bug(omp): tag stripping leaves unsigned text with stale Responses payload and blocks subsequent turns #766

Activity

1. sisttri commented on Oct 23, 2026

   

   sisttri

   on Oct 23, 2026

   Last edited by sisttri

   Author

   More actions

   I hit this immediately after running /fork, then /rename in OMP. The next prompt was refused with comparison=content; retrying and restarting the forked session did not help.

   Comparing the parent and forked transcripts showed that all seven affected messages already had the same text, signature state, and native payload in the parent. Forking copied the existing inconsistency. Adding or removing the rename record made no difference to the offline request payload.

   So /fork may expose the existing replay mismatch when the new session prepares its first request, but I have not isolated that transition yet. /rename currently appears unrelated. Please include the first request after a fork in regression coverage, and compare fork-only with fork-then-rename.
2. magic-alfonso commented on Oct 23, 2026

   

   magic-alfonsoBot

   on Oct 23, 2026

   More actions

   Thanks for the precise report and the reproduction, it makes this easy to check. The planner and dispatch check you point at are ours, and we're verifying each step against Oh My Pi's own source now, including the first request after a fork. We'll reply here with what we find and which fix we pick. Please hold off on a pull request until then.
3. magic-alfonso commented on Oct 23, 2026

   

   magic-alfonsoBot

   on Oct 23, 2026

   More actions

   Confirmed. Your trace is exact on Oh My Pi 18.12.3 and 18.12.6. A saved session copies the mismatch through a restart and through /fork, with or without /rename.

   We're fixing it on our side by making the request check follow exactly what Oh My Pi replays for these messages. Nothing is rewritten in the request, the session files or the native payload, so native reasoning and phase replay stay intact, and affected sessions recover without any edit. We considered dropping the stale payload, as you proposed, but that loses the text's phase and can lose native-only reasoning items. Signature, structure and every other kind of mismatch still refuse as they do today.

   The fix ships in the next patch, crediting you. Thanks again for the precise report and for holding the PR.
4. sisttri commented on Oct 23, 2026

   

   sisttri

   on Oct 23, 2026

   Author

   More actions

   I hit this again with a newly generated assistant reply containing two tool calls. The persisted text was Hello, while its native payload was equivalent to §12§ Hello\n with phase: commentary.

   stage=provider dispatch elapsed=232ms
   row=911 expectedRows=914 actualRows=914
   expectedRole=assistant actualRole=assistant
   expectedCalls=2 actualCalls=2 expectedResults=0 actualResults=0
   comparison=content
   

   This adds an important case to the original report: stripPersistedAssistantText() also calls .trim() and strips tag notation beyond the leading prefix. My initial prefix-only workaround missed the trailing newline. This supersedes the leading-prefix-only matching criterion in the issue's local mitigation proposal. I agree that preserving native replay, phase and reasoning is preferable for the upstream fix you described.

   Exact path to inspect

   • stripPersistedAssistantText: tag cleanup followed by .trim().
   • strippedAssistantContent / OMP hook: returns rewritten text.
   • OMP 18.12.6, packages/coding-agent/src/extensibility/extensions/runner.ts, emitAssistantMessage: removes the rewritten block's textSignature; packages/coding-agent/src/sdk.ts, transformAssistantMessage: assigns replacement content while retaining providerPayload.
   • piResponsesAssistantTexts plans typed text/null phase; OMP packages/ai/src/providers/openai-shared.ts, buildResponsesInput, replays native text/commentary phase.

   Portable reproduction — no private environment required

   I tested this in a separate directory with a freshly installed @oh-my-pi/pi-ai@18.12.6 under Bun 1.4.2. All text, model/provider names, IDs, tools and arguments below are synthetic. No API key, model request, session transcript, database, global configuration or local hotfix is required.

   git clone https://github.com/cortexkit/magic-context.git mc-repro
   git -C mc-repro checkout 79ce01a522ae5a9d65d6bb2ac81aadf16fa8285a
   mkdir omp-repro
   cd omp-repro
   bun add @oh-my-pi/pi-ai@18.12.6
   # Save the following TypeScript as repro.ts here.
   MC_ROOT=../mc-repro bun repro.ts

   The script starts from the post-OMP-rewrite message shape, JSON-round-trips it, and exercises the real cleanup function, planner and OMP encoder. It isolates the mismatch; it does not instantiate the host's extension runner or the full context pipeline.

