ENABLE_MCP_LARGE_OUTPUT_FILES

Updated October 13, 2026 by Alex Sorokoletov

ENABLE_MCP_LARGE_OUTPUT_FILES is a Claude Code environment variable: Enable large output files for MCP. Its release history is not tracked here. It is not in the official reference.

Status	Present in v2.1.294
Category	MCP
Official docs	Not listed

How to set it

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

export ENABLE_MCP_LARGE_OUTPUT_FILES=<value>
claude

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

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

Related variables

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.
ENABLE_CLAUDEAI_MCP_SERVERS: Enable Claude.ai-hosted MCP servers.
CLAUDE_CODE_MCP_SERVE_TOOL_OUTPUT
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.
CLAUDE_CODE_MCP_SERVER_NAME: Added in v2.1.85 to identify which MCP server a helper process was acting on behalf of.

Frequently asked questions

What does ENABLE_MCP_LARGE_OUTPUT_FILES do?

Enable large output files for MCP

Which Claude Code version has ENABLE_MCP_LARGE_OUTPUT_FILES?

Its release history is not tracked here.

How do I set ENABLE_MCP_LARGE_OUTPUT_FILES?

Export it before starting Claude Code (export ENABLE_MCP_LARGE_OUTPUT_FILES=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.