Redditor xtraa reports ChatGPT Web replaces rather than appends the final prompt at the context limit, corrupting conversation state and making in-chat handoff summaries unreliable — a concrete context-boundary state-corruption failure for long-session workflows if reproduced.

state: watchingheat: lowuncertainty: mediumconvergesscott: mediumcontext-window-state-corruption agent-session-handoff long-session-continuityOpenAI

What is this?

Per the case, Redditor xtraa reports that ChatGPT Web, at the context limit, appears to replace rather than append the final user prompt — silently corrupting conversation state and breaking the common practice of generating in-chat handoff summaries before starting a fresh session. The supplied web results do not surface the original post, so the specific bug is unverified: no independent reproduction or vendor acknowledgment appears in the material. What the snippets do establish is the surrounding territory: handoff-prompt workflows are a widespread documented practice across ChatGPT, Claude, and Codex; users on OpenAI's own forum call in-chat handoff summaries 'fragile' and request first-class handoff features; and production compaction systems (Claude Code's /compact, Codex CLI's server-side compact endpoint) show context-boundary rewriting and summarization is a real, nontrivial engineering surface where replacement-style bugs are plausible. A hermitedge.com piece on backend-owned session state (prompt assembled as summary + recent turns, not full appended history) is consistent with ChatGPT not literally appending everything — which makes the reported failure mode coherent, but does not confirm it.

Why it matters to Scott

Independent users are hitting the exact failure Scott's long-running-agents canon predicts — the grounding shows OpenAI's own forum users calling in-chat handoff summaries 'fragile' — and this report adds a genuinely new mechanism: the vendor's first-party client allegedly breaking the append-only invariant at the context boundary, which extends his unverified-conversation / verification-boundary line beyond attackers and compaction lossiness to the UI itself. Relevance is capped at medium because it is a single unverified report on consumer ChatGPT Web, not the API harness surface he builds on; if reproduced or acknowledged it converts into a dated receipt for the durable-external-state argument in Breaking the 1hr Barrier, so it's worth tracking as a checkable claim.

ip:source.breaking-the-1hr-barrierip:framework.long-running-agentsip:concept.session-isolationip:source.the-unverified-conversation-why-llms-can-t-trust-their-own-history-ebookip:concept.checkpoint-disciplinedev:concept.agent-authored-context-compactionradar:concept.context-compactionradar:concept.context-managementradar:concept.long-running-agentsradar:openai-compaction-self-injectionradar:ollama-silent-context-truncationradar:claude-code-memory-index-truncation

queries asked of Scott's wikis

agent session handoff prompt reliability
in-chat summary vs external memory file
context compaction lossy summarization long session
append-only conversation history assumption
agent-maintained wiki session continuity resume
harness context window boundary handling

Measured heat

now 0 pts/hpeak 6 pts/hcomments 0/hpeers p23momentum: steady1 platformsage 401h

points/hour across evidence · reading as of 2026-10-12 02:59:37.977291+11:00 · deterministic, not a model opinion

How the heat travelled

09-24 23:25	⭐ origin directly observed	ChatGPT context-limit bug: new final prompt appears to overwrite the previous prompt instead of being appended, making reliable handoffs impossible xtraa on r/OpenAI	—
09-27 15:57	first on r/ClaudeAI · published · +64.5h	Invisible chat compactions? Niceneasy92	—
10-09 09:34	first on r/OpenAI · published · +346.1h	Editing an earlier prompt after refreshing the page sends it as a new message at the bottom instead Moon_Dew	—
09-24 23:25	amplified on r/OpenAI	reddit.post.1wpgvy6 xtraa	peak 2 · 0 comments · 8% of case engagement
09-27 15:57	amplified on r/ClaudeAI 👑	reddit.post.1wrnt8h Niceneasy92	peak 7 · 10 comments · 71% of case engagement
10-09 09:34	amplified on r/OpenAI	reddit.post.1x1gxp9 Moon_Dew	peak 3 · 2 comments · 20% of case engagement
09-25 01:20	our radar first saw it · +1.9h	discovery anchor: reddit.post.1wpgvy6	—

pace: p54 vs 1032 stories at the 336h mark (now 401h old) — ahead of agentdrive-persistent-shared-storage (1.1x), behind aws-project-spend-limits (0.9x)

Evidence (3) — ⭐ canonical anchor

source	object	author	score	comments
🟠 reddit ⭐	ChatGPT context-limit bug: new final prompt appears to overwrite the previous prompt instead of being appended, making reliable handoffs impossible OpenAI	xtraa	2	0
🟠 reddit	Invisible chat compactions? ClaudeAI	Niceneasy92	5	10
🟠 reddit	Editing an earlier prompt after refreshing the page sends it as a new message at the bottom instead OpenAI	Moon_Dew	3	2

