diff --git a/.env.example b/.env.example
index b32ad6a..8a189e0 100644
--- a/.env.example
+++ b/.env.example
@@ -30,6 +30,10 @@ MATRIX_CONTROL_ROOM_ID=
 # Required: without it the bot can't tell its own messages apart from real ones and would
 # reply to itself in a loop, so it refuses to start.
 MATRIX_BOT_USER_ID=
+# Comma-separated Matrix IDs of OTHER agents sharing the control room (currently just
+# @hermes:...) — without this, claude-bot treats every message another bot posts as
+# fresh chat input and replies to it, which that bot may then react to in turn.
+OTHER_AGENT_USER_IDS=@hermes:matrix.apps.williamturner.eu
 # Comma-separated "owner/repo" list the chat router is allowed to open code-change PRs
 # against. A plain chat message mentioning a repo NOT in this list is treated as chat,
 # never as a code task — the router only matches confidently against known repos.
diff --git a/agent/src/matrixBot.js b/agent/src/matrixBot.js
index b60243b..46c8771 100644
--- a/agent/src/matrixBot.js
+++ b/agent/src/matrixBot.js
@@ -11,6 +11,15 @@ const GITEA_URL = process.env.GITEA_URL;
 // to the endpoint itself. This is also the only reliable way to filter the bot's own
 // messages now that there's no command prefix to naturally exclude them by.
 const BOT_USER_ID = process.env.MATRIX_BOT_USER_ID;
+// Other agents sharing this room (currently just Hermes) — their own messages must be
+// ignored the same way claude-bot ignores its own, or claude-bot's classifier treats
+// every message another bot posts as fresh chat input and replies to it, which that
+// bot may then react to in turn. Found the hard way: a single @hermes mention cascaded
+// into claude-bot replying to Hermes's own thread messages ("Hermes says: ...").
+const OTHER_AGENT_USER_IDS = (process.env.OTHER_AGENT_USER_IDS || "")
+  .split(",")
+  .map((id) => id.trim())
+  .filter(Boolean);
 const KNOWN_REPOS = (process.env.KNOWN_REPOS || "")
   .split(",")
   .map((r) => r.trim())
@@ -47,6 +56,7 @@ export async function startMatrixBot() {
   client.on("room.message", async (roomId, event) => {
     if (roomId !== CONTROL_ROOM_ID) return;
     if (event.sender === BOT_USER_ID) return;
+    if (OTHER_AGENT_USER_IDS.includes(event.sender)) return;
     const body = event.content?.body;
     if (!body) return;
     // Messages explicitly addressed to another agent in this room (currently just
@@ -67,6 +77,7 @@ export async function startMatrixBot() {
       }
 
       const reply = await chatReply(body);
+      console.log("chat reply sent, length:", reply.length);
       await client.sendText(roomId, truncate(reply));
     } catch (err) {
       console.error("message handling failed", err);
diff --git a/docker-compose.yml b/docker-compose.yml
index 525be44..a59d913 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -77,7 +77,15 @@ services:
       # rooms (DMs to it would respond unprompted, per Hermes's own default behavior).
       MATRIX_ALLOWED_USERS: ${MATRIX_HUMAN_USER_ID}
       MATRIX_REQUIRE_MENTION: "true"
-      OPENROUTER_API_KEY: ${OPENROUTER_API_KEY}
+      # Routed through the local litellm gateway, not OpenRouter directly — same pattern
+      # as claude-agent's chat path, one place to hold the OpenRouter credential and swap
+      # models. Hermes's "main"/custom-endpoint provider is any OpenAI-compatible API
+      # reachable via OPENAI_BASE_URL + OPENAI_API_KEY. Note: this does NOT give Hermes
+      # access to the Claude Pro/Max subscription — that's blocked by Anthropic itself for
+      # any caller other than the real Claude Code CLI, proven earlier in this session
+      # (reproduced with plain curl straight to api.anthropic.com, LiteLLM or not).
+      OPENAI_BASE_URL: http://litellm:4000/v1
+      OPENAI_API_KEY: ${LITELLM_MASTER_KEY}
       # Left disabled: Hermes itself warns that a network-reachable API server combined
       # with the default unsandboxed ('local') terminal backend gives any caller full
       # terminal/file access within the container. Matrix is the actual interface in use;
@@ -113,10 +121,10 @@ services:
       MATRIX_BOT_TOKEN: ${MATRIX_BOT_TOKEN}
       MATRIX_CONTROL_ROOM_ID: ${MATRIX_CONTROL_ROOM_ID}
       MATRIX_BOT_USER_ID: ${MATRIX_BOT_USER_ID}
+      OTHER_AGENT_USER_IDS: ${OTHER_AGENT_USER_IDS}
       KNOWN_REPOS: ${KNOWN_REPOS}
-      # All model calls now go through the local litellm service, not OpenRouter directly —
-      # one gateway for OpenRouter's models (incl. its auto-router) and, for the
-      # claude-subscription route, Anthropic itself via the forwarded OAuth token above.
+      # Chat replies go through the local litellm service (OpenRouter's models, incl. its
+      # auto-router), not OpenRouter directly.
       LITELLM_BASE_URL: http://litellm:4000
       LITELLM_MASTER_KEY: ${LITELLM_MASTER_KEY}
     volumes: