Method runCompaction

src/agent/loop.ts:2487–2521

* Summarize the combined history (base messages + this run's new messages), * collapsing all but the most recent turns into one summary system message. * * Returns the NEW combined message list, or null if compaction didn't run * (below threshold, or summarization failed — caller keeps t

(
    combined: Message[],
    ctxWindow: number,
    signal: AbortSignal | undefined,
  )

      // first. Advisory only (doesn't skip execution); the soft-failure loop detector is the real
      // circuit-breaker if the model ignores this and starts thrashing.
      if (!userAskedExecution && !scopeNudged) {
        const wandering = toolCalls.find(tc =>
          isExecutionAction(tc.function.name, tc.function.arguments ?? ''),
        );
        if (wandering) {
          scopeNudged = true;
          const smsg: Message = {
            role: 'user',
            content:
              '[SYSTEM] The user asked you to write/redesign code, not to run a dev server or install ' +
              'packages. Finish and save the file changes, then report what you changed in a short ' +
              'summary. Do NOT start dev servers, install dependencies, or debug the environment unless ' +
              'the user explicitly asks — those steps are out of scope and waste time.',
          };
          newMessages.push(smsg);
          sessionStore.recordTurn(sessionId, [smsg], { input: 0, output: 0, costUsd: 0 });
        }
      }

      const errLoop = detectErrorLoop(recentErrors);
      if (errLoop) {
        let advice = ' Change approach instead of repeating the same kind of call.';
        if (errLoop.code === 'FILE_NOT_FOUND') {
          advice =
            ' STOP guessing file paths. The "did you mean …" suggestions in the errors show the REAL ' +
            'names — this project likely uses different extensions than you assume (e.g. .jsx, not .tsx). ' +
            'Run `glob` or `ls` to get exact paths, then read those. Do not keep trying filename variations.';
        }
        const msg: Message = {
          role: 'user',
          content:
            `[SYSTEM] \`${errLoop.name}\` has returned ${errLoop.code} ${errLoop.count} times with different ` +
            `arguments.${advice} If you genuinely can't proceed, say so in ONE sentence and stop. Do not loop.`,
        };
        // Answer the just-emitted tool_calls before skipping execution, or the assistant's
        // tool_calls are orphaned and OpenAI-format providers 400 on the next request.
        if (toolCalls.length > 0) {
          const skipped = skippedToolResults(toolCalls, 'loop guard: same error kind repeated');