Interpretation history

2026-10-09T17:29:00Z
A second independent ChatGPT Web conversation-state corruption bug (edit-after-refresh misbehavior, reddit.post.1x1gxp9) was attached, establishing a pattern of state-management failures on the same product surface. The flagship context-limit overwrite claim remains single-source and unreproduced; the cross-provider corroboration (Claude invisible compaction) survives only in comments after the primary post was removed. The case now has two distinct ChatGPT Web state-corruption reports but no independent verification of the specific overwrite mechanism.
2026-10-09T13:51:10Z
evidence attached: reddit.post.1x1gxp9 — Another concrete ChatGPT Web conversation-state corruption bug (edit-after-refresh misbehavior), same product surface as the open case.
2026-09-28T01:45:08Z
The primary Claude-side corroborating post is now [removed], and the surviving comments reframe that phenomenon as routine, likely cache-expiry-triggered invisible compaction with poor disclosure — not state corruption — which also raises the alternative that xtraa's 'replaced final prompt' was silent compaction misread as an overwrite. The class survives on two independent commenter accounts, but the flagship ChatGPT Web final-prompt-replacement claim now stands alone and unverified, so the case drops from corroborated to watching.
2026-09-27T16:30:51Z
The Niceneasy92 Claude-side report of invisible compaction degrading handoff state upgrades this from a single-provider anecdote to a cross-provider failure class hitting the exact handoff workflow, with two independent reporters; the flagship ChatGPT Web overwrite mechanism itself remains single-source and unreproduced.
2026-09-27T16:26:17Z
evidence attached: reddit.post.1wrnt8h — A parallel Claude-side report of invisible compaction degrading long-session state and handoff summaries corroborates the cross-provider context-boundary state-loss class.
2026-09-25T01:41:56Z
grounded: converges/medium — Independent users are hitting the exact failure Scott's long-running-agents canon predicts — the grounding shows OpenAI's own forum users calling in-chat handof
2026-09-25T01:34:53Z
case created — Detailed reproducible-steps report of a context-boundary state bug squarely relevant to long-session continuity, checkable via independent reproduction or vendor acknowledgment.

Decision trace

10-10 04:30attention_routeThe editor compared this story and chose to keep watching.
10-10 04:29attention_candidatematerial_reprice
10-10 04:29repriceA second independent ChatGPT Web conversation-state corruption bug (edit-after-refresh misbehavior, reddit.post.1x1gxp9) was attached, establishing a pattern of state-management failures on the same p
10-10 01:26attention_routeThe editor compared this story and chose to keep watching.
10-10 00:51attention_candidateattach
10-10 00:51attachAnother concrete ChatGPT Web conversation-state corruption bug (edit-after-refresh misbehavior), same product surface as the open case.
10-10 00:42propose_attachAnother concrete ChatGPT Web conversation-state corruption bug (edit-after-refresh misbehavior), same product surface as the open case.
10-05 06:51review_screenjev screen: no material development (noul=0.23)
09-28 11:45repriceThe primary Claude-side corroborating post is now [removed], and the surviving comments reframe that phenomenon as routine, likely cache-expiry-triggered invisible compaction with poor disclosure — no
09-28 11:43jev_reprice_gatechanges_anything noul=0.48 would_skip=False
09-28 11:43review_screenThe primary Claude-side corroborating post (reddit.post.1wrnt8h) is now [removed], changing evidentiary confidence in the 'class corroboration' the assessment relies on; surviving comments a
09-28 11:42review_screenjev screen borderline (noul=0.37) — luna review
09-28 02:30repriceThe Niceneasy92 Claude-side report of invisible compaction degrading handoff state upgrades this from a single-provider anecdote to a cross-provider failure class hitting the exact handoff workflow, w
09-28 02:26attachA parallel Claude-side report of invisible compaction degrading long-session state and handoff summaries corroborates the cross-provider context-boundary state-loss class.
09-28 02:23propose_attachA parallel Claude-side report of invisible compaction degrading long-session state and handoff summaries corroborates the cross-provider context-boundary state-loss class.
09-25 11:41groundIndependent users are hitting the exact failure Scott's long-running-agents canon predicts — the grounding shows OpenAI's own forum users calling in-chat handoff summaries 'fragile'
09-25 11:34createDetailed reproducible-steps report of a context-boundary state bug squarely relevant to long-session continuity, checkable via independent reproduction or vendor acknowledgment.