Expand Future Work section in README

README.md

@@ -28,7 +28,7 @@ All types support `merge`, `clone`, `deinit`, and JSON serialization/deserializa
 |---|---|---|---|
 | `POST /<key>` | 201 | Create CRDT from JSON body |
 | `GET /<key>` | 200/404 | Read CRDT as JSON |
-| `PATCH /<key>` | 202 | Merge client replica into existing CRDT |
+| `PATCH /<key>` | 200/202 | Merge client replica into existing CRDT (202 when congested) |
 | `DELETE /<key>` | 204 | Remove CRDT (idempotent) |
 | `POST /register` | 201 | Get next server replica ID |
 | `GET /<key>` (WebSocket upgrade) | 101 | Real-time sync via WebSocket |
@@ -63,11 +63,27 @@ WASM module exporting functions for collaborative text editing via the RGA CRDT.
 
 ## Future Work
 
-- **Tombstone garbage collection**: Removed nodes accumulate without bound in RGA and OR-Set
-- **No persistence**: All state is in-memory only
-- **No authentication/authorization**: All endpoints are open
-- **No rate limiting**: No protection against overload
-- **Client-server only**: No peer-to-peer architecture
+- **Delta sync**: Every PATCH sends the full CRDT state. For large RGA
+  documents this wastes bandwidth. Transmitting only what changed would
+  be faster and cheaper.
+
+- **TLS and auth**: The API is open. TLS termination and authentication
+  should be handled externally before requests reach the server.
+
+- **Tombstone garbage collection**: Removed RGA and OR-Set entries
+  accumulate forever. A compaction pass would reclaim memory once all
+  replicas acknowledge a deletion.
+
+- **Persistence**: All state is in-memory. A client application using the
+  library can add its own persistence layer (write-ahead log, snapshot,
+  database).
+
+- **Blocking notification channel**: WebSocket subscriber channels are
+  bounded queues (32 slots). When full, `queue.putOne` blocks the entire
+  actor thread, stalling all CRDT operations. Should use a drop-policy
+  or separate notification queue instead.
+
+- **Client-server only**: No peer-to-peer architecture.
 
 ## External Dependencies
 
@@ -108,7 +124,7 @@ The server listens on `[::]:8080` with IPv4 `0.0.0.0:8080` fallback.
 # Create a counter
 curl -X POST http://localhost:8080/my-counter \
   -H "Content-Type: application/json" \
-  -d '{"type":"counter","counter":{"counters":[[0,1]]}}'
+  -d '{"counter":[[0,1]]}'
 
 # Read it back
 curl http://localhost:8080/my-counter
@@ -119,7 +135,7 @@ curl -X POST http://localhost:8080/register
 # Merge a replica
 curl -X PATCH http://localhost:8080/my-counter \
   -H "Content-Type: application/json" \
-  -d '{"type":"counter","counter":{"counters":[[1,2]]}}'
+  -d '{"counter":[[1,2]]}'
 
 # Delete
 curl -X DELETE http://localhost:8080/my-counter