking | Added between v2.1.143 and v2.1.212 | Picks the model that classifies each proposed edit — deliberately separate from the model doing the work. A small, fast model here keeps the safety check cheap… |
CLAUDE_CODE_AUTO_MODE_OUTCOME_CODESPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Structured outcome codes for the classifier's verdicts instead of free text. Makes autonomous-edit outcomes machine-readable — the basis for telemetry,… |
CLAUDE_CODE_AUTO_MODE_PRIOR_ASSISTANT_CONTEXTContext and compaction | Added between v2.1.143 and v2.1.212 | Feeds prior assistant turns into the decision, so the classifier can see the reasoning behind an edit. Intent matters — the same diff can be safe or reckless… |
CLAUDE_CODE_AUTO_MODE_REPO_VISIBILITYPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Lets behavior depend on whether the repo is public or private. Being more conservative in public repos, where a bad edit is instantly visible, is the obvious… |
CLAUDE_CODE_AUTO_MODE_SEGMENTED_TRANSCRIPTPermissions and sandbox | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_AUTO_MODE_SERVERPermissions and sandbox | — Documented | — |
CLAUDE_CODE_AUTO_MODE_SIBLING_CONTEXTContext and compaction | Removed between v2.1.219 and v2.1.221 | Includes sibling files (or sessions) when classifying. Lets the gate reason about consistency across related files instead of judging each change in isolation. |
CLAUDE_CODE_AUTO_MODE_TEMPERATUREPermissions and sandbox | Added between v2.1.143 and v2.1.212 | Temperature for the classifier. Low values make the safe/hold call deterministic and repeatable — exactly what you want for a gate that fires on every write. |
CLAUDE_CODE_AUTO_MODE_TIERPermissions and sandbox | Added in v2.1.286 | — |
CLAUDE_CODE_AWS_CHAIN_RESOLVE_TIMEOUT_MSCloud providers | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_BASALT_COVEOther | Added between v2.1.143 and v2.1.212 | An internal codename — one of five this stretch (PEWTER_OWL, LANTERN_PRISM, WALNUT_SPIRE, and a PEWTER_OWL_TOOL). Named flags with no changelog entry are… |
CLAUDE_CODE_BASE_REFOther | Present since v2.1.69 or earlier | Git base ref for diff operations |
CLAUDE_CODE_BASE_REFSOther | — | Specifies base git references (branches, tags, or SHAs) for diff comparison when Claude Code operates in a worktree or feature branch. In multi-worktree agent… |
CLAUDE_CODE_BASH_EDIT_DIFFShell and tools | Added between v2.1.266 and v2.1.269 Documented | — |
CLAUDE_CODE_BASH_OUTPUT_AUDIENCE_NOTEShell and tools | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_BASH_SANDBOX_SHOW_INDICATORPermissions and sandbox | Present since v2.1.69 or earlier | Show indicator when bash runs in sandbox |
CLAUDE_CODE_BENCH_LIVE_COUNTSOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_BG_CLASSIFIER_MODELModels and thinking | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_BG_TASKS_REPORT_RUNNINGSessions | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_BISON_CAIRNOther | Added between v2.1.215 and v2.1.217 | — |
CLAUDE_CODE_BLOCKING_LIMIT_OVERRIDETerminal and UI | Present since v2.1.69 or earlier | Override token limit for input blocking |
CLAUDE_CODE_BREEZY_HORIZONOther | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_BRIDGE_CHILD_ARTIFACTSessions | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_BRIDGE_CHILD_AUTO_DEFAULTSessions | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_BRIDGE_CHILD_MACHINE_SETTINGSSessions | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_BRIDGE_MCP_CARRIERMCP | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_BRIDGE_OWNER_ACCOUNT_UUIDSessions | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_BRIDGE_OWNER_ORG_UUIDSessions | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_BRIDGE_PROMPT_SHA256Sessions | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_BRIDGE_SESSION_IDSessions | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_BRIDGE_SOURCE_DIRSessions | Added in v2.1.286 | — |
CLAUDE_CODE_BRIEFOther | Added between v2.1.70 and v2.1.72 | Toggle brief/concise output mode — shorter responses from Claude. Useful for scripted workflows or agents that don't need verbose explanations. |
CLAUDE_CODE_BRIEF_UPLOADOther | Added between v2.1.70 and v2.1.72 | Brief mode specifically for upload operations. Likely suppresses progress details when uploading files or context to the session. |
CLAUDE_CODE_BS_AS_CTRL_BACKSPACEOther | Added between v2.1.108 and v2.1.114 Documented | Treats a bare backspace keypress as Ctrl+Backspace (delete-word). Default: on Windows unless the terminal is mintty or cygwin. Exists because Windows terminals… |
CLAUDE_CODE_BUBBLEWRAPPermissions and sandbox | Present since v2.1.69 or earlier | Set to 1 when running in bubblewrap sandbox (Linux) [6] |
CLAUDE_CODE_BYOC_ENABLE_DATADOGTelemetry | Added between v2.1.128 and v2.1.138 | Opt-in Datadog telemetry for BYOC (Bring Your Own Cloud) Bedrock/Vertex deployments. Route Claude Code operational metrics to Datadog alongside your existing… |
CLAUDE_CODE_CALM_MOCHIOther | Added in v2.1.290 | — |
CLAUDE_CODE_CARVED_SLATEOther | Removed between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_CCR_EARLY_HYDRATE_PREFETCHOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_CCR_EARLY_PLUGINS_SYNCPlugins and skills | Added in v2.1.286 | — |
CLAUDE_CODE_CCR_EARLY_REMOTE_CONNECTNetwork and proxy | Removed in v2.1.290 | — |
CLAUDE_CODE_CCR_EARLY_SKILLS_SYNCPlugins and skills | Added in v2.1.287 | — |
CLAUDE_CODE_CCR_FOLD_FIRST_TURN_RESCANOther | Added in v2.1.287 | — |
CLAUDE_CODE_CCR_LAZY_SUBAGENT_HYDRATEAgents and subagents | Removed between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_CCR_SKIP_FRESH_MIGRATIONSFeature toggles | Added in v2.1.287 | — |
CLAUDE_CODE_CCR_SURFACEOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_CERT_STOREAuthentication | Added between v2.1.100 and v2.1.104 Documented | Controls which certificate authority store Claude Code uses for TLS verification. The v2.1.101 changelog[1] explains that the OS CA certificate store is now… |
CLAUDE_CODE_CHILD_SESSIONSessions | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_CHROME_MCP_ORG_DENIEDMCP | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_CLASSIFIER_SUMMARYOther | Added between v2.1.118 and v2.1.123 | Carries the output of a prompt classifier as a structured summary. Where CLAUDE_CODE_VERIFY_PROMPT triggers classification, this variable holds the result so… |
CLAUDE_CODE_CLIENT_CERTAuthentication | Present since v2.1.69 or earlier Documented | Path to client certificate for mTLS |
CLAUDE_CODE_CLIENT_DATA_URLNetwork and proxy | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_CLIENT_KEYAuthentication | Present since v2.1.69 or earlier Documented | Path to client private key |
CLAUDE_CODE_CLIENT_KEYPMAuthentication | Removed between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_CLIENT_KEY_PASSPHRASEAuthentication | Present since v2.1.69 or earlier Documented | Passphrase for encrypted client key |
CLAUDE_CODE_CLOUD_SESSION_IDSessions | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_COLD_COMPACTContext and compaction | Added between v2.1.123 and v2.1.126 | — |
CLAUDE_CODE_COMMIT_BETWEEN_KEYSOther | Removed in v2.1.284 | — |
CLAUDE_CODE_COMMIT_LOGDebugging | Removed between v2.1.224 and v2.1.227 | Likely controls whether or where Claude Code logs commit operations. This could enable audit trails for automated commits made by agents and sub-agents —… |
CLAUDE_CODE_COMPILED_ACORNOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_CONFIG_PROBEOther | Added in v2.1.286 | — |
CLAUDE_CODE_CONFIG_WATCH_EVENTSOther | Added in v2.1.288 | — |
CLAUDE_CODE_CONNECT_TIMEOUT_MSNetwork and proxy | Added between v2.1.266 and v2.1.269 Documented | — |
CLAUDE_CODE_CONTAINER_IDOther | Present since v2.1.69 or earlier | Container/pod identifier sent in HTTP headers |
CLAUDE_CODE_COORDINATOR_EXTRA_TOOLSAgents and subagents | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_COORDINATOR_FORCE_WORKER_INHERIT_MODELAgents and subagents | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_COORDINATOR_MODEAgents and subagents | Added between v2.1.143 and v2.1.212 | Runs a session as a coordinator over child agents, with companions for its toolset and whether memory flows down the tree. The agent-teams plumbing that was… |
CLAUDE_CODE_COORDINATOR_PROPAGATE_NESTED_MEMORYAgents and subagents | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_COORDINATOR_SKILL_GUIDANCEAgents and subagents | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_COORDINATOR_WORKER_CHECKIN_SECONDSAgents and subagents | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_COWORK_FRAME_ARTIFACTSOther | Added in v2.1.228 | — |
CLAUDE_CODE_COZY_TEAPOTOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_CURRIED_TRINKETOther | Added in v2.1.290 | — |
CLAUDE_CODE_CUSTOM_OAUTH_URLAuthentication | Present since v2.1.69 or earlier | Custom OAuth endpoint URL |
CLAUDE_CODE_DAEMON_COLD_STARTOther | Added between v2.1.118 and v2.1.123 | Set when the daemon starts from a completely cold state rather than resuming warm. Lets the daemon emit different startup telemetry and skip cache-warm… |
CLAUDE_CODE_DAPPER_LAGOONOther | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_DATADOG_FLUSH_INTERVAL_MSTelemetry | Present since v2.1.69 or earlier | Datadog metrics flush interval (ms) |
CLAUDE_CODE_DD_ERROR_TRACKING_FLUSH_INTERVAL_MSTelemetry | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_DEBUG_LOGS_DIRDebugging | Present since v2.1.69 or earlier Documented | Custom directory for debug logs |
CLAUDE_CODE_DEBUG_LOG_LEVELDebugging | Added between v2.1.70 and v2.1.72 Documented | Set debug logging verbosity level. More granular than the existing DEBUG=1 boolean — probably accepts levels like "info", "warn", "error", "debug". |
CLAUDE_CODE_DEBUG_REPAINTSDebugging | Added between v2.1.79 and v2.1.83 | Enables debug logging for terminal repaint operations. This release fixes several rendering issues — screen flashing blank after idle, scrollback jumping when… |
CLAUDE_CODE_DECSTBMOther | Added between v2.1.108 and v2.1.114 | Enables DECSTBM (VT100 Set Top and Bottom Margins) for scrolling regions in the TUI. The mechanism behind /tui fullscreen's flicker-free rendering — pins… |
CLAUDE_CODE_DESIGN_OAUTH_CLIENT_IDAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_DESKTOP_APP_VERSIONOther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_DESKTOP_SKILL_SWITCHESPlugins and skills | Added in v2.1.293 | — |
CLAUDE_CODE_DEV_RAW_CHANGELOG_URLNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_DIAGNOSTICS_FILEOther | Removed in v2.1.290 | Path to write diagnostics output |
CLAUDE_CODE_DIR_SYNC_ARCHIVEOther | Removed between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_DIR_SYNC_DISABLE_ANCHORINGFeature toggles | Removed in v2.1.285 | — |
CLAUDE_CODE_DIR_SYNC_ENGINEOther | Removed in v2.1.285 | — |
CLAUDE_CODE_DIR_SYNC_FFWDOther | Removed in v2.1.285 | — |
CLAUDE_CODE_DIR_SYNC_GITOther | Removed in v2.1.285 | — |
CLAUDE_CODE_DIR_SYNC_OVERLAYOther | Removed between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_DIR_SYNC_STREAMNetwork and proxy | Removed in v2.1.285 | — |
CLAUDE_CODE_DISABLE_1M_CONTEXTContext and compaction | Present since v2.1.69 or earlier Documented | Disable extended 1M token context window |
CLAUDE_CODE_DISABLE_ADAPTIVE_THINKINGModels and thinking | Present since v2.1.69 or earlier Documented | Disable adaptive thinking mode |
CLAUDE_CODE_DISABLE_ADMIN_ENV_UNIONFeature toggles | Added between v2.1.222 and v2.1.224 Documented | — |
CLAUDE_CODE_DISABLE_ADVISOR_TOOLShell and tools | Added between v2.1.79 and v2.1.83 Documented | Disables what appears to be an internal advisory tool. The "Advisor" pattern suggests a meta-tool that provides guidance or recommendations to the model during… |
CLAUDE_CODE_DISABLE_AGENTS_FLEETAgents and subagents | Removed between v2.1.138 and v2.1.143 | Kill switch for the entire agent fleet subsystem — no selection, no auto-relaunch, no fleet coordination. Its existence implies the fleet is on by default for… |
CLAUDE_CODE_DISABLE_AGENT_VIEWAgents and subagents | Added between v2.1.138 and v2.1.143 Documented | Disables Agent View. Renamed successor to CLAUDE_CODE_DISABLE_AGENTS_FLEET (removed this release). If you're managing Claude Code via policy config and aren't… |
CLAUDE_CODE_DISABLE_ALTERNATE_SCREENTerminal and UI | Added between v2.1.128 and v2.1.138 Documented | Prevents the TUI from using the terminal alternate screen buffer. If Claude Code's UI is eating your terminal history, breaking tmux scrollback, or failing in… |
CLAUDE_CODE_DISABLE_ARTIFACTFeature toggles | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_ATTACHMENTSFeature toggles | Present since v2.1.69 or earlier Documented | File/image attachments |
CLAUDE_CODE_DISABLE_ATTRIBUTION_BASELINE_REUSEFeature toggles | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_DISABLE_ATTRIBUTION_CROSS_REPOFeature toggles | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_DISABLE_AUTH_REFRESH_LOCKAuthentication | Added in v2.1.286 Documented | Turns off the lock that coordinates a GCP or AWS credential refresh across processes. With the lock on, one process refreshes and opens a single login browser… |
CLAUDE_CODE_DISABLE_AUTO_MEMORYMemory and CLAUDE.md | Present since v2.1.69 or earlier Documented | Disable automatic memory (MEMORY.md) |
