From a7cb270999ecc25731b18648d4431c6687968041 Mon Sep 17 00:00:00 2001
From: Keith the Silly Goose <keith@42bolton.macnet.nz>
Date: Mon, 12 Jan 2026 16:11:26 +1300
Subject: [PATCH] fix(agent): buffer streaming output until <final> tag appears

- Enforces strict buffering when enforceFinalTag is enabled.
- Prevents 'thinking out loud' planning steps (e.g. '*Locating Manulife*') from leaking to WhatsApp.
- Hardens <final> tag stripping to remove nested/hallucinated tags.
---
 src/agents/pi-embedded-subscribe.ts | 22 ++++++++++++++--------
 src/utils/provider-utils.ts         |  5 +++++
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/agents/pi-embedded-subscribe.ts b/src/agents/pi-embedded-subscribe.ts
index a6dcabe06..209936806 100644
--- a/src/agents/pi-embedded-subscribe.ts
+++ b/src/agents/pi-embedded-subscribe.ts
@@ -369,8 +369,12 @@ export function subscribeEmbeddedPiSession(params: {
     state.thinking = inThinking;
 
     // 2. Handle <final> blocks (stateful, strip content OUTSIDE)
-    // If enforcement is disabled, just return processed text as-is.
-    if (!params.enforceFinalTag) return processed;
+    // If enforcement is disabled, we still strip the tags themselves to prevent
+    // hallucinations (e.g. Minimax copying the style) from leaking, but we
+    // do not enforce buffering/extraction logic.
+    if (!params.enforceFinalTag) {
+      return processed.replace(FINAL_TAG_SCAN_RE, "");
+    }
 
     // If enforcement is enabled, only return text that appeared inside a <final> block.
     let result = "";
@@ -414,14 +418,16 @@ export function subscribeEmbeddedPiSession(params: {
         }));
     }
 
-    // Fallback: if we are at the end of the process and never saw a final tag,
-    // but we have processed text, use the processed text.
-    // NOTE: This fallback only triggers if we explicitly pass a state that we can check.
-    if (!everInFinal && processed.trim().length > 0) {
-      return processed;
+    // Strict Mode: If enforcing final tags, we MUST NOT return content unless
+    // we have seen a <final> tag. Otherwise, we leak "thinking out loud" text
+    // (e.g. "**Locating Manulife**...") that the model emitted without <think> tags.
+    if (!everInFinal) {
+      return "";
     }
 
-    return result;
+    // Hardened Cleanup: Remove any remaining <final> tags that might have been
+    // missed (e.g. nested tags or hallucinations) to prevent leakage.
+    return result.replace(FINAL_TAG_SCAN_RE, "");
   };
 
   const emitBlockChunk = (text: string) => {
diff --git a/src/utils/provider-utils.ts b/src/utils/provider-utils.ts
index e15fce2e6..841b60938 100644
--- a/src/utils/provider-utils.ts
+++ b/src/utils/provider-utils.ts
@@ -24,6 +24,11 @@ export function isReasoningTagProvider(provider: string | undefined | null): boo
   if (normalized.includes("google-antigravity")) {
     return true;
   }
+
+  // Handle Minimax (M2.1 is chatty/reasoning-like)
+  if (normalized.includes("minimax")) {
+    return true;
+  }
   
   return false;
 }