Models
Frontier models served by Foundation Machines, and how Sebastion AI picks one for you.
Models
Foundation Machines exposes a curated set of frontier models. The
/v1/chat/completions gateway lets you pick a model with the model
parameter; the /v1/audit endpoint and the Sebastion AI GitHub App
choose one for you based on your plan.
Frontier models
| Vendor | Model | Context | API id | Status |
|---|---|---|---|---|
| Anthropic | Claude Haiku 4.5 | 200K | claude-haiku-4.5 | Available |
| Anthropic | Claude Sonnet 4.6 | 200K | claude-sonnet-4.6 | Available |
| Anthropic | Claude Opus 4.7 | 200K | claude-opus-4.7 | Available |
| OpenAI | GPT-5.4 | 256K | gpt-5.4 | Available |
| OpenAI | GPT-5.4 mini | 256K | gpt-5.4-mini | Available |
| Gemini 3 Flash | 1M | gemini-3-flash | Available | |
| Moonshot | Kimi K2.5 | 200K | kimi-k2.5 | Forthcoming |
For /v1/chat/completions (the gateway)
When calling the chat-completions gateway you pass model explicitly.
The set you can choose from depends on your plan tier.
| Plan | Allowed models |
|---|---|
| Free | claude-haiku-4.5, gpt-5.4-mini, gemini-3-flash |
| Pro | adds claude-sonnet-4.6, gpt-5.4 |
| Team | adds claude-opus-4.7 |
| Enterprise | full set, including any forthcoming models on launch |
Calls with a model outside your plan return 403 model_forbidden.
For /v1/audit and the Sebastion AI GitHub App
Sebastion AI does not take a model parameter. You upgrade your
plan; Sebastion routes you to a stronger model automatically.
| Plan | Audit model |
|---|---|
| Free | claude-sonnet-4.6 |
| Pro | claude-opus-4.7 |
| Team | claude-opus-4.7 (multi-model cross-check coming) |
| Enterprise | best frontier model + on-prem option |
This applies to both the GitHub App and direct POST /v1/audit calls.
The live catalogue
Beyond the headline models above we may serve additional variants for testing. List the live catalogue:
curl https://api.foundationmachines.ai/v1/models \
-H "Authorization: Bearer fm_..."The data array returned by /v1/models is the source of truth for
what is currently routable. Plans gate which subset of that catalogue
you can actually call from /v1/chat/completions.