specillum
llms.txt1 starsChanged 13 days agoApache-2.0View on GitHub
Specillum is an open-source MCP (Model Context Protocol) server that lets AI coding agents such as Claude Code, OpenAI Codex and Cursor use your real, logged-in Chrome, while giving every agent its own isolated browser window ("pod"). Agents cannot see or touch your tabs or each other's tabs. Apache-2.0, by Jason (@jasonwpgml). Key facts: - One shared Chrome ("station") with a dedicated profile: log in once with npx specillum open, and every agent reuses those live sessions. - Each MCP…
The file
We split this llms.txt into the rules it gives an agent
1 rule. About 0 are common, 1 is distinctive, and 0 are very specific to this project.
≈0
Common · estimate
Many files like this have a rule of this kind.
≈1
Distinctive · estimate
This author's own choices. Worth a look.
0
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- Distinctive: line 10
Read-only data tools (network, response, page_data) return the JSON a pod's pages received or embed, with headers dropped, secrets masked …
≈ “Common” is an estimate: at least 1 in 5 of the 3,592 llms.txt files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
# Specillum
> Specillum is an open-source MCP (Model Context Protocol) server that lets AI coding agents such as Claude Code, OpenAI Codex and Cursor use your real, logged-in Chrome, while giving every agent its own isolated browser window ("pod"). Agents cannot see or touch your tabs or each other's tabs. Apache-2.0, by Jason (@jasonwpgml).
Key facts:
- One shared Chrome ("station") with a dedicated profile: log in once with `npx specillum open`, and every agent reuses those live sessions.
- Each MCP connection gets a pod: a separate Chrome window. Tools only operate on pages inside that pod, including new tabs and popups it opens.
- Pods close automatically when the agent disconnects.
- Token-efficient snapshot: visible interactive elements as one line each with refs like `[e12]` that stay stable while the element exists. `match` finds one element and `changes` returns only what changed.
- Read-only data tools (network, response, page_data) return the JSON a pod's pages received or embed, with headers dropped, secrets masked and sizes capped.
- Recipes (the recipe tool) save a series of steps for one site and replay them by element role and name, so a repeated task does not need the page read again. A run stops at the first failed step.
- Tools: pod_status, pod_window, navigate, history, snapshot, read, click, type, press, select, hover, drag, upload, pdf, har, scroll, wait, screenshot, dialog, tabs, network, response, page_data, console, mock, evaluate, recipe, storage.
- SPECILLUM_TOOLS picks tool groups (files, data, debug, recipes, storage) on top of core, so agents only pay tokens for the tools they use. storage is only on when named.
- Optional limits: SPECILLUM_ALLOWED_DOMAINS keeps pods on listed sites; uploads only come from the agent's directory and SPECILLUM_UPLOAD_DIRS.
- Works with any MCP client over stdio. Built on Playwright (playwright-core) over the Chrome DevTools Protocol.
- Tested on Windows; macOS and Linux browser paths are included.
## Docs
- [README](https://github.com/jasonwpgml/specillum#readme): setup for Claude Code, Codex and Cursor, tools, security model, FAQ
- [CONTRIBUTING](https://github.com/jasonwpgml/specillum/blob/main/CONTRIBUTING.md)
- [NOTICE](https://github.com/jasonwpgml/specillum/blob/main/NOTICE): attribution required for redistribution
## Attribution
Reuse is welcome under Apache-2.0. Keep the NOTICE file and credit "Specillum by Jason (@jasonwpgml)" with a link to https://github.com/jasonwpgml/specillum.
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