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

# App SDK

<Update label="v1.0.0" description="2026-08-11">
  The App SDK is stable. `attio` and `create-attio` were previously published as dated
  `0.0.1-experimental.<date>` builds. From 1.0.0 they follow
  [semantic versioning](https://semver.org/spec/v2.0.0.html), and are always released together at the
  same version.

  ### What stable means

  * Everything exported from `attio`, `attio/client` and `attio/server` will not change incompatibly
    within the 1.x line unless marked as `experimental` or `deprecated`. Breaking changes require a
    new major version.
  * Additive changes ship as minor versions and fixes ship as patches, so `^1.0.0` picks up both.
  * Individual APIs that are still taking shape are marked as experimental in their documentation and
    carry an `Experimental_` prefix. They are excluded from the guarantee above and can change or be
    removed in a minor release. Apps submitted for review
    [must not use them](https://docs.attio.com/share/code-review).

  ### What you can build

  * [Extensions](https://docs.attio.com/sdk/extensions/overview): record actions, bulk record actions,
    record widgets, object actions and call recording text actions.
  * [Workflow blocks](https://docs.attio.com/sdk/workflow-blocks/overview): triggers and steps that
    appear in Attio's workflow builder, each with its own configurator UI.
  * [Workspace settings](https://docs.attio.com/sdk/settings/overview): a settings schema and a
    settings page for your app.
  * [Forms](https://docs.attio.com/sdk/guides/building-forms) and a component library for extension UI.
  * [Queries against Attio data](https://docs.attio.com/sdk/guides/querying-attio-data), server
    functions, [inbound webhooks](https://docs.attio.com/sdk/guides/receiving-http-requests),
    [connections to external services](https://docs.attio.com/sdk/guides/authenticating-to-external-services)
    and a key-value store.

  If you have not built on Attio before, start with
  [creating an app](https://docs.attio.com/sdk/guides/creating-an-app).
</Update>