CLAUDE_CODE_DISABLE_AWAITING_USER_IDLEFeature toggles | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_DISABLE_BACKGROUND_TASKSSessions | Present since v2.1.69 or earlier Documented | Disable background tasks entirely |
CLAUDE_CODE_DISABLE_BEDROCK_CONTENT_TYPE_DEFAULTCloud providers | Removed between v2.1.245 and v2.1.247 Documented | — |
CLAUDE_CODE_DISABLE_BEDROCK_CONTENT_TYPE_GUARDCloud providers | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_BG_EXIT_HANDOFFSessions | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_BG_SHELL_PRESSURE_REAPShell and tools | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_BUNDLED_SKILLSPlugins and skills | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_CFC_PROMPTFeature toggles | Added between v2.1.252 and v2.1.266 Documented | — |
CLAUDE_CODE_DISABLE_CLAUDE_API_SKILLPlugins and skills | Removed between v2.1.252 and v2.1.266 | Disables the built-in Claude API skill. The Claude API skill auto-triggers when code imports anthropic or @anthropic-ai/sdk, providing SDK-aware guidance. In… |
CLAUDE_CODE_DISABLE_CLAUDE_CODE_SKILLPlugins and skills | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_DISABLE_CLAUDE_MDSMemory and CLAUDE.md | Present since v2.1.69 or earlier Documented | Disable loading CLAUDE.md files |
CLAUDE_CODE_DISABLE_COMMAND_INJECTION_CHECKFeature toggles | Removed between v2.1.88 and v2.1.89 | Previously allowed disabling command injection detection. The safety check is now mandatory — no opt-out. This aligns with the changelog's hook hardening:… |
CLAUDE_CODE_DISABLE_CRONFeature toggles | Removed in v2.1.293 Documented | Disable cron/scheduled task functionality. Claude Code recently added /cron for recurring tasks — this lets you turn it off entirely. |
CLAUDE_CODE_DISABLE_DANGEROUS_RM_TIMEOUTNetwork and proxy | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_DISABLE_DIR_SYNCFeature toggles | Removed in v2.1.285 | — |
CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETASFeature toggles | Present since v2.1.69 or earlier Documented | Experimental beta API features |
CLAUDE_CODE_DISABLE_EXPLORE_INHERIT_CAPFeature toggles | Added between v2.1.215 and v2.1.217 | Lets the built-in Explore search agent run at the parent model instead of a cheaper capped default. First shipped v2.1.217; undocumented. |
CLAUDE_CODE_DISABLE_EXPLORE_PLAN_AGENTSAgents and subagents | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_FAST_MODEModels and thinking | Present since v2.1.69 or earlier Documented | Disable the /fast toggle that uses the same model with faster output |
CLAUDE_CODE_DISABLE_FEEDBACK_SURVEYTelemetry | Present since v2.1.69 or earlier Documented | Survey prompts |
CLAUDE_CODE_DISABLE_FILE_CHECKPOINTINGFeature toggles | Present since v2.1.69 or earlier Documented | Git-based file checkpointing/backup |
CLAUDE_CODE_DISABLE_GIT_INSTRUCTIONSFeature toggles | Present since v2.1.69 or earlier Documented | — |
CLAUDE_CODE_DISABLE_HOME_SETTINGS_SEEDFeature toggles | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_DISABLE_HOOK_FORWARDINGFeature toggles | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_DISABLE_INLINE_SHELL_RM_PROMPTShell and tools | Added in v2.1.288 Documented | Turns off the new prompt that catches a dangerous rm inside an inline bash -c or sh -c script. Left unset, such a command asks before running even under… |
CLAUDE_CODE_DISABLE_LAUNCH_COMPOSERFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_DISABLE_LEGACY_MODEL_REMAPModels and thinking | Present since v2.1.69 or earlier Documented | — |
CLAUDE_CODE_DISABLE_MCP_TASK_BACKGROUNDMCP | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_DISABLE_MEMORY_BULK_INFLATEMemory and CLAUDE.md | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_DISABLE_MEMORY_MASS_DELETE_HOLDMemory and CLAUDE.md | Added in v2.1.218 | — |
CLAUDE_CODE_DISABLE_MEMORY_PERIODIC_RESYNCMemory and CLAUDE.md | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_DISABLE_MEMORY_RO_UNSAVED_NOTICEMemory and CLAUDE.md | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_DISABLE_MEMORY_STREAM_LISTNetwork and proxy | Added between v2.1.143 and v2.1.212 | Turns off the incremental metadata-streaming path inside multi-store memory sync. That path (gated by the new tengu_memory_stream_list, default on) calls a… |
CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACKModels and thinking | Added in v2.1.285 Documented | Present in the v2.1.285 build and absent from that release's notes. |
CLAUDE_CODE_DISABLE_MOUSETerminal and UI | Added between v2.1.87 and v2.1.88 Documented | Disables all mouse input handling in the terminal UI. Claude Code captures mouse events for interactive elements like clickable buttons and text selection, but… |
CLAUDE_CODE_DISABLE_MOUSE_CLICKSTerminal and UI | Added between v2.1.87 and v2.1.88 Documented | Granular mouse click disable, added in v2.1.88. Superseded by the broader CLAUDE_CODE_DISABLE_MOUSE flag. The two-tier mouse control approach lasted one… |
CLAUDE_CODE_DISABLE_MTLS_RELOAD_ON_STALE_CONNECTIONNetwork and proxy | Added between v2.1.229 and v2.1.234 Documented | — |
CLAUDE_CODE_DISABLE_NESTED_CHAIN_IDLEFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_DISABLE_NESTED_USER_REPAIRFeature toggles | Added in v2.1.238 | — |
CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFICFeature toggles | Removed in v2.1.287 Documented | Non-critical network requests |
CLAUDE_CODE_DISABLE_NONSTREAMING_FALLBACKNetwork and proxy | Added between v2.1.79 and v2.1.83 Documented | Disables the fallback path that retries failed streaming requests as non-streaming calls. The changelog explicitly documents this variable. |
CLAUDE_CODE_DISABLE_NOTIFICATION_PRESENCE_CHECKFeature toggles | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_OFFICIAL_MARKETPLACE_AUTOINSTALLPlugins and skills | Present since v2.1.69 or earlier Documented | Disable automatic plugin installation from marketplace |
CLAUDE_CODE_DISABLE_ORG_MEMORYMemory and CLAUDE.md | Added between v2.1.143 and v2.1.212 | Kill switch for a new organization-scoped memory subsystem. The sync entrypoint returns early — disabled — the moment this variable is set. |
CLAUDE_CODE_DISABLE_PERMISSION_PROMPT_NOTIFY_HOOKSPermissions and sandbox | Added between v2.1.229 and v2.1.234 Documented | — |
CLAUDE_CODE_DISABLE_PLUGIN_FORWARDINGPlugins and skills | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_DISABLE_POLICY_SKILLSPlugins and skills | Added between v2.1.87 and v2.1.88 Documented | Disables policy-enforced skills. Skills in Claude Code are specialized prompt-driven capabilities (like /commit or /review-pr) that can be configured at the… |
CLAUDE_CODE_DISABLE_POWERSHELL_CMD_RM_DENYShell and tools | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_DISABLE_PRECOMPACT_SKIPContext and compaction | Present since v2.1.69 or earlier | Disable skipping pre-compaction checks |
CLAUDE_CODE_DISABLE_PROACTIVITYFeature toggles | Added in v2.1.290 | Turns off the proactivity selector, a behavior gated by tengu_proactivity_selector and on by default. When set, the value is carried into relaunched and… |
CLAUDE_CODE_DISABLE_REFUSAL_FALLBACKFeature toggles | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_REFUSAL_RETRYNetwork and proxy | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_DISABLE_STARTUP_WORK_GATEFeature toggles | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_DISABLE_STRUCTURED_OUTPUTSFeature toggles | Added in v2.1.288 Documented | Turns structured outputs off for gateways or providers (such as Mantle) that reject them. The changelog ties this to session titles, memory recall and prompt… |
CLAUDE_CODE_DISABLE_SUBSTITUTION_RM_PROMPTFeature toggles | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_DISABLE_TERMINAL_TITLETerminal and UI | Present since v2.1.69 or earlier Documented | Stop Claude Code from setting the terminal title |
CLAUDE_CODE_DISABLE_THINKINGModels and thinking | Present since v2.1.69 or earlier Documented | Completely disable extended thinking |
CLAUDE_CODE_DISABLE_TURN_HANDOFFFeature toggles | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_DISABLE_UNKNOWN_MODEL_WINDOW_ENFORCEMENTModels and thinking | Added between v2.1.222 and v2.1.224 Documented | — |
CLAUDE_CODE_DISABLE_VIRTUAL_SCROLLTerminal and UI | Added between v2.1.70 and v2.1.72 Documented | Disable virtual scrolling in terminal UI. Useful if virtual scroll causes rendering issues in certain terminal emulators or when piping output. |
CLAUDE_CODE_DISABLE_VITALS_EMITTERFeature toggles | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_DISABLE_WEB_FETCHShell and tools | Added in v2.1.285 Documented | Turns off the WebFetch tool. An environment variable, so it disables WebFetch without a managed-settings file. Added in v2.1.285. |
CLAUDE_CODE_DISABLE_WINDOWS_SHELL_LAUNCHERShell and tools | Added between v2.1.266 and v2.1.269 Documented | — |
CLAUDE_CODE_DISABLE_WORKFLOWSAgents and subagents | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_DISABLE_WORKING_SYNCFeature toggles | Removed between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_DISPATCH_V2DOther | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_DISPATCH_V2SOther | Removed in v2.1.294 | — |
CLAUDE_CODE_DONT_INHERIT_ENVOther | Present since v2.1.69 or earlier | Start shell with empty environment |
CLAUDE_CODE_DOWNLOAD_DEADLINE_MS_FOR_TESTINGOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_EAGER_FLUSHOther | Present since v2.1.69 or earlier | Eagerly flush output buffers |
CLAUDE_CODE_EDITOR_CODELIVERYOther | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_EFFORT_LEVELModels and thinking | Removed in v2.1.284 Documented | Reasoning effort: low, medium, or high (default). Controls adaptive thinking depth [4] |
CLAUDE_CODE_ELEGANT_MEADOWOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_EMIT_SESSION_STATE_EVENTSSessions | Added between v2.1.79 and v2.1.83 Documented | Controls whether Claude Code emits session state change events. This fits the growing SDK and Remote Control infrastructure — external consumers (IDE… |
CLAUDE_CODE_EMIT_STARTUP_TIMINGOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_EMIT_TOOL_USE_SUMMARIESShell and tools | Present since v2.1.69 or earlier | Emit tool use summary events |
CLAUDE_CODE_ENABLE_APPEND_SUBAGENT_PROMPTAgents and subagents | Added between v2.1.108 and v2.1.114 | Authorizes SDK callers to append a custom string to a subagent's system prompt via options.appendSubagentSystemPrompt. Without this flag, the option is… |
CLAUDE_CODE_ENABLE_AUTO_MODEPermissions and sandbox | Added between v2.1.143 and v2.1.212 Documented | The master switch. Redundant on Bedrock/Vertex/Foundry now that Auto mode is default-on, but still the toggle everywhere else. It gates everything below. |
CLAUDE_CODE_ENABLE_AWAY_SUMMARYFeature toggles | Added between v2.1.104 and v2.1.107 Documented | Enables generation of a summary when the user returns after being away from an active session. |
CLAUDE_CODE_ENABLE_BACKGROUND_PLUGIN_REFRESHPlugins and skills | Removed between v2.1.245 and v2.1.247 Documented | Enables automatic background plugin refresh when the runtime detects updates are needed. Without this, refresh is synchronous and delays session startup. |
CLAUDE_CODE_ENABLE_CFCFeature toggles | Present since v2.1.69 or earlier Documented | Enable Claude for Chrome browser automation |
CLAUDE_CODE_ENABLE_DESIGN_SYNCFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_ENABLE_EXPERIMENTAL_ADVISOR_TOOLShell and tools | Added between v2.1.108 and v2.1.114 | Enables the experimental Advisor Tool — a server-side tool with its own advisorModel config option. Requires first-party auth; falls back to the… |
CLAUDE_CODE_ENABLE_FEEDBACK_SURVEY_FOR_OTELTelemetry | Added between v2.1.128 and v2.1.138 Documented | Re-enables the session quality survey for enterprise deployments with OTEL enabled. Backs the v2.1.136 changelog bullet explicitly. If your org collects Claude… |
CLAUDE_CODE_ENABLE_FINE_GRAINED_TOOL_STREAMINGNetwork and proxy | Present since v2.1.69 or earlier Documented | Enable fine-grained (eager) input streaming for tools |
CLAUDE_CODE_ENABLE_FUNCTION_HOOKSFeature toggles | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERYModels and thinking | Added between v2.1.128 and v2.1.138 Documented | Query available models from a gateway rather than a hardcoded list. For enterprise setups where model availability is controlled centrally — a new model rolls… |
CLAUDE_CODE_ENABLE_LAUNCH_COMPOSERFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_ENABLE_MENU_KIND_LANESFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_ENABLE_MORNING_BRIEFFeature toggles | Removed between v2.1.212 and v2.1.215 | — |
CLAUDE_CODE_ENABLE_NARRATIONFeature toggles | Removed in v2.1.284 | — |
CLAUDE_CODE_ENABLE_OPUS_4_7_FAST_MODEModels and thinking | Added between v2.1.128 and v2.1.138 Documented | — |
CLAUDE_CODE_ENABLE_PROMPT_SUGGESTIONFeature toggles | Present since v2.1.69 or earlier Documented | Enables a prompt suggestion feature in the Claude Code UI. This likely surfaces contextual follow-up prompts or autocomplete suggestions based on the current… |
CLAUDE_CODE_ENABLE_PROXY_AUTH_HELPERAuthentication | Added between v2.1.108 and v2.1.114 | Set to "1" to enable the proxy auth helper subsystem. Lets Claude Code shell out to an external program to fetch proxy credentials dynamically — for… |
CLAUDE_CODE_ENABLE_REFRESH_MCP_TOOLSMCP | Added between v2.1.143 and v2.1.212 | Enables an on-demand MCP-tool refresh capability, grouped with CLAUDE_CODE_ENABLE_TASKS and CLAUDE_CODE_ENABLE_REMOTE_RECAP. It lets a session re-fetch an MCP… |
