diff --git a/plugin/index.ts b/plugin/index.ts
index bb7c30e..c77f9a5 100644
--- a/plugin/index.ts
+++ b/plugin/index.ts
@@ -54,6 +54,47 @@ function normalizeSender(event: Record<string, unknown>, ctx: Record<string, unk
   return undefined;
 }
 
+function extractUntrustedConversationInfo(text: string): Record<string, unknown> | undefined {
+  const marker = "Conversation info (untrusted metadata):";
+  const idx = text.indexOf(marker);
+  if (idx < 0) return undefined;
+  const tail = text.slice(idx + marker.length);
+  const m = tail.match(/```json\s*([\s\S]*?)\s*```/i);
+  if (!m) return undefined;
+  try {
+    const parsed = JSON.parse(m[1]);
+    return parsed && typeof parsed === "object" ? (parsed as Record<string, unknown>) : undefined;
+  } catch {
+    return undefined;
+  }
+}
+
+function deriveDecisionInputFromAgentCtx(
+  ctx: Record<string, unknown>,
+): { channel: string; channelId?: string; senderId?: string; content: string } {
+  const channel = normalizeChannel(ctx);
+  const content = typeof ctx.input === "string" ? ctx.input : "";
+  const conv = extractUntrustedConversationInfo(content) || {};
+  const channelIdRaw =
+    (typeof ctx.channelId === "string" && ctx.channelId) ||
+    (typeof conv.channel_id === "string" && conv.channel_id) ||
+    (typeof conv.chat_id === "string" && conv.chat_id.startsWith("channel:")
+      ? conv.chat_id.slice("channel:".length)
+      : undefined);
+  const senderIdRaw =
+    (typeof ctx.senderId === "string" && ctx.senderId) ||
+    (typeof conv.sender_id === "string" && conv.sender_id) ||
+    (typeof conv.sender === "string" && conv.sender) ||
+    undefined;
+
+  return {
+    channel,
+    channelId: channelIdRaw,
+    senderId: senderIdRaw,
+    content,
+  };
+}
+
 function pruneDecisionMap(now = Date.now()) {
   for (const [k, v] of sessionDecision.entries()) {
     if (now - v.createdAt > DECISION_TTL_MS) sessionDecision.delete(k);
@@ -305,36 +346,10 @@ export default {
       try {
         const c = (ctx || {}) as Record<string, unknown>;
         const e = (event || {}) as Record<string, unknown>;
-        const sessionKey = typeof c.sessionKey === "string" ? c.sessionKey : undefined;
-        if (!sessionKey) return;
-
-        const senderId = normalizeSender(e, c);
-        const content = typeof e.content === "string" ? e.content : "";
-        const channel = normalizeChannel(c);
-        const channelId = typeof c.channelId === "string" ? c.channelId : undefined;
-
-        const live = getLivePluginConfig(api, baseConfig as WhisperGateConfig);
-        ensurePolicyStateLoaded(api, live);
-        const decision = evaluateDecision({
-          config: live,
-          channel,
-          channelId,
-          channelPolicies: policyState.channelPolicies,
-          senderId,
-          content,
-        });
-        sessionDecision.set(sessionKey, { decision, createdAt: Date.now() });
-        pruneDecisionMap();
-        api.logger.debug?.(
-          `whispergate: session=${sessionKey} sender=${senderId ?? "unknown"} channel=${channel || "unknown"} decision=${decision.reason}`,
-        );
-
-        if (shouldDebugLog(live as DebugConfig, channelId)) {
-          const summary = debugCtxSummary(c, e);
-          api.logger.info(
-            `whispergate: debug message_received session=${sessionKey} decision=${decision.reason} ` +
-              `shouldNoReply=${decision.shouldUseNoReply} shouldInject=${decision.shouldInjectEndMarkerPrompt} ctx=${JSON.stringify(summary)}`,
-          );
+        const preChannelId = typeof c.channelId === "string" ? c.channelId : undefined;
+        const livePre = getLivePluginConfig(api, baseConfig as WhisperGateConfig) as WhisperGateConfig & DebugConfig;
+        if (shouldDebugLog(livePre, preChannelId)) {
+          api.logger.info(`whispergate: debug message_received preflight ctx=${JSON.stringify(debugCtxSummary(c, e))}`);
         }
       } catch (err) {
         api.logger.warn(`whispergate: message hook failed: ${String(err)}`);
@@ -345,23 +360,35 @@ export default {
       const key = ctx.sessionKey;
       if (!key) return;
 
