CLAUDE_AGENTS_SELECT

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_AGENTS_SELECT is a Claude Code environment variable: 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 without changing the fleet-wide configuration. Added between v2.1.118 and v2.1.123 and still present in v2.1.294. It is not in the official reference.

How to set it

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

export CLAUDE_AGENTS_SELECT=<value>
claude

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

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

Release notes that mention it

• Claude Code v2.1.123 — Background Daemons, Agent Fleets, and CoWork Memory
• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models

Related variables

• CLAUDE_AGENT_SDK_DISABLE_BUILTIN_AGENTS: Disable built-in agent types.
• CLAUDE_AGENTS_AUTO_RELAUNCHED_AT: Timestamp set when the agent fleet was automatically relaunched after a crash.
• CLAUDE_CODE_DISABLE_AGENTS_FLEET: Kill switch for the entire agent fleet subsystem — no selection, no auto-relaunch, no fleet coordination.
• CLAUDE_CODE_DISABLE_EXPLORE_PLAN_AGENTS
• CLAUDE_CODE_EXPERIMENTAL_OBSERVER_AGENTS: Agents that watch a session rather than act in it.
• CLAUDE_CODE_WORKFLOW_MAX_CONCURRENT_AGENTS
• CLAUDE_CODE_WORKFLOW_SIZE_WARNING_AGENTS
• CLAUDE_AGENT: Short-form identifier for the current agent, used in inter-agent messaging and log attribution.

Frequently asked questions

All variables, searchable: Claude Code environment variables.