CLAUDE_CODE_ENABLE_REMOTE_RECAPSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTINGFeature toggles | Present since v2.1.69 or earlier | Enable file checkpointing in SDK mode |
CLAUDE_CODE_ENABLE_TASKSFeature toggles | Present since v2.1.69 or earlier Documented | Enable the task system |
CLAUDE_CODE_ENABLE_TELEMETRYTelemetry | Present since v2.1.69 or earlier Documented | Enable telemetry collection |
CLAUDE_CODE_ENABLE_TODO_TOOLSShell and tools | Added between v2.1.229 and v2.1.234 Documented | — |
CLAUDE_CODE_ENABLE_TOKEN_USAGE_ATTACHMENTAuthentication | Present since v2.1.69 or earlier | Attach token usage info to messages |
CLAUDE_CODE_ENABLE_XAAFeature toggles | Added between v2.1.79 and v2.1.83 | Enables an internal feature flagged as "XAA." The acronym is opaque, but the ENABLE_ prefix and proximity to other experimental flags suggest this is an opt-in… |
CLAUDE_CODE_ENHANCED_TELEMETRY_BETATelemetry | Present since v2.1.69 or earlier | Enable enhanced telemetry (beta) |
CLAUDE_CODE_ENTRYPOINTOther | Present since v2.1.69 or earlier | Application entry point; auto-set based on context (e.g. cli, vscode, sdk-py) [7] |
CLAUDE_CODE_ENVIRONMENT_KINDOther | Present since v2.1.69 or earlier | Environment: byoc, anthropic_cloud, bridge |
CLAUDE_CODE_ENVIRONMENT_RUNNER_VERSIONOther | Added between v2.1.143 and v2.1.212 | Environment runner version |
CLAUDE_CODE_EVAL_ALLOW_ARTIFACT_PUBLISHOther | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_EVAL_ALLOW_FLAG_OVERRIDESTerminal and UI | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_EVAL_ARTIFACT_STUB_DIROther | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_EVAL_CONFINEDOther | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_EVAL_INTERVIEW_SESSIONSessions | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_EXECPATHOther | Added in v2.1.92 | Overrides the detected executable path for the Claude Code binary. This matters in environments where the binary is symlinked, wrapped in a shell script, or… |
CLAUDE_CODE_EXIT_AFTER_FIRST_RENDEROther | Present since v2.1.69 or earlier | Exit after first UI render (testing) |
CLAUDE_CODE_EXIT_AFTER_STOP_DELAYOther | Present since v2.1.69 or earlier Documented | Delay before exit after stop signal (ms) |
CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMSAgents and subagents | Present since v2.1.69 or earlier Documented | Enable Agent Teams (the official release of Swarms). Each agent works in an independent Git Worktree [1] |
CLAUDE_CODE_EXPERIMENTAL_OBSERVER_AGENTSAgents and subagents | Added between v2.1.143 and v2.1.212 | Agents that watch a session rather than act in it. The natural counterpart to autonomy: if agents edit on their own, you want independent observers checking… |
CLAUDE_CODE_EXTRA_BODYOther | Present since v2.1.69 or earlier Documented | Additional JSON merged into API request bodies |
CLAUDE_CODE_EXTRA_METADATAOther | Added between v2.1.77 and v2.1.79 | Passes additional metadata to API requests beyond what Claude Code includes by default. This likely attaches custom key-value pairs to the Anthropic API call… |
CLAUDE_CODE_FABLE_BRIDGE_DIALOG_TIMEOUT_MSNetwork and proxy | Removed between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_FEDERATION_CACHE_DIROther | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_FILE_READ_MAX_OUTPUT_TOKENSAuthentication | Present since v2.1.69 or earlier Documented | Max tokens for file read output |
CLAUDE_CODE_FLAG_FETCH_WAIT_MSOther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_FLEETVIEW_SIMPLEOther | Added between v2.1.215 and v2.1.217 | Forces the simplified FleetView layout, the multi-agent monitoring surface. First shipped v2.1.216; undocumented. |
CLAUDE_CODE_FLEET_PAST_SESSIONSSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_FOOTER_INDICATOROther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_FORCE_BRIDGESessions | Removed between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_FORCE_EVALUATE_MEMORYMemory and CLAUDE.md | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_FORCE_FIRST_LAUNCHFeature toggles | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_FORCE_FULLSCREEN_UPSELLTerminal and UI | Added between v2.1.108 and v2.1.114 | Forces the fullscreen TUI upsell prompt past the normal fullscreenUpsellSeenCount cap and the tengu_ochre_hollow gate. Internal test/demo affordance. |
CLAUDE_CODE_FORCE_FULL_LOGODebugging | Removed between v2.1.245 and v2.1.247 | Force full ASCII logo display on startup |
CLAUDE_CODE_FORCE_GLOBAL_CACHEShell and tools | Removed between v2.1.87 and v2.1.88 | Previously forced use of a global cache directory. Likely superseded by improved cache management that no longer needs a manual override. |
CLAUDE_CODE_FORCE_MEMORY_SURVEYMemory and CLAUDE.md | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_FORCE_MID_CONVERSATION_SYSTEMFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_FORCE_RC_LONG_TURN_NUDGEFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_FORCE_SANDBOXPermissions and sandbox | Present since v2.1.69 or earlier | — |
CLAUDE_CODE_FORCE_SESSION_PERSISTENCESessions | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_FORCE_STRIKETHROUGHFeature toggles | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_FORCE_SYNC_OUTPUTFeature toggles | Added between v2.1.128 and v2.1.138 Documented | Disable streaming output in favor of synchronous writes. If you're capturing Claude Code output in a script and seeing partial lines or buffering artifacts,… |
CLAUDE_CODE_FORCE_TERMINAL_IMAGESTerminal and UI | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_FORCE_TIP_IDFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_FORCE_WINDOWS_CREDMANFeature toggles | Added between v2.1.143 and v2.1.212 | Forces credential storage through the Windows Credential Manager. A FORCE_ override in the credential-backend family next to… |
CLAUDE_CODE_FORK_SUBAGENTAgents and subagents | Added between v2.1.114 and v2.1.117 Documented | Changelog-confirmed[1]: set to 1 to run subagents as forked processes (v2.1.117 on external builds, v2.1.121 extended to non-interactive SDK/-p sessions).… |
CLAUDE_CODE_FORWARD_SUBAGENT_TEXTAgents and subagents | Added between v2.1.143 and v2.1.212 Documented | Includes subagent text and thinking in stream-json output, paired with a new --forward-subagent-text flag. Shipped in v2.1.211 (npm 2026-07-15) and the one… |
CLAUDE_CODE_FORWARD_USER_INTENTOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_FRAME_TIMING_LOGDebugging | Removed between v2.1.269 and v2.1.283 | Enable per-frame render timing logs in the terminal UI. A diagnostic variable — when set, it likely writes timing data for each UI frame render cycle, useful… |
CLAUDE_CODE_FRAME_TIMING_SAMPLE_EVERYOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_GATEWAY_HINT_HEADERSOther | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_GATEWAY_MODEL_DISCOVERY_TIMEOUT_MSNetwork and proxy | Added between v2.1.266 and v2.1.269 Documented | — |
CLAUDE_CODE_GATEWAY_TOKENAuthentication | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_GATEWAY_TOKEN_FILE_DESCRIPTORAuthentication | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_GAULT_KESTRELOther | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_GB_BASE_URLNetwork and proxy | Present since v2.1.69 or earlier | An internal base URL override, possibly for a "gradebook" or grading service used during internal testing. Its removal suggests the endpoint was consolidated… |
CLAUDE_CODE_GB_DISK_CACHE_WHEN_TELEMETRY_OFFTelemetry | Added between v2.1.143 and v2.1.212 | Opts GrowthBook (GB) flag data back into the on-disk cache under a telemetry-off profile, where feature-flag caching would otherwise be skipped. Shipped… |
CLAUDE_CODE_GB_REFRESH_INTERVAL_MSOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_GENTLE_PARASOLOther | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_GIT_BASH_PATHShell and tools | Present since v2.1.69 or earlier Documented | Git Bash executable path (Windows) |
CLAUDE_CODE_GLOB_HIDDENShell and tools | Present since v2.1.69 or earlier Documented | Include hidden files in globs |
CLAUDE_CODE_GLOB_NO_IGNOREShell and tools | Present since v2.1.69 or earlier Documented | Ignore .gitignore rules in globs |
CLAUDE_CODE_GLOB_TIMEOUT_SECONDSNetwork and proxy | Present since v2.1.69 or earlier Documented | Timeout for glob operations; default 20s (WSL: 60s) |
CLAUDE_CODE_GOAL_CHECKIN_MINUTESOther | Removed in v2.1.293 Documented | — |
CLAUDE_CODE_GORSE_PLOVEROther | Added in v2.1.218 | — |
CLAUDE_CODE_GROWTHBOOK_KICK_FROM_INITOther | Added in v2.1.287 | — |
CLAUDE_CODE_GROWTHBOOK_KICK_ON_WARM_CACHEOther | Added in v2.1.288 | — |
CLAUDE_CODE_GZIP_CCR_REQUEST_BODIESNetwork and proxy | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_GZIP_DATADOG_LOGSTelemetry | Added in v2.1.288 | — |
CLAUDE_CODE_GZIP_REQUEST_BODIESNetwork and proxy | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_GZIP_REQUEST_BODY_BLOCKSNetwork and proxy | Removed in v2.1.293 | Selects one of two gzip modes (1 or 2) for API request bodies at least 512KB in size; any other value, and the default, leaves it off. It sits alongside the… |
CLAUDE_CODE_GZIP_REQUEST_BODY_LEVELNetwork and proxy | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_HANDBACK_PROVENANCEOther | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_HARBOR_KITEOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_CODE_HARBOR_KITE_CLOUDOther | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_HARBOR_KITE_PACING_OFFOther | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_HARMONIC_RIDDLEOther | Added in v2.1.290 | — |
CLAUDE_CODE_HERON_TALLOWOther | Removed in v2.1.229 | — |
CLAUDE_CODE_HFI_BEARER_TOKENAuthentication | Removed in v2.1.290 | — |
CLAUDE_CODE_HIDE_CWDTerminal and UI | Added between v2.1.118 and v2.1.123 Documented | Changelog-confirmed[1] (v2.1.119): hides the working directory display in the startup logo. Useful for shared terminals, screen shares, or documentation… |
CLAUDE_CODE_HIDE_SETTINGS_HINTTerminal and UI | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_HOLD_REPORT_PARK_AT_INITOther | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_HOLD_UNANSWERED_PARKED_PERMISSIONPermissions and sandbox | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_HOME_SEED_HOLD_TIMEOUT_MSNetwork and proxy | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_HOME_SEED_VERDICT_TIMEOUT_MSNetwork and proxy | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_HOOKS_SAME_THREADOther | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_HOSTED_DESKTOPOther | Added in v2.1.290 | — |
CLAUDE_CODE_HOST_AUTH_ENV_VARAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_HOST_AUTH_REFRESH_TIMEOUT_MSAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_HOST_CREDS_FILEOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_HOST_GATEWAY_LINEAGEOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_HOST_HTTP_PROXY_PORTNetwork and proxy | Removed between v2.1.245 and v2.1.247 | HTTP proxy port for host |
CLAUDE_CODE_HOST_PLATFORMOther | Present since v2.1.69 or earlier | Override platform detection: win32, darwin, linux |
CLAUDE_CODE_HOST_PROMPT_SUPERSEDES_RECORDOther | Added in v2.1.285 | — |
CLAUDE_CODE_HOST_SCHEDULED_RUNOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_HOST_SESSION_IDSessions | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_HOST_SKILL_CATALOGPlugins and skills | Added in v2.1.292 | A JSON object ({"skills": [...]}) of 1 to 64 folder names that scopes which synced claude.ai skills a remote session loads. It is read only when a remote… |
CLAUDE_CODE_HOST_SOCKS_PROXY_PORTNetwork and proxy | Present since v2.1.69 or earlier | SOCKS proxy port for host |
CLAUDE_CODE_HOST_WORKTREEOther | Added in v2.1.288 | — |
CLAUDE_CODE_HOST_WORKTREE_FENCEOther | Added in v2.1.288 | — |
CLAUDE_CODE_HOVER_RESTOther | Added in v2.1.238 | — |
CLAUDE_CODE_HTTPS_PROXYNetwork and proxy | Added between v2.1.114 and v2.1.117 | Claude-namespaced HTTPS proxy URL. See CLAUDE_CODE_HTTP_PROXY above. |
CLAUDE_CODE_HTTP_PROXYNetwork and proxy | Added between v2.1.114 and v2.1.117 | Claude-namespaced HTTP proxy URL. Claude-namespacing avoids collisions with system HTTP_PROXY for other tools in the shell that should use a different proxy.… |
CLAUDE_CODE_HUMBLE_HAMMOCKOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_IDE_HOST_OVERRIDETerminal and UI | Present since v2.1.69 or earlier Documented | Custom host address for IDE communication |
CLAUDE_CODE_IDE_SKIP_AUTO_INSTALLTerminal and UI | Present since v2.1.69 or earlier Documented | Skip automatic IDE extension install |
CLAUDE_CODE_IDE_SKIP_VALID_CHECKTerminal and UI | Present since v2.1.69 or earlier Documented | Bypass IDE extension validation checks |
CLAUDE_CODE_IDLE_COMPACT_MIN_TOKENSAuthentication | Added in v2.1.290 Documented | Sets the minimum conversation size, in tokens, before idle compaction runs. The value is floored at 100,000 and defaults to 200,000 when unset. Idle compaction… |
CLAUDE_CODE_IDLE_THRESHOLD_MINUTESOther | Added in v2.1.84 | Sets the threshold (in minutes) before a session is considered idle. The changelog describes a new "idle-return prompt" that nudges users returning after 75+… |
CLAUDE_CODE_IDLE_TOKEN_THRESHOLDAuthentication | Removed between v2.1.245 and v2.1.247 | Works alongside CLAUDE_CODE_IDLE_THRESHOLD_MINUTES to gate when the idle-return prompt appears. The token threshold likely ensures the prompt only fires for… |
