Borrowing it
Nothing to install: this file belongs to extracurricular-ai/codex-rewind. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/extracurricular-ai/codex-rewind/main/.codex/skills/update-v8-version/SKILL.mdgit clone --depth 1 https://github.com/extracurricular-ai/codex-rewindWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/extracurricular-ai/codex-rewind/update-v8-version)<a href="https://agentmods.dev/skills/extracurricular-ai/codex-rewind/update-v8-version"><img src="https://agentmods.dev/badge/skills/extracurricular-ai/codex-rewind/update-v8-version.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00086 | $0.00836 |
| Opus 5 | $0.00043 | $0.00418 |
| Sonnet 5 | $0.00017 | $0.00167 |
| Haiku 4.5 | $0.00009 | $0.00084 |
Grade A, and why
update-v8-version scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
100% identical to update-v8-version — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Update V8 Version
Core Workflow
-
Read
third_party/v8/README.mdand follow its version-bump sequence. Treat that document as the release-process source of truth. -
Inspect and update the concrete repo surfaces that carry the pin:
codex-rs/Cargo.tomlcodex-rs/Cargo.lockMODULE.bazelthird_party/v8/BUILD.bazelthird_party/v8/README.md- the matching
third_party/v8/rusty_v8_<version>.sha256manifest when the remaining prebuilt inputs change
-
Keep the existing checksum helpers in the loop:
python3 .github/scripts/rusty_v8_bazel.py update-module-bazel python3 .github/scripts/rusty_v8_bazel.py check-module-bazel python3 -m unittest discover -s .github/scripts -p test_rusty_v8_bazel.py -
Validate the release-candidate path before broadening the work:
- Prefer checking the
v8-canaryCI result for the candidate branch or PR when one exists, using GitHub check tooling orghas appropriate. - If CI is unavailable or the user asked for a local-only check, run the closest local validation that is practical for the changed surface and say explicitly that it is a local substitute, not the full hosted canary.
- Prefer checking the
-
If the canary path passes, stop there. Summarize the result and encourage the user to commit the candidate changes or proceed with the release flow they requested. Do not publish tags, releases, or pushes unless the user asked.
Failure Path
Enter this path only when the canary or local build path fails.
- Capture the failing target, workflow job, and first actionable error.
- Compare the currently pinned version with the target version at the relevant
upstream tag or SHA. Inspect both:
denoland/rusty_v8- upstream V8 source at the target Bazel-pinned version
- Track build-relevant deltas rather than broad source churn:
- generated binding layout changes
- archive or asset naming changes
- GN/Bazel target changes
- custom libc++ / libc++abi / llvm-libc inputs
- sandbox or pointer-compression feature relationships
- patch hunks in
patches/that no longer apply or no longer match upstream
- Trace each failing delta back into Codex's build graph:
MODULE.bazelthird_party/v8/BUILD.bazel.github/scripts/rusty_v8_bazel.py.github/workflows/v8-canary.yml.github/workflows/rusty-v8-release.yml
- Update only the pieces required to restore the target version's build and artifact contract. Keep patch explanations and doc changes close to the affected files.
- Re-run the focused validation. If it becomes green, return to the normal workflow and stop with a concise summary plus the remaining release step.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 8d ago First seen · 73 lines · 86 tokens per session scan A c3d4037f1d7c
update-v8-version is a skill published in the GitHub repository extracurricular-ai/codex-rewind (49 stars, last pushed 2d ago), licensed Apache-2.0. It adds 86 tokens to every session and 836 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to update-v8-version, differing in 0 lines, and is treated as a copy.
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