fix(session-memory): deduplicate assistant messages when thinking is stripped

Pandah97 · Pandah97 · commit ab1ef1cd622c · 2026-06-18T00:02:08.000+08:00
When a model with thinking/reasoning is used, the session JSONL persists two copies of each assistant response: the raw version (with thinking blocks + text) and a cleaned version (text only). The session-memory hook's getRecentSessionContent() treated both as valid, producing duplicate lines in generated memory files. Fix by tracking the last assistant text and skipping consecutive duplicates. This handles the dedup at the consumer level without changing the storage layer. Fixes #92563.
diff --git a/src/hooks/bundled/session-memory/transcript.ts b/src/hooks/bundled/session-memory/transcript.ts
@@ -31,6 +31,7 @@ export async function getRecentSessionContent(
     const lines = content.trim().split("\n");
 
     const allMessages: string[] = [];
+    let lastAssistantText: string | undefined;
     for (const line of lines) {
       try {
         const entry = JSON.parse(line);
@@ -47,7 +48,17 @@ export async function getRecentSessionContent(
             }
             const text = extractTextMessageContent(msg.content);
             if (text && !text.startsWith("/")) {
+              // Skip consecutive duplicate assistant messages — the session JSONL
+              // persists both raw (with thinking blocks) and cleaned copies when
+              // thinking/reasoning is enabled, which would otherwise produce
+              // duplicate entries in memory files.
+              if (role === "assistant" && text === lastAssistantText) {
+                continue;
+              }
               allMessages.push(`${role}: ${text}`);
+              if (role === "assistant") {
+                lastAssistantText = text;
+              }
             }
           }
         }

Original file line number	Diff line number	Diff line change
`@@ -31,6 +31,7 @@ export async function getRecentSessionContent(`
`31`	`31`	`const lines = content.trim().split("\n");`
`32`	`32`
`33`	`33`	`const allMessages: string[] = [];`
	`34`	`+ let lastAssistantText: string \| undefined;`
`34`	`35`	`for (const line of lines) {`
`35`	`36`	`try {`
`36`	`37`	`const entry = JSON.parse(line);`
`@@ -47,7 +48,17 @@ export async function getRecentSessionContent(`
`47`	`48`	`}`
`48`	`49`	`const text = extractTextMessageContent(msg.content);`
`49`	`50`	`if (text && !text.startsWith("/")) {`
	`51`	`+ // Skip consecutive duplicate assistant messages — the session JSONL`
	`52`	`+ // persists both raw (with thinking blocks) and cleaned copies when`
	`53`	`+ // thinking/reasoning is enabled, which would otherwise produce`
	`54`	`+ // duplicate entries in memory files.`
	`55`	`+ if (role === "assistant" && text === lastAssistantText) {`
	`56`	`+ continue;`
	`57`	`+ }`
`50`	`58`	allMessages.push(`${role}: ${text}`);
	`59`	`+ if (role === "assistant") {`
	`60`	`+ lastAssistantText = text;`
	`61`	`+ }`
`51`	`62`	`}`
`52`	`63`	`}`
`53`	`64`	`}`