MCP_DISCOVERY_CACHE

Updated October 13, 2026 by Alex Sorokoletov

MCP_DISCOVERY_CACHE is a Claude Code environment variable. Its release history is not tracked here. It is listed in the official reference.

Status	Present in v2.1.294
Category	MCP
Official docs	Listed

How to set it

For one session, export it in the shell that starts Claude Code:

export MCP_DISCOVERY_CACHE=<value>
claude

To apply it to every session, add it to the env object of a settings file:

// ~/.claude/settings.json
{
  "env": {
    "MCP_DISCOVERY_CACHE": "<value>"
  }
}

Related variables

MCP_DISCOVERY_CACHE_MAX_STALE_S
MCP_DISCOVERY_CACHE_STRIKES
MCP_DISCOVERY_CACHE_TTL_S
CLAUDE_CODE_ENABLE_REFRESH_MCP_TOOLS: Enables an on-demand MCP-tool refresh capability, grouped with CLAUDE_CODE_ENABLE_TASKS and CLAUDE_CODE_ENABLE_REMOTE_RECAP.
CLAUDE_CODE_MAX_MCP_DESCRIPTION_LENGTH
CLAUDE_CODE_MCP_ALLOWLIST_ENV: Specifies an allowlist of environment variables that MCP servers can access.
CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS
CLAUDE_CODE_MCP_INSTR_DELTA: Delta/incremental MCP instruction updates.

Frequently asked questions

Which Claude Code version has MCP_DISCOVERY_CACHE?

Its release history is not tracked here.

How do I set MCP_DISCOVERY_CACHE?

Export it before starting Claude Code (export MCP_DISCOVERY_CACHE=value), or add it to the "env" object in ~/.claude/settings.json to apply it to every session.

All variables, searchable: Claude Code environment variables.