What is purescript-agent-skills CLAUDE.md?

A set of instructions for Claude Code about the PureScript ecosystem, including packages, versions, data sources, and common language conventions. PureScript is a programming language related to Haskell.

Use it when helping developers choose PureScript packages, write PureScript code, or follow the ecosystem's preferred patterns.

It gives an agent practical project-specific context that general training may miss, reducing suggestions based on the wrong libraries or conventions.

How afcondon/purescript-agent-skills configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to afcondon/purescript-agent-skills. 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/afcondon/purescript-agent-skills/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/afcondon/purescript-agent-skills

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/afcondon/purescript-agent-skills/claude-md/github.svg)](https://agentmods.dev/instructions/afcondon/purescript-agent-skills/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/afcondon/purescript-agent-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/afcondon/purescript-agent-skills/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/afcondon/purescript-agent-skills/claude-md"><img src="https://agentmods.dev/badge/instructions/afcondon/purescript-agent-skills/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,029 This file is loaded in full into every session.

When invoked 1,029 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.

Model	Per session	Once invoked
Fable 5.1	$0.01029	$0.01029
Opus 5.5	$0.00412	$0.00412
Sonnet 5.5	$0.00206	$0.00206
Haiku 4.5	$0.00103	$0.00103

Measured 2mo ago against content hash 41f3b1d85cff, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

purescript-agent-skills 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 2mo 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.

CLAUDE.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

PureScript Ecosystem Guide

Goal

Create a concise, AI-to-AI reference of the PureScript package ecosystem. The primary audience is Claude (or other AI assistants) helping developers write PureScript. The guide should provide the practical knowledge that's missing from training data — which packages to reach for, cultural conventions, and "don't do this, do that" guidance.

Why This Exists

PureScript is a niche language. Claude's PureScript knowledge is largely inferred from Haskell training data, which leads to:

Suggesting Haskell idioms that don't apply (e.g., type class instances for JSON instead of codec values)
Not knowing about key packages (e.g., codec-argonaut, halogen, httpure)
Missing ecosystem conventions (e.g., Aff for async, Effect for sync, never IO)
Not understanding the package split patterns (e.g., affjax vs affjax-web vs affjax-node)

Data Sources

Package set (current versions)

/Users/afc/work/afc-work/CodeExplorer/minard/database/_registry-index/package-set-71.0.0.json

568 packages with current version numbers
Quick lookup for what's available

Registry index (all versions, with manifests)

/Users/afc/work/afc-work/registry-index/

2-char prefix directory structure (e.g., af/fj/affjax)
Each file contains JSONL: one JSON object per published version
Includes: name, version, license, description, location (GitHub), dependencies
1282 total manifest files

Package source code

For deeper review, fetch from GitHub using the location info in manifests. Use gh api or clone repos as needed.

Output Format

Per-package review (for important packages)

## package-name

**What:** One-sentence description
**When to use:** The trigger condition — when should an AI suggest this?
**Key exports:** 3-5 most important types/functions
**Instead of:** What NOT to do (the common mistake this prevents)
**Ecosystem role:** core | contrib | community | niche
**Status:** active | maintained | dormant | deprecated
**Note:** Any PureScript-specific convention that differs from Haskell

Read the full file on GitHub · 93 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.

2mo ago First seen · 93 lines · 1,029 tokens per session scan A 41f3b1d85cff

Subscribe to this mod's changes

purescript-agent-skills CLAUDE.md is an instructions file published in the GitHub repository afcondon/purescript-agent-skills (2 stars, last pushed 1mo ago), licensed MIT. It adds 1,029 tokens to every session, about $0.0041 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.

Languages

purescript-agent-skills CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
purescript-agent-skills CLAUDE.mdafcondon/purescript-agent-skills	Instructions file	2	1mo ago	MIT	A	1,029	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

purescript-agent-skills: Instructions file for Claude Code