Claude Code

Why Use OpenRouter with Claude Code?

OpenRouter adds a reliability and management layer between Claude Code and Anthropic’s API, giving you and your organization several key benefits.

Provider Failover for High Availability

Anthropic’s API occasionally experiences outages or rate limiting. When you route Claude Code through OpenRouter, your requests automatically fail over between multiple Anthropic providers. If one provider is unavailable or rate-limited, OpenRouter seamlessly routes to another, keeping your coding sessions uninterrupted.

Organizational Budget Controls

For teams and organizations, OpenRouter provides centralized budget management. You can set spending limits, allocate credits across team members, and prevent unexpected cost overruns. This is especially valuable when multiple developers are using Claude Code across your organization.

Usage Visibility and Analytics

OpenRouter gives you complete visibility into how Claude Code is being used across your team. Track usage patterns, monitor costs in real-time, and understand which projects or team members are consuming the most resources. All of this data is available in your OpenRouter Activity Dashboard.

Quick Start

This guide will get you running Claude Code powered by OpenRouter in just a few minutes.

Step 1: Install Claude Code

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

1
irm https://claude.ai/install.ps1 | iex

Step 2: Connect Claude to OpenRouter

Instead of logging in with Anthropic directly, connect Claude Code to OpenRouter. This requires setting a few environment variables.

Requirements:

1. Use https://openrouter.ai/api for the base url
2. Provide your OpenRouter API key as the auth token
3. Important: Explicitly blank out the Anthropic API key to prevent conflicts

$
# Open your shell profile in nano
$
nano ~/.zshrc  # or ~/.bashrc for Bash users
$
$
# Add these lines to the file:
$
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
$
$
# After saving, restart your terminal for changes to take effect

Step 3: Clear any cached Anthropic login

If you were previously logged in to Claude Code with an Anthropic account, you must run /logout once to remove the cached session. Claude Code warns about auth conflicts when both a cached login and ANTHROPIC_AUTH_TOKEN are present, and the conflict can cause unexpected behaviour on startup — typically surfacing as confusing model-not-found errors (e.g. for openrouter/auto, openrouter/pareto-code, or any other OpenRouter-only model).

> /logout

Then quit and re-launch claude so it picks up the new environment variables.

Step 4: Start your session

Navigate to your project directory and start Claude Code:

$
cd /path/to/your/project
$
claude

You are now connected! Any prompt you send will be routed through OpenRouter.

Step 5: Verify

You can confirm your connection by running the /status command inside Claude Code.

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

You can also check the OpenRouter Activity Dashboard to see your requests appearing in real-time.

How It Works

OpenRouter exposes an input that is compatible with the Anthropic Messages API.

1. Direct Connection: When you set ANTHROPIC_BASE_URL to https://openrouter.ai/api, Claude Code speaks its native protocol directly to OpenRouter. No local proxy server is required.
2. Anthropic Skin: OpenRouter’s “Anthropic Skin” behaves exactly like the Anthropic API. It handles model mapping and passes through advanced features like “Thinking” blocks and native tool use.
3. Billing: You are billed using your OpenRouter credits. Usage (including reasoning tokens) appears in your OpenRouter dashboard.

Configuring Models

Claude Code uses several environment variables to determine which models to use for different tasks. You can override these to route each role through a specific model:

$
export ANTHROPIC_DEFAULT_OPUS_MODEL="~anthropic/claude-opus-latest"
$
export ANTHROPIC_DEFAULT_SONNET_MODEL="~anthropic/claude-sonnet-latest"
$
export ANTHROPIC_DEFAULT_HAIKU_MODEL="~anthropic/claude-haiku-latest"
$
export CLAUDE_CODE_SUBAGENT_MODEL="~anthropic/claude-opus-latest"

Add these to the same shell profile or project settings file where you set ANTHROPIC_BASE_URL and ANTHROPIC_AUTH_TOKEN.

Claude Code is optimized for Anthropic models and may not work correctly with other providers.

Fast Mode

Anthropic’s fast mode provides up to 2.5x faster output at premium pricing. Fast mode is only available on Claude Opus 4.6 and Claude Opus 4.7 — no other Anthropic model supports it.

