diff --git a/playbooks/deploy-althing-chamber.yaml b/playbooks/deploy-althing-chamber.yaml
index d2bf6b2..73026cc 100644
--- a/playbooks/deploy-althing-chamber.yaml
+++ b/playbooks/deploy-althing-chamber.yaml
@@ -2,14 +2,16 @@
 # Docker host following the PFI /opt/docker/ convention (ana-docker by
 # default, but the playbook works against any host with Docker in place).
 #
-# Brings up THREE compose services from a single image:
+# Brings up FOUR compose services:
 #   althing-chamber       — FastAPI/HTMX web UI, port 7881 host → 8000 container
 #   althing-forseti       — moderator daemon, no port
 #   althing-agent-runner  — Phase 2 worldtree-driver dispatcher, no port
+#   althing-valkey        — Phase 3.1 valkey 8 alpine, pub/sub bridge (internal only)
 #
-# All three processes share the SQLite store via the same bind-mount under
-# /opt/docker/conf/althing-chamber/data. eventbus.bridge_from_db is the
-# cross-process glue.
+# The three althing services use the same image (built from vh/althing);
+# valkey is a stock upstream image. SQLite-backed state shares between the
+# three althing services via the bind-mount under /opt/docker/conf/althing-chamber/data;
+# streaming events ride pub/sub on the docker default network via valkey.
 #
 # Idempotent: rerunning is safe. Creates-gates skip work that's already
 # done; `docker compose up -d` is itself idempotent (no restart unless
@@ -139,3 +141,7 @@ verify:
   - name: agent-runner container running
     shell: docker ps --filter name=^/althing-agent-runner$ --format '{{.Status}}' | grep -q '^Up'
     changed_when: "false"
+
+  - name: valkey container running + healthy
+    shell: docker ps --filter name=^/althing-valkey$ --format '{{.Status}}' | grep -q 'healthy'
+    changed_when: "false"
diff --git a/stacks/althing-chamber/README.md b/stacks/althing-chamber/README.md
index b2bb922..70c03b5 100644
--- a/stacks/althing-chamber/README.md
+++ b/stacks/althing-chamber/README.md
@@ -1,13 +1,15 @@
 # althing-chamber
 
-Web UI + moderator daemon + agent-runner for the althing inter-agent
-message bus. Three services share a single SQLite store via a
-bind-mount; the chamber serves FastAPI/HTMX, the forseti daemon runs
-the moderation + curation loops, and the agent-runner daemon claims
-floor grants for worldtree-driver agents and dispatches them to
-Worldtree's conversation API. Cross-process glue is
-`eventbus.bridge_from_db` polling the same DB all three processes
-write.
+Web UI + moderator daemon + agent-runner + Valkey IPC bridge for the
+althing inter-agent message bus. Four services on the compose default
+network. The chamber serves FastAPI/HTMX, the forseti daemon runs the
+moderation + curation loops, the agent-runner daemon claims floor
+grants for worldtree-driver agents and dispatches them to Worldtree's
+conversation API, and Valkey carries the Phase 3.1 cross-process
+streaming events (msg_start/delta/thinking/complete/curated) that are
+too high-volume to flow through SQLite. SQLite-backed state still
+shares between chamber + forseti + agent-runner via the bind-mount;
+streaming events ride pub/sub on the docker default network.
 
 **Server:** ana-docker
 **URL:** `http://10.250.50.70:7881` (configurable via `.env`)
@@ -22,10 +24,13 @@ by the deploy playbook. Not pulled from a registry.
 | `althing-chamber` | FastAPI/HTMX web UI; SSE subscribers; `/health` endpoint | host 7881 → container 8000 | `python urllib /health` |
 | `althing-forseti` | Moderator + curator daemon; writes events that chamber's bridge picks up | — (no HTTP) | none (process-up signal only) |
 | `althing-agent-runner` | Phase 2: claims worldtree-driver floor grants and dispatches to Worldtree's conversation API | — (no HTTP) | none (process-up signal only) |
+| `althing-valkey` | Phase 3.1: Valkey 8 redis-protocol pub/sub bridge — carries streaming events from agent-runner → chamber | — (internal-only, `valkey:6379` on default network) | `valkey-cli ping` |
 
-All three use the same `${ALTHING_IMAGE}`; the `command:` line in compose
-picks which entrypoint (`althing-chamber` / `althing-forseti` /
-`althing-agent-runner`) runs in each container.
+The three althing services (chamber/forseti/agent-runner) use the same
+`${ALTHING_IMAGE}`; the `command:` line in compose picks which entrypoint
+runs in each container. Valkey is a stock upstream image (no custom build).
+chamber + agent-runner `depends_on: valkey: service_healthy` so the pub/sub
+bridge is up before either side starts publishing or subscribing.
 
