feat(bps): align with SWIP-74 rev 8 (BPS-lite)

openapi/Swarm.yaml

@@ -979,9 +979,12 @@ paths:
     get:
       summary: Subscribe to a BPS cohort
       description: |
-        WebSocket. The node joins the cohort `keccak256(keccak256("bps-claim" | topic) | owner)`
-        at `broker` and sends every broadcast as a binary frame with the full SOC bytes
-        (`id | signature | span | payload`). Broadcasts not signed by `owner` are dropped.
+        WebSocket. The node joins the BPS-lite (SWIP-74) cohort `{topic, FEED_TOPIC, owner}`
+        at `broker` as `identity` and sends every update as a binary frame
+        `challenge (32) | index (8, big-endian) | soc`, where `soc` is the full single-owner
+        chunk (`id | signature | span | payload`) signed by `owner` with
+        `id = keccak256(keccak256(topic | challenge) | index)`. Updates that do not verify,
+        or whose index is below the subscriber's cursor, are dropped.
         The endpoint is read-only: any client frame closes the socket with 4002.
         Close codes: 4002 invalid message, 4003 broker stream closed.
       tags:
@@ -1011,6 +1014,12 @@ paths:
             $ref: "SwarmCommon.yaml#/components/schemas/EthereumAddress"
           required: true
           description: Ethereum address identifying the joiner.
+        - in: query
+          name: cursor
+          schema:
+            type: integer
+          required: false
+          description: Lowest update index to deliver. Defaults to 0.
       responses:
         "200":
           description: Establishes a WebSocket subscription for incoming broadcasts
@@ -1025,20 +1034,22 @@ paths:
 
   "/bps/publish/{owner}/{topic}":
     get:
-      summary: Claim and publish to a BPS cohort
+      summary: Publish to a BPS cohort as its principal
       description: |
-        WebSocket. Text frames carry JSON control messages; binary frames carry SOCs.
+        WebSocket. The node joins the BPS-lite (SWIP-74) cohort `{topic, FEED_TOPIC, owner}`
+        at `broker` declaring `owner` as its address.
 
-        1. Server sends `{"type":"challenge","challenge":"<hex>","broker":"<hex>","id":"<hex>"}`.
-        2. Client signs a SOC with `id` wrapping the payload `challenge | broker` and sends
-           `{"type":"claim","signature":"<hex 65 bytes, no 0x prefix>"}` within 30 seconds.
-        3. Server verifies the claim locally, forwards it to the broker and sends
-           `{"type":"claim_sent"}`. This does not mean the broker accepted it; a rejection
-           closes the socket with 4003.
-        4. Client sends each broadcast as a binary frame containing a full SOC at the cohort address.
+        1. Server sends `{"type":"challenge","challenge":"<hex>","broker":"<hex>","dataTopic":"<hex>","authTopic":"<hex>"}`.
+           `dataTopic` is `keccak256(topic | challenge)`, the session feed for updates;
+           `authTopic` is `keccak256("bps-service:v1" | 0x02 | topic | challenge)`.
+        2. Client sends binary frames `kind (1) | index (8, big-endian) | soc`, where `kind` is
+           1 (DATA) or 2 (AUTH) and `soc` is a single-owner chunk signed by `owner` with
+           `id = keccak256(sessionTopic | index)`. An AUTH chunk is empty and only authenticates
+           the stream. The first frame must arrive within 30 seconds. Indexes must not be reused
+           across sessions; frames below the broker's cursor are dropped silently.
 
-        Close codes: 4001 invalid claim, 4002 invalid message (bad SOC, wrong frame type,
-        claim timeout), 4003 broker stream closed.
+        Close codes: 4001 invalid soc, 4002 invalid message (wrong frame type, unknown kind,
+        auth timeout), 4003 broker stream closed.
       tags:
         - BPS
       parameters:
@@ -1060,12 +1071,6 @@ paths:
             $ref: "SwarmCommon.yaml#/components/schemas/SwarmAddress"
           required: true
           description: Overlay address of the broker node. Must not be this node.
-        - in: query
-          name: identity
-          schema:
-            $ref: "SwarmCommon.yaml#/components/schemas/EthereumAddress"
-          required: true
-          description: Ethereum address identifying the joiner.
       responses:
         "200":
           description: Establishes a WebSocket subscription for publishing broadcasts

pkg/api/api_test.go

@@ -26,6 +26,7 @@ import (
 	mockac "github.com/ethersphere/bee/v2/pkg/accesscontrol/mock"
 	accountingmock "github.com/ethersphere/bee/v2/pkg/accounting/mock"
 	"github.com/ethersphere/bee/v2/pkg/api"
+	"github.com/ethersphere/bee/v2/pkg/bps"
 	"github.com/ethersphere/bee/v2/pkg/crypto"
 	"github.com/ethersphere/bee/v2/pkg/feeds"
 	"github.com/ethersphere/bee/v2/pkg/file/pipeline"
@@ -95,7 +96,7 @@ type testServerOptions struct {
 	Resolver           resolver.Interface
 	Pss                pss.Interface
 	Gsoc               gsoc.Listener
-	Bps                api.BPSService
+	Bps                bps.Interface
 	WsPath             string
 	WsPingPeriod       time.Duration
 	Logger             log.Logger