CLAUDE_CODE_INCLUDE_PARTIAL_MESSAGESOther | Removed between v2.1.245 and v2.1.247 | Include partial/streaming messages in output |
CLAUDE_CODE_INLINE_TOOLSShell and tools | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_INSTALLED_VIA_NPM_WRAPPEROther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_INTRO_FRAMEOther | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_INVESTIGATE_FIRSTOther | Removed between v2.1.222 and v2.1.224 | Instructs the agent to read and investigate before acting — enforcing "read before write." Converts an agent that might immediately start editing into one that… |
CLAUDE_CODE_INVOKED_SKILLSPlugins and skills | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_IS_COWORKOther | Present since v2.1.69 or earlier | Indicates running in cowork (multi-agent) mode |
CLAUDE_CODE_JSONL_TRANSCRIPTOther | Removed between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_JUNIPER_SUNDIALOther | Added in v2.1.218 | — |
CLAUDE_CODE_KB_COHESION_FIXESOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_LANTERN_PRISMOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_LARCH_CISTERNOther | Added between v2.1.215 and v2.1.217 | — |
CLAUDE_CODE_LEGACY_BUNDLEOther | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_LOOP_KEEPALIVEOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_LOOP_PERSISTENTOther | Added between v2.1.128 and v2.1.138 | Persist loop state across session boundaries. Loops don't die when the session restarts — they resume. Turns /loop from a within-session tool into a durable… |
CLAUDE_CODE_LUMINOUS_WHISTLEOther | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_MANAGED_CONFIG_PREFETCHOther | Added in v2.1.292 | Turns on a hedged prefetch of the organization's managed settings during startup, so the first managed-settings fetch runs earlier in the launch sequence.… |
CLAUDE_CODE_MANAGED_SETTINGS_PATHOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_MARKETPLACE_NAMEPlugins and skills | Removed in v2.1.293 | — |
CLAUDE_CODE_MARKETPLACE_URLNetwork and proxy | Added in v2.1.238 | — |
CLAUDE_CODE_MARL_CORMORANTOther | Removed between v2.1.219 and v2.1.221 | — |
CLAUDE_CODE_MAX_CONCURRENT_SUBAGENTSAgents and subagents | Added between v2.1.215 and v2.1.217 Documented | Ceiling on subagents running at once, default 20; when full Claude Code tells the model to stop and the user to raise this variable. Gated by… |
CLAUDE_CODE_MAX_CONTEXT_TOKENSAuthentication | Added between v2.1.96 and v2.1.100 Documented | Sets an explicit ceiling on the context window size used during a session. Rather than relying on the model's default maximum, this variable lets operators cap… |
CLAUDE_CODE_MAX_EFFORT_REMINDERModels and thinking | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_MAX_MCP_DESCRIPTION_LENGTHMCP | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_MAX_OUTPUT_TOKENSAuthentication | Present since v2.1.69 or earlier Documented | Maximum output tokens; validated per-model |
CLAUDE_CODE_MAX_RETRIESNetwork and proxy | Present since v2.1.69 or earlier Documented | Maximum API request retries |
CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSIONAgents and subagents | Added between v2.1.143 and v2.1.212 Documented | Per-session ceiling on subagent spawns (default 200). When the cap is hit, Claude Code injects a prompt — "Subagent spawn limit reached. Complete the remaining… |
CLAUDE_CODE_MAX_SUBAGENT_SPAWN_DEPTHAgents and subagents | Removed between v2.1.245 and v2.1.247 Documented | Nesting-depth cap on delegation, default 1 — subagents no longer spawn their own subagents, and the team roster stays flat. Gated by tengu_hazel_trellis. First… |
CLAUDE_CODE_MAX_TOOL_USE_CONCURRENCYShell and tools | Present since v2.1.69 or earlier Documented | Max concurrent tool executions; default 10 |
CLAUDE_CODE_MAX_TURNSOther | Added between v2.1.138 and v2.1.143 Documented | Hard cap on conversation turns. The single most important variable in this release for anyone running unattended agents. Set it to 50, 100, or whatever your… |
CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSIONShell and tools | Added between v2.1.143 and v2.1.212 Documented | Per-session ceiling on WebSearch tool calls (default 200), gated by a web_search_session_cap. Its exhaustion string tells the model "this session has used its… |
CLAUDE_CODE_MCP_ALLOWLIST_ENVMCP | Added in v2.1.94 Documented | Specifies an allowlist of environment variables that MCP servers can access. MCP servers run as subprocesses and inherit the parent environment by default,… |
CLAUDE_CODE_MCP_APPS_HOSTMCP | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_MCP_AUTO_BACKGROUND_MSMCP | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_MCP_CONNECTOR_PREWAIT_MSNetwork and proxy | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_MCP_INSTR_DELTAMCP | Removed in v2.1.91 | Delta/incremental MCP instruction updates. Instead of sending full MCP server instructions every turn, this likely enables sending only changes — reducing… |
CLAUDE_CODE_MCP_MEMORY_CGROUPMCP | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_MCP_PREWAIT_SERVERSMCP | Added in v2.1.286 | — |
CLAUDE_CODE_MCP_PREWAIT_SERVERS_MSMCP | Added in v2.1.286 | — |
CLAUDE_CODE_MCP_SERVER_NAMEMCP | Added in v2.1.85 | Added in v2.1.85 to identify which MCP server a helper process was acting on behalf of. Removed after just two versions. |
CLAUDE_CODE_MCP_SERVER_URLNetwork and proxy | Added in v2.1.85 | The companion to MCP_SERVER_NAME, providing the server endpoint URL. Also removed. Together these formed a pair for routing MCP requests through a single… |
CLAUDE_CODE_MCP_SERVE_AUTH_TOKENAuthentication | Added in v2.1.285 | — |
CLAUDE_CODE_MCP_SERVE_SETTINGSMCP | Added in v2.1.285 | — |
CLAUDE_CODE_MCP_SERVE_TOOL_OUTPUTMCP | Added in v2.1.287 | — |
CLAUDE_CODE_MCP_STARTUP_WAIT_MSMCP | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_MCP_TOOL_IDLE_TIMEOUTNetwork and proxy | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_MEMORY_API_BASE_URLNetwork and proxy | Added between v2.1.224 and v2.1.227 | — |
CLAUDE_CODE_MEMORY_API_TOKENAuthentication | Added between v2.1.224 and v2.1.227 | — |
CLAUDE_CODE_MEMORY_PUSH_DELETE_MODEMemory and CLAUDE.md | Added between v2.1.143 and v2.1.212 | Controls how deletions propagate when memory is pushed upstream — a delete-mode knob for the memory subsystem that gained account- and organization-scoped sync… |
CLAUDE_CODE_MEMORY_SUBAGENT_APPENDAgents and subagents | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_MESSAGING_SOCKETOther | Added between v2.1.222 and v2.1.224 Documented | — |
CLAUDE_CODE_MESSAGING_TOKENAuthentication | Added in v2.1.228 Documented | Controls access to the local inbox for cross-session messages. A sender opens the socket named in CLAUDE_CODE_MESSAGING_SOCKET and sends this token first. If… |
CLAUDE_CODE_MID_CONVERSATION_SYSTEMOther | Removed between v2.1.143 and v2.1.212 | Inject a system message mid-conversation. Your harness can update Claude's constraints, inject new context, or shift behavioral guidelines without ending the… |
CLAUDE_CODE_MOCK_REMOTE_SETTINGSSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_MOCK_TRIALOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_MODEL_CAPABILITIESModels and thinking | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_MODEL_CATALOGModels and thinking | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_MODEL_CATALOG_URLNetwork and proxy | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_MORNING_BRIEF_PROMPTOther | Removed between v2.1.212 and v2.1.215 | — |
CLAUDE_CODE_NANKEEN_KESTRELOther | Added between v2.1.143 and v2.1.212 | Windows-only sandbox gate. The gate function returns false on any non-Windows OS, true if this variable is set, otherwise defers to the server gate… |
CLAUDE_CODE_NATIVE_CURSORTerminal and UI | Added between v2.1.128 and v2.1.138 Documented | Use native terminal cursor control. Extension of the terminal-native capabilities that came in with v2.1.113's binary launcher. If cursor positioning looks off… |
CLAUDE_CODE_NEW_INITOther | Added between v2.1.77 and v2.1.79 Documented | Toggles a refactored initialization path that reduces startup memory usage. The changelog explicitly highlights "~18MB" savings across all scenarios, which is… |
CLAUDE_CODE_NONBLOCKING_STDOUTOther | Added between v2.1.252 and v2.1.266 Documented | — |
CLAUDE_CODE_NONSTREAMING_TIMEOUT_RETRIESNetwork and proxy | Added in v2.1.285 Documented | Caps how many times a timed-out non-streaming fallback request is re-sent. Added in v2.1.285. |
CLAUDE_CODE_NO_FLICKERTerminal and UI | Added between v2.1.87 and v2.1.88 Documented | Enables flicker-free alternate-screen rendering. The changelog[1] explicitly documents this as CLAUDE_CODE_NO_FLICKER=1. |
CLAUDE_CODE_NO_MODEL_FALLBACKModels and thinking | Added between v2.1.212 and v2.1.215 | When set, the availability chain collapses to [primary]: buildAvailabilityFallbackChain() returns only the model you selected, and a tripwire error fires if… |
CLAUDE_CODE_OAUTH_401_WAIT_MSAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_OAUTH_CLIENT_IDAuthentication | Present since v2.1.69 or earlier | Custom OAuth client ID |
CLAUDE_CODE_OAUTH_REFRESH_TOKENAuthentication | Present since v2.1.69 or earlier Documented | OAuth refresh token |
CLAUDE_CODE_OAUTH_SCOPESAuthentication | Removed in v2.1.293 Documented | OAuth scopes for refresh token |
CLAUDE_CODE_OAUTH_TOKENAuthentication | Present since v2.1.69 or earlier Documented | Pre-configured OAuth access token |
CLAUDE_CODE_OAUTH_TOKEN_FILE_DESCRIPTORAuthentication | Present since v2.1.69 or earlier | File descriptor to read OAuth token from |
CLAUDE_CODE_OPUS_4_6_FAST_MODE_OVERRIDEModels and thinking | Added between v2.1.138 and v2.1.143 Documented | Pin Fast mode to Opus 4.6. Fast mode upgraded to Opus 4.7 by default in v2.1.142. If you're evaluating 4.7 or have a reproducibility requirement — benchmarks,… |
CLAUDE_CODE_ORGANIZATION_UUIDOther | Present since v2.1.69 or earlier | Organization UUID |
CLAUDE_CODE_OTEL_CONTENT_MAX_LENGTHTelemetry | Added between v2.1.212 and v2.1.215 Documented | Caps the length of content attributes on OpenTelemetry spans and logs; the truncation function takes the minimum of this value (default 60 KB) and the standard… |
CLAUDE_CODE_OTEL_DIAG_STDERRTelemetry | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_OTEL_FLUSH_TIMEOUT_MSTelemetry | Present since v2.1.69 or earlier Documented | OpenTelemetry flush timeout; default 5000ms |
CLAUDE_CODE_OTEL_HEADERS_HELPER_DEBOUNCE_MSTelemetry | Present since v2.1.69 or earlier Documented | Debounce for OTEL headers helper |
CLAUDE_CODE_OTEL_SHUTDOWN_TIMEOUT_MSTelemetry | Removed between v2.1.245 and v2.1.247 Documented | OpenTelemetry shutdown timeout; default 2000ms |
CLAUDE_CODE_OVERLOADED_RETRY_BASE_DELAY_MSNetwork and proxy | Added in v2.1.292 Documented | Sets the base delay, in milliseconds, for the backoff when a request comes back overloaded (HTTP 529). The retry loop seeds its wait from this value on… |
CLAUDE_CODE_OVERLOADED_RETRY_MAX_DELAY_MSNetwork and proxy | — Documented | — |
CLAUDE_CODE_OVERRIDE_DATETerminal and UI | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_OWNERSHIP_FRAMEOther | Removed between v2.1.215 and v2.1.217 | — |
CLAUDE_CODE_PACKAGE_MANAGER_AUTO_UPDATEOther | Added between v2.1.128 and v2.1.138 Documented | Control whether Claude Code auto-updates itself. If you manage Claude Code versions centrally (fleet policy, pinned version in a Dockerfile, corp registry),… |
CLAUDE_CODE_PARCHMENT_FERNOther | Removed in v2.1.285 | — |
CLAUDE_CODE_PARKED_PERMISSION_WAIT_MSPermissions and sandbox | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_PARKED_RUN_BEFORE_CLEAROther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_PARKED_STOP_RETIRESOther | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_PARSED_WILLOWOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_PERFETTO_TRACETelemetry | Present since v2.1.69 or earlier | Enable Perfetto trace output to file path (server-gated) |
CLAUDE_CODE_PERFETTO_WRITE_INTERVAL_STelemetry | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_PERFORCE_MODEOther | Added between v2.1.96 and v2.1.100 Documented | Activates Perforce VCS integration. The changelog[1] specifies: "when set, Edit/Write/NotebookEdit fail on read-only files with a p4 edit hint instead of… |
CLAUDE_CODE_PER_TURN_TIMINGOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_PEWTER_OWLOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_PEWTER_OWL_TOOLShell and tools | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_PLAN_ARTIFACTSOther | Removed between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_PLAN_MODE_INTERVIEW_PHASEOther | Removed between v2.1.143 and v2.1.212 | Enable interview phase in plan mode |
CLAUDE_CODE_PLAN_MODE_REQUIREDOther | Present since v2.1.69 or earlier | Require agents to use plan mode for all tasks |
CLAUDE_CODE_PLAN_V2_AGENT_COUNTAgents and subagents | Present since v2.1.69 or earlier | Number of agents in Plan v2 mode (1–10) |
CLAUDE_CODE_PLAN_V2_EXPLORE_AGENT_COUNTAgents and subagents | Present since v2.1.69 or earlier | Exploration agents in Plan v2 (1–10) |
CLAUDE_CODE_PLUGIN_ARCHIVE_URLNetwork and proxy | Added in v2.1.238 | — |
CLAUDE_CODE_PLUGIN_ATTRIBUTIONPlugins and skills | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_PLUGIN_BINARY_ASSETSPlugins and skills | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_PLUGIN_CACHE_DIRPlugins and skills | Present since v2.1.69 or earlier Documented | Local cache directory for downloaded plugins |
