TASK_MAX_OUTPUT_LENGTH

Updated October 23, 2026 by Alex Sorokoletov

TASK_MAX_OUTPUT_LENGTH is a Claude Code environment variable: Max output length for Task tool results. Its release history is not tracked here. It is listed in the official reference.

Status	Present in v2.1.310
Category	Other
Official docs	Listed

How to set it

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

export TASK_MAX_OUTPUT_LENGTH=<value>
claude

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

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

Related variables

CLAUDE_CODE_FILE_READ_MAX_PDF_PAGES_PER_MESSAGE: Caps how many PDF pages the Read tool loads within a single message.
CLAUDE_CODE_FILE_READ_MAX_PDF_PAGES_PER_TURN: Caps the running total of PDF pages the Read tool loads across a turn, working with the per-message cap above.
CLAUDE_CODE_MAX_TURNS: Hard cap on conversation turns.
CLAUDE_CODE_TASK_LIST_ID: Task list ID for agent coordination.
ANTHROPIC_BETAS: Comma-separated beta feature headers.
ANTHROPIC_CUSTOM_HEADERS: Custom HTTP headers (newline-separated Key: Value).
ANTHROPIC_FEDERATION_RULE_ID
ANTHROPIC_ORGANIZATION_ID

Frequently asked questions

What does TASK_MAX_OUTPUT_LENGTH do?

Max output length for Task tool results

Which Claude Code version has TASK_MAX_OUTPUT_LENGTH?

Its release history is not tracked here.

How do I set TASK_MAX_OUTPUT_LENGTH?

Export it before starting Claude Code (export TASK_MAX_OUTPUT_LENGTH=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.