Use Claude Code Action with Aperture

Configure the Claude Code GitHub Action to send requests through Aperture by Tailscale so that CI runners use their Tailscale identity for authentication instead of per-repository API keys.

Prerequisites

• An Aperture instance with an Anthropic provider configured and at least one Anthropic model enabled.
• A Tailscale account with Owner, Admin, or Network admin permissions.
• A GitHub repository with GitHub Actions enabled and admin access to create repository secrets.

Step 1: Create a CI tag and grant access to Aperture

CI runners need a Tailscale tag, network access to the Aperture device, and a grant that authorizes model usage.

1. Open the Access controls page in the admin console.

2. In the tagOwners section, add tag:ci if it does not already exist:

   "tagOwners": {
     "tag:ci": []
   }
   

   An empty owner list means Owners, Admins, and Network admins can apply the tag.

3. Add a grant that gives tag:ci devices network access to the Aperture device and permission to use Anthropic models:

   {
     "grants": [
       {
         "src": ["tag:ci"],
         "dst": ["<aperture-hostname>"],
         "ip": ["tcp:80"],
         "app": {
           "tailscale.com/cap/aperture": [
             { "role": "user" },
             { "models": "anthropic/**" }
           ]
         }
       }
     ]
   }
   

   Replace "<aperture-hostname>" with the hostname or Tailscale IP address of your Aperture device if it differs from the default. Adjust the models pattern to restrict CI runners to specific models, such as anthropic/claude-sonnet-4-6.

4. Save the tailnet policy file. The rules take effect immediately.

For more information on grant syntax and model patterns, refer to control model access.

Step 2: Set up Tailscale authentication for GitHub Actions

The Tailscale GitHub Action needs credentials to join your tailnet as an ephemeral node.

Workload identity federation (recommended)

Workload identity federation uses GitHub's OIDC tokens to authenticate, eliminating secrets that can expire or leak.

1. Create a federated identity in the Tailscale admin console. Set the issuer to GitHub Actions and configure the subject claim to match your repository. Assign the auth_keys scope and the tag:ci tag.
2. Copy the Client ID and Audience values.
3. In your GitHub repository, create two repository secrets:
   • TS_OAUTH_CLIENT_ID: your federated identity Client ID.
   • TS_AUDIENCE: your federated identity Audience.

Workload identity federation requires the id-token: write permission in your GitHub Actions workflow, which you add in step 3.

OAuth client

If your organization does not use workload identity federation, create an OAuth client instead.

1. Create an OAuth client in the admin console with the auth_keys scope and the tag:ci tag.
2. Copy the Client ID and Client secret.
3. In your GitHub repository, create two repository secrets:
   • TS_OAUTH_CLIENT_ID: your OAuth Client ID.
   • TS_OAUTH_SECRET: your OAuth Client secret.

For detailed instructions on either option, refer to the Tailscale GitHub Action documentation.

Step 3: Add Claude Code Action to the workflow

Create or update a workflow file (for example, .github/workflows/claude.yml) with the following content. This example uses workload identity federation. If you use an OAuth client, replace audience with oauth-secret and reference secrets.TS_OAUTH_SECRET.

name: Claude Code
on:
  pull_request:

permissions:
  id-token: write
  pull-requests: write
  contents: read

jobs:
  claude:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Connect to tailnet
        uses: tailscale/github-action@v4
        with:
          oauth-client-id: ${{ secrets.TS_OAUTH_CLIENT_ID }}
          audience: ${{ secrets.TS_AUDIENCE }}
          tags: tag:ci
          ping: ai

      - name: Run Claude Code
        uses: anthropics/claude-code-action@v1
        with:
          anthropic_api_key: "-"
        env:
          ANTHROPIC_BASE_URL: "http://ai"
          CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC: "1"

Key settings

Permissions

The permissions block sets the minimum GitHub token permissions the workflow needs:

Verify the connection

1. Open a pull request with a small code change to trigger the workflow.
2. In the workflow run's Actions tab, confirm:
   • The Connect to tailnet step connected and the ping: <aperture-hostname> check succeeded.
   • The Run Claude Code step completed and shows API calls to http://<aperture-hostname>.
3. Open the Aperture dashboard at http://<aperture-hostname>/ui/ from a device on your tailnet. Go to the Logs page and confirm the request appears with tag:ci as the caller identity.

Troubleshoot common issues

Next steps

• Set per-user spending limits to cap how much CI pipelines spend on AI requests.
• Restrict CI runners to specific models by narrowing the models pattern in the grant, for example anthropic/claude-sonnet-4-5 instead of anthropic/**.
• Export usage data to S3 for long-term retention and compliance.
• Build a custom webhook to receive real-time notifications when CI runners make AI requests.
• For a complete guide that sets up AI-powered code reviews with cost control and compliance, refer to route AI code reviews through Aperture.