Borrowing it
Nothing to install: this file belongs to Rul1an/assay. 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/Rul1an/assay/main/CLAUDE.mdgit clone --depth 1 https://github.com/Rul1an/assayWrote 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/rul1an/assay/claude-md)<a href="https://agentmods.dev/instructions/rul1an/assay/claude-md"><img src="https://agentmods.dev/badge/instructions/rul1an/assay/claude-md/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.
<a href="https://agentmods.dev/instructions/rul1an/assay/claude-md"><img src="https://agentmods.dev/badge/instructions/rul1an/assay/claude-md.svg" alt="Reviewed on agentmods" width="80" 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 | $0.04811 | $0.04811 |
| Opus 5.5 | $0.01924 | $0.01924 |
| Sonnet 5.5 | $0.00962 | $0.00962 |
| Haiku 4.5 | $0.00481 | $0.00481 |
Grade A, and why
assay CLAUDE.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 24d 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 — 359 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Assay - AI Agent Context
Cross-agent work must first read and follow AGENTS.md. That file is the shared source of truth for branch ownership, ADR-042/043 scope, review quorum, and verification. This file adds Assay-specific technical context and does not override that contract.
What is Assay?
Assay is a Policy-as-Code engine for Model Context Protocol (MCP) that validates AI agent behavior. It provides deterministic testing (trace replay), runtime security (eBPF/LSM kernel enforcement on Linux), and policy gates (tool argument/sequence validation).
Workspace Structure
Rust monorepo, workspace version 6.3.0, 22 workspace packages (21 under crates/ plus
assay-python-sdk; 7 are publish = false). Curated view, grouped by role:
crates/
# Core engine + CLI
assay-core/ Core evaluation engine (Runner, Store, MCP, Trace, Report, Providers, VCR, Replay Bundle)
assay-cli/ CLI binary ("assay") - all user-facing commands
assay-metrics/ Standard metrics (MustContain, RegexMatch, ArgsValid, SequenceValid, etc.)
assay-common/ Shared types (no_std compatible for eBPF)
assay-canonical/ Deterministic canonicalization: RFC 8785 (JCS) bytes, sha256 content IDs, semantic digests
# Evidence + distribution
assay-evidence/ Evidence bundles (tar.gz with manifest.json + events.ndjson), lint, diff, sanitize
assay-registry/ Pack Registry client (HTTP, DSSE verification, OIDC auth, local caching, lockfile v2)
gateway-evidence-replay/ Deterministic replay verifier for gateway-path evidence bundles (standalone)
# Policy + runtime enforcement
assay-policy/ Policy compilation (Tier 1: kernel, Tier 2: userspace)
assay-mcp-server/ MCP server/proxy for runtime policy enforcement (JSON-RPC over stdio)
assay-monitor/ Runtime eBPF/LSM monitoring (Linux only)
assay-ebpf/ Kernel eBPF programs (LSM hooks + tracepoints)
# Measured-run substrate (internal/experimental "Assay-Runner", API unstable)
assay-runner-core/ Runner orchestration, archive assembly, layer normalizers
assay-runner-linux/ Linux-only platform adapter, cgroup placement primitives
assay-runner-schema/ Versioned schema types + constants for Runner v0 contracts
# Protocol adapters (evidence translation)
assay-adapter-api/ Adapter API contracts (shared trait surface)
assay-adapter-a2a/ A2A protocol adapter
assay-adapter-acp/ ACP protocol adapter
assay-adapter-ucp/ UCP protocol adapter
# Simulation + tooling
assay-sim/ Attack simulation harness (chaos, differential, integrity testing)
assay-xtask/ Build tooling
assay-python-sdk/ Python SDK (PyO3 bindings + pytest plugin; crate name "assay-it")
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.
- 24d ago Changed · -5 tokens per session eae8c743fd1e
- 1mo ago Changed · +3 lines · +62 tokens per session 9710800222c1
- 1mo ago Changed 0cb6566ada99
- 1mo ago Changed c27d868bcbe3
- 1mo ago Changed 966f2f65508c
- 1mo ago Changed · +10 lines · +184 tokens per session fa40e6eab1aa
- 2mo ago Changed 00a3dbb7437f
- 2mo ago Changed · +4 lines · +46 tokens per session 2abd37cf4c2a
- 2mo ago First seen · 342 lines · 4,524 tokens per session scan A 86d5740831bf
assay CLAUDE.md is an instructions file published in the GitHub repository Rul1an/assay (15 stars, last pushed yesterday), licensed MIT. It adds 4,811 tokens to every session, about $0.0192 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 2026-08-31.
assay CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| assay CLAUDE.mdRul1an/assay | Instructions file | 15 | yesterday | MIT | A | 4,811 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | yesterday | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |