core skillA
core is agent-read markdown (skill) from modem-dev/ossrules: Core agent-browser usage guide. Read this before running any agent-browser commands. Covers the snapshot-and-ref workflow, navigating pages, interacting with elements (click, fill, type, select), extracting text and data, taking screenshots, managing tabs, handling forms and auth, waiting for content, running multiple browser sessions in parallel, and troubleshooting common failures. Use when the user asks to interact with a website, fill a form, click something, extract data, take a screenshot,.
Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.
What the file says
# agent-browser core
Fast browser automation CLI for AI agents. Chrome/Chromium via CDP, no Playwright or Puppeteer dependency. Accessibility-tree snapshots with compact `@eN` refs let agents interact with pages in ~200-400 tokens instead of parsing raw HTML.
Most normal web tasks (navigate, read, click, fill, extract, screenshot) are covered here. Load a specialized skill when the task falls outside browser web pages — see [When to load another skill](#when-to-load-another-skill).
## The core loop
Open the page and check the response for a WebMCP summary. If an advertised tool directly matches the authorized task, prefer that tool to reconstructing the same operation with DOM interactions. Fetch only its metadata, check the input schema and intended effect against the user request, then invoke it:
```bash
agent-browser open <url>
agent-browser webmcp list <tool> --frame <frame-id> --json
agent-browser webmcp invoke <tool> --frame <frame-id> --params '{"key":"value"}'
```
…Read the whole file at its exact version.
How to install
mdr add modem-dev/ossrules/core@git:20260917.d487f87mdr add modem-dev/ossrules/core@sha256:670c32aa9050cc41Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.
[](https://markdownregistry.com/a/art_rvnnxro7mntvneim)
1 badge views in 30 days
Versions
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 (37490 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
modem-dev/ossrules · 52 stars · license MIT · pushed 2026-09-21 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_rvnnxro7mntvneim GET https://markdownregistry.com/api/v1/resolve?ref=modem-dev/ossrules/core GET https://markdownregistry.com/api/v1/blob/670c32aa9050cc41f748d990f2a16916ea5db046b048e376a30d6be21ec64c39
Your agent 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.
More from modem-dev/ossrules
Every file in modem-dev/ossrules