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.
npx agentmods add instructions/prismatic7/masa/agents-mdgit clone --depth 1 https://github.com/prismatic7/MASAWhat 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 | $0.00430 | $0.00430 |
| Opus 5 | $0.00215 | $0.00215 |
| Sonnet 5 | $0.00086 | $0.00086 |
| Haiku 4.5 | $0.00043 | $0.00043 |
Grade A, and why
MASA 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 yesterday.
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 — 34 lines — stays where its author put it; the contents beside it link to each section on GitHub.
MASA repository contract
This repository contains the normative MASA Sound Matter Aware protocol and its local reference tooling.
Authority order
- Versioned files under
spec/define normative behavior. - Versioned JSON Schema files under
schemas/define normative structure. - Versioned registries under
ontology/define controlled vocabulary and relation metadata. - Conformance fixtures and tests define executable expectations.
- TypeScript declarations and libraries are generated or implemented conveniences. They never override the language-neutral artifacts.
Invariants
- Preserve source, representation, claim, operation, policy, and lineage as distinct objects.
- Keep claim kind, actor, confidence, source health, freshness, and disclosure separate.
- Keep unknown, withheld, unavailable, deleted, and not-applicable states distinct.
- Never mutate or replace an imported representation under the same identifier after consequential transformation.
- Every descendant has a parent relation and an operation receipt.
- Every consequential operation has a policy evaluation, including refusal and non-action.
- Unknown namespaced extensions survive ordinary local round trips. They are excluded from public projections unless explicitly approved.
- Validation is offline. Validators and the MCP server do not dereference remote resources.
- Public export is allowlist-based and creates a new projection. It never sanitizes a private record in place.
- The reference implementation performs no digital signal processing. Processing operations are contracted to external engines and accounted through receipts.
- Do not describe a profile, class, adapter, or integration as conformant without a recorded passing suite.
Development
Use Node.js 22.20 or newer and pnpm 10.32.1. Run pnpm check before calling the local reference implementation complete. Tests must use isolated temporary directories and may not write into sibling repositories.
Do not add an application-specific term to the masa: namespace until at least two implementations justify the promotion and a versioned decision records it. Concrete applications keep their own extension namespaces in their own repositories.
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.
- yesterday First seen · 34 lines · 430 tokens per session scan A 90fe1b297a70
MASA AGENTS.md is an instructions file published in the GitHub repository prismatic7/MASA (0 stars, last pushed 13d ago), licensed MIT. It adds 430 tokens to every session, about $0.0022 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
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).
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.
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.
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.
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).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.