Use OpenRouter in Claude Code

Steps

1. 1
   Step 1.

   Install Claude Code (macOS, Linux, WSL).

   Terminal

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   curl -fsSL https://claude.ai/install.sh | bash

2. 2
   Step 2.

   Or install with npm (requires Node.js 18 or newer).

   Terminal

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   npm install -g @anthropic-ai/claude-code

3. 3
   Step 3.

   Add these environment variables to your shell profile (~/.zshrc or ~/.bashrc). ANTHROPIC_API_KEY must be explicitly empty.

   Terminal

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   export OPENROUTER_API_KEY="<your-openrouter-api-key>"
   export ANTHROPIC_BASE_URL="https://openrouter.ai/api"
   export ANTHROPIC_AUTH_TOKEN="$OPENROUTER_API_KEY"
   export ANTHROPIC_API_KEY="" # Important: Must be explicitly empty
   export CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1 # Optional: enables the gateway model picker

4. 4
   Step 4.

   Reload your shell so the new values are live.

   Snippet

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   source ~/.zshrc # or ~/.bashrc, or open a new terminal

5. 5
   Step 5.

   Alternative: put the same values in a project-level .claude/settings.local.json in your project root (do not commit your key).

   JSON

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   {
     "env": {
       "ANTHROPIC_BASE_URL": "https://openrouter.ai/api",
       "ANTHROPIC_AUTH_TOKEN": "<your-openrouter-api-key>",
       "ANTHROPIC_API_KEY": "",
       "CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY": "1"
     }
   }

6. 6
   Step 6.

   If you previously logged in to Claude Code with an Anthropic account, run /logout once, then quit and relaunch claude.

   Snippet

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   > /logout

7. 7
   Step 7.

   Start a session in your project.

   Terminal

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   cd /path/to/your/project
   claude

8. 8
   Step 8.

   Verify with /status. The output should name ANTHROPIC_AUTH_TOKEN and the OpenRouter base URL.

   Snippet

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   > /status
   Auth token: ANTHROPIC_AUTH_TOKEN
   Anthropic base URL: https://openrouter.ai/api

9. 9
   Step 9.

   Optional: route each Claude Code model class to a specific OpenRouter model.

   Terminal

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   export ANTHROPIC_DEFAULT_FABLE_MODEL="~anthropic/claude-fable-latest[1m]"
   export ANTHROPIC_DEFAULT_OPUS_MODEL="~anthropic/claude-opus-latest[1m]"
   export ANTHROPIC_DEFAULT_SONNET_MODEL="~anthropic/claude-sonnet-latest[1m]"
   export ANTHROPIC_DEFAULT_HAIKU_MODEL="~anthropic/claude-haiku-latest"
   export CLAUDE_CODE_SUBAGENT_MODEL="~anthropic/claude-opus-latest[1m]"

10. 10
    Step 10.

    Optional: enable the /fast command (requires Claude Code v2.1.96 or newer). Pin ANTHROPIC_DEFAULT_OPUS_MODEL to a specific Opus id such as anthropic/claude-opus-5 for fast mode to actually apply.

    Terminal

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    export CLAUDE_CODE_SKIP_FAST_MODE_ORG_CHECK=1