For each supported Opus version, there are two equivalent ways to request fast mode on OpenRouter:

1. Send speed: "fast" with anthropic/claude-opus-4.7 or anthropic/claude-opus-4.6 — OpenRouter reroutes the request to the matching *-fast model (for example, anthropic/claude-opus-4.6 → anthropic/claude-opus-4.6-fast).
2. Call the *-fast model directly — anthropic/claude-opus-4.7-fast or anthropic/claude-opus-4.6-fast.

Both options route through the Anthropic first-party provider, and the required beta header is injected automatically.

Using /fast in Claude Code

Claude Code has a built-in /fast command that toggles fast mode. When enabled, Claude Code sends speed: "fast" in its requests alongside the configured Opus model. OpenRouter fully supports this parameter — you just need to set the following environment variable:

$
export CLAUDE_CODE_SKIP_FAST_MODE_ORG_CHECK=1

Pricing

Fast mode is priced at 6x the standard token rates for the underlying Claude Opus model (4.6 or 4.7). See Anthropic’s fast mode pricing for current rates. When fast mode is active, the response’s usage object includes "speed": "fast" to confirm the request was processed at the higher speed tier.

Routing behavior

Fast mode is only served by the Anthropic first-party provider, since other providers (e.g. Amazon Bedrock, Google Vertex) do not support it.

Agent SDK

The Anthropic Agent SDK lets you build AI agents programmatically using Python or TypeScript. Since the Agent SDK uses Claude Code as its runtime, you can connect it to OpenRouter using the same environment variables described above.

For complete setup instructions and code examples, see our Anthropic Agent SDK integration guide.

GitHub Action

You can use OpenRouter with the official Claude Code GitHub Action.To adapt the example workflow for OpenRouter, make two changes to the action step:

1. Pass your OpenRouter API key via anthropic_api_key (store it as a GitHub secret named OPENROUTER_API_KEY)
2. Set the ANTHROPIC_BASE_URL environment variable to https://openrouter.ai/api

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- name: Run Claude Code
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  uses: anthropics/claude-code-action@v1
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  with:
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    anthropic_api_key: ${{ secrets.OPENROUTER_API_KEY }}
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  env:
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    ANTHROPIC_BASE_URL: https://openrouter.ai/api

Cost Tracking Statusline

You can add a custom statusline to Claude Code that tracks your OpenRouter API costs in real-time. The statusline displays the provider, model, cumulative cost, and cache discounts for your session.

Download the statusline scripts from the openrouter-examples repository, make them executable, and add the following to your ~/.claude/settings.json:

1
{
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  "statusLine": {
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    "type": "command",
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    "command": "/path/to/statusline.sh"
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  }
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}

The script uses your ANTHROPIC_AUTH_TOKEN environment variable, which should already be set to your OpenRouter API key if you followed the setup above.

Troubleshooting

• Model-not-found errors for OpenRouter models (e.g. openrouter/auto, openrouter/pareto-code): Usually caused by a credential conflict that surfaces as auth-conflict warnings on startup. There are two distinct scenarios. (1) If you have a cached Anthropic OAuth login from before switching to OpenRouter, run /logout inside Claude Code, then quit and re-launch claude to clear the cached session. (2) If your shell profile still has a real ANTHROPIC_API_KEY set (e.g. an old Anthropic console key), /logout will not help — it only clears the cached OAuth session, not shell environment variables. Instead, ensure ANTHROPIC_API_KEY="" is set in your shell profile per Step 2, then restart your terminal. Verify with /status that the auth token is ANTHROPIC_AUTH_TOKEN and the base URL is https://openrouter.ai/api.
• Auth Errors: Ensure ANTHROPIC_API_KEY is set to an empty string (""). If it is unset (null), Claude Code might fall back to its default behavior and try to authenticate with Anthropic servers. If you still see auth errors after setting it, run /logout (see above).
• Context Length Errors: If you hit context limits, consider breaking your task into smaller chunks or starting a new session.
• Privacy: OpenRouter does not log your source code prompts unless you explicitly opt-in to prompt logging in your account settings. See our Privacy Policy for details.