CLAUDE_CODE_USE_MANTLE

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_USE_MANTLE is a Claude Code environment variable: Activates Mantle-based authentication for Amazon Bedrock. The changelog[1] describes this as "integrated Amazon Bedrock support via Mantle" with CLAUDE_CODE_USE_MANTLE=1. Added in v2.1.94 and still present in v2.1.294. It is listed in the official reference.

How to set it

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

export CLAUDE_CODE_USE_MANTLE=<value>
claude

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

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

Release notes that mention it

• Claude Code v2.1.96 — No New Environment Variables: Bedrock Auth Hotfix
• Claude Code v2.1.94 — 5 New Environment Variables: Mantle Authentication, MCP Sandboxing, and Team Onboarding
• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models

Related variables

• ANTHROPIC_BEDROCK_MANTLE_BASE_URL
• CLAUDE_CODE_SKIP_MANTLE_AUTH: Skips Mantle authentication.
• CLAUDE_CODE_USE_ANTHROPIC_AWS: Selects "Claude Platform on AWS" as the API provider.
• CLAUDE_CODE_USE_ANTHROPIC_GOOGLE_CLOUD: A new provider-backend toggle sitting in Claude Code's exact provider family — beside CLAUDE_CODE_USE_BEDROCK, USE_VERTEX, USE_FOUNDRY, USE_ANTHROPIC_AWS, USE_MANTLE, and USE_GATEWAY — and read by the same guard that suppresses error reporting under a managed provider.
• CLAUDE_CODE_USE_BEDROCK: Use Amazon Bedrock as backend.
• CLAUDE_CODE_USE_FOUNDRY: Use Anthropic Foundry as backend.
• CLAUDE_CODE_USE_VERTEX: Use Google Vertex AI as backend.
• ANTHROPIC_AWS_API_KEY

Frequently asked questions

All variables, searchable: Claude Code environment variables.