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/pauljphilp/effect-json/claude-mdgit clone --depth 1 https://github.com/PaulJPhilp/effect-jsonWrote 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/pauljphilp/effect-json/claude-md)<a href="https://agentmods.dev/instructions/pauljphilp/effect-json/claude-md"><img src="https://agentmods.dev/badge/instructions/pauljphilp/effect-json/claude-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 | $0.02595 | $0.02595 |
| Opus 5 | $0.01298 | $0.01298 |
| Sonnet 5 | $0.00519 | $0.00519 |
| Haiku 4.5 | $0.00260 | $0.00260 |
Grade A, and why
effect-json 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 3d 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 — 356 lines — stays where its author put it; the contents beside it link to each section on GitHub.
effect-json Development Guide
effect-json is a published npm library providing type-safe, schema-driven JSON serialization for TypeScript and Effect.
📦 Published: https://www.npmjs.com/package/effect-json 🐙 Repository: https://github.com/PaulJPhilp/effect-json 📊 Version: 0.1.0 (production)
Project Overview
effect-json provides three JSON serialization backends unified under a single Effect-native API:
- JSON: Standard JSON.parse/stringify with precise error reporting
- JSONC: JSON with Comments support (strips single-line and multi-line comments)
- SuperJSON: Type-preserving serialization (Date, Set, Map, BigInt, etc.)
All operations return Effect types for composability with the Effect ecosystem.
Architecture
Core Principles
- Effect-First Design: All APIs return
Effect<Success, Error>types - Tagged Errors: Use
ParseError,ValidationError,StringifyErrorfor precise error handling - Schema Validation: Effect.Schema for all parsing/stringification
- Pluggable Backends: Backend interface allows extensibility
- Type Safety: TypeScript strict mode, full type inference
Project Structure
effect-json/
├── packages/effect-json/ # Main package
│ ├── src/
│ │ ├── api.ts # Public API (parse, stringify, etc.)
│ │ ├── backends/ # JSON, JSONC, SuperJSON implementations
│ │ │ ├── types.ts # Backend interface
│ │ │ ├── json.ts # Standard JSON backend
│ │ │ ├── jsonc.ts # JSON with Comments
│ │ │ └── superjson.ts # Type-preserving backend
│ │ ├── errors.ts # Tagged error types
│ │ ├── schema.ts # Schema validation utilities
│ │ ├── config.ts # Service layer (DI)
│ │ ├── utils/ # String utilities
│ │ └── __tests__/ # Test suites
│ ├── dist/ # Built output (gitignored)
│ └── package.json
├── docs/ # Planning documentation
└── .github/workflows/ # CI/CD pipelines
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.
- 3d ago First seen · 356 lines · 2,595 tokens per session scan A ce14d6972b1e
effect-json CLAUDE.md is an instructions file published in the GitHub repository PaulJPhilp/effect-json (10 stars, last pushed 2mo ago), licensed MIT. It adds 2,595 tokens to every session, about $0.0130 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.