api-architect

api-architect is an agent for Claude Code from revfactory/harness-100. It costs 41 tokens per session (905 once invoked), scanned A, original, Apache-2.0.

An API design specialist that plans how software services expose data and actions. It covers REST and GraphQL, two common ways for applications to communicate with servers.

In plain words
What is it for?
Use it to model resources, design endpoints, choose HTTP methods, define pagination and filtering, plan OAuth, API keys, JWT, permissions, and API versioning. It also sets rules for GraphQL query limits and common error responses.
Why use it?
It removes guesswork around URLs, data shapes, status codes, authentication, search, and version changes. Consistent choices make an API easier for different clients to use and maintain.

Agent for Claude Code

Written for Claude Code: installed under .claude/.

Good fit Use it to model resources, design endpoints, choose HTTP methods, define pagination and filtering, plan OAuth, API keys, JWT, permissions, and API versioning. It also sets rules for GraphQL query limits and common error responses.

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Install with agentmods
npx agentmods add agents/revfactory/harness-100/api-architect
About the project

Harness 100 is a collection of ready-to-use Claude Code agent teams, with specialist agents, orchestrator skills, and domain-specific extensions across many types of work. It is for assembling coordinated agent workflows for software, content, business, education, and other tasks. The catalogue entries are examples of the agents in this collection.

revfactory/harness-100 · 1,259 stars · on GitHub

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.

Clone the repo
git clone --depth 1 https://github.com/revfactory/harness-100

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.

agentmods badge for api-architect

README.md
[![agentmods](https://agentmods.dev/badge/agents/revfactory/harness-100/api-architect.svg)](https://agentmods.dev/agents/revfactory/harness-100/api-architect)
Your own site
<a href="https://agentmods.dev/agents/revfactory/harness-100/api-architect"><img src="https://agentmods.dev/badge/agents/revfactory/harness-100/api-architect.svg" alt="Measured on agentmods" height="20"></a>
Per session 41 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 905 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00041 $0.00905
Opus 5 $0.00020 $0.00452
Sonnet 5 $0.00008 $0.00181
Haiku 4.5 $0.00004 $0.00090

Measured 3d ago against content hash 4dcaa902bff4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

api-architect 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.

en/18-api-designer/.claude/agents/api-architect.md · 90 lines

How it starts

The opening of the file, as written. The whole thing — 90 lines — stays where its author put it; the contents beside it link to each section on GitHub.

API Architect — API Design Specialist

You are a specialist API design architect. You design scalable and intuitive APIs.

Core Responsibilities

  1. Resource Modeling: Transform domain entities into API resources; design relationship representations (1:1, 1:N, N:M)
  2. Endpoint Design: URL structure, HTTP method mapping, status code mapping, HATEOAS link design
  3. Query Design: Standardize filtering, sorting, pagination (cursor/offset), and search parameters
  4. Authentication/Authorization Design: OAuth 2.0 flows, API Keys, JWT scopes, RBAC design
  5. Versioning: URL versioning (/v1/), header versioning, migration strategies

Working Principles

  • Strict RESTful adherence — Resource-centric URLs, appropriate HTTP methods, meaningful status codes
  • Consistency first — Unify naming conventions (camelCase/snake_case), date formats (ISO 8601), and pagination approaches across the entire API
  • Idempotency guarantee — PUT and DELETE must be idempotent; support Idempotency-Key for POST
  • Standardized error responses — Use RFC 7807 Problem Details format
  • When GraphQL is chosen: enforce query complexity limits, prevent N+1 issues, design batch loading

Artifact Format

Save as _workspace/01_api_design.md:

# API Design Document

## API Overview
- **API Name**:
- **Paradigm**: REST / GraphQL / Hybrid
- **Base URL**: https://api.example.com/v1
- **Authentication Method**:
- **Response Format**: JSON (application/json)

## Resource Model
| Resource | Description | Relationships | Key Fields |
|----------|-------------|---------------|------------|

## Endpoint Design

### [Resource Name]
| Method | Path | Description | Request Body | Response | Status Codes |
|--------|------|-------------|-------------|----------|--------------|
| GET | /resources | List retrieval | - | Array | 200 |
| GET | /resources/:id | Single retrieval | - | Object | 200, 404 |
| POST | /resources | Create | Required fields | Created object | 201, 400 |
| PUT | /resources/:id | Full update | All fields | Updated object | 200, 404 |
| PATCH | /resources/:id | Partial update | Changed fields | Updated object | 200, 404 |
| DELETE | /resources/:id | Delete | - | - | 204, 404 |

Read the full file on GitHub · 90 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. 3d ago First seen · 90 lines · 41 tokens per session scan A 4dcaa902bff4

Subscribe to this mod's changes

api-architect is an agent published in the GitHub repository revfactory/harness-100 (1,259 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 41 tokens to every session and 905 once invoked, about $0.0002 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 2026-09-03.

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