diff --git a/README.md b/README.md
index 0c82cd2..4f1b621 100644
--- a/README.md
+++ b/README.md
@@ -223,9 +223,30 @@ clusters. A cluster's spiked positions become a libmagic-style signature;
 clusters with enough members and enough fixed positions self-**nominate** for
 promotion (a human does the one irreversible step, redefining "known").
 
-**Status:** the offline science (phase A) is implemented and calibrated; the live
-catalog process (phase B) is designed and its scoring core (`assign_file`) is in
-place, but its batch-runner plumbing is not yet built.
+**Status:** both phases are implemented and calibrated. Phase A (offline Gibbs)
+is the science; phase B (`src/catalog.jl`) is the live catalog: a durable
+single-owner state that sweeps `binary/`, folds each new file into a cluster with
+the deterministic CRP-predictive rule, and writes promotion nominations.
+
+The catalog process is run periodically (cron), single-threaded — it is the
+**only** writer of the catalog, so it needs no locking:
+
+```bash
+julia --project=. bin/cluster_sweep.jl            # incremental live sweep of new binary/ files
+julia --project=. bin/cluster_sweep.jl --compact  # offline Gibbs re-cluster (seed / recompact)
+```
+
+The catalog is a single durable file (`FS_CLUSTER_CATALOG`, default
+`data/catalog.json`) committed with the same sidecar-first
+temp→fsync→rename→fsync-dir discipline as the stage-2 sidecars, so a crash can
+neither corrupt it nor lose a write. On the **first** run (empty catalog) the
+sweep auto-promotes to a `--compact` pass to seed clusters; later runs assign
+incrementally, touching only files they have not seen. A cluster that clears the
+member/magic thresholds writes a nomination — a hex magic template, member count,
+and example filenames — into `FS_NOMINATED_DIR` (default `data/nominated/`) for a
+human to glance at and promote. Under the calibrated `bg_mass > α`, the live
+sweep never mints single-file clusters; genuinely new formats surface from the
+periodic `--compact` re-clustering of the background residue, not the live path.
 
 Calibration is its own offline script (like training — never in the request
 path), scored against magic-collapsed ground truth (so `docx`≡`zip` and the whole
@@ -359,6 +380,8 @@ init, so the artifact is exactly regenerable from the same inputs.
 | `FS_CLUSTER_BG_MASS`      | `5.0`          | Mass of the uniform background component      |
 | `FS_PROMOTE_MIN_MEMBERS`  | `20`           | Cluster size threshold for promotion nomination |
 | `FS_PROMOTE_MIN_MAGIC`    | `3`            | Required fixed signature positions to nominate |
+| `FS_CLUSTER_CATALOG`      | `data/catalog.json` | Durable stage-5 catalog file (single-owner) |
+| `FS_NOMINATED_DIR`        | `data/nominated` | One JSON per self-nominated cluster (human promote gate) |
 
 > To get real parallelism, start Julia with enough threads (`-t N`) to cover all
 > pools. If `FS_WORKERS + FS_KNOWN_WORKERS + FS_UNKNOWN_WORKERS + FS_TEXT_WORKERS`
@@ -398,13 +421,15 @@ src/
   metadata.jl     exiftool extraction + normalized sidecar (stage 2)
   content.jl      binary-vs-text sniff for unknown files (stage 3)
   language.jl     natural + programming language enrichment for text (stage 4)
-  cluster.jl      header-byte clustering for unknown-format discovery (stage 5, offline)
+  cluster.jl      header-byte clustering model + Gibbs + scoring core (stage 5, science)
+  catalog.jl      durable single-owner format catalog + sweep + nominations (stage 5, phase B)
   worker.jl       parametrized worker loop + classify/enrich/triage/language handlers
   server.jl       HTTP routes/handlers
 bin/
   server.jl           entry point
   train.jl            offline training script → model/classifier.jld2
   cluster_calibrate.jl offline stage-5 hyperparameter calibration + NCD baseline
+  cluster_sweep.jl    stage-5 phase-B runner: sweep binary/, update catalog, write nominations
 model/
   classifier.jld2       committed trained weights (loaded at startup)
   DESIGN_clustering.md  stage-5 design rationale + calibration results