What is surf-codebase?

A development guide for surf-cli, a Chrome extension and command-line system for browser automation. It documents how the command line, native host, extension, and Chrome DevTools interface connect.

Use it to navigate or modify surf-cli, add commands, implement browser-control operations, or work on Chrome, accessibility, network, and debugging features.

It shows where browser commands, page interactions, screenshots, network handling, and message routing belong in the codebase.

How nicobailon/surf-cli configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to nicobailon/surf-cli. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/nicobailon/surf-cli/main/.claude/skills/surf-codebase/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/nicobailon/surf-cli

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/nicobailon/surf-cli/surf-codebase/github.svg)](https://agentmods.dev/skills/nicobailon/surf-cli/surf-codebase)

Your own site

<a href="https://agentmods.dev/skills/nicobailon/surf-cli/surf-codebase"><img src="https://agentmods.dev/badge/skills/nicobailon/surf-cli/surf-codebase/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/nicobailon/surf-cli/surf-codebase"><img src="https://agentmods.dev/badge/skills/nicobailon/surf-cli/surf-codebase.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 960 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

NVIDIA SkillSpector pass 7 Sept 2026

How audits are shown

Origin original No closer match found in the catalogue.

Token cost

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	$0.00042	$0.00960
Opus 5.5	$0.00017	$0.00384
Sonnet 5.5	$0.00008	$0.00192
Haiku 4.5	$0.00004	$0.00096

Measured 2d ago against content hash 019bd3342efe, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

surf-codebase 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 2d 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.

.claude/skills/surf-codebase/SKILL.md · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

surf-cli Codebase

Architecture

cli.cjs --socket:/tmp/surf.sock--> host.cjs --native-msg--> service-worker/index.ts --CDP/chrome-APIs--> browser

Add CLI Command

Add to TOOLS in native/cli.cjs:158 (args, opts, examples)
Add handler in src/service-worker/index.ts:50 handleMessage() switch
CDP op? → add method src/cdp/controller.ts:60
DOM interaction? → add handler src/content/accessibility-tree.ts:99

Add CDP Operation

Add method to CDPController class src/cdp/controller.ts:60
Use this.send(tabId, "Domain.method", params)
Handle events in handleCDPEvent() if needed

Core Files

src/service-worker/index.ts (~2500L) - Central msg router, CDP ops, screenshot cache, tab registry

Msg types: EXECUTE_CLICK, EXECUTE_TYPE, READ_PAGE, EXECUTE_SCREENSHOT
Screenshot cache: generateScreenshotId(), cacheScreenshot(), getScreenshot()
Tab names: tabNameRegistry Map<name,tabId>

src/cdp/controller.ts (~1000L) - CDP wrapper, CDPController class

Mouse: click(), rightClick(), doubleClick(), hover(), drag()
Keyboard: type(), pressKey(), pressKeyChord()
Screenshots: captureScreenshot(), captureRegion()
Network/Console: enableNetworkTracking(), getNetworkRequests(), getResponseBody(), subscribeToNetwork(), enableConsoleTracking(), getConsoleMessages()
Emulation: emulateNetwork(), emulateCPU(), emulateGeolocation()

src/content/accessibility-tree.ts (~1900L) - Content script, generates a11y tree YAML, element interactions

Handlers: GENERATE_ACCESSIBILITY_TREE, CLICK_ELEMENT, FORM_INPUT, GET_ELEMENT_COORDINATES, WAIT_FOR_ELEMENT, WAIT_FOR_URL
Element refs: e1, e2... in window.__piRefs for stable references

native/cli.cjs (~2100L) - CLI parser, socket client

TOOLS: command defs with args/opts
ALIASES: shortcut→command map
AUTO_SCREENSHOT_TOOLS: commands that auto-capture
parseArgs(), sendRequest()

native/host.cjs (~2100L) - Socket server, AI integration

handleToolRequest(): main dispatcher
mapToolToMessage(): tool→extension msg converter
queueAiRequest(): AI request serialization
AI clients: chatgptClient, geminiClient, perplexityClient

Read the full file on GitHub · 106 lines

Changes

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.

2d ago Changed 019bd3342efe
2mo ago First seen · 106 lines · 42 tokens per session scan A 072b3a3ddded

Subscribe to this mod's changes

surf-codebase is a skill published in the GitHub repository nicobailon/surf-cli (684 stars, last pushed 2d ago), licensed MIT. It adds 42 tokens to every session and 960 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

ai-agents browser-automation chrome cli devtools

surf-codebase next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
surf-codebasenicobailon/surf-cli	Skill	684	2d ago	MIT	A	42	Claude Code
canvasleeguooooo/chrome-use	Skill	231	yesterday	Apache-2.0	A	124	Claude Code
coreleeguooooo/chrome-use	Skill	231	yesterday	Apache-2.0	A	39	Claude Code
electronleeguooooo/chrome-use	Skill	231	yesterday	Apache-2.0	A	112	Claude Code
sessionsleeguooooo/chrome-use	Skill	231	yesterday	Apache-2.0	A	68	Claude Code
slackleeguooooo/chrome-use	Skill	231	yesterday	Apache-2.0	A	88	Claude Code
networkleeguooooo/chrome-use	Skill	231	yesterday	Apache-2.0	A	62	Claude Code

surf-cli: Skill for Claude Code