CLAUDE_CODE_PLUGIN_DIRSPlugins and skills | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_PLUGIN_DIR_WATCHPlugins and skills | Removed in v2.1.292 Documented | — |
CLAUDE_CODE_PLUGIN_GIT_TIMEOUT_MSNetwork and proxy | Present since v2.1.69 or earlier Documented | Git clone timeout for plugin installation |
CLAUDE_CODE_PLUGIN_KEEP_MARKETPLACE_ON_FAILUREPlugins and skills | Added in v2.1.90 Documented | Preserves the local marketplace plugin cache when git pull fails. Source code shows that without this flag, a failed pull triggers a full delete-and-reclone of… |
CLAUDE_CODE_PLUGIN_NAMEPlugins and skills | Added in v2.1.238 | — |
CLAUDE_CODE_PLUGIN_PREFER_HTTPSPlugins and skills | Added between v2.1.138 and v2.1.143 Documented | Force HTTPS for plugin source resolution. If you're in a network environment where HTTP traffic is intercepted or plugins could be fetched without TLS, this… |
CLAUDE_CODE_PLUGIN_SEED_DIRPlugins and skills | Present since v2.1.69 or earlier Documented | Seed directory for pre-installed plugins |
CLAUDE_CODE_PLUGIN_USE_ZIP_CACHEPlugins and skills | Present since v2.1.69 or earlier | Use zip-based caching instead of git |
CLAUDE_CODE_POLICY_HELPER_PS1_PATHOther | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_POLICY_HELPER_PSMODULEPATHOther | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_POLISHED_DEWDROPOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_POLL_EVENTSOther | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_POLL_EVENT_DECLARATIONSOther | Added in v2.1.287 | — |
CLAUDE_CODE_POST_FOR_SESSION_INGRESS_V2Sessions | Removed between v2.1.219 and v2.1.221 | Use POST-based session ingress v2 |
CLAUDE_CODE_POST_TURN_MEMORYMemory and CLAUDE.md | Removed in v2.1.290 | — |
CLAUDE_CODE_POST_TURN_MEMORY_CONFIGMemory and CLAUDE.md | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_POST_TURN_MEMORY_SYNCMemory and CLAUDE.md | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_POWERSHELL_RESPECT_EXECUTION_POLICYShell and tools | Added between v2.1.138 and v2.1.143 Documented | Restore PowerShell execution policy checks. v2.1.143 made bypass-policy the default to reduce the most common Windows friction. If your environment uses… |
CLAUDE_CODE_POWERUP_ONBOARDINGOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MSSessions | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_PRINT_ENGINE_LOOPOther | Removed between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_PROACTIVEOther | Added in v2.1.128 | — |
CLAUDE_CODE_PROCESS_WRAPPEROther | Added between v2.1.143 and v2.1.212 Documented | Names an executable that Claude Code must launch itself through. When the CLI spawns a copy of itself — the background daemon, agent-view workers, subagents —… |
CLAUDE_CODE_PROFILE_QUERYDebugging | Added between v2.1.143 and v2.1.212 | Likely merged into general profiling |
CLAUDE_CODE_PROFILE_STARTUPDebugging | Present since v2.1.69 or earlier | Enable startup profiling; set to 1 |
CLAUDE_CODE_PROJECTS_SESSIONSessions | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_PROJECT_DIR_NAMEOther | Added between v2.1.229 and v2.1.234 Documented | — |
CLAUDE_CODE_PROMPT_CACHE_TTLOther | Removed between v2.1.245 and v2.1.247 Documented | — |
CLAUDE_CODE_PROPAGATE_TRACEPARENTOther | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_PROVIDER_MANAGED_BY_HOSTTerminal and UI | Added between v2.1.79 and v2.1.83 Documented | Indicates that the API provider configuration is managed by the host application rather than by Claude Code itself. |
CLAUDE_CODE_PROXY_AUTHENTICATEAuthentication | Added between v2.1.108 and v2.1.114 | Carries the WWW-Authenticate challenge from the proxy into the helper. Enables challenge-response schemes by reading what the proxy actually asked for. |
CLAUDE_CODE_PROXY_AUTH_HELPER_TTL_MSAuthentication | Added between v2.1.108 and v2.1.114 | Cache TTL for helper-returned credentials. Parsed as integer milliseconds; zero or negative falls back to default. |
CLAUDE_CODE_PROXY_HOSTNetwork and proxy | Added between v2.1.108 and v2.1.114 | Proxy hostname, passed alongside the URL so helpers that route credentials by hostname don't need to re-parse. |
CLAUDE_CODE_PROXY_RESOLVES_HOSTSNetwork and proxy | Present since v2.1.69 or earlier Documented | Proxy handles DNS resolution (skip local DNS) |
CLAUDE_CODE_PROXY_URLNetwork and proxy | Added between v2.1.108 and v2.1.114 | Full proxy URL, injected into the helper subprocess's environment. Claude-namespaced because the helper protocol is Claude-specific and must not collide with… |
CLAUDE_CODE_PWSH_PARSE_TIMEOUT_MSNetwork and proxy | Added in v2.1.85 | Sets the timeout for PowerShell command parsing on Windows. The PowerShell tool shipped as a preview in v2.1.84 with CLAUDE_CODE_USE_POWERSHELL_TOOL — this… |
CLAUDE_CODE_QUESTION_EXTENDEDOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_QUESTION_OPTIONAL_DESCRIPTIONSOther | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_QUESTION_PREVIEW_FORMATOther | Present since v2.1.69 or earlier | Format for permission question previews |
CLAUDE_CODE_RATE_LIMIT_TIEROther | Added between v2.1.114 and v2.1.117 | Rate-limit bucket for the current session, independent of subscription type. Enterprise customers may have custom limits that differ from their plan defaults —… |
CLAUDE_CODE_RC_PERMISSION_NUDGEPermissions and sandbox | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_REFUSAL_FALLBACK_CATCH_ALLOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_RELAUNCH_HOME_TRUSTOther | Added in v2.1.284 | — |
CLAUDE_CODE_RELAUNCH_PROACTIVITY_BASELINEOther | Added in v2.1.290 | — |
CLAUDE_CODE_RELAUNCH_PROACTIVITY_EVER_ONOther | Added in v2.1.290 | — |
CLAUDE_CODE_RELAUNCH_PROACTIVITY_LEVELOther | Added in v2.1.290 | — |
CLAUDE_CODE_RELAUNCH_TERMINAL_SIZETerminal and UI | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_REMOTESessions | Present since v2.1.69 or earlier Documented | Indicates running in remote/server mode |
CLAUDE_CODE_REMOTE_ENVIRONMENT_TYPESessions | Present since v2.1.69 or earlier | Remote environment type sent in telemetry |
CLAUDE_CODE_REMOTE_HERMETIC_MODESessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_REMOTE_MEMORY_DIRMemory and CLAUDE.md | Present since v2.1.69 or earlier | Memory directory for remote sessions |
CLAUDE_CODE_REMOTE_RAW_EVENTS_FILESessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_REMOTE_SDK_URLNetwork and proxy | Added in v2.1.290 | — |
CLAUDE_CODE_REMOTE_SEND_KEEPALIVESSessions | Present since v2.1.69 or earlier | Send keepalive pings in remote mode |
CLAUDE_CODE_REMOTE_SESSION_IDSessions | Present since v2.1.69 or earlier Documented | Remote session identifier |
CLAUDE_CODE_REMOTE_SESSION_ORIGINSessions | Added between v2.1.215 and v2.1.217 | Provenance tag for cloud/remote sessions, checked against the value "review". First shipped v2.1.217; undocumented. |
CLAUDE_CODE_REMOTE_SESSION_UUIDSessions | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_CODE_REMOTE_SETTINGS_PATHSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_REMOTE_SETTINGS_POLL_MSSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_REMOTE_TOOLS_ADOPT_MCPMCP | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_REMOTE_TOOLS_ASK_SEATSShell and tools | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_REMOTE_TOOLS_CALLER_SESSIONS_MAXShell and tools | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_REMOTE_TOOLS_FORWARDShell and tools | Removed in v2.1.284 | — |
CLAUDE_CODE_REMOTE_TOOLS_HOST_ALLOWS_UNATTENDEDShell and tools | Added in v2.1.290 | — |
CLAUDE_CODE_REMOTE_TOOLS_JUMP_QUEUEShell and tools | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_REMOTE_TOOLS_PIN_STORED_LOGINShell and tools | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_REMOTE_TOOLS_POLICYShell and tools | Added between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_REMOTE_TOOLS_SERVEShell and tools | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_REMOTE_TOOLS_SESSION_CHANNELShell and tools | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_REMOTE_TOOLS_SPECULATIVE_CLASSIFIERShell and tools | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_REMOVE_PROMPT_STRINGSOther | Added in v2.1.290 | — |
CLAUDE_CODE_REPLOther | Added between v2.1.87 and v2.1.88 | Boolean toggle for the new native REPL path introduced by v2.1.113's native-binary launcher. Forces on or off regardless of entrypoint detection — the… |
CLAUDE_CODE_REPORT_FINDINGSOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_REPO_CHECKOUTSOther | Added between v2.1.104 and v2.1.107 | Specifies a directory path (or paths) where Claude Code should create and manage git worktree checkouts. By default, worktrees land in a temporary location… |
CLAUDE_CODE_RESTRICTEDPermissions and sandbox | Added between v2.1.247 and v2.1.252 Documented | — |
CLAUDE_CODE_RESULT_NONCEOther | Added in v2.1.285 | — |
CLAUDE_CODE_RESUME_FROM_SESSIONSessions | Added between v2.1.104 and v2.1.107 | Instructs Claude Code to bootstrap a new session's context from an existing session ID. Rather than starting fresh, the new session loads key context —… |
CLAUDE_CODE_RESUME_INTERRUPTED_TURNSessions | Present since v2.1.69 or earlier Documented | Resume an interrupted agent turn |
CLAUDE_CODE_RESUME_INTERRUPTED_TURN_MAX_AGE_MSSessions | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_RESUME_PROMPTSessions | Added between v2.1.138 and v2.1.143 Documented | Set the prompt injected when resuming a session. If you build on top of Claude Code's resume capability and want Claude to get oriented differently on re-entry… |
CLAUDE_CODE_RESUME_PROMPT00Sessions | Removed between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_RESUME_REASONSessions | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_RESUME_SOURCE_ALIVESessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_RESUME_THRESHOLD_MINUTESSessions | Removed between v2.1.245 and v2.1.247 | Sets the time window (in minutes) during which a session is eligible for automatic resume. Claude Code already supports --resume for continuing sessions, and… |
CLAUDE_CODE_RESUME_TOKEN_THRESHOLDAuthentication | Added between v2.1.88 and v2.1.89 | Sets the token count threshold for session resume eligibility. Complementing the time-based threshold above, this adds a context-size dimension: if a session's… |
CLAUDE_CODE_RESUME_TOLERATES_CONTEXT_APPENDSContext and compaction | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_RESUME_TOLERATES_CONTEXT_SEEDSContext and compaction | Added in v2.1.290 | — |
CLAUDE_CODE_RETIRE_UNANSWERED_PARKED_PERMISSIONPermissions and sandbox | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_RETRY_WATCHDOGNetwork and proxy | Added between v2.1.114 and v2.1.117 Documented | Tunes the retry watchdog that detects API calls silently looping without progress. v2.1.123 fixed an OAuth 401 retry loop when… |
CLAUDE_CODE_RETRY_WATCHDOG_MAX_WAIT_MSNetwork and proxy | — Documented | — |
CLAUDE_CODE_RIPPLING_TULIPOther | Added in v2.1.290 | — |
CLAUDE_CODE_RUSTLING_PIXELOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_SABLE_THRUSHOther | Removed between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_SAFE_MODEOther | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_SANDBOXEDPermissions and sandbox | Added in v2.1.94 | Indicates or enforces that Claude Code is running in a sandboxed environment. The v2.1.92 changelog[1] restored the apply-seccomp helper for Linux sandbox in… |
CLAUDE_CODE_SAVE_HOOK_ADDITIONAL_CONTEXTContext and compaction | Removed between v2.1.96 and v2.1.100 | Extra context passed to save hooks |
CLAUDE_CODE_SCRIPT_CAPSOther | Added between v2.1.96 and v2.1.100 Documented | Limits per-session script invocations. The changelog[1] pairs this with subprocess sandboxing via PID namespace isolation on Linux (when… |
CLAUDE_CODE_SCROLL_SPEEDTerminal and UI | Added between v2.1.87 and v2.1.88 Documented | Controls the scroll speed within the terminal UI. Default scroll behavior in terminal applications is typically one line per scroll event, which can feel… |
CLAUDE_CODE_SCROLL_SPEEDITerminal and UI | Removed in v2.1.228 | — |
CLAUDE_CODE_SCROLL_SPEEDI30Terminal and UI | Removed between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_SDK_HAS_HOST_AUTH_REFRESHAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SDK_HAS_OAUTH_REFRESHAuthentication | Added between v2.1.100 and v2.1.104 | Signals to the Claude Code runtime that the SDK caller has already provided an OAuth refresh token. |
CLAUDE_CODE_SDK_READS_SESSION_STATESessions | Added in v2.1.284 | — |
CLAUDE_CODE_SEARCH_HINTS_IN_LISTOther | Removed between v2.1.87 and v2.1.88 | Controlled whether search hints appeared in list views. The feature was probably either made default or removed as the UI evolved. |
CLAUDE_CODE_SENDMESSAGE_HANDBACKOther | Added in v2.1.285 | — |
CLAUDE_CODE_SEND_FEEDBACKOther | Added between v2.1.143 and v2.1.212 Documented | Kill switch for the new /bug feedback relay. The gate function bails if DISABLE_FEEDBACK_COMMAND or DISABLE_BUG_COMMAND is set, requires an… |
CLAUDE_CODE_SESSIONEND_HOOKS_TIMEOUT_MSNetwork and proxy | Added between v2.1.77 and v2.1.79 Documented | Set the timeout in milliseconds for hooks that run when a Claude Code session ends. Session-end hooks (like SessionEnd in the hooks config) run cleanup scripts… |
CLAUDE_CODE_SESSION_ACCESS_TOKENAuthentication | Present since v2.1.69 or earlier | Session-scoped access token |
