[BUG] Assistant text messages not written to transcript - only thinking blocks persist #21751

Activity

1. github-actions

   added

   bugSomething isn't workingSomething isn't working

   has reproHas detailed reproduction stepsHas detailed reproduction steps

   platform:linuxIssue specifically occurs on LinuxIssue specifically occurs on Linux

   area:core

   memory

   on Jan 29, 2026
2. github-actions commented on Jan 29, 2026

   

   github-actionsBot

   on Jan 29, 2026 – with GitHub Actions

   More actions

   Found 3 possible duplicate issues:

   1. [Bug] Unable to resume conversation #15825
   2. [BUG] Conversation chain breaks mid-session - earlier messages lost on resume #21617
   3. Last message in conversation can disappear #18568

   This issue will be automatically closed as a duplicate in 3 days.

   • If your issue is a duplicate, please close it and 👍 the existing issue instead
   • To prevent auto-closure, add a comment or 👎 this comment

   🤖 Generated with Claude Code

   👎React with 👎1Reacted by Mitsuyuki Osabe
3. carrotRakko commented on Jan 29, 2026

   

   carrotRakko

   on Jan 29, 2026

   Author

   More actions

   These are not duplicates. Here's why:

   Issue	Problem	Root cause
   #15825	Error when trying to resume	Runtime error (400/stack trace)
   #18568	Last message disappears	Unknown (UI/display issue?)
   #21617	Earlier messages lost on resume	Broken parentUuid chain
   #21751 (this)	Assistant text blocks not written to transcript	Transcript write failure

   Key distinctions:

   • [Bug] Unable to resume conversation #15825: A runtime error prevents resume entirely. My issue has no errors - resume "works" but loads incomplete data.
   • Last message in conversation can disappear #18568: The last message disappears (UI/display). My issue: intermediate assistant messages are never written to the transcript file.
   • [BUG] Conversation chain breaks mid-session - earlier messages lost on resume #21617: I filed that issue myself. It describes the symptom (memory loss on resume). This issue ([BUG] Assistant text messages not written to transcript - only thinking blocks persist #21751) describes the root cause (transcript write failure). They are related, not duplicates.

   Evidence: I analyzed 3 session transcripts and found 118 instances where assistant text blocks were dropped while thinking blocks were written. This is a file I/O issue, not a display or resume issue.

   ---

   ✍️ Author: Claude Code (Dev Container) with @carrotRakko
4. carrotRakko commented on Jan 30, 2026

   

   carrotRakko

   on Jan 30, 2026

   Author

   More actions

   Root cause identified: text is written to the wrong file, not missing

   After further investigation, I found that the text block is not "missing" — it's being written to the prompt_suggestion subagent file instead of the main transcript.

   Evidence

   Same API response (same message.id), different destinations:

   Main transcript (thinking):

   {
     "uuid": "f1da7b3d-...",
     "isSidechain": false,
     "agentId": null,
     "message.id": "msg_01BhizEVteEZjjrZoAvtWnSi",
     "content_type": "thinking"
   }

   Subagent file agent-aprompt_suggestion-*.jsonl (text):

   {
     "uuid": "66cddcc7-...",
     "parentUuid": "f1da7b3d-...",
     "isSidechain": true,
     "agentId": "aprompt_suggestion-e546c0",
     "message.id": "msg_01BhizEVteEZjjrZoAvtWnSi",
     "content_type": "text"
   }

   The thinking and text blocks from the same API response are being split across different files.

   Reproduction rate: 100%

   I analyzed all sessions from today and found that every single orphan's parentUuid exists in a subagent file:

   Session	Orphans	Found in subagent files
   45649bf7	1	1 (100%)
   48c052ca	18	18 (100%)
   75212a62	31	31 (100%)
   a001d58d	3	3 (100%)
   c74b8d79	25	25 (100%)
   Total	78	78 (100%)

   All caused by prompt_suggestion

   Notably, all 78 orphans were caused by aprompt_suggestion-* subagent files — not by explicit Task tool usage. This means the bug occurs even when users don't intentionally use subagents.

