Skip to main content

Class: ATRepository

Defined in: src/atproto/repository/at-repository.ts:124

AT Protocol repository implementation.

Remarks​

Implements IRepository for fetching records and blobs from user PDSes. Uses @atproto/api SDK for AT Protocol compliance and the identity resolver for DID-to-PDS endpoint resolution.

Architecture:

ATRepository
  ├── IIdentityResolver (DID → PDS URL)
  ├── AtpAgent (per-PDS HTTP client)
  └── IPolicy (circuit breaker + retry)

Resilience: All PDS requests are wrapped in a resilience policy that provides:

  • Circuit breaker: Fast-fail when PDS is unhealthy
  • Retry: Automatic retry with exponential backoff

Caching: This implementation does NOT cache responses. Caching should be handled by a higher-level service (e.g., BlobProxyService for blobs).

Example​

const repository = new ATRepository({
  identity: didResolver,
  resiliencePolicy: createResiliencePolicy({
    circuitBreaker: { name: 'pds', failureThreshold: 5 },
    retry: { name: 'pds', maxAttempts: 3 }
  }),
  logger,
  config: { timeoutMs: 30000 }
});

// Fetch a single record
const record = await repository.getRecord<PreprintRecord>(uri);

// List records from a collection
for await (const record of repository.listRecords<PreprintRecord>(did, nsid)) {
  console.log(record.value.title);
}

// Fetch a blob
const stream = await repository.getBlob(did, cid);

Implements​

Constructors​

new ATRepository()​

new ATRepository(options): ATRepository

Defined in: src/atproto/repository/at-repository.ts:153

Creates a new ATRepository.

Parameters​

options​

ATRepositoryOptions

Repository options

Returns​

ATRepository

Example​

const repository = new ATRepository({
  identity: didResolver,
  resiliencePolicy,
  logger
});

Methods​

getBlob()​

getBlob(did, cid): Promise<ReadableStream<Uint8Array>>

Defined in: src/atproto/repository/at-repository.ts:406

Fetches a blob from a user's PDS.

Parameters​

did​

DID

Repository DID

cid​

CID

Blob CID

Returns​

Promise<ReadableStream<Uint8Array>>

Blob data as readable stream

Remarks​

This method fetches blobs for proxying only; Chive does not store blob data. The stream should be piped directly to the client.

Process: resolve DID to PDS endpoint, construct blob URL using {pdsUrl}/xrpc/com.atproto.sync.getBlob, fetch blob with resilience, and return as ReadableStream.

Throws​

BlobFetchError Thrown when blob fetch fails.

Example​

const pdfStream = await repository.getBlob(
  toDID('did:plc:abc123')!,
  toCID('bafyreib2rxk...')!
);

// Pipe to response
return new Response(pdfStream, {
  headers: { 'Content-Type': 'application/pdf' }
});

Implementation of​

IRepository.getBlob

getRecord()​

getRecord<T>(uri, options?): Promise<null | RepositoryRecord<T>>

Defined in: src/atproto/repository/at-repository.ts:198

Fetches a single record by AT URI.

Type Parameters​

• T

Record value type

Parameters​

uri​

AtUri

AT URI of the record

options?​

GetRecordOptions

Fetch options (CID for specific version)

Returns​

Promise<null | RepositoryRecord<T>>

Record if found, null if not found

Remarks​

This method fetches the record from the user's PDS. If the record doesn't exist or the PDS is unreachable, returns null.

Process:

  1. Parse AT URI to extract DID, collection, rkey
  2. Resolve DID to PDS endpoint
  3. Get or create AtpAgent for PDS
  4. Fetch record via com.atproto.repo.getRecord
  5. Return typed RepositoryRecord

Throws​

RecordFetchError Thrown when fetch fails due to network error or parse error. NOT thrown for 404 (returns null instead).

Example​

const record = await repository.getRecord<PreprintRecord>(
  toAtUri('at://did:plc:abc123/pub.chive.preprint.submission/xyz789')!
);

if (record) {
  console.log('Title:', record.value.title);
  console.log('Author:', record.author);
  console.log('CID:', record.cid);
}

Implementation of​

IRepository.getRecord

listRecords()​

listRecords<T>(did, collection, options?): AsyncIterable<RepositoryRecord<T>>

Defined in: src/atproto/repository/at-repository.ts:293

Lists records from a collection in a user's repository.

Type Parameters​

• T

Record value type

Parameters​

did​

DID

Repository DID

collection​

NSID

Collection NSID

options?​

ListRecordsOptions

List options (limit, cursor, reverse)

Returns​

AsyncIterable<RepositoryRecord<T>>

Async iterable of records

Remarks​

Returns an async iterable for memory-efficient streaming of large collections. Automatically handles pagination via cursors.

Process:

  1. Resolve DID to PDS endpoint
  2. Get or create AtpAgent for PDS
  3. Fetch records in pages via com.atproto.repo.listRecords
  4. Yield records one at a time
  5. Continue until no more pages or limit reached

Example​

const preprints = repository.listRecords<PreprintRecord>(
  toDID('did:plc:abc123')!,
  toNSID('pub.chive.preprint.submission')!,
  { limit: 10 }
);

for await (const record of preprints) {
  console.log('Preprint:', record.value.title);
}

Implementation of​

IRepository.listRecords