Introduction
What Tessen's developer platform offers today, who can use each part, and where to start.
Tessen is an intelligence platform. For developers it is an HTTP API at https://api.tessen.ai/v1 that serves Tessen's model families, a Console where you create keys and watch usage, and tools — the Tessen CLI and OpenCode — for coding with Tessen. These documents describe what runs in production today. Anything restricted, in preview, planned or unavailable is labelled as such, on the page and in the contents.
What you can use today
| Capability | Availability | Who can use it |
|---|---|---|
| Chat completions on Z1, Z1 Code and H1 | Restricted access | Accounts in the commercial pilot, paid from a prepaid wallet. |
Project ZERO Alpha (project-zero) | Restricted access | Developers enrolled by Tessen, free, up to 200 requests a day. |
| Streaming, tool calling, multi-turn conversations | Available | On every model you can call. |
| Embeddings | Available | Any account with an API key. |
Public price list (GET /v1/pricing/families) | Available | Anyone, no key needed. |
| Console: keys, Playground, wallet, usage | Available | Anyone with a Tessen account. |
| Tessen CLI and OpenCode | Developer Alpha | Accounts enrolled in ZERO Alpha. |
| Image generation | Not available | The endpoint exists and answers that image generation is not enabled. |
| Structured output enforcement (JSON schema), Tessen SDK packages, webhooks | Not available | Nothing is published for these. See their pages for the exact state. |
| Tessen Node | Planned | Not released. |
Z1, Z1 Code and H1 are in a private pilot. A developer outside the pilot who requests one of them is refused with 400 model_not_found. Public purchase of credit is not open. Pilot and production access explains what that means and how it will change.
How the pieces fit
- Sign in to the Console
Create a Tessen account at https://console.tessen.ai with email, Google or GitHub.
- Create an API key
The Console shows the key once. It begins tes_.
- Send a request
POST to https://api.tessen.ai/v1/chat/completions with the key as a Bearer token.
- Read the result
The response carries the answer, the token counts and — on Tessen's model families — the exact cost.