Terminal pair programmer
How to use Aider with Rapid Router
Aider talks to any OpenAI-compatible endpoint through environment variables. Prefix the model with openai/ so aider routes it to the OpenAI-shaped client.
Setup
- Export the two variables below, or put them in .env in your project.
- Run aider with --model openai/<catalog model string>.
- Aider shows the model name in its banner; /tokens shows the spend it estimates.
export OPENAI_API_BASE=https://rapidrouter.ai/api/v1
export OPENAI_API_KEY=<your Rapid Router key>
aider --model openai/anthropic/claude-sonnet-5Field names as in Aider at the time of writing; their UI moves, the three values do not. Aider site.
Pick a model
The catalog lists every live model with its price per million tokens. For a coding tool, a strong model for edits and a cheap one for questions is the usual pair; the cost calculator shows what a month of your usage costs on each.
Common questions
Which model string do I put in Aider?
Any id from the catalog, in the vendor/model shape, for example anthropic/claude-sonnet-5. The models page lists every live id with its price; copy it exactly.
Does Aider need anything else to work with Rapid Router?
No. Rapid Router exposes the OpenAI chat completions API at https://rapidrouter.ai/api/v1, which is the shape Aider already sends. Streaming, tool calling and JSON mode work where the model supports them.
How is usage from Aider billed?
Per request at the provider's list price per million tokens, debited from your prepaid balance. Create a separate key for Aider and the dashboard shows its spend on its own; you can cap it monthly.
Is there a free allowance to test with?
Yes. Every account gets a daily allowance of free requests on eligible models before any top-up, so the first session costs nothing.