# Build on your pod

> The doors into a Synap pod, and which one to use for an app, a script, an integration or an agent.

URL: https://docs.synap.live/docs/build · Last reviewed against the code: 2026-10-20

A pod is a backend first. Everything the apps do goes through the same doors you can use: the same records, the same
permissions and the same governance. An agent or an app that writes through any door gets the same proposal and
approval rules.

## The doors

| Door | Path on the pod | Use it for | Auth |
|---|---|---|---|
| **tRPC API**, through the SDK | `/trpc` | TypeScript and React apps that act as a signed-in person | Sign-in session (cookie or session token); no API keys |
| **Hub REST API** | `/api/hub/*` | Scripts, agents, integrations in any language | API key (`hub-protocol.read` / `.write`) |
| **MCP** | `/mcp` | AI clients: Claude Code, Codex, Cursor, ChatGPT and others | API key or OAuth |
| **Webhooks** | your URL | Being told when something changes | HMAC signature |
| **External chat** | `/api/external/chat/*` | Streaming an AI conversation backed by your pod | API key (`chat.stream`) |
| **External skills** | `/api/external/skills/*` | Listing and invoking skills | API key (`skills.invoke`) |

Every pod publishes the OpenAPI description of its Hub REST API at `/api/hub/openapi.json`.

## The packages

| Package | What it is |
|---|---|
| [`@synap-core/sdk`](https://www.npmjs.com/package/@synap-core/sdk) | Typed tRPC client for apps where a person signs in. See [SDK](/docs/build/sdk). |
| [`@synap-core/react`](https://www.npmjs.com/package/@synap-core/react) | React provider and hooks over the SDK (TanStack Query). |
| [`@synap-core/hub-rest-client`](https://www.npmjs.com/package/@synap-core/hub-rest-client) | Zero-dependency client for the Hub REST API, for agents and scripts that hold an API key. |
| [`@synap-core/sdk-realtime`](https://www.npmjs.com/package/@synap-core/sdk-realtime) | Socket.IO client for change notifications. |
| [`@synap-core/api-types`](https://www.npmjs.com/package/@synap-core/api-types) | The pod's tRPC `AppRouter` type. |
| [`@synap-core/types`](https://www.npmjs.com/package/@synap-core/types) | Domain types and schemas. |
| [`@synap-core/cli`](https://www.npmjs.com/package/@synap-core/cli) | The user CLI: connects computers and agents to a pod. |

## Where to start

- An app in TypeScript where a person signs in: [SDK first query](/docs/build/sdk).
- A script, a site or an integration: an [API key](/docs/build/api-keys) and the
  [Hub REST API](/docs/reference/hub-api).
- React to changes in another system: [Webhooks](/docs/build/webhooks).
- A coding agent that writes code against Synap: [Coding with agents](/docs/build/coding-with-agents).
- An AI agent: [Connect an agent](/docs/build/agents), then [MCP](/docs/build/agents/mcp) and
  [agent skills](/docs/build/agents/skills).
- How the data model works: [Kind and facets](/docs/build/concepts/kind-and-facets).