# Constal SDK documentation

> SDK concepts, workflows, operations, and reference for humans and agents.

- [Constal SDK](https://constal.ai/docs/sdk.md): Author executable Agent, Channel, Auth Provider, Policy, Credential Provider, Tool, and runtime integration contracts in TypeScript.
- [Set up an SDK project](https://constal.ai/docs/sdk/project.md): Create a minimal TypeScript package that the managed builder can validate, reproduce, and deploy.
- [Build an Agent with the SDK](https://constal.ai/docs/sdk/agents.md): Define script or durable Agent behavior, call models, read history, and return replay-safe results.
- [Durable execution](https://constal.ai/docs/sdk/durable-execution.md): Use waits, subtasks, handles, commits, state-machine steps, map/reduce, branches, and ledger views without breaking replay.
- [Resources and Tools](https://constal.ai/docs/sdk/resources-and-tools.md): Declare logical capabilities, expose model-facing Tools, and invoke pinned Resource operations with correct effect semantics.
- [Build Channels and Auth Providers](https://constal.ai/docs/sdk/channels-and-auth.md): Normalize a custom protocol into canonical events and authenticate ingress with bounded identity evidence.
- [Policies and analytics](https://constal.ai/docs/sdk/policies-and-analytics.md): Author deterministic executable Policy and emit bounded custom analytics from Agent or Channel runtime code.
- [Build Credential Providers](https://constal.ai/docs/sdk/credential-providers.md): Define reusable lifecycle code for imported, minted, rotating, or browser-authorized Credentials.
- [SDK export reference](https://constal.ai/docs/sdk/reference.md): Find the public builders, runtime interfaces, resource contracts, protocol helpers, and validation families exported by @constal/sdk.