api-designer

A read-only specialist for designing web APIs, the interfaces through which software exchanges data. It covers REST, GraphQL, and gRPC, and can write OpenAPI specifications and advise on versions, pagination, and HATEOAS patterns.

In plain words
What is it for?
Use it to plan an API, document its endpoints, choose a versioning approach, design pagination, or review REST, GraphQL, and gRPC patterns.
Why use it?
It provides focused design guidance without changing your code. It helps make API decisions consistent before implementation begins.

Agent

Install

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.

agentmods
npx agentmods add agents/de-monkey-v/marketplace/api-designer
Clone the repo
git clone --depth 1 https://github.com/de-monkey-v/marketplace
Per session 51 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,513 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin unknown 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 $0.00051 $0.01513
Opus 5 $0.00026 $0.00757
Sonnet 5 $0.00010 $0.00303
Haiku 4.5 $0.00005 $0.00151

Measured 2d ago against content hash 70d5d92951bd, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

api-designer scanned grade A with 1 finding 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- **Bash** - Run OpenAPI validators, curl tests, documentation generators
plugins/claude-team/agents/api-designer.md · 157 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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 First seen · 157 lines · 51 tokens per session scan A 70d5d92951bd

Subscribe to this mod's changes

api-designer is an agent published in the GitHub repository de-monkey-v/marketplace (2 stars, last pushed 5mo ago), with no licence file. It adds 51 tokens to every session and 1,513 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.