CLAUDE_CODE_SESSION_IDSessions | Added between v2.1.118 and v2.1.123 Documented | Stable identifier for the current session, passed into subprocess environments. Lets subprocess tools — hooks, MCP servers, custom scripts — correlate their… |
CLAUDE_CODE_SESSION_KINDSessions | Added between v2.1.118 and v2.1.123 | Classifies the session: interactive, SDK/headless, subagent, background, or Remote Control. Hooks can branch on kind — a hook that opens a browser link makes… |
CLAUDE_CODE_SESSION_LOGSessions | Added between v2.1.118 and v2.1.123 | Path to the session's transcript file, surfaced to subprocesses. Lets hooks and post-processing scripts find the transcript without traversing ~/.claude/ or… |
CLAUDE_CODE_SESSION_NAMESessions | Added between v2.1.118 and v2.1.123 | Human-readable session name backing the v2.1.121 terminal tab title feature. Hooks and status-line integrations can read it without querying the CLI. |
CLAUDE_CODE_SESSION_ORIGINSessions | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_SESSION_START_ANNOUNCEMENTS_BEFORE_PROMPTSessions | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_SHELLShell and tools | Present since v2.1.69 or earlier Documented | Override shell for Bash tool (must be bash or zsh) |
CLAUDE_CODE_SHELL_LAUNCHER_SCRIPTShell and tools | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_SHELL_PREFIXShell and tools | Present since v2.1.69 or earlier Documented | Prefix command for shell execution |
CLAUDE_CODE_SHELL_PREFIXI50Shell and tools | Removed between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_SILENT_TURN_REMINDEROther | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_SILENT_TURN_REMINDER_SECONDSOther | Added in v2.1.290 | — |
CLAUDE_CODE_SILENT_TURN_REMINDER_TEXTOther | Added in v2.1.238 | — |
CLAUDE_CODE_SILENT_TURN_REMINDER_TURNSOther | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_SIMPLEOther | Present since v2.1.69 or earlier Documented | Simplified mode; disables CLAUDE.md and attachments (renamed from CLAUDE_CODE_SIMPLETON) |
CLAUDE_CODE_SIMPLETONOther | — | Renamed to CLAUDE_CODE_SIMPLE |
CLAUDE_CODE_SIMPLE_SYSTEM_PROMPTOther | Added between v2.1.114 and v2.1.117 Documented | Switches to a reduced system prompt, stripping out the non-essential guidance sections that bulk up the default prompt. Useful in latency-sensitive or… |
CLAUDE_CODE_SIMULATE_PROXY_USAGENetwork and proxy | Removed in v2.1.294 | Simulates proxy-based API routing without an actual proxy. This is a testing tool — it lets developers verify that their Claude Code configuration behaves… |
CLAUDE_CODE_SKILL_ATTRIBUTIONPlugins and skills | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_SKILL_DESCRIPTIONPlugins and skills | Removed between v2.1.212 and v2.1.215 | — |
CLAUDE_CODE_SKILL_DESC_REFRAMEPlugins and skills | Removed between v2.1.215 and v2.1.217 | — |
CLAUDE_CODE_SKILL_NAMEPlugins and skills | Removed between v2.1.247 and v2.1.252 | — |
CLAUDE_CODE_SKILL_PROPOSALSPlugins and skills | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_SKIP_ANTHROPIC_AWS_AUTHCloud providers | Added in v2.1.90 Documented | Skips credential resolution for the Anthropic AWS provider. Source code shows two effects: (1) passes skipAuth: true to the AnthropicAws client constructor,… |
CLAUDE_CODE_SKIP_ANTHROPIC_GOOGLE_CLOUD_AUTHCloud providers | Removed in v2.1.290 | The skip-auth companion to the toggle above, grouped in the auth-bypass list with SKIP_BEDROCK_AUTH, SKIP_VERTEX_AUTH, SKIP_FOUNDRY_AUTH,… |
CLAUDE_CODE_SKIP_AWS_CRED_CACHECloud providers | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_SKIP_BEDROCK_AUTHCloud providers | Present since v2.1.69 or earlier Documented | Skip Bedrock authentication |
CLAUDE_CODE_SKIP_FAST_MODE_NETWORK_ERRORSModels and thinking | Added between v2.1.77 and v2.1.79 Documented | Controls whether Claude Code suppresses or bypasses network errors that occur specifically in fast mode. Fast mode uses the same Opus 4.6 model with faster… |
CLAUDE_CODE_SKIP_FAST_MODE_ORG_CHECKModels and thinking | Removed in v2.1.293 Documented | Disables the organization-level eligibility check for fast mode. Fast mode (toggled via /fast) normally verifies that the user's organization supports it. |
CLAUDE_CODE_SKIP_FOUNDRY_AUTHCloud providers | Present since v2.1.69 or earlier Documented | Skip Foundry authentication |
CLAUDE_CODE_SKIP_HFI_VERSION_CHECKFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SKIP_MANTLE_AUTHCloud providers | Added in v2.1.94 Documented | Skips Mantle authentication. This is the escape hatch for environments where Mantle is enabled at the org level but a specific workflow needs direct API access… |
CLAUDE_CODE_SKIP_MODEL_ACCESS_MEMORYModels and thinking | Added in v2.1.285 Documented | — |
CLAUDE_CODE_SKIP_PLUGIN_MCP_SERVERSMCP | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SKIP_PLUGIN_MCP_SERVERS_EXCEPTMCP | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SKIP_PRECOMPACT_LOADContext and compaction | — | Optimize large session file loading |
CLAUDE_CODE_SKIP_PROJECT_BACKFILLFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SKIP_PROJECT_BACKFILL_LFeature toggles | Removed between v2.1.224 and v2.1.227 | — |
CLAUDE_CODE_SKIP_PROMPT_HISTORYFeature toggles | Present since v2.1.69 or earlier Documented | Disable prompt history saving |
CLAUDE_CODE_SKIP_REPO_UPLOADFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SKIP_VERTEX_AUTHCloud providers | Present since v2.1.69 or earlier Documented | Skip Vertex AI authentication |
CLAUDE_CODE_SLACK_TAG_TOKENAuthentication | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_SLEEPY_SNOWFLAKEOther | Added in v2.1.284 | — |
CLAUDE_CODE_SLOW_OPERATION_THRESHOLD_MSOther | Present since v2.1.69 or earlier | Threshold for slow filesystem operation warnings |
CLAUDE_CODE_SPAWNED_BY_SERVEROther | Present since v2.1.69 or earlier | Was used to indicate a server-spawned process. Added in v2.1.69's remote/server mode batch. Removed after just one version — likely internalized or replaced by… |
CLAUDE_CODE_SPAWN_TIMESTAMP_MSOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SQUISHY_NEWTOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_SSE_PORTOther | Present since v2.1.69 or earlier | Server-Sent Events port |
CLAUDE_CODE_STALL_TIMEOUT_MS_FOR_TESTINGNetwork and proxy | Present since v2.1.69 or earlier | — |
CLAUDE_CODE_STARTUP_FAILURE_RESULTSOther | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_STELLAR_DRIFTOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_STOP_HOOK_BLOCK_CAPOther | Added between v2.1.138 and v2.1.143 Documented | Cap how long a stop hook can block session termination. If you've ever hit Ctrl+C and had Claude Code hang before actually closing — this is why, and this is… |
CLAUDE_CODE_STREAMED_BUMBLEBEENetwork and proxy | Added in v2.1.290 | — |
CLAUDE_CODE_STREAMED_BUMBLEBEE_TEXTNetwork and proxy | Added in v2.1.290 | — |
CLAUDE_CODE_STREAMING_TEXTNetwork and proxy | Removed between v2.1.73 and v2.1.76 | Likely controlled an experimental streaming text mode that has now graduated to being the default behavior. v2.1.78 introduced line-by-line response streaming… |
CLAUDE_CODE_SUBAGENT_CACHE_EVICTAgents and subagents | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SUBAGENT_MODELAgents and subagents | Present since v2.1.69 or earlier Documented | Force a specific model for sub-agent operations |
CLAUDE_CODE_SUBAGENT_MODELUAgents and subagents | — | The trailing-U variant flagged as a likely typo in v2.1.84 has been removed. CLAUDE_CODE_SUBAGENT_MODEL (without the U) remains. Clean housekeeping. |
CLAUDE_CODE_SUBAGENT_MODEL_FORCEAgents and subagents | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_SUBAGENT_PROMPT_CACHE_TTLAgents and subagents | Added between v2.1.241 and v2.1.245 Documented | — |
CLAUDE_CODE_SUBAGENT_PROMPT_SNAPSHOTAgents and subagents | Added in v2.1.290 | — |
CLAUDE_CODE_SUBPROCESS_ENV_SCRUBPermissions and sandbox | Added between v2.1.77 and v2.1.79 Documented | When set to 1, strips Anthropic and cloud provider credentials from subprocess environments — the Bash tool, hooks, and MCP stdio servers. The changelog… |
CLAUDE_CODE_SUBSCRIPTION_TYPEOther | Added between v2.1.114 and v2.1.117 | Current subscription plan identifier. Lets the process branch on tier without an API call — used by v2.1.118's unified /usage to render plan-specific limits… |
CLAUDE_CODE_SUPERVISEDOther | Added between v2.1.138 and v2.1.143 | Mark a session as supervised — a human is watching. In supervised mode Claude is more likely to surface decisions for human confirmation rather than resolving… |
CLAUDE_CODE_SUPPRESS_SESSION_ATTRIBUTIONSessions | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SYNC_PLUGINSPlugins and skills | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SYNC_PLUGINSI3Plugins and skills | Removed in v2.1.228 | — |
CLAUDE_CODE_SYNC_PLUGINS_BUFFERED_DOWNLOADPlugins and skills | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SYNC_PLUGINS_DOWNLOAD_STALL_MSPlugins and skills | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SYNC_PLUGINS_INSTALL_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SYNC_PLUGINS_MCP_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_SYNC_PLUGIN_INSTALLPlugins and skills | Present since v2.1.69 or earlier Documented | Install plugins synchronously (block until done) |
CLAUDE_CODE_SYNC_PLUGIN_INSTALL_TIMEOUT_MSNetwork and proxy | Present since v2.1.69 or earlier Documented | Timeout for synchronous plugin install |
CLAUDE_CODE_SYNC_REUSE_WITHIN_MSOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_SYNC_SESSION_REFSSessions | Added between v2.1.143 and v2.1.212 | Enables syncing of session references in remote and child sessions. The gate function is true only when this variable is truthy and a CLAUDE_CODE_SESSION_ID is… |
CLAUDE_CODE_SYNC_SKILLSPlugins and skills | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_SYNC_SKILLS_INSTALL_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_SYNC_SKILLS_WAIT_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_SYNTAX_HIGHLIGHTOther | Removed in v2.1.286 Documented | Disable syntax highlighting when set to false |
CLAUDE_CODE_SYSTEM_PROMPT_GB_FEATUREOther | Added between v2.1.108 and v2.1.114 | Names a GrowthBook feature flag whose value overrides the system prompt — but only when CLAUDE_CODE_REMOTE is set. Anthropic can A/B-test remote-session… |
CLAUDE_CODE_TAGSOther | Present since v2.1.69 or earlier | Custom tags for telemetry events |
CLAUDE_CODE_TAG_ISMETA_MESSAGESOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TASK_LIST_IDOther | Present since v2.1.69 or earlier Documented | Task list ID for agent coordination |
CLAUDE_CODE_TEAMMATE_COMMANDAgents and subagents | Present since v2.1.69 or earlier | Command for teammate/cowork functionality |
CLAUDE_CODE_TEAM_ONBOARDINGAgents and subagents | Removed between v2.1.143 and v2.1.212 | Replaced by newer onboarding paths (CLAUDE_CODE_POWERUP_ONBOARDING, /doctor's CLAUDE.md-trimming check). |
CLAUDE_CODE_TEAM_TEARDOWN_PARK_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_TEE_SDK_STDOUTOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TERMINAL_MCP_TOOLSMCP | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TERMINAL_RECORDINGTerminal and UI | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TEST_ALLOW_REAL_NETWORKOther | Added between v2.1.238 and v2.1.241 | — |
CLAUDE_CODE_TEST_FIXTURES_ROOTOther | Present since v2.1.69 or earlier | Root directory for test fixtures |
CLAUDE_CODE_TEST_FORCE_DENYFeature toggles | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TEST_NO_GIT_BASHShell and tools | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TEST_NO_PWSHOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TETHER_LIVEOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_THINKING_DISPLAY_UPDATESModels and thinking | Added between v2.1.238 and v2.1.241 | Overrides whether Claude's in-progress thinking and connector text render during a turn. When set it takes precedence over the thinking_display_updates dynamic… |
CLAUDE_CODE_THISTLE_GREBEOther | Added between v2.1.215 and v2.1.217 | — |
CLAUDE_CODE_THRIFTY_SONICOther | Added in v2.1.222 | — |
CLAUDE_CODE_TICKLISH_WHISPEROther | Added in v2.1.284 | — |
CLAUDE_CODE_TICKLISH_WHISPER_TIMEOUT_MSNetwork and proxy | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_TMPDIROther | Present since v2.1.69 or earlier Documented | Temp directory for operations |
CLAUDE_CODE_TMUX_PREFIXTerminal and UI | Present since v2.1.69 or earlier | Tmux prefix key shown in detach instructions |
CLAUDE_CODE_TMUX_PREFIX_CONFLICTSTerminal and UI | Present since v2.1.69 or earlier | Show prefix twice when key conflicts in tmux |
CLAUDE_CODE_TMUX_SESSIONTerminal and UI | Present since v2.1.69 or earlier | Tmux session name shown in UI header |
CLAUDE_CODE_TMUX_TRUECOLORTerminal and UI | Added between v2.1.79 and v2.1.83 Documented | Controls truecolor (24-bit) rendering when running inside tmux. Tmux has historically been tricky with truecolor support — it requires both the terminal… |
CLAUDE_CODE_TOASTY_THIMBLEOther | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_TODO_REMINDER_MODEOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TOOL_MEMORY_CGROUP_EXCLUDEShell and tools | Added between v2.1.245 and v2.1.247 Documented | — |
CLAUDE_CODE_TOOL_MEMORY_LIMITShell and tools | Added between v2.1.229 and v2.1.234 Documented | — |
