chrono24-mcp: Instructions file for Codex

AGENTS.md

chrono24-mcp AGENTS.md is an instructions file for Codex, OpenCode from samiashi/chrono24-mcp. It costs 2,872 tokens per session, scanned A, original, MIT.

Project instructions for chrono24-mcp, an MCP server that lets AI clients search and retrieve watch-marketplace data from Chrono24 by browsing its website. MCP is a standard way for AI tools to expose callable functions.

In plain words
What is it for?
Use them to build, test, lint, format, type-check, or run the Chrono24 MCP server.
Why use it?
They explain the repository's architecture, commands, testing requirements, and important rules for working with scraped data.

Instructions file for CodexOpenCode

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

This is samiashi/chrono24-mcp's own configuration. It tells Codex and OpenCode how to work on chrono24-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 chrono24-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to samiashi/chrono24-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/samiashi/chrono24-mcp/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/samiashi/chrono24-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 chrono24-mcp AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/samiashi/chrono24-mcp/agents-md.svg)](https://agentmods.dev/instructions/samiashi/chrono24-mcp/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/samiashi/chrono24-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/samiashi/chrono24-mcp/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 2,872 This file is loaded in full into every session.
When invoked 2,872 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 $0.02872 $0.02872
Opus 5 $0.01436 $0.01436
Sonnet 5 $0.00574 $0.00574
Haiku 4.5 $0.00287 $0.00287

Measured 2d ago against content hash 9a2b04ac5772, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

chrono24-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 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 · 97 lines

How it starts

The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Guidance for coding agents working in this repository.

What this is

An MCP server (chrono24-mcp) exposing Chrono24 watch-marketplace tools to LLM clients over stdio. There is no official Chrono24 API; all data comes from scraping Chrono24's website through a real browser to pass their Cloudflare managed challenge. TypeScript, official MCP SDK, zod schemas, cheerio parsers.

Commands

npm ci              # install exactly per lockfile
npm run build       # tsc -> build/
npm run typecheck   # tsc --noEmit
npm run lint        # eslint (flat config in eslint.config.js)
npm run format      # prettier --write .
npm test            # vitest, offline parser tests against test/fixtures/*.html (safe for CI)
npm run smoke       # LIVE end-to-end test: spawns server, lists tools, searches, fetches detail (needs Google Chrome; hits chrono24.com)
npm run capture-fixtures  # LIVE: refresh test/fixtures by re-fetching brand/search/detail pages
node build/index.js   # run the server manually on stdio

Before committing run npm run format && npm run lint && npm run typecheck && npm test - CI (.github/workflows/ci.yml) runs exactly those plus build. Prettier config: 110 print width, double quotes, trailing commas. ESLint: typescript-eslint recommended + prettier compat; empty catch blocks are allowed.

Smoke overrides for testing a published package instead of the local build:

SMOKE_COMMAND=npx SMOKE_ARGS='["-y","chrono24-mcp@latest"]' SMOKE_CWD=/tmp npm run smoke

Do NOT add live-network tests to CI: GitHub runners' IPs are blocked by Cloudflare. Parser tests use recorded HTML fixtures in test/fixtures/.

Architecture

src/index.ts           MCP server entry: registers 25 tools + 3 prompts, zero-result query hints, spread-sampling degradation via registerTool/registerPrompt (readOnlyHint annotations, output schemas + structuredContent), parsed-result caching, not-found detection, disk-persisted taxonomy, graceful shutdown (signals + stdin close)
src/fetcher.ts         Playwright-core fetcher: strict request serialization (createSerializer mutex - concurrent MCP tool calls share one page), persistent Chrome profile, memoized launch, crash recovery via context close listener, status-aware challenge sniffing, warmup-on-demand retry, politeness delay, stale SingletonLock recovery, in-page fetchJson for same-origin JSON APIs
src/parsers/search.ts  Search URL builder + listing-card parser (current markup era), facet param allowlist, locale-aware price parsing (parseLocalizedNumber)
src/parsers/detail.ts  Detail page parser: schema.org Product JSON-LD + spec table; hasDetailContent detects removed listings
src/parsers/taxonomy.ts  Brand list (manufacturerIds select), model catalog (--mod links), facet selects, drift warnings
src/parsers/ratings.ts Dealer ratings JSON normalizer (totals, filteredTotal, star filters)
src/parsers/stats.ts   Price percentile stats (computeStats) + rank-interpolated population estimates (estimateStats)
src/parsers/guide.ts   Model-page editorial guide parser: h3 sections + per-reference price table (static SEO content)
src/cache.ts           TTL + LRU cache (default 200 entries; search 180s, detail 1800s, taxonomy 86400s) - stores parsed payloads, never raw HTML
src/diskStore.ts       Generic keyed JSON disk cache (taxonomy, per-brand models, probed UA - all inside the profile dir)
src/config.ts          Env-var config (numeric envs validated via numFrom; garbage falls back to defaults)
src/tools/schemas.ts   Zod input AND output schemas (single source of truth for tool contracts)
test/parsers.test.ts   Offline vitest suite over recorded fixtures - keep green, extend when parsers change
test/cache.test.ts     TTL/LRU cache behavior
test/fetcher.test.ts   Serializer (request mutex) behavior

Read the full file on GitHub · 97 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 Changed · +19 lines · +1,365 tokens per session 9a2b04ac5772
  2. 6d ago First seen · 78 lines · 1,507 tokens per session scan A 2651c38931db

Subscribe to this mod's changes

chrono24-mcp AGENTS.md is an instructions file published in the GitHub repository samiashi/chrono24-mcp (1 stars, last pushed 5d ago), licensed MIT. It adds 2,872 tokens to every session, about $0.0144 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.

Related

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.

vercel/next.js · 7,296 tokens

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.

openai/codex · 5,182 tokens

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).

microsoft/vscode · 6,785 tokens

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).

microsoft/vscode · 5,001 tokens

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.

langchain-ai/langchain · 4,469 tokens

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.

github/spec-kit · 7,104 tokens