derive-client SKILL.md skillA
derive-client from vercel-labs/agent-browser is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add vercel-labs/agent-browser/derive-client@git:20260719.ad97a04Pins git:20260719.ad97a04 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- vercel-labs/agent-browser
- Path
skill-data/derive-client/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260719.ad97a04, committed Jul 19, 2026
- Size
- 5,379 bytes
- Repository stars
- 44,324
- License
- Apache-2.0
Reverse-engineer a website's internal API by recording browser traffic into a HAR file, then generate a standalone client or CLI that calls the endpoints directly, with no browser needed after the first recording. Use when asked to "derive a client", "build a CLI for <site>", "reverse engineer this site's API", "record network requests", "turn this site into an API", or when the same site will be automated repeatedly and direct HTTP calls would beat driving the browser every time.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Derive an API client from a recorded session Driving a browser is the right tool for the first visit and the wrong tool for the hundredth. This skill records a site's network traffic once while you use it, then turns the captured requests into a standalone client (script, CLI, or library) that talks to the site's internal API directly. The recording alone contains everything needed: agent-browser embeds text response bodies (JSON/HTML/JS) in the HAR by default, so endpoint shapes can be studied offline after the browser is closed. ## Workflow ``` 1. Record Start HAR capture, drive the flows you want in the client 2. Identify Find the real API endpoints among the noise 3. Extract Pull request shapes, response schemas, and auth material 4. Generate Write the client, one function per flow 5. Verify Call every endpoint for real before declaring done ``` ## 1. Record ```bash agent-browser network har start # embeds text response bodies by default # ... drive the site: search, open a detail page, paginate, etc. ... agent-browser network har stop /tmp/site.har ``` …
Read the whole file at its exact version.
How to install
mdr add vercel-labs/agent-browser/derive-client@sha256:ca31e7fd950cc4bdThe line at the top of this page pins the label git:20260719.ad97a04, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_oruxtvyl4wm4bist)
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Versions
The registry has recorded 1 version of this file, committed on Jul 19, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (5379 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
vercel-labs/agent-browser · 44,324 stars · license Apache-2.0 · pushed 2026-10-20 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_oruxtvyl4wm4bist GET https://markdownregistry.com/api/v1/resolve?ref=vercel-labs/agent-browser/derive-client GET https://markdownregistry.com/api/v1/blob/ca31e7fd950cc4bdf65263959fdac2a8bbaa05f1cd020947944c79be4a3a0875
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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