   // Run with Bun from a directory containing @oh-my-pi/pi-ai@18.12.6.
   // MC_ROOT points to a Magic Context checkout; no DB/session/credentials needed.
   import assert from 'node:assert/strict';
   import {resolve, dirname} from 'node:path';
   import {pathToFileURL} from 'node:url';
   const root = process.env.MC_ROOT;
   assert(root, 'Set MC_ROOT to a Magic Context checkout');
   const load = (path: string) => import(pathToFileURL(path).href);
   const {piResponsesAssistantTexts} = await load(resolve(root,
     'packages/pi-plugin/src/pi-dispatch-responses-history.ts'));
   const {stripPersistedAssistantText} = await load(resolve(root,
     'packages/plugin/src/hooks/magic-context/tag-content-primitives.ts'));
   const sdkEntry = Bun.resolveSync('@oh-my-pi/pi-ai', import.meta.dir);
   const {buildResponsesInput} = await load(resolve(dirname(sdkEntry),
     'providers/openai-shared.ts'));
   const model = {api:'openai-responses', provider:'example', id:'gpt-5',
     input:['text'], identity:{class:'gpt'}, compat:{}};
   
   for (const rawText of ['§12§ Hello\n', '  Hello\n', 'Hello §12§\n']) {
     const cleaned = stripPersistedAssistantText(rawText);
     assert.equal(cleaned, 'Hello');
     const calls = [1,2].map(n => ({type:'toolCall',
       id:`call_example_${n}|fc_example_${n}`, name:`example_tool_${n}`,
       arguments:{value:n}}));
     // State after OMP accepts the assistant_message rewrite: textSignature
     // removed from the rewritten block, original providerPayload retained.
     const message = JSON.parse(JSON.stringify({role:'assistant',
       api:model.api, provider:model.provider, model:model.id,
       stopReason:'toolUse', timestamp:1,
       content:[{type:'text', text:cleaned}, ...calls],
       providerPayload:{type:'openaiResponsesHistory', provider:model.provider,
         dt:true, items:[{type:'message', role:'assistant', id:'msg_example',
           phase:'commentary', status:'completed', content:[{
             type:'output_text', text:rawText, annotations:[]}]},
           ...[1,2].map(n => ({type:'function_call', id:`fc_example_${n}`,
             call_id:`call_example_${n}`, name:`example_tool_${n}`,
             arguments:JSON.stringify({value:n}), status:'completed'}))]}}));
     const before = JSON.stringify(message);
     const planned = piResponsesAssistantTexts(message, model);
     const input = buildResponsesInput({model, context:{messages:[message]},
       nativeHistory:{replay:true}, repairOrphanOutputs:true});
     const actual = input.filter(x=>x.type==='message' && x.role==='assistant')
       .flatMap(x=>x.content.filter(p=>p.type==='output_text')
         .map(p=>JSON.stringify([p.text,x.phase ?? null])));
     assert.deepEqual(planned, [JSON.stringify(['Hello', null])]);
     assert.deepEqual(actual, [JSON.stringify([rawText, 'commentary'])]);
     assert.notDeepEqual(planned, actual); // Characterizes the reported bug.
     assert.deepEqual(input.filter(x=>x.type==='function_call').map(x=>({
       call_id:x.call_id,name:x.name,arguments:x.arguments})),
       [1,2].map(n=>({call_id:`call_example_${n}`,name:`example_tool_${n}`,
         arguments:JSON.stringify({value:n})})));
     assert.equal(JSON.stringify(message), before);
     console.log(JSON.stringify({rawText, cleaned, planned, actual, calls:2}));
   }
   console.log('Reproduced all 3 text/phase mismatches without a model request.');

   Expected output on the pinned baseline: all three cases report planned ["Hello",null] versus actual [rawText,"commentary"], with both tool calls preserved, followed by Reproduced all 3 text/phase mismatches without a model request. These assertions characterize the bug; they intentionally expect inequality and should change when converted to the fixed OMP-path regression.

   Acceptance coverage for the upstream fix

   • An OMP-path planner/dispatch regression should match the actual encoder for all three cleanup cases, preserving the native payload and commentary phase.
   • Cover native-only reasoning, signed/unmodified text, multiple text blocks, tool IDs/arguments, and already persisted messages after restart/fork.
   • Keep rejection coverage for genuine mutations after preparation (text/phase/tool arguments/signatures); do not simply relax the fence or apply broad whitespace normalization at dispatch.
   • Keep the behavior host-specific and verify stock Pi / OpenCode paths are unchanged.

   My expanded local mitigation passes 19 tests / 63 assertions. Latest full-history offline replay also changes from a content mismatch to a match, but its row count differs from the live pass because the complete live configuration was not replayed. I have not claimed an online round-trip after that update. This is separate from the tag-snapshot initialization issue #769.
5. magic-alfonso commented on Oct 25, 2026

   

   magic-alfonsoBot

   on Oct 25, 2026

   More actions

   Shipped in 0.49.21 (@cortexkit/pi-magic-context). This is on Oh My Pi's OpenAI Responses route, when Oh My Pi drops a reply's text signature after Magic Context strips its tag. The request check now accepts Oh My Pi's replayed saved text if Magic Context's own tag cleanup, applied to that text, gives exactly what Magic Context prepared. That covers a trailing newline and tags elsewhere in the text, as well as the leading tag.

   Anything else still refuses: a signature that's present, a different model, provider or API, a different payload type, or a different number of text pieces. Restart Oh My Pi after updating; there's no migration. Thanks, @sisttri.
6. magic-alfonso

   closed this as completedon Oct 25, 2026