CLAUDE_REPL_MODE0

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_REPL_MODE0 is a Claude Code environment variable: Prototype naming for the REPL mode configuration. Replaced by the properly named CLAUDE_REPL_MODE in this release. Its release history is not tracked here. It is not in the official reference.

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

How to set it

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

export CLAUDE_REPL_MODE0=<value>
claude

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

// ~/.claude/settings.json
{
  "env": {
    "CLAUDE_REPL_MODE0": "<value>"
  }
}

Release notes that mention it

Related variables

CLAUDE_CODE_REPL: Boolean toggle for the new native REPL path introduced by v2.1.113's native-binary launcher.
CLAUDE_REPL_MODE: Sets the operating mode for the REPL interface.
CLAUDE_REPL_VARIANT: Selects which REPL implementation to load.
CLAUDE_CODE_ARTIFACT_REPL
CLAUDE_REPL_VERBOSE
ANTHROPIC_BETAS: Comma-separated beta feature headers.
ANTHROPIC_CUSTOM_HEADERS: Custom HTTP headers (newline-separated Key: Value).
ANTHROPIC_FEDERATION_RULE_ID

Frequently asked questions

What does CLAUDE_REPL_MODE0 do?

Prototype naming for the REPL mode configuration. Replaced by the properly named CLAUDE_REPL_MODE in this release.

Which Claude Code version has CLAUDE_REPL_MODE0?

Its release history is not tracked here.

How do I set CLAUDE_REPL_MODE0?

Export it before starting Claude Code (export CLAUDE_REPL_MODE0=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.