deprecation-mcp: Instructions file for Codex

AGENTS.md

deprecation-mcp AGENTS.md is an instructions file for Codex, OpenCode from tsvillain/deprecation-mcp. It costs 468 tokens per session, scanned A, original, MIT.

Project instructions for maintaining AGENTS.md, the file that records how the deprecation-mcp project is built, tested, and operated.

In plain words
What is it for?
Use them when changing the deprecation checker, its data file, tests, build commands, or drift-detection script.
Why use it?
They keep essential project knowledge and safety constraints visible to coding agents working on the repository.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is tsvillain/deprecation-mcp's own configuration. It tells Codex and OpenCode how to work on deprecation-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything deprecation-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to tsvillain/deprecation-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.

Copy the file
curl -O https://raw.githubusercontent.com/tsvillain/deprecation-mcp/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/tsvillain/deprecation-mcp

Made for: Codex, OpenCode.

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.

agentmods badge for deprecation-mcp AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/tsvillain/deprecation-mcp/agents-md/github.svg)](https://agentmods.dev/instructions/tsvillain/deprecation-mcp/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/tsvillain/deprecation-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/tsvillain/deprecation-mcp/agents-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.

agentmods 80×15 button for deprecation-mcp AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/tsvillain/deprecation-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/tsvillain/deprecation-mcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 468 This file is loaded in full into every session.
When invoked 468 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00468 $0.00468
Opus 5 $0.00234 $0.00234
Sonnet 5 $0.00094 $0.00094
Haiku 4.5 $0.00047 $0.00047

Measured 9d ago against content hash 1d106acf7c38, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

deprecation-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 9d 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 · 27 lines

What it actually says

Project agent memory

This file is the project's committed home for project-intrinsic agent knowledge: build, test, release, architecture, and sharp-edge notes that should travel with the code.

  • deprecation-mcp: open MCP server (stdio, @modelcontextprotocol/sdk), one tool check_deprecation. No payment/billing/metering code — keep it that way; this ships as a plain open server.
  • Build/test: npm install && npm run build && npm test (pretest builds; node:test runs against dist/).
  • Data lives in data/deprecations.json, read at server startup (see src/data.ts) — no DB, no scraper, no network calls at runtime. Every record needs a real source_url and accurate last_verified_at; see README.md "Updating the dataset" for the bar. loadRecords() fails loudly (stderr + exit 1) on a missing/malformed/malshaped data file instead of throwing — keep diagnostics on stderr only, stdout is the MCP JSON-RPC channel.
  • Lookup/status logic: src/lookup.ts. Tests: src/test/lookup.test.ts.
  • Drift detection: src/scripts/check-drift.ts (npm run check-drift) fetches each record's source_url, compares a sha256 hash to the record's content_hash, and only ever flags — it never writes status, deprecated_on, etc. into data/deprecations.json. Runs weekly via .github/workflows/check-drift.yml, which opens/updates a drift-check-labeled GitHub issue. See README.md "Drift detection" for the known false-positive limitation on 3 records with dynamic page content. When you re-verify a record by hand, recompute its content_hash too.

Maintaining this file

Keep this file for knowledge useful to almost every future agent session in this project. Do not repeat what the codebase already shows; point to the authoritative file or command instead. Prefer rewriting or pruning existing entries over appending new ones. When updating this file, preserve this bar for all agents and keep entries concise.

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. 9d ago First seen · 27 lines · 468 tokens per session scan A 1d106acf7c38

Subscribe to this mod's changes

deprecation-mcp AGENTS.md is an instructions file published in the GitHub repository tsvillain/deprecation-mcp (0 stars, last pushed 1mo ago), licensed MIT. It adds 468 tokens to every session, about $0.0023 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.

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