# feature surface

The detailed implemented surface, moved out of the README. As always,
[`semantic-parity.md`](semantic-parity.md) is the authority on what is
*proved*, row by row; this lists what is *built*.

- **live feeds** at `/subscribe` and `/subscribe-v2`, with collection and DID
  filters, cursor replay, runtime option updates, RFC 7692 permessage-deflate
  on v1, frozen v1 zstd, and fetchable dictionary-negotiated v2 zstd
- **a disk-backed historical archive** through `listSegments`, `getSegment`,
  `getBlock`, and `planBackfill`. Sealed `jss` v1 segments are byte-compatible
  with upstream. Sealed headers, block envelopes, DID blooms, and collection
  summaries are resident and refresh atomically after seal, compaction, and
  timestamp rewrite; planning opens no segment files, and cold replay reads
  only selected compressed blocks
- **whole-network bootstrap** with concurrent live capture and deterministic
  merge. Repository completion is coupled to ordinary archive-writer durability
  independently of the dispatch/checkpoint batch, so a restart does not replay
  work already committed. Startup resumes the existing active segment,
  truncating and fsyncing only a framing-torn suffix while failing closed on
  complete-frame corruption and sealed high-water checksum failure
- **Sync 1.1 commit verification** — PLC key rotation, MST inversion, op-CID
  checks, replay protection, durable repository-chain state, and transparent
  authenticated whole-repo repair with ordered pending replay. The live
  scheduler implements Atmos-shaped 32-worker per-DID FIFO, bounded
  drop-oldest, and completion-order batching
- **RocksDB-backed metadata** and archive publication coupled to segment fsync
  boundaries
- **tombstone-aware compaction** and continuing repair of repositories that
  were unavailable or changed during bootstrap
- **crash-resumable timestamp imports** with a durable RocksDB rule map,
  topology-preserving sealed-segment repair, and bearer-gated operator XRPC
- **operations views** at `/status` — a summary field report plus hosts,
  accounts, collections, and segments tabs, with durable PDS diagnostics,
  per-repository reconstruction, and authoritative root verification against
  the PDS commit root. Prometheus metrics are on the optional debug listener at
  `/metrics`