CLAUDE_CODE_AGENT_COST_STEER

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_AGENT_COST_STEER is a Claude Code environment variable: Controls cost-aware behavior for subagent delegation. As Claude Code's multi-agent architecture matures — named subagents now appear in @ mention typeahead[1] — the cost of spawning parallel agents becomes a real concern. Removed between v2.1.138 and v2.1.143, so current releases ignore it. 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_CODE_AGENT_COST_STEER=<value>
claude

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

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

Release notes that mention it

• Claude Code v2.1.89 — 4 New Environment Variables: Agent Cost Steering, Session Resume Controls, and 50% StructuredOutput Fix
• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models

Related variables

• CLAUDE_AGENT: Short-form identifier for the current agent, used in inter-agent messaging and log attribution.
• CLAUDE_AGENT_SDK_CLIENT_APP: Client application name.
• CLAUDE_AGENT_SDK_DISABLE_BUILTIN_AGENTS: Disable built-in agent types.
• CLAUDE_AGENT_SDK_MCP_NO_PREFIX: Don't prefix MCP tool names with server name.
• CLAUDE_AGENT_SDK_VERSION: Agent SDK version sent in User-Agent header.
• CLAUDE_CODE_AGENT: Full agent descriptor passed into a spawned agent process — likely the agent's frontmatter (tools, allowed/disallowed lists, system prompt path) so the child can reconstruct its runtime without re-reading disk.
• CLAUDE_CODE_AGENT_LIST_IN_MESSAGES: An early agent-listing toggle, made obsolete by the Agent View and coordinator surfaces that now own how agents are shown.
• CLAUDE_CODE_AGENT_RULE_DISABLED: Disable agent rules.

Frequently asked questions

All variables, searchable: Claude Code environment variables.