fix(agents): keep continuation bootstrap marker across short reads by sunlit-deng · Pull Request #108253 · openclaw/openclaw

sunlit-deng · 2026-07-15T10:46:18Z

What Problem This Solves

Fixes an issue where continuation sessions could re-inject full bootstrap context when the transcript tail read returned short before the full-bootstrap completion marker. On filesystems that allow short positional reads, continuation-skip could misread an existing completed turn as missing and restart the heavier bootstrap path.

Why This Change Was Made

The continuation marker scanner now fills its bounded tail window until EOF or the requested window is read, preserving the existing scan size and compaction semantics.

User Impact

Continuation runs keep their intended lightweight bootstrap behavior even when the transcript file read completes in multiple chunks.

Evidence

node scripts/run-vitest.mjs src/agents/bootstrap-files.test.ts: 40 passed.
git diff --check: passed.
Real production-module proof with FileHandle.read capped at 16 bytes per call:

Baseline on origin/main (bb3fae834810cf466be70668b1bce2bd16e31227):
entrypoint: hasCompletedBootstrapTurn
read-boundary: fs.open FileHandle.read capped at 16 bytes per call
marker-detected: false
compaction-negative-control: false

After this branch:
entrypoint: hasCompletedBootstrapTurn
read-boundary: fs.open FileHandle.read capped at 16 bytes per call
marker-detected: true
compaction-negative-control: false

live-proof.mjs

import fs from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { pathToFileURL } from "node:url";

const repoRoot = process.cwd();
const { FULL_BOOTSTRAP_COMPLETED_CUSTOM_TYPE, hasCompletedBootstrapTurn } = await import(
  pathToFileURL(path.join(repoRoot, "src/agents/bootstrap-files.ts")).href
);

const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-bootstrap-marker-proof-"));
const realOpen = fs.open.bind(fs);

fs.open = async (...args) => {
  const handle = await realOpen(...args);
  const realRead = handle.read.bind(handle);
  return new Proxy(handle, {
    get(target, prop, receiver) {
      if (prop === "read") {
        return (buffer, offset, length, position) =>
          realRead(buffer, offset, Math.min(length, 16), position);
      }
      return Reflect.get(target, prop, receiver);
    },
  });
};

async function writeTranscript(name, records) {
  const sessionFile = path.join(tmpDir, `${name}.jsonl`);
  await fs.writeFile(sessionFile, `${records.map((record) => JSON.stringify(record)).join("\n")}\n`);
  return sessionFile;
}

try {
  const markerFile = await writeTranscript("marker", [
    { type: "message", message: { role: "user", content: "hello" } },
    { type: "message", message: { role: "assistant", content: "hi" } },
    {
      type: "custom",
      customType: FULL_BOOTSTRAP_COMPLETED_CUSTOM_TYPE,
      data: { timestamp: 1 },
    },
  ]);
  const compactedFile = await writeTranscript("compacted", [
    {
      type: "custom",
      customType: FULL_BOOTSTRAP_COMPLETED_CUSTOM_TYPE,
      data: { timestamp: 1 },
    },
    { type: "compaction", summary: "trimmed" },
  ]);

  console.log(`entrypoint: hasCompletedBootstrapTurn`);
  console.log(`read-boundary: fs.open FileHandle.read capped at 16 bytes per call`);
  console.log(`marker-detected: ${await hasCompletedBootstrapTurn(markerFile)}`);
  console.log(`compaction-negative-control: ${await hasCompletedBootstrapTurn(compactedFile)}`);
} finally {
  fs.open = realOpen;
  await fs.rm(tmpDir, { recursive: true, force: true });
}

AI-assisted: built with Codex

Co-authored-by: sunlit-deng <[email protected]>

steipete · 2026-07-15T22:51:04Z

Merged via squash.

Prepared head SHA: 89fd47b0e6f3dd1262b53a48e6648c62147780f9
Landed commit: 8cc8feee4d35e8df338ed73b11202b8422cdb06a

…penclaw#108253) * fix(agents): keep bootstrap markers across short reads * refactor(infra): share bounded file window reads Co-authored-by: sunlit-deng <[email protected]> --------- Co-authored-by: Peter Steinberger <[email protected]>

Replace single-shot handle.read() calls in two session tail-read paths with readFileWindowFully so multibyte-range positional reads do not silently return incomplete tail data on network filesystems. - readRecentTranscriptTailLinesAsync: tail-window read for recent session messages now loops until the requested window fills - readLastMessagePreviewFromOpenTranscriptAsync: last-message preview tail read now loops until the requested window fills The same readFileWindowFully helper was introduced in openclaw#108253 and expanded with a sync variant in openclaw#108127 (both by sunlit-deng).

…ads (#108655) * fix(sessions): complete tail-read windows despite short positional reads Replace single-shot handle.read() calls in two session tail-read paths with readFileWindowFully so multibyte-range positional reads do not silently return incomplete tail data on network filesystems. - readRecentTranscriptTailLinesAsync: tail-window read for recent session messages now loops until the requested window fills - readLastMessagePreviewFromOpenTranscriptAsync: last-message preview tail read now loops until the requested window fills The same readFileWindowFully helper was introduced in #108253 and expanded with a sync variant in #108127 (both by sunlit-deng). * fix(sessions): complete sync title preview reads --------- Co-authored-by: Peter Steinberger <[email protected]>

…ads (openclaw#108655) * fix(sessions): complete tail-read windows despite short positional reads Replace single-shot handle.read() calls in two session tail-read paths with readFileWindowFully so multibyte-range positional reads do not silently return incomplete tail data on network filesystems. - readRecentTranscriptTailLinesAsync: tail-window read for recent session messages now loops until the requested window fills - readLastMessagePreviewFromOpenTranscriptAsync: last-message preview tail read now loops until the requested window fills The same readFileWindowFully helper was introduced in openclaw#108253 and expanded with a sync variant in openclaw#108127 (both by sunlit-deng). * fix(sessions): complete sync title preview reads --------- Co-authored-by: Peter Steinberger <[email protected]>

openclaw-barnacle Bot added agents Agent runtime and tooling size: S labels Jul 15, 2026

fix(agents): keep bootstrap markers across short reads

880d679

sunlit-deng force-pushed the sunlit/fix/bootstrap-marker-short-read branch from c9b6ce0 to 880d679 Compare July 15, 2026 15:13

steipete self-assigned this Jul 15, 2026

refactor(infra): share bounded file window reads

89fd47b

Co-authored-by: sunlit-deng <[email protected]>

openclaw-barnacle Bot added the commands Command implementations label Jul 15, 2026

steipete merged commit 8cc8fee into openclaw:main Jul 15, 2026
119 of 120 checks passed

Monkey-wusky mentioned this pull request Jul 16, 2026

fix(sessions): complete tail-read windows despite short positional reads #108655

Merged

masatohoshino mentioned this pull request Jul 16, 2026

fix(anthropic): complete transcript reverse-scan windows across short reads #109431

Merged

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fix(agents): keep continuation bootstrap marker across short reads#108253

fix(agents): keep continuation bootstrap marker across short reads#108253
steipete merged 2 commits into
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sunlit-deng:sunlit/fix/bootstrap-marker-short-read

sunlit-deng commented Jul 15, 2026

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sunlit-deng commented Jul 15, 2026

What Problem This Solves

Why This Change Was Made

User Impact

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steipete commented Jul 15, 2026

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