CLAUDE_CODE_TOOL_USE_IDShell and tools | Added between v2.1.266 and v2.1.269 | — |
CLAUDE_CODE_TOTAL_TOKENS_REMINDERAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TOTAL_TOKENS_REMINDER_AFTER_USER_TURNAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TOTAL_TOKENS_REMINDER_BUDGETAuthentication | Removed in v2.1.294 | — |
CLAUDE_CODE_TRANSCRIPT_LOCAL_GCOther | Added between v2.1.215 and v2.1.217 Documented | Toggles local garbage-collection of on-disk session transcripts, backed by tengu_transcript_local_gc. First shipped v2.1.217; undocumented. |
CLAUDE_CODE_TRIGGER_IDOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_TUI_JUST_SWITCHEDOther | Added between v2.1.108 and v2.1.114 | Set to "fullscreen" immediately after /tui fullscreen. The next render reads it to show a one-time confirmation hint, then clears the flag. |
CLAUDE_CODE_TUI_TRIALOther | Added between v2.1.234 and v2.1.237 | — |
CLAUDE_CODE_TURN_UPDATESOther | Added in v2.1.229 | — |
CLAUDE_CODE_TWO_STAGE_CLASSIFIEROther | Removed between v2.1.245 and v2.1.247 | Added in v2.1.72 as an opt-in flag for two-stage intent classification. Its removal after just two versions suggests the feature graduated out of flag-gating —… |
CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREOther | Added between v2.1.104 and v2.1.107 | Points to a test fixture file used during the preflight phase of UltraReview — Claude Code's automated PR review pipeline. In test and CI environments, this… |
CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREA2Other | Removed between v2.1.224 and v2.1.227 | — |
CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0Other | Removed between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_ULTRAREVIEW_QUOTA_FIXTUREOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_CODE_USER_DIALOG_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_USER_EMAILOther | Present since v2.1.69 or earlier | Pre-configured user email |
CLAUDE_CODE_USE_ANTHROPIC_AWSCloud providers | Added in v2.1.90 Documented | Selects "Claude Platform on AWS" as the API provider. Source code confirms this is a distinct provider alongside Bedrock, Vertex, and Foundry — the provider… |
CLAUDE_CODE_USE_ANTHROPIC_GOOGLE_CLOUDCloud providers | Added between v2.1.212 and v2.1.215 | A new provider-backend toggle sitting in Claude Code's exact provider family — beside CLAUDE_CODE_USE_BEDROCK, USE_VERTEX, USE_FOUNDRY, USE_ANTHROPIC_AWS,… |
CLAUDE_CODE_USE_BEDROCKCloud providers | Present since v2.1.69 or earlier Documented | Use Amazon Bedrock as backend |
CLAUDE_CODE_USE_CCR_V2Other | Present since v2.1.69 or earlier | Use Claude Code Router v2 for cowork sessions |
CLAUDE_CODE_USE_COWORK_PLUGINSPlugins and skills | Present since v2.1.69 or earlier | Use cowork_plugins directory instead of default |
CLAUDE_CODE_USE_FOUNDRYCloud providers | Present since v2.1.69 or earlier Documented | Use Anthropic Foundry as backend |
CLAUDE_CODE_USE_GATEWAYOther | Added between v2.1.143 and v2.1.212 | Routes traffic through an Anthropic-operated gateway (with loopback and log-level tuning). Centralized model access for managed fleets, behind the v2.1.206… |
CLAUDE_CODE_USE_MANTLECloud providers | Added in v2.1.94 Documented | Activates Mantle-based authentication for Amazon Bedrock. The changelog[1] describes this as "integrated Amazon Bedrock support via Mantle" with… |
CLAUDE_CODE_USE_NATIVE_FILE_SEARCHOther | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_CODE_USE_POWERSHELL_TOOLShell and tools | Added between v2.1.79 and v2.1.83 Documented | Enables a PowerShell-specific tool variant for Windows environments. This suggests the team is building first-class PowerShell support rather than routing… |
CLAUDE_CODE_USE_VERTEXCloud providers | Present since v2.1.69 or earlier Documented | Use Google Vertex AI as backend |
CLAUDE_CODE_VERIFY_PROMPTOther | Removed between v2.1.143 and v2.1.212 | The verify flow was reworked; the standalone prompt override no longer maps to how verification runs. |
CLAUDE_CODE_VERSIONOther | Added between v2.1.128 and v2.1.138 | Exposes the CLI version to subprocesses, hooks, and MCP servers. Your hooks and MCP tools can now read CLAUDE_CODE_VERSION directly — gate behavior on minimum… |
CLAUDE_CODE_VOICE_FORWARD_INTERIMS_TYPEDOther | Added between v2.1.138 and v2.1.143 | Stream interim voice transcription results as you speak rather than waiting for the final transcript. |
CLAUDE_CODE_WALNUT_SPIREOther | Removed between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_WALNUT_SPIREIOOther | Removed in v2.1.222 | — |
CLAUDE_CODE_WEBFETCH_CACHE_TTL_MSShell and tools | Added between v2.1.229 and v2.1.234 Documented | — |
CLAUDE_CODE_WEBFETCH_DEADLINE_MSShell and tools | Added between v2.1.266 and v2.1.269 Documented | — |
CLAUDE_CODE_WEBFETCH_USE_CCR_PROXYNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_WEBSEARCH_USE_CCR_PROXYNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_WEBSOCKET_AUTH_FILE_DESCRIPTORAuthentication | Present since v2.1.69 or earlier | File descriptor for WebSocket credentials |
CLAUDE_CODE_WEB_FETCH_AGENTAgents and subagents | Added between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_WEB_SEARCH_FAST_ARGShell and tools | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_CODE_WEB_SEARCH_REFILLS_PER_HOURShell and tools | Added in v2.1.290 Documented | Sets how many web-search budget refills accrue per hour, overriding the value the feature gate serves. It accepts 0 to 3600 and defaults to 100 when unset; the… |
CLAUDE_CODE_WHIMSICAL_ELEPHANTOther | Added in v2.1.284 | — |
CLAUDE_CODE_WILLOW_TERNOther | Added between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_WISE_COMETOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_CODE_WORKER_CHECKIN_SCHEDULEOther | Added between v2.1.269 and v2.1.283 Documented | — |
CLAUDE_CODE_WORKER_EPOCHOther | Present since v2.1.69 or earlier | Worker epoch for versioning internal state |
CLAUDE_CODE_WORKER_EPOCHIF0Other | Removed between v2.1.229 and v2.1.234 | — |
CLAUDE_CODE_WORKFLOWSAgents and subagents | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_WORKFLOW_LAUNCH_SHA256Agents and subagents | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_WORKFLOW_MAX_CONCURRENT_AGENTSAgents and subagents | Added between v2.1.266 and v2.1.269 Documented | — |
CLAUDE_CODE_WORKFLOW_PREFIX_STAGGER_MSAgents and subagents | Added in v2.1.229 Documented | — |
CLAUDE_CODE_WORKFLOW_PROMPT_PROVENANCEAgents and subagents | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_CODE_WORKFLOW_SIZE_WARNING_AGENTSAgents and subagents | Removed between v2.1.245 and v2.1.247 | — |
CLAUDE_CODE_WORKFLOW_SIZE_WARNING_TOKENSAuthentication | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_CODE_WORKSPACE_HOST_PATHSOther | Removed in v2.1.290 | Specifies host-side filesystem paths that should be mapped or accessible within a workspace context. This is relevant for containerized and remote development… |
CLAUDE_CODE_YOU_SHOULD_KNOW_DEBUGDebugging | Added in v2.1.286 | — |
CLAUDE_CONFIG_DIROther | Present since v2.1.69 or earlier Documented | Custom config directory |
CLAUDE_CONTEXT_COLLAPSEContext and compaction | Removed between v2.1.269 and v2.1.283 | Collapses context on the fly, with a dedicated model to do it. A more aggressive context-management primitive than auto-compact, aimed at keeping long agentic… |
CLAUDE_CONTEXT_COLLAPSE_MODELContext and compaction | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_COWORK_MEMORY_EXTRA_GUIDELINESTerminal and UI | Added between v2.1.77 and v2.1.79 | Injects additional memory guidelines into cowork (teammate) sessions. In multi-agent "cowork" mode — where a leader spawns teammate Claude sessions in split… |
CLAUDE_COWORK_MEMORY_GUIDELINESTerminal and UI | Added between v2.1.118 and v2.1.123 | Policy document for the CoWork shared memory system — a new abstraction distinct from user memory (~/.claude/) and project memory (CLAUDE.md). Multiple agents… |
CLAUDE_COWORK_MEMORY_INDEX_CONTENTMemory and CLAUDE.md | Added between v2.1.118 and v2.1.123 | Content of the CoWork memory index. Where guidelines set policy, this carries structured summaries agents use to find relevant prior work without replaying… |
CLAUDE_COWORK_MEMORY_PATH_OVERRIDETerminal and UI | Present since v2.1.69 or earlier | — |
CLAUDE_DEBUGDebugging | Present since v2.1.69 or earlier | Enable debug logging |
CLAUDE_DISABLE_ADOPTFeature toggles | Added between v2.1.143 and v2.1.212 Documented | — |
CLAUDE_EFFORTModels and thinking | Added between v2.1.128 and v2.1.138 Documented | Set thinking effort level at spawn time without the interactive /effort picker. Scriptable effort control: run high effort on the architect agent, low effort… |
CLAUDE_ENABLE_BYTE_WATCHDOGNetwork and proxy | Added between v2.1.104 and v2.1.107 Documented | Activates a byte-level watchdog on API response streams. The v2.1.105 changelog describes a fix for stalled API streams: "streams now abort after 5 minutes of… |
CLAUDE_ENABLE_BYTE_WATCHDOG_BEDROCKCloud providers | Added between v2.1.138 and v2.1.143 Documented | Enable the byte watchdog on Bedrock connections. The watchdog fires when a connection opens but produces no bytes within a window — catching silent stalls that… |
CLAUDE_ENABLE_STREAM_WATCHDOGNetwork and proxy | Present since v2.1.69 or earlier Documented | Enable stream health monitoring |
CLAUDE_ENV_FILEOther | Present since v2.1.69 or earlier Documented | Path to environment file for session variables |
CLAUDE_FORCE_DISPLAY_SURVEYFeature toggles | Present since v2.1.69 or earlier | Force feedback survey display |
CLAUDE_GATEWAY_ALLOW_LOOPBACKOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_GATEWAY_DRAIN_TIMEOUT_MSNetwork and proxy | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_GATEWAY_LOG_LEVELDebugging | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_GATEWAY_PROXY_IS_EGRESS_BOUNDARYNetwork and proxy | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_IMPORT_CONVERSATIONSOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_INTERNAL_ASSISTANT_TEAM_NAMEAgents and subagents | Added in v2.1.108 | Passes the current Agent Teams team name (prefixed assistant-) to a spawned child process. Agent Teams surfaces in the UI as "Agent Teams is not yet available… |
CLAUDE_INTERNAL_FC_OVERRIDESTerminal and UI | Added between v2.1.118 and v2.1.123 | Internal overrides for function-call (tool-use) behavior. Injects overrides that bypass normal routing — for testing new tool schemas or shadowing production… |
CLAUDE_IN_CHROME_DOMAIN_RULE_TOOLShell and tools | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_IN_CHROME_MANAGED_MCP_REFUSALMCP | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_IN_CHROME_MCP_SERVER_NAMEMCP | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_JOB_DIROther | Added between v2.1.118 and v2.1.123 Documented | Working directory for a background job, independent of the daemon's own cwd. Background jobs may target a different directory than the session that spawned… |
CLAUDE_LOCAL_OAUTH_API_BASEAuthentication | Added in v2.1.85 | Overrides the base URL for local OAuth API operations. This extends the auth customization story started by CLAUDE_AI_ORIGIN in v2.1.84, giving operators finer… |
CLAUDE_LOCAL_OAUTH_APPS_BASEAuthentication | Added in v2.1.85 | Overrides the base URL for the local OAuth applications registry. Together with CLAUDE_LOCAL_OAUTH_API_BASE, this completes a two-part override for the OAuth… |
CLAUDE_LOCAL_OAUTH_CONSOLE_BASEAuthentication | Added in v2.1.86 | Overrides the base URL for the OAuth console interface. This is the third piece of the local OAuth override triptych: CLAUDE_LOCAL_OAUTH_API_BASE handles token… |
CLAUDE_MEMORY_STORESMemory and CLAUDE.md | Added between v2.1.138 and v2.1.143 | Configure which memory backends are active. With the memory system now supporting typed files, project-scoped MEMORY.md indexes, and persistent cross-session… |
CLAUDE_MOCK_HEADERLESS_429Other | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_NAMESOther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_PIDOther | Added between v2.1.212 and v2.1.215 Documented | Holds the CLI's own process ID and powers a self-protection shim: the injected shell wrapper around pkill/pgrep refuses to signal any match equal to… |
CLAUDE_PLUGIN_DATAPlugins and skills | Added between v2.1.77 and v2.1.79 | Provides a filesystem path where plugins can store persistent state that survives plugin updates and reinstalls. Previously, plugin data lived alongside the… |
CLAUDE_PLUGIN_OPTION_Plugins and skills | — | A prefix-style variable (note the trailing underscore) for passing configuration options to installed plugins. This follows the pattern of… |
CLAUDE_PLUGIN_ROOTPlugins and skills | Present since v2.1.69 or earlier | Root directory for plugins |
CLAUDE_PREVIEW_CLASSIFIER_FLOOROther | Removed between v2.1.241 and v2.1.245 | — |
CLAUDE_PROJECT_DIROther | Present since v2.1.69 or earlier | Override project directory |
CLAUDE_PROJECT_UUIDOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_PTY_HEARTBEAT_MSOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_PTY_HOST_EXECOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_PTY_ORPHAN_CHECK_MSOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_PTY_RECORDOther | Added between v2.1.118 and v2.1.123 | Enables PTY session recording for a background agent — captures the raw terminal byte stream as a bit-for-bit replay artifact, not just a transcript. Likely… |
