BrowserMesh AGENTS.md

Repository instructions for BrowserMesh, an open-source system that lets an external AI client control isolated browser sessions through MCP, a tool-connection protocol.

In plain words
What is it for?
Use them when implementing or maintaining BrowserMesh, especially its browser-session isolation, MCP interface, architecture, tests, and documentation requirements.
Why use it?
They define the project’s architecture, responsibilities, and required behavior so changes remain consistent with its specifications and contracts.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/scrolldynasty/browsermesh/agents-md
Clone the repo
git clone --depth 1 https://github.com/scrollDynasty/BrowserMesh

Made for: Codex, OpenCode.

Per session 4,022 This file is loaded in full into every session.
When invoked 4,022 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.04022 $0.04022
Opus 5 $0.02011 $0.02011
Sonnet 5 $0.00804 $0.00804
Haiku 4.5 $0.00402 $0.00402

Measured 2d ago against content hash 266bca703fe7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

BrowserMesh AGENTS.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 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.

AGENTS.md · 837 lines

How it starts

The opening of the file, as written. The whole thing — 837 lines — stays where its author put it; the contents beside it link to each section on GitHub.

BrowserMesh — Autonomous Implementation Agent Instructions

CLAUDE.md is the always-in-context working subset of this charter: sections 1–4, 14–16, and 22, plus the commands and gotchas that only ever lived in docs/development.md. This file remains canonical; when the two disagree, this one wins. Repeatable procedures are skills in .claude/skills/.

You are the principal software engineer and autonomous coding agent responsible for implementing and maintaining the open-source project BrowserMesh.

Your objective is not merely to write code.

Your objective is to independently bring BrowserMesh to a complete, tested, internally consistent v0.1 implementation that satisfies:

  • docs/SPEC.md;
  • docs/architecture.md;
  • applicable ADRs;
  • public MCP contracts;
  • the project's Definition of Done.

Work autonomously inside the repository.

Do not stop after a single file, feature, milestone, or successful test.

1. Responsibility boundary

This is a critical invariant.

BrowserMesh v0.1 is not an internal AI-agent runtime.

The intended flow is:

User
  ↓
external AI client
  ↓ MCP
BrowserMesh
  ↓
isolated browser sessions

Examples of external AI/MCP clients include:

  • Claude Code;
  • Codex;
  • Cursor;
  • Qwen;
  • other MCP-compatible clients.

The external client performs:

  • reasoning;
  • planning;
  • workflow orchestration;
  • deciding which BrowserMesh tools to call.

BrowserMesh performs browser execution.

Do not introduce into v0.1:

  • internal Agent entities;
  • Agent registries;
  • browser_agent_* tools;
  • LLM-owned session principals;
  • Agent ownership;
  • Agent mailboxes;
  • agent-to-agent messaging;
  • browser_message_* tools;
  • internal LLM calls;
  • prompt orchestration;
  • autonomous reasoning loops inside BrowserMesh;
  • Claude/Codex/Qwen process spawning.

Session name and metadata are neutral workflow labels only.

They are not principals, permissions, Agent identities, mailboxes, or leases.

A future generic client/workflow lease is only allowed if explicitly introduced by the specification/ADR for a real multi-client access-protection requirement.

Read the full file on GitHub · 837 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.

  1. 2d ago First seen · 837 lines · 4,022 tokens per session scan A 266bca703fe7

Subscribe to this mod's changes

BrowserMesh AGENTS.md is an instructions file published in the GitHub repository scrollDynasty/BrowserMesh (4 stars, last pushed 2d ago), licensed Apache-2.0. It adds 4,022 tokens to every session, about $0.0201 per session on Opus 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 2026-08-31.