Aider with AI Gateway

Aider is an open-source, terminal-based AI pair programming tool that edits code in your local git repository. You can configure it to use AI Gateway for unified model access and spend monitoring.

Run the Vercel CLI setup command for Aider:

npx vercel ai-gateway setup --agent aider

The command writes the gateway base URL and a default model into ~/.aider.conf.yml, registers the gateway's models in .aider.model.metadata.json and .aider.model.settings.yml so Aider knows their context windows, and exports AIDER_OPENAI_API_KEY from a managed block in your shell startup file. Re-run it to refresh the model registrations.

If you can't use the Vercel CLI, configure Aider manually:

1. Create an API key

   Go to the AI Gateway section in the Vercel dashboard sidebar and click API keys to create a new API key.

2. Export the key

   Aider reads its OpenAI-compatible key from AIDER_OPENAI_API_KEY. Export it in your shell:

   Terminal

   export AIDER_OPENAI_API_KEY="your-ai-gateway-api-key"

   To persist the key, add the same line to your shell's startup file.

3. Point Aider at the gateway

   Add the gateway base URL and a default model to ~/.aider.conf.yml:

   ~/.aider.conf.yml

   openai-api-base: https://ai-gateway.vercel.sh/coding-agent/v1
   model: openai/openai/gpt-6-astra

   The openai/ prefix is what routes the model ID through openai-api-base, so the model value is openai/ followed by the gateway's creator/model-name slug. openai/openai/gpt-6-astra means the gateway model openai/gpt-6-astra.

4. Register model metadata

   Aider has no built-in catalog entries for prefixed IDs, so it falls back to small default context windows. Register the gateway's models in .aider.model.metadata.json next to your config file:

   ~/.aider.model.metadata.json

   {
     "openai/openai/gpt-6-astra": {
       "max_input_tokens": 1050000,
       "litellm_provider": "openai",
       "mode": "chat"
     }
   }

   Then set the diff edit format in .aider.model.settings.yml:

   ~/.aider.model.settings.yml

   - name: openai/openai/gpt-6-astra
     edit_format: diff
     use_repo_map: true

   The Vercel CLI generates both files from the gateway's live catalog, including context windows and per-token pricing, and drops models without size data.

5. Start Aider

   Terminal

   aider

   Switch models with /model in a session or on the command line:

   Terminal

   aider --model openai/anthropic/claude-sonnet-5

View your usage, spend, and request activity in the AI Gateway section in the Vercel dashboard sidebar. See the observability documentation for more details.

• Browse the models catalog for available models
• Configure spend limits on your API key
• Read the Aider documentation for editor and git workflow options