   Impact

   • Real-time: Both thinking and text are in state, so UI renders correctly
   • On /resume: Only main transcript is loaded → text is missing → broken chain → messages before the break become unreachable

   Potential workaround

   Disable prompt suggestions:

   // ~/.claude/settings.json
   {
     "promptSuggestionEnabled": false
   }

   However, there are reports that this setting doesn't work (#14629, #15709, #15427, #17572).

   What's still unknown

   Why do thinking and text from the same API response get different isSidechain values? This likely requires code-level investigation.

   Analysis commands

   To verify orphan parentUuids exist in subagent files:

   # Extract orphan parentUuids
   orphan_parents=$(jq -sr '
     (map(select(.uuid)) | INDEX(.uuid)) as $by_uuid |
     [.[] | select(.type == "user" and .parentUuid and ($by_uuid[.parentUuid] | not))] |
     .[].parentUuid
   ' transcript.jsonl)
   
   # Search in subagent files
   for uuid in $orphan_parents; do
     grep -l "$uuid" subagents/*.jsonl 2>/dev/null
   done

   ---

   ✍️ Author: Claude Code (Dev Container) with @carrotRakko
5. carrotRakko commented on Jan 30, 2026

   

   carrotRakko

   on Jan 30, 2026

   Author

   More actions

   Workaround confirmed: disable prompt suggestions

   I verified that disabling prompt suggestions prevents this bug from occurring.

   Configuration options (both work)

   Option 1: Environment variable

   export CLAUDE_CODE_ENABLE_PROMPT_SUGGESTION=false

   Option 2: Settings file (~/.claude/settings.json)

   {
     "promptSuggestionEnabled": false
   }

   You can also toggle this via /config → "Prompt suggestions" → false.

   Verification results (v2.1.25)

   Test	Without workaround	With workaround
   aprompt_suggestion-*.jsonl created	Yes (12 files / 52 turns)	No (0 files)
   subagents/ directory	Exists	Does not exist
   Orphan count	Variable	0

   Trade-off

   You lose the "suggested next prompt" feature in the UI.

   ---

   ✍️ Author: Claude Code (Dev Container) with @carrotRakko
6. genesiscz commented on Feb 9, 2026

   

   genesiscz

   on Feb 9, 2026

   More actions

   Can confirm. Also can confirm the promptSuggestionEnabled: false fixes the problem.

   @carrotRakko Can you share what agents/skills are you using to respond/analyze like this with? Is it automated? Is it open source? What's the workflow? Would love to have this too!
7. carrotRakko commented on Feb 10, 2026

   

   carrotRakko

   on Feb 10, 2026

   Author

   More actions

   @genesiscz Thanks for confirming!

   To answer your question — there's no special tooling, automation, or framework behind this. It's just Claude Code (the CLI) with Opus, used interactively.

   Workflow: I describe the problem → Claude Code investigates (reads files, writes jq scripts, iterates on findings), writes the analysis, and posts it → I review and approve. That's it. The ✍️ Author: Claude Code ... with @carrotRakko signature on each comment means exactly this — AI-drafted, human-reviewed.

   Not open source: Claude Code itself is not open source (#22002), so there's no code to share. If it were, I'd have submitted a PR to fix this instead of filing an issue.

   If there's a "secret sauce," it's less about tools and more about the working relationship — treating Claude Code not as a tool to prompt, but as a collaborator to grow with.

   ---

   ✍️ Author: Claude Code (Reizan Container) with @carrotRakko
8. github-actions

   added

   staleIssue is inactiveIssue is inactive

   on Feb 24, 2026
9. github-actions commented on Mar 11, 2026

   

   github-actionsBot

   on Mar 11, 2026 – with GitHub Actions

   More actions

   Closing for now — inactive for too long. Please open a new issue if this is still relevant.
10. github-actions

    closed this as not plannedon Mar 11, 2026
11. github-actions commented on Mar 19, 2026

    

    github-actionsBot

    on Mar 19, 2026 – with GitHub Actions

    More actions

    This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.
12. github-actions

    locked as resolved and limited conversation to collaborators on Mar 19, 2026