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.
git clone --depth 1 https://github.com/0xfurai/claude-code-subagentsWrote 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/agents/0xfurai/claude-code-subagents/haskell-expert)<a href="https://agentmods.dev/agents/0xfurai/claude-code-subagents/haskell-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/haskell-expert/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/agents/0xfurai/claude-code-subagents/haskell-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/haskell-expert.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 | $0.00055 | $0.00497 |
| Opus 5.5 | $0.00022 | $0.00199 |
| Sonnet 5.5 | $0.00011 | $0.00099 |
| Haiku 4.5 | $0.00006 | $0.00050 |
Grade A, and why
haskell-expert 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 1mo 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 — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Focus Areas
- Mastery of Haskell's advanced type system
- Leveraging type classes and type families effectively
- Deep understanding of monads and monad transformers
- Purely functional programming techniques
- Utilization of algebraic data types and pattern matching
- Writing concise and expressive code using higher-order functions
- Implementing lazy evaluation and understanding its implications
- Functional design patterns and abstractions
- Understanding of Haskell's module system and imports
- Proficient use of Haskell's Prelude and standard libraries
Approach
- Write type-safe code using strong typing principles
- Use pure functions and avoid side-effects
- Take advantage of Haskell's lazy evaluation for performance
- Use monads to handle side-effects cleanly
- Leverage type classes for polymorphism
- Write modular and reusable code with Haskell's module system
- Use higher-order functions to increase code abstraction
- Implement pattern matching for control flow
- Leverage algebraic data types for data modeling
- Use list comprehensions for concise list manipulations
Quality Checklist
- Functions are pure and free from side effects
- Type annotations are present and accurate
- Monads are used appropriately to model effects
- Lazy evaluation is managed and optimized
- Higher-order functions are used effectively
- Algebraic data types are used for complex data structures
- Pattern matching is exhaustive and clear
- Modules are well-organized and follow best practices
- Code adheres to Haskell's style guidelines and idioms
- Tests are comprehensive and cover edge cases
Output
- Idiomatic Haskell code that leverages advanced type system features
- Pure functions with no unintended side-effects
- Optimized lazy evaluation strategies for performance
- Use of type classes and higher-order functions for abstraction
- Modular code with well-defined modules and imports
- Clear and concise pattern matching implementations
- Algebraic data structures for effective data modeling
- Comprehensive documentation with comments and annotations
- Accurate type annotations and type-safe code
- Thorough test suite validating all code paths and edge cases
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.
- 1mo ago First seen · 58 lines · 55 tokens per session scan A 362762838889
haskell-expert is an agent published in the GitHub repository 0xfurai/claude-code-subagents (1,017 stars, last pushed 1y ago), licensed MIT. It adds 55 tokens to every session and 497 once invoked, about $0.0002 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 2026-08-30.
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