Borrowing it
Nothing to install: this file belongs to WhenLabs-org/when. 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/WhenLabs-org/when/main/CLAUDE.mdgit clone --depth 1 https://github.com/WhenLabs-org/whenWrote 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/instructions/whenlabs-org/when/claude-md)<a href="https://agentmods.dev/instructions/whenlabs-org/when/claude-md"><img src="https://agentmods.dev/badge/instructions/whenlabs-org/when/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/whenlabs-org/when/claude-md"><img src="https://agentmods.dev/badge/instructions/whenlabs-org/when/claude-md.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00951 | $0.00951 |
| Opus 5.5 | $0.00380 | $0.00380 |
| Sonnet 5.5 | $0.00190 | $0.00190 |
| Haiku 4.5 | $0.00095 | $0.00095 |
Grade A, and why
when CLAUDE.md 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 1mo 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
92% identical to when AGENTS.md — 22 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 — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Project: @whenlabs/when
The WhenLabs developer toolkit — 6 tools, one install
Tech Stack
- Language: TypeScript 5.7
- Testing: Vitest 3.0
- Package Manager: pnpm
- Monorepo: pnpm-workspaces
- Deployment: Docker
- CI/CD: GitHub Actions
- Bundler: tsup 8.0
Docker
Dockerfile Best Practices
- Use multi-stage builds: a
builderstage for compilation/dependencies and a slimrunnerstage for the final image - Copy dependency manifests first (
package.json,package-lock.json) and install before copying source — leverages layer caching - Use specific base image tags (e.g.,
node:20-alpine) — never uselatestin production - Run the application as a non-root user:
RUN adduser --disabled-password appuser && USER appuser
.dockerignore
- Always include a
.dockerignorefile to exclude:node_modules,.git,.env, build artifacts, test files - This reduces build context size and prevents secrets from leaking into the image
Layer Caching
- Order Dockerfile instructions from least to most frequently changing for optimal caching
- Pin dependency versions in lock files so the install layer is cached until dependencies actually change
- Use
COPY --from=builderto copy only build artifacts into the final stage
Security
- Never store secrets in the image — use runtime environment variables or secret management
- Scan images for vulnerabilities:
docker scout cvesor integrate Trivy/Snyk in CI - Keep images minimal — use
alpineordistrolessbase images to reduce attack surface - Set
HEALTHCHECKinstructions for container orchestrators to monitor application health
Compose
- Use
docker-compose.ymlfor local development with all services (DB, cache, app) - Mount source code as a volume for hot-reloading in development
- Use
depends_onwith health checks to control startup order
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.
- 1mo ago First seen · 98 lines · 951 tokens per session scan A bdf222d3a43b
when CLAUDE.md is an instructions file published in the GitHub repository WhenLabs-org/when (4 stars, last pushed 8d ago), licensed MIT. It adds 951 tokens to every session, about $0.0038 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 92% identical to when AGENTS.md, differing in 22 lines, and is treated as a copy.
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