Claude Code v2.1.76 — 3 New Environment Variables: MCP Elicitation and Worktree Improvements#
Published on March 14, 2026
Part of the Claude Code Version Tracker series. | Official Changelog
Claude Code v2.1.76 adds 3 new environment variables and a new /effort slash command compared to v2.1.75. The headline feature is MCP elicitation support — MCP servers can now request structured input from users mid-task via interactive dialogs, with new hooks to intercept and automate those responses.
What Changed#
| v2.1.75 | v2.1.76 | |
|---|---|---|
| Environment variables | 176 | 179 (+3) |
| Model IDs | 16 | 16 (no change) |
| Feature gates | 41 | 41 (no change) |
| Dynamic configs | 29 | 29 (no change) |
| Slash commands | 22 | 22 (+1 via changelog)[1] |
New Environment Variables (3)#
| Variable | Likely Purpose |
|---|---|
CLAUDE_CODE_ACCOUNT_TAGGED_ID | 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 typically includes metadata like the account type or organization prefix baked into the string. This likely supports routing or billing disambiguation in multi-tenant environments — particularly useful for Team and Enterprise plans where usage attribution needs to distinguish between individual and organizational accounts. |
CLAUDE_CODE_SKIP_FAST_MODE_NETWORK_ERRORS | 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 output, but the accelerated path may have different failure modes or endpoints. This variable likely lets users gracefully degrade to standard mode when fast-mode infrastructure is unreachable, rather than surfacing transient network errors that would interrupt workflow. The changelog confirms a related fix for "background agent behavior and model fallback notifications." |
CLAUDE_CODE_WORKSPACE_HOST_PATHS | Specifies host-side filesystem paths that should be mapped or accessible within a workspace context. This is relevant for containerized and remote development scenarios where Claude Code runs inside a devcontainer or remote environment but needs to reference files on the host machine. Combined with the existing CLAUDE_CODE_HOST_PLATFORM and CLAUDE_CODE_HOST_HTTP_PROXY_PORT variables, this extends the host-to-container bridge to include explicit path mappings — critical for worktree operations and file checkpointing to resolve correctly across the boundary. |
New Slash Command (1)#
| Command | What It Does |
|---|---|
/effort | Sets the model effort level for the current session.[1] Claude Code already supported an effortLevel setting and the CLAUDE_CODE_EFFORT_LEVEL environment variable, but this slash command lets users toggle between effort levels (like "low", "medium", "high") interactively without restarting. Lower effort levels reduce token usage and response time for simple tasks; higher effort levels enable deeper reasoning for complex problems. |
What These Tell Us#
The MCP protocol is becoming bidirectional. The biggest architectural change in this release isn't an environment variable — it's MCP elicitation support. Until now, MCP servers could provide tools and resources to Claude Code, but communication was essentially one-way: Claude calls tools, tools return results. Elicitation flips that by letting MCP servers ask the user questions mid-task through structured dialogs. The new Elicitation and ElicitationResult hooks mean SDK consumers can intercept and programmatically answer these prompts, which unlocks fully automated pipelines that integrate with MCP servers requiring confirmation or credentials. This is a foundational change for the MCP ecosystem.
Remote and containerized development is getting first-class path support. CLAUDE_CODE_WORKSPACE_HOST_PATHS joins a growing family of host-bridge variables, but it solves a specific pain point: when Claude Code runs in a container, file operations (worktrees, checkpoints, glob searches) need to resolve paths that exist on the host, not just inside the container. The simultaneous addition of worktree.sparsePaths for large monorepos using git sparse-checkout confirms that Anthropic is actively optimizing for enterprise-scale repositories where you can't afford to clone the full tree into every worktree.
Resilience over rigidity. CLAUDE_CODE_SKIP_FAST_MODE_NETWORK_ERRORS and the changelog's fix for "auto-compaction retrying indefinitely (now stops after 3 attempts)" share a philosophy: fail gracefully instead of blocking the user. This release includes 14 bug fixes — an unusually high count — suggesting a stabilization push after the rapid feature additions in v2.1.73-75.
Sources#
[1] Claude Code CHANGELOG.md — The /effort command appears in the official changelog for v2.1.76 but was not captured by our binary string extraction. This can happen when command names are constructed dynamically or registered through plugin/settings infrastructure rather than appearing as static strings.
This analysis is conducted for independent security research and interoperability purposes under fair use principles. All trademarks belong to their respective owners. The information presented here documents publicly observable behavior of installed software and is not intended to circumvent any technological protection measures, infringe on intellectual property rights, or encourage unauthorized use. Use these findings at your own discretion.
Related Versions#
- Claude Code v2.1.75 — 2 New Environment Variables — auto-compact window, plugin options
- Claude Code v2.1.74 — 2 New Environment Variables — frame timing diagnostics, session-end hook timeouts
- Claude Code v2.1.73 — Slash Commands Inventory — first baseline of built-in slash commands
- Claude Code v2.1.72 — 6 New Environment Variables — brief mode, cron control, two-stage classifier
Related: Context Window Management Guide | Claude Code Productivity Tips | The Agentic Engineering Playbook