# aturi.to

> Universal links, an Atmosphere Explorer, and a browser extension for atproto — the protocol behind Bluesky, Leaflet, Tangled and the wider "Atmosphere" network. aturi.to turns a link from any atproto client into the underlying `at://` record, then offers every other client that can open it.

aturi.to is free, keyless and open source (GPL-3.0-or-later). The public API needs no
account, no API key and no rate-limit registration: every operation is a plain GET with
permissive CORS. There is no paid tier, so there is nothing to upgrade to and no sales
step to clear — just be reasonable about volume.

## When to use this

Reach for aturi.to when the task involves an atproto/Bluesky link or record and you need
one of these five things:

- **A web URL turned into its `at://` URI.** You have `https://bsky.app/profile/x/post/y`,
  a Leaflet document, a Tangled repo, a pdsls page — anything in the Atmosphere — and you
  need the canonical record identifier behind it. Call `resolveAtmosphereLink`.
- **The same record opened in a different client.** You have a record and want every other
  app that renders it, each with a ready-to-open URL. Same call: read `waypoints[]`.
- **A "does this page have atproto data?" check on an arbitrary URL.** For pages outside
  the known client catalog, `readAtTags` reads the AT Tags the page publishes about itself.
  A page with none is a successful "no", not an error.
- **The client catalog itself**, with no record in hand — which apps exist, what record
  types each renders, which can be handed a link that opens their composer. Call
  `listWaypoints`.
- **A rich preview for a Bluesky post.** `getPostOembed` is a standard oEmbed provider.

Do **not** reach for aturi.to to post, like, follow, or change anything: the API is
strictly read-only and there is no write surface. It is also not a general atproto host —
it reads the network, it does not store records. To read a repository directly, talk to
that account's PDS over the standard `com.atproto.*` XRPC methods instead.

## How to call it

Start from the machine-readable spec; it types every parameter and response and gives each
operation a unique `operationId`, so LLM function-calling bridges can convert it directly
into tool definitions.

- [OpenAPI 3.1 specification](https://aturi.to/openapi.json): the full API surface — five GET endpoints, typed schemas, error codes.
- [Developer docs as Markdown](https://aturi.to/docs.md): the whole developer guide in one plain-text fetch.
- [Developer docs](https://aturi.to/docs): the same guide as a web page.

Errors are always JSON with a stable machine-readable `code` (`missing_parameter`,
`invalid_parameter`, `unsupported_format`, `not_found`, `upstream_error`,
`internal_error`), a human-readable `error`, and usually a `hint` naming the fix. Branch
on `code`, never on the prose. Note that two operations return `ok: false` with HTTP 200
when the answer is a definite negative — a page with no atproto record is a result, not a
failure — so branch on the `ok` field rather than on the status code.

## API endpoints

- [GET /api/resolve](https://aturi.to/api/resolve?url=https%3A%2F%2Fbsky.app%2Fprofile%2Faturi.to): resolve a page URL or `at://` URI into a record plus every client that can open it.
- [GET /api/waypoints](https://aturi.to/api/waypoints): the client catalog; filter with `?type=post|profile|list|record` and `?capability=compose`.
- [GET /api/at-tags](https://aturi.to/api/at-tags?url=https%3A%2F%2Faturi.to): read the AT Tags a given page declares about itself.
- [GET /api/did-doc](https://aturi.to/api/did-doc): CORS-safe proxy for a `did:web` DID document.
- [GET /api/oembed](https://aturi.to/api/oembed): oEmbed rich-preview payload for a Bluesky post.

## Packages

Both are MIT, zero-runtime-dependency, and published to npm. Use these instead of the HTTP
API when you are building a client and want resolution to happen locally.

- [@aturi.to/waypoints](https://www.npmjs.com/package/@aturi.to/waypoints): AT URI parsing, reverse URL matching, and the waypoint catalog as a library.
- [@aturi.to/waypoints-react](https://www.npmjs.com/package/@aturi.to/waypoints-react): the React "open in…" picker and client icons.

## Site

- [Home](https://aturi.to/): what aturi.to is and the three surfaces it offers.
- [About](https://aturi.to/about): what the project is, who maintains it, and how it is funded.
- [Contact](https://aturi.to/contact): how to reach the maintainer, report a bug, or disclose a vulnerability.
- [Atmosphere Explorer](https://aturi.to/explore): browse any account's PDS records in the browser.
- [Universal links](https://aturi.to/links): how the `aturi.to/{handle}` link format works.
- [Browser extension](https://aturi.to/extension): jump between Atmosphere clients in one click.
- [Lexicon directory](https://aturi.to/explore/lexicons): known atproto record types.

## Optional

- [Source code](https://github.com/atpota-to/aturi): the whole site, extension and packages.
- [Terms](https://aturi.to/terms): terms of use.
- [Privacy](https://aturi.to/extension/privacy): the extension's privacy policy.
- [Sitemap](https://aturi.to/sitemap.xml): every static page.