-      const rec = sessionDecision.get(key);
-      if (!rec) {
-        const liveMiss = getLivePluginConfig(api, baseConfig as WhisperGateConfig) as WhisperGateConfig & DebugConfig;
-        if (shouldDebugLog(liveMiss, ctx.channelId)) {
-          api.logger.info(`whispergate: debug before_model_resolve session=${key} decision=missing`);
+      const live = getLivePluginConfig(api, baseConfig as WhisperGateConfig) as WhisperGateConfig & DebugConfig;
+      ensurePolicyStateLoaded(api, live);
+
+      let rec = sessionDecision.get(key);
+      if (!rec || Date.now() - rec.createdAt > DECISION_TTL_MS) {
+        if (rec) sessionDecision.delete(key);
+        const c = (ctx || {}) as Record<string, unknown>;
+        const derived = deriveDecisionInputFromAgentCtx(c);
+        const decision = evaluateDecision({
+          config: live,
+          channel: derived.channel,
+          channelId: derived.channelId,
+          channelPolicies: policyState.channelPolicies,
+          senderId: derived.senderId,
+          content: derived.content,
+        });
+        rec = { decision, createdAt: Date.now() };
+        sessionDecision.set(key, rec);
+        pruneDecisionMap();
+        if (shouldDebugLog(live, derived.channelId ?? ctx.channelId)) {
+          api.logger.info(
+            `whispergate: debug before_model_resolve recompute session=${key} decision=${decision.reason} ` +
+              `shouldNoReply=${decision.shouldUseNoReply} shouldInject=${decision.shouldInjectEndMarkerPrompt}`,
+          );
         }
-        return;
-      }
-      if (Date.now() - rec.createdAt > DECISION_TTL_MS) {
-        sessionDecision.delete(key);
-        return;
       }
 
       if (!rec.decision.shouldUseNoReply) return;
 
-      sessionDecision.delete(key);
-      const live = getLivePluginConfig(api, baseConfig as WhisperGateConfig);
       api.logger.info(
         `whispergate: override model for session=${key}, provider=${live.noReplyProvider}, model=${live.noReplyModel}, reason=${rec.decision.reason}`,
       );
@@ -375,24 +402,35 @@ export default {
     api.on("before_prompt_build", async (_event, ctx) => {
       const key = ctx.sessionKey;
       if (!key) return;
-      const rec = sessionDecision.get(key);
-      if (!rec) {
-        const liveMiss = getLivePluginConfig(api, baseConfig as WhisperGateConfig) as WhisperGateConfig & DebugConfig;
-        if (shouldDebugLog(liveMiss, ctx.channelId)) {
-          api.logger.info(`whispergate: debug before_prompt_build session=${key} decision=missing`);
-        }
-        return;
-      }
 
-      if (Date.now() - rec.createdAt > DECISION_TTL_MS) {
-        sessionDecision.delete(key);
-        return;
+      const live = getLivePluginConfig(api, baseConfig as WhisperGateConfig) as WhisperGateConfig & DebugConfig;
+      ensurePolicyStateLoaded(api, live);
+
+      let rec = sessionDecision.get(key);
+      if (!rec || Date.now() - rec.createdAt > DECISION_TTL_MS) {
+        if (rec) sessionDecision.delete(key);
+        const c = (ctx || {}) as Record<string, unknown>;
+        const derived = deriveDecisionInputFromAgentCtx(c);
+        const decision = evaluateDecision({
+          config: live,
+          channel: derived.channel,
+          channelId: derived.channelId,
+          channelPolicies: policyState.channelPolicies,
+          senderId: derived.senderId,
+          content: derived.content,
+        });
+        rec = { decision, createdAt: Date.now() };
+        if (shouldDebugLog(live, derived.channelId ?? ctx.channelId)) {
+          api.logger.info(
+            `whispergate: debug before_prompt_build recompute session=${key} decision=${decision.reason} ` +
+              `shouldNoReply=${decision.shouldUseNoReply} shouldInject=${decision.shouldInjectEndMarkerPrompt}`,
+          );
+        }
       }
 
       sessionDecision.delete(key);
       if (!rec.decision.shouldInjectEndMarkerPrompt) {
-        const liveSkip = getLivePluginConfig(api, baseConfig as WhisperGateConfig) as WhisperGateConfig & DebugConfig;
-        if (shouldDebugLog(liveSkip, ctx.channelId)) {
+        if (shouldDebugLog(live, ctx.channelId)) {
           api.logger.info(
             `whispergate: debug before_prompt_build session=${key} inject=false reason=${rec.decision.reason}`,
           );