CLAUDE_RELAUNCH_SESSION_ADD_DIRSSessions | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_REMOTE_CONTROL_SESSION_NAME_PREFIXSessions | Added in v2.1.92 Documented | Sets a prefix for Remote Control session names. The changelog[1] mentions improved session naming for Remote Control — this variable lets teams enforce naming… |
CLAUDE_REMOTE_TOOLS_BRIDGE_URLNetwork and proxy | Added between v2.1.224 and v2.1.227 | — |
CLAUDE_REMOTE_WORKFLOW_ARGSAgents and subagents | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_REMOTE_WORKFLOW_SCRIPTAgents and subagents | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_REPL_MODEOther | Removed between v2.1.96 and v2.1.100 | Sets the operating mode for the REPL interface. This likely controls behavior such as output format (JSON vs plain text), verbosity level, or whether the REPL… |
CLAUDE_REPL_MODE0Other | — | Prototype naming for the REPL mode configuration. Replaced by the properly named CLAUDE_REPL_MODE in this release. |
CLAUDE_REPL_VARIANTOther | Removed between v2.1.269 and v2.1.283 | Selects which REPL implementation to load. Multiple variants coexist in the native binary; this key lets Anthropic A/B-test REPL behavior without separate… |
CLAUDE_REPL_VERBOSEOther | Removed between v2.1.269 and v2.1.283 | — |
CLAUDE_RUNNER_ACCOUNT_EMAILOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_ACCOUNT_IDOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_ACTIVITY_FDOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_RUNNER_API_BASE_URLNetwork and proxy | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_ATTEMPTOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_CHECKOUT_PATHOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_CLAUDE_BINOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_CLIENT_PLATFORMOther | Added in v2.1.229 | — |
CLAUDE_RUNNER_CORRELATION_IDOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_DEBUG_LOG_PATHDebugging | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_DISABLE_AWAITING_ACTION_OVERRIDETerminal and UI | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_RUNNER_EXIT_REASONOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_FAIL_FAST_FETCHOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_FETCH_DEPTHOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_RUNNER_GIT_MOUNT_URLNetwork and proxy | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_ORDER_IDOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_ORDER_SERVER_TIMEOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_POOL_IDOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_PRIMARY_REPO_REVISIONOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_PRIMARY_REPO_URLNetwork and proxy | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_REPO_REFOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_REPO_SOURCESOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_REPO_URLNetwork and proxy | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_SESSION_IDSessions | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_SESSION_UUIDSessions | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_SKIP_GIT_VERIFYFeature toggles | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_STALL_GIVEUPOther | Added between v2.1.241 and v2.1.245 | — |
CLAUDE_RUNNER_TRUST_CANONICAL_PREWARMOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_USE_GIT_PROXYNetwork and proxy | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_WORKSPACE_PATHSOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_RUNNER_WORK_ORDER_FILEOther | Added between v2.1.222 and v2.1.224 | — |
CLAUDE_SCRIPT_HOOK_ACKOther | Added between v2.1.252 and v2.1.266 | — |
CLAUDE_SDK_CAN_USE_TOOL_SHADOWEDShell and tools | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_SECURESTORAGE_CONFIG_DIROther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_SERVE_DRAIN_TIMEOUT_MSNetwork and proxy | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_SESSION_INGRESS_TOKEN_FILEAuthentication | Added between v2.1.79 and v2.1.83 | — |
CLAUDE_SLOW_FIRST_BYTE_MSOther | Added between v2.1.108 and v2.1.114 | Default 30,000ms. Logs a "Slow first byte: no stream chunk" observability event when the connection opens but produces no chunks within the window. Complements… |
CLAUDE_SNIPOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_SSH_LOCAL_BINARYOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_SSH_VERSIONOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_STAGE_FILE_ROOTOther | Added between v2.1.143 and v2.1.212 | — |
CLAUDE_STREAM_FIRST_BYTE_TIMEOUT_MSNetwork and proxy | Added between v2.1.241 and v2.1.245 Documented | — |
CLAUDE_STREAM_IDLE_TIMEOUT_MSNetwork and proxy | Added in v2.1.84 Documented | Configures the streaming idle watchdog threshold — the maximum time Claude Code waits for data on an open SSE connection before treating it as stalled. The… |
CLAUDE_SUBAGENT_BG_SHELL_MAX_MSAgents and subagents | Removed between v2.1.252 and v2.1.266 Documented | Time cap for shell commands run by background subagents. A background agent running a full test suite or a slow build command used to be bounded only by the… |
CLAUDE_TEST_PROJECT_DIROther | Added between v2.1.269 and v2.1.283 | — |
CLAUDE_TMPDIROther | Present since v2.1.69 or earlier | Alternative temp directory; fallback for CLAUDE_CODE_TMPDIR |
CLAUDE_TRUSTED_DEVICE_TOKENAuthentication | Added in v2.1.86 | Stores a token that marks the current device as trusted, likely enabling persistent authentication sessions without repeated re-authorization. |
CLAUDE_WORKFLOW_NAME_ONLYAgents and subagents | Added between v2.1.143 and v2.1.212 | Restricts a remote/headless run to a single named workflow. It appears immediately after CLAUDE_REMOTE_WORKFLOW_SCRIPT and CLAUDE_REMOTE_WORKFLOW_ARGS in the… |
CLAUDE_WORKSHOP_PROGRESSOther | Added between v2.1.224 and v2.1.227 | — |
DATABASE_URLNetwork and proxy | — Documented | — |
DEBUGDebugging | — Documented | — |
DISABLE_AUTOUPDATERFeature toggles | — Documented | Automatic update checker |
DISABLE_AUTO_COMPACTContext and compaction | — Documented | Disable automatic compaction only (manual /compact still works) |
DISABLE_AUTO_MIGRATE_TO_NATIVEFeature toggles | — | Native installer migration |
DISABLE_BUG_COMMANDFeature toggles | — | /bug command |
DISABLE_CLAUDE_CODE_SM_COMPACTContext and compaction | — | Disable session memory compaction |
DISABLE_COMPACTContext and compaction | — Documented | Disable all compaction (manual + auto) |
DISABLE_COST_WARNINGSFeature toggles | — Documented | API cost warnings |
DISABLE_DOCTOR_COMMANDFeature toggles | — Documented | /doctor diagnostic command |
DISABLE_ERROR_REPORTINGFeature toggles | — Documented | Automatic error reporting |
DISABLE_EXTRA_USAGE_COMMANDFeature toggles | — Documented | Extra usage display |
DISABLE_FEEDBACK_COMMANDFeature toggles | — Documented | /feedback command |
DISABLE_GROWTHBOOKFeature toggles | — Documented | — |
DISABLE_INSTALLATION_CHECKSFeature toggles | — Documented | Installation verification |
DISABLE_INSTALL_GITHUB_APP_COMMANDFeature toggles | — Documented | GitHub app install command |
DISABLE_INTERLEAVED_THINKINGModels and thinking | — Documented | Interleaved thinking beta |
DISABLE_LOGIN_COMMANDDebugging | — Documented | /login command |
DISABLE_LOGOUT_COMMANDDebugging | — Documented | /logout command |
DISABLE_MICROCOMPACTContext and compaction | — | Micro-compaction (small context cleanups) |
DISABLE_PROMPT_CACHINGFeature toggles | — Documented | Prompt caching globally |
DISABLE_PROMPT_CACHING_FABLEModels and thinking | — Documented | — |
DISABLE_PROMPT_CACHING_HAIKUModels and thinking | — Documented | Prompt caching for Haiku |
DISABLE_PROMPT_CACHING_OPUSModels and thinking | — Documented | Prompt caching for Opus |
DISABLE_PROMPT_CACHING_SONNETModels and thinking | — Documented | Prompt caching for Sonnet |
DISABLE_TELEMETRYTelemetry | — Documented | All telemetry |
DISABLE_UPDATESFeature toggles | — Documented | Explicitly documented in the v2.1.118 changelog. Prevents Claude Code from auto-checking for or applying npm updates. Intended for environments where updates… |
DISABLE_UPGRADE_COMMANDFeature toggles | — Documented | /upgrade command |
DO_NOT_TRACKOther | — Documented | — |
ENABLE_BETA_TRACING_DETAILEDFeature toggles | — Documented | Enable detailed beta tracing |
ENABLE_BTWFeature toggles | — | Enable "by the way" suggestions |
ENABLE_CLAUDEAI_MCP_SERVERSMCP | — Documented | Enable Claude.ai-hosted MCP servers |
ENABLE_CLAUDE_CODE_SM_COMPACTContext and compaction | — | Force enable session memory compaction |
ENABLE_ENHANCED_TELEMETRY_BETATelemetry | — | Enable enhanced telemetry (beta) |
ENABLE_LSP_TOOLShell and tools | — | Enable Language Server Protocol tool |
ENABLE_MCP_LARGE_OUTPUT_FILESMCP | — | Enable large output files for MCP |
ENABLE_PROMPT_CACHING_1HFeature toggles | — Documented | — |
ENABLE_PROMPT_CACHING_1H_BEDROCKCloud providers | — Documented | Enable 1-hour prompt caching on Bedrock |
ENABLE_SESSION_BACKGROUNDINGSessions | — | Enable session backgrounding |
ENABLE_TOOL_SEARCHShell and tools | — Documented | Tool search/deferred loading: auto, true, false, or 0–100% |
FALLBACK_FOR_ALL_PRIMARY_MODELSModels and thinking | — Documented | Enable fallback for all primary models |
FORCE_AUTOUPDATE_PLUGINSPlugins and skills | — Documented | Force auto-update plugins |
FORCE_HYPERLINKFeature toggles | — Documented | — |
FORCE_PROMPT_CACHING_5MFeature toggles | — Documented | — |
GITHUB_TOKENAuthentication | — Documented | — |
GIT_CONFIG_COUNTOther | — Documented | — |
HTTPS_PROXYNetwork and proxy | — Documented | HTTPS proxy server URL |
HTTP_PROXYNetwork and proxy | — Documented | HTTP proxy server URL |
IS_DEMOOther | — Documented | Indicates demo mode |
MAX_MCP_OUTPUT_TOKENSAuthentication | — Documented | Max tokens for MCP tool output |
MAX_STRUCTURED_OUTPUT_RETRIESNetwork and proxy | — Documented | — |
MAX_THINKING_TOKENSAuthentication | — Documented | Likely controlled via API settings now |
MCP_CLIENT_SECRETMCP | — Documented | Client secret for MCP OAuth |
MCP_CONNECTION_NONBLOCKINGNetwork and proxy | — Documented | Make MCP connections non-blocking |
MCP_CONNECT_TIMEOUT_MSNetwork and proxy | — Documented | — |
MCP_DISCOVERY_CACHEMCP | — Documented | — |
MCP_DISCOVERY_CACHE_MAX_STALE_SMCP | — Documented | — |
MCP_DISCOVERY_CACHE_STRIKESMCP | — Documented | — |
MCP_DISCOVERY_CACHE_TTL_SMCP | — Documented | — |
MCP_OAUTH_CALLBACK_PORTAuthentication | — Documented | OAuth callback server port |
MCP_PROTOCOL_NEGOTIATIONMCP | — Documented | — |
MCP_REMOTE_SERVER_CONNECTION_BATCH_SIZENetwork and proxy | — Documented | Remote MCP connection batch size |
MCP_SDK_GENERATIONMCP | — Documented | — |
MCP_SERVER_CONNECTION_BATCH_SIZENetwork and proxy | — Documented | Concurrent MCP server connections |
MCP_TIMEOUTNetwork and proxy | — Documented | MCP server connection timeout |
MCP_TOOL_TIMEOUTNetwork and proxy | — Documented | Individual MCP tool execution timeout |
NO_PROXYNetwork and proxy | — Documented | Domains to bypass proxy (comma-separated) |
NPM_TOKENAuthentication | — Documented | — |
OTEL_ATTRIBUTE_VALUE_LENGTH_LIMITTelemetry | — Documented | — |
OTEL_LOG_ASSISTANT_RESPONSESTelemetry | — Documented | — |
OTEL_LOG_MANAGED_SETTINGSTelemetry | — Documented | — |
OTEL_LOG_RAW_API_BODIESTelemetry | — Documented | — |
OTEL_LOG_TOOL_CONTENTTelemetry | — Documented | Include tool input/output in telemetry |
OTEL_LOG_TOOL_DETAILSTelemetry | — Documented | Include tool execution details |
OTEL_LOG_USER_PROMPTSTelemetry | — Documented | Include user prompts in telemetry |
OTEL_METRICS_INCLUDE_ACCOUNT_UUIDTelemetry | — Documented | — |
OTEL_METRICS_INCLUDE_ENTRYPOINTTelemetry | — Documented | — |
OTEL_METRICS_INCLUDE_REPOSITORYTelemetry | — Documented | — |
OTEL_METRICS_INCLUDE_RESOURCE_ATTRIBUTESTelemetry | — Documented | — |
OTEL_METRICS_INCLUDE_SESSION_IDTelemetry | — Documented | — |
OTEL_METRICS_INCLUDE_VERSIONTelemetry | — Documented | — |
PIP_INDEX_URLNetwork and proxy | — Documented | — |
SLASH_COMMAND_TOOL_CHAR_BUDGETShell and tools | — Documented | Character budget for slash command tool output |
TASK_MAX_OUTPUT_LENGTHOther | — Documented | Max output length for Task tool results |
USE_BUILTIN_RIPGREPOther | — Documented | Force use of built-in ripgrep |
VERTEX_REGION_CLAUDE_3_5_HAIKUCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_3_5_SONNETCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_3_7_SONNETCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_0_OPUSCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_0_SONNETCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_1_OPUSCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_5_OPUSCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_5_SONNETCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_6_OPUSCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_6_SONNETCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_7_OPUSCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_4_8_OPUSCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_5_5_OPUSCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_5_5_SONNETCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_5_OPUSCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_5_SONNETCloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_FABLE_5Cloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_FABLE_5_1Cloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_HAIKU_4_5Cloud providers | — Documented | — |
VERTEX_REGION_CLAUDE_HAIKU_5_5Cloud providers | — Documented | — |