title: Data Sources & Integration updated: 2026-03-24#

Twisted pulls data from four external sources and authenticates users via Bluesky OAuth. Each source has a distinct role — no single source is authoritative for everything.

Source Overview#

Constellation#

Constellation is a public, self-hosted index of AT Protocol backlinks. It answers "who linked to this?" across the entire network — making it the right source for aggregated social signals instead of maintaining our own counters.

Key Endpoints#

GET /xrpc/blue.microcosm.links.getBacklinks — Get records linking to a target.

• subject (required) — The target (AT-URI, DID, or URL)
• source (required) — Collection and path, e.g. sh.tangled.feed.star:subject.uri
• did — Filter to specific users (repeatable)
• limit — Default 16, max 100
• reverse — Reverse ordering

GET /xrpc/blue.microcosm.links.getBacklinksCount — Count of links to a target.

• subject, source — Same as above

GET /xrpc/blue.microcosm.links.getManyToManyCounts — Secondary link counts in many-to-many relationships.

• subject, source, pathToOther (required)
• did, otherSubject, limit (optional)

Usage in Twisted#

This replaces the need to index and count interaction records ourselves. Our Tap pipeline still indexes interaction records for search and graph discovery, but Constellation is the source of truth for counts and lists.

Integration Notes#

• No authentication required. Constellation asks for a user-agent header with project name and contact.
• Responses are paginated via cursor. Plan for multiple pages when listing (e.g., all followers).
• The API is read-only — social actions (star, follow, react) are still AT Protocol record writes to the user's PDS.

Tangled XRPC (Knots)#

Knots are Tangled's git hosting servers. Each repo lives on a specific knot, identified by the knot DID in the repo's AT Protocol record.

Endpoints Used#

• sh.tangled.repo.tree — File tree for a ref
• sh.tangled.repo.blob — File content
• sh.tangled.repo.log — Commit history
• sh.tangled.repo.branches / sh.tangled.repo.tags — Refs
• sh.tangled.repo.getDefaultBranch — Default branch name
• sh.tangled.repo.diff / sh.tangled.repo.compare — Diffs
• sh.tangled.repo.languages — Language breakdown
• sh.tangled.knot.version — Knot software version

Routing#

The app resolves which knot hosts a repo by reading the repo's AT Protocol record (which contains the knot DID), then resolving the knot DID to its service endpoint. XRPC calls go directly to that knot.

The Tangled appview at tangled.org serves HTML only — there is no JSON API at the appview level.

AT Protocol (PDS)#

Standard AT Protocol record access for reading and writing user data.

Read Operations#

• com.atproto.repo.getRecord — Fetch a single record by collection + rkey
• com.atproto.repo.listRecords — List records in a collection with pagination

Used for: profiles, repo metadata, issues, PRs, comments, stars, follows, reactions.

Write Operations (Authenticated)#

• com.atproto.repo.createRecord — Create a new record (star, follow, react, issue, comment)
• com.atproto.repo.deleteRecord — Delete a record (unstar, unfollow)

All writes go to the authenticated user's PDS using their OAuth session.

Identity Resolution#

• Handle → DID via com.atproto.identity.resolveHandle
• DID → DID document via PLC Directory (plc.directory) or .well-known/did.json
• DID document → PDS endpoint (from #atprotoPersonalDataServer service)

Tap (Firehose)#

Tap provides a filtered firehose of AT Protocol events. Our indexer consumes Tap via WebSocket, indexing records into the search database.

What We Index via Tap#

• Repos, issues, PRs, comments, strings, profiles — for full-text search
• Follows — for graph discovery during backfill
• Issue state and PR status changes — for state filtering in search

What We Don't Need to Count via Tap#

Stars, followers, reactions — Constellation handles counts and lists. We still process these events for graph discovery but don't need to maintain our own counters.

Tap Protocol#

• WebSocket connection with cursor-based resume
• Events contain: operation (create/update/delete), DID, collection, rkey, CID, record payload
• Acks required after processing each event
• Backfill via /repos/add endpoint to request historical data for specific users

Bluesky OAuth#

Authentication uses AT Protocol OAuth via @atcute/oauth-browser-client.

Flow#

1. User enters their handle
2. App resolves handle → DID → PDS → authorization server metadata
3. App initiates OAuth with requested scopes
4. User authorizes in browser, redirected back to app
5. App exchanges code for tokens
6. Session provides dpopFetch for authenticated XRPC calls

Scopes#

The app requests scopes for:

• sh.tangled.feed.star — Star/unstar repos
• sh.tangled.graph.follow — Follow/unfollow users
• sh.tangled.feed.reaction — Add reactions
• sh.tangled.actor.profile — Edit profile
• sh.tangled.repo.issue / sh.tangled.repo.issue.comment — Create issues and comments
• sh.tangled.repo.pull.comment — Comment on PRs

Capacitor Integration#

On native platforms, OAuth callback uses a deep link URL scheme registered with Capacitor. The app listens via App.addListener('appUrlOpen', ...) to catch the redirect.

Session Management#

Tokens are stored in secure storage (encrypted localStorage on web, Capacitor Secure Storage on native). Sessions auto-refresh. The app supports multiple accounts with an account switcher.