> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bizbionic.com/llms.txt
> Use this file to discover all available pages before exploring further.

# REST policy

> Prefer A2A. REST is not the public product surface for new features.

# REST policy

**Prefer A2A** (`POST /rpc` + skill names) for all new integrations.

REST exists only as a thin compatibility layer for a small allowlisted set of routes. New product capabilities are added as:

1. A2A skills
2. A2UI surfaces (humans)
3. REST **only** if a non-agent external consumer explicitly requires it

Do not invent REST paths from OpenAPI docs paths like `/a2a/campaigns.list` — those are documentation-only.

There is **no** public `POST /api/messages/send` (or similar) for SMS. Unknown `/api/*`, `/v1/*`, and `/rest/*` routes return **404** with a pointer to `POST /rpc`.

Thin HTTP that does exist (auth required unless noted): session/keys helpers under `/api/auth/*`, `/api/keys`, `/api/billing/cost` — not a product CRUD surface for campaigns/contacts.

## Next steps

* [API model](/api-model)
* [A2A RPC](/connect/a2a-rpc)