/export only exports the loaded portion of a long thread #50014

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1. argszero commented on Sep 19, 2026

   

   argszero

   on Sep 19, 2026

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   I'd like to work on this.

   The report is exact, and the repository already contains the control case for it: the same dialog has a second format that does not have the bug.

   Why the markdown file starts partway in — the markdown export is built in the TUI from the loaded window, while the JSON export is built on the server from storage.

   Step	Location (v2)
   /export command, both formats	packages/tui/src/routes/session/index.tsx:1113 (id: "session.export", slash: { name: "export" })
   markdown branch — client-side	:1132 formatSessionTranscript(sessionData, messages(), options.thinking, options.tools)
   JSON branch — server-side	:1134 client.api.session.export({ sessionID, sanitize })
   what messages() is	:160 const messages = () => data.session.message.list(route.sessionID) — the same list the timeline pages into
   the formatter itself	:3608 formatSessionTranscript(session, messages, thinking, tools) — a pure formatter over the array it is handed; it cannot page
   server side of the JSON path	packages/server/src/handlers/session.ts:166 → SessionTransfer.export → packages/core/src/session/transfer.ts reads sessions.messages({ sessionID, order: "asc" })

   So the markdown formatter can only ever see the messages the client has currently loaded, and the loaded window is exactly what scrolling changes — which is why step 5 of your repro produces the full file. The JSON format of the same dialog returns the whole session, because transfer.export reads the messages from storage with no window at all. Same session, same dialog, different data source: a free A/B check for anyone verifying the fix.

   Two surfaces, not one. The sibling command at :1105 (Copy session transcript) calls the same formatSessionTranscript(sessionData, messages(), true), so copying from a long thread silently copies the same partial window.

   Fix options

   1. Point the markdown path at the complete history as well — page the rest in (or use the full-items view) before formatting, keeping the formatter where it is.
   2. Move the markdown rendering server-side and expose a format next to the existing sanitize on session.export, so both formats are built from transfer.export's complete message list. This removes the second, divergent copy of the transcript logic and makes "complete by construction" true for every format.

   My default is (2), because the server-side source is already complete and the endpoint already has the query-parameter shape for it; (1) is the smaller diff if you'd rather not grow the export API. Happy to implement either.

   One related question: should an export that cannot see the whole session fail or warn instead of writing a file that looks complete? That is the part of the report that costs users data, and it is independent of which fix above you prefer — I would make the markdown path refuse to write when the client cannot prove it has the full range, unless you'd rather keep it best-effort.

   Happy to have the issue assigned if either direction looks right.

   👍React with 👍1Reacted by Jack Stringer
2. neriousy

   marked tui: Markdown export omits messages outside loaded history #50732 as a duplicate of this issue on Oct 20, 2026
3. Tarquinen commented on Oct 20, 2026

   

   Tarquinen

   on Oct 20, 2026

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   This was fixed by #50733. That PR merged into the v2 branch, so GitHub didn't close this issue automatically. Closing as completed.

   — from 𝕺𝖕𝖊𝖓𝕮𝖔𝖉𝖊
4. Tarquinen

   closed this as completedon Oct 20, 2026