Borrowing it
Nothing to install: this file belongs to xyzzylabs/wasm-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/xyzzylabs/wasm-mcp/main/AGENTS.mdgit clone --depth 1 https://github.com/xyzzylabs/wasm-mcpWrote 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.
[](https://agentmods.dev/instructions/xyzzylabs/wasm-mcp/agents-md)<a href="https://agentmods.dev/instructions/xyzzylabs/wasm-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/xyzzylabs/wasm-mcp/agents-md.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00997 | $0.00997 |
| Opus 5 | $0.00498 | $0.00498 |
| Sonnet 5 | $0.00199 | $0.00199 |
| Haiku 4.5 | $0.00100 | $0.00100 |
Grade A, and why
wasm-mcp 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 6d 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.
How it starts
The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Project rules for AI agents
This file follows the cross-tool AGENTS.md
convention. Tool-specific alias files (CLAUDE.md, etc.) import
this file via @AGENTS.md so every agent reads the same rules
with no drift.
What wasm-mcp is
A general-purpose, public MCP server for the WebAssembly specifications. It exposes structured instructions (mnemonics, opcodes, type signatures, validation and execution rules), value / function types, the binary and text formats, and spec section retrieval over the Model Context Protocol — locally over stdio or hosted as a Cloudflare Worker over HTTP. The data is SHA-pinned to a specific commit of WebAssembly/spec and indexed at build time; the running server does pure local lookups.
The WebAssembly/spec repository carries three specifications in
parallel under /document/:
core— the WebAssembly core specification (instruction set, validation, execution, binary + text formats).js-api— the JavaScript embedding API (WebAssembly.instantiate,WebAssembly.Module,WebAssembly.Memory, …). Web IDL-based.web-api— additional Web-platform integration (streaming compilation,fetchintegration).
All three share one pinned commit. core (reStructuredText +
SpecTec) is the first-class target; js-api and web-api (Bikeshed)
are covered by the section_get / section_list / spec_search
tools via a spec argument. The instruction and type tools are
intrinsically core-only.
The server is the product. Tools, dependencies, and documentation should read as if written for any reader interested in the WebAssembly spec — engine implementers, tooling authors, educators, other agents — not for one specific downstream consumer.
Hard rules
- The tool surface stays narrow. Read-only, deterministic, no execution, no auth, no writes. New tools land only if they expose structured spec data and meet that contract. In particular: never compile, validate-by-running, instantiate, or run any WebAssembly or arbitrary code from a tool. Validation rules are returned as data (the prose / typing judgement), not by applying them.
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.
- 6d ago First seen · 101 lines · 997 tokens per session scan A 8ceda99d9de6
wasm-mcp AGENTS.md is an instructions file published in the GitHub repository xyzzylabs/wasm-mcp (2 stars, last pushed 2d ago), licensed MIT. It adds 997 tokens to every session, about $0.0050 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.
Other instructions, from other repositories
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.