 The agent-runner is safe to enable preemptively — when no
 `driver=worldtree` handles are declared in config, it polls
diff --git a/stacks/althing-chamber/compose.yaml b/stacks/althing-chamber/compose.yaml
index 8529bd6..5388c03 100644
--- a/stacks/althing-chamber/compose.yaml
+++ b/stacks/althing-chamber/compose.yaml
@@ -1,17 +1,25 @@
-# althing-chamber + forseti + agent-runner — web UI + moderator daemon +
-# Worldtree-driver agent-runner for the althing inter-agent message bus.
+# althing-chamber stack — chamber + forseti + agent-runner + valkey.
 #
-# Three services share the althing SQLite store via a single bind-mount:
+# Four services on the compose default network:
 #   althing-chamber       — FastAPI/HTMX app (port 7881 host → 8000 container)
 #   althing-forseti       — moderator daemon (no port; cross-process glue via the DB)
 #   althing-agent-runner  — Phase 2 daemon: claims worldtree-driver grants and
 #                           dispatches to Worldtree's conversation API (no port)
+#   valkey                — Phase 3.1 sibling service: Valkey 8 alpine, redis-protocol
+#                           pub/sub bridge for cross-process streaming events from
+#                           agent-runner → chamber SSE subscribers. Reached via
+#                           docker DNS at `valkey:6379` on the default network.
+#                           No exposed port; internal-only.
 #
-# eventbus.bridge_from_db is load-bearing — forseti's DB commits reach
-# chamber's SSE subscribers via the bridge, not via shared memory or IPC.
-# Both processes read+write the same `~/.althing/althing.db` SQLite file
-# at /app/data/althing.db inside the container, backed by the host's
-# /opt/docker/conf/althing-chamber/data bind-mount.
+# Three storage / IPC channels:
+#   - SQLite bind-mount at /app/data backs the althing.db state shared by
+#     chamber + forseti + agent-runner (eventbus.bridge_from_db drains DB
+#     commits into chamber's SSE).
+#   - Valkey pub/sub on docker-default network carries the Phase 3 streaming
+#     events (msg_start/thinking/delta/complete/curated) that don't go
+#     through SQLite — too high-volume + ephemeral for the DB.
+#   - chamber's healthcheck-blocked startup gate on valkey ensures the
+#     subscriber side is up before chamber begins handling SSE traffic.
 #
 # Image is built on the host from the vh/althing git repo by the deploy
 # playbook (`playbooks/deploy-althing-chamber.yaml`), which clones into
@@ -26,10 +34,26 @@
 # All tunables live in .env — edit that, not this file.
 
 services:
+  valkey:
+    image: valkey/valkey:8-alpine
+    container_name: althing-valkey
+    restart: unless-stopped
+    # No exposed port — chamber + agent-runner reach via docker DNS
+    # at `valkey:6379` on the compose default network. No volume —
+    # the pub/sub channel doesn't persist anything between restarts.
+    healthcheck:
+      test: ["CMD", "valkey-cli", "ping"]
+      interval: 5s
+      timeout: 3s
+      retries: 5
+
   althing-chamber:
     image: ${ALTHING_IMAGE}
     container_name: althing-chamber
     restart: unless-stopped
+    depends_on:
+      valkey:
+        condition: service_healthy
     ports:
       - "${ALTHING_BIND:-0.0.0.0}:${ALTHING_PORT}:8000"
     environment:
@@ -81,6 +105,9 @@ services:
     image: ${ALTHING_IMAGE}
     container_name: althing-agent-runner
     restart: unless-stopped
+    depends_on:
+      valkey:
+        condition: service_healthy
     environment:
       - ALTHING_ROOT=/app/data
       - ALTHING_DB=/app/data/althing.db