Aider API: Use FreeTheAI Models
Aider uses FreeTheAI through its OpenAI compatible setting: two environment variables and the openai/ model prefix.
Steps
Set the environment variables
On macOS and Linux:
bashexport OPENAI_API_BASE=https://api.freetheai.org/v1 export OPENAI_API_KEY=ftai_your_key_hereOn Windows
Run these, then open a new terminal:
powershellsetx OPENAI_API_BASE https://api.freetheai.org/v1 setx OPENAI_API_KEY ftai_your_key_hereStart Aider
In your project folder, add openai/ in front of the FreeTheAI model ID:
bashaider --model openai/glm-5.3
How this guide was checked: Checked against Aider's docs (OpenAI compatible APIs) on 2026-09-29.
Tips
- Aider warns about unknown model settings for FreeTheAI models. It still works; the warning is about context size defaults.
Troubleshooting
Why does Aider need openai/ before the model?
The prefix tells Aider to use the OpenAI compatible client with your OPENAI_API_BASE.
Common errors
- 401: the key is wrong or incomplete. Paste the whole key.
- 403: follow a provider of the model, or confirm your email.
- 404: the model ID or URL is wrong.
- 429: daily limit reached, or too many requests at once.