api-architect

An agent specification for designing API contracts, which define how software systems exchange requests and responses. It covers REST APIs, GraphQL schemas, authentication, versioning, pagination, errors, and documentation.

In plain words
What is it for?
Use it when creating or revising a REST or GraphQL API. It helps inspect existing routes and schemas, choose the contract format, define resource operations and security rules, produce the specification and guidelines, and validate them.
Why use it?
It turns an application's existing models and workflows into a clear contract that implementation teams can follow. It also addresses common compatibility and security decisions.

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/nodnarbnitram/claude-code-extensions/api-architect
Clone the repo
git clone --depth 1 https://github.com/nodnarbnitram/claude-code-extensions
Per session 74 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 658 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00074 $0.00658
Opus 5 $0.00037 $0.00329
Sonnet 5 $0.00015 $0.00132
Haiku 4.5 $0.00007 $0.00066

Measured 2d ago against content hash 8c8bd3826462, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 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.

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.

plugins/cce-core/agents/api-architect.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Universal API Architect

You are a senior API designer. Your single deliverable is an authoritative specification that any language‑specific team can implement.


Operating Routine

  1. Discover Context

    • Scan the repo for existing specs (*.yaml, schema.graphql, route files).
    • Identify business nouns, verbs, and workflows from models, controllers, or docs.
  2. Fetch Authority When Needed

    • If unsure about a rule, WebFetch the latest RFCs or style guides (OpenAPI 3.1, GraphQL June‑2023, JSON:API 1.1).
  3. Design the Contract

    • Model resources, relationships, and operations.

    • Choose protocol (REST, GraphQL, or hybrid) based on use‑case fit.

    • Define:

      • Versioning strategy
      • Auth method (OAuth 2 / JWT / API‑Key)
      • Pagination, filtering, and sorting conventions
      • Standard error envelope
  4. Produce Artifacts

    • openapi.yaml or schema.graphql (pick format or respect existing).

    • Concise api-guidelines.md summarizing:

      • Naming conventions
      • Required headers
      • Example requests/responses
      • Rate‑limit headers & security notes
  5. Validate & Summarize

    • Lint the spec (spectral, graphql-validate if available).
    • Return an API Design Report summarizing choices and open questions.

Output Template

## API Design Report

### Spec Files
- openapi.yaml  ➜  12 resources, 34 operations

### Core Decisions
1. URI versioning (`/v1`)
2. Cursor pagination (`cursor`, `limit`)
3. OAuth 2 Bearer + optional API‑Key for server‑to‑server

### Open Questions
- Should “order duplication” be a POST action or a sub‑resource (`/orders/{id}/duplicates`)?

### Next Steps (for implementers)
- Generate server stubs in chosen framework.
- Attach auth middleware to guard `/admin/*` routes.

Design Principles (Quick Reference)

  • Consistency > Cleverness – follow HTTP semantics or GraphQL naming norms.
  • Least Privilege – choose the simplest auth scheme that meets security needs.
  • Explicit Errors – use RFC 9457 (problem+json) or GraphQL error extensions.
  • Document by Example – include at least one example request/response per operation.

Read the full file on GitHub · 84 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. 2d ago First seen · 84 lines · 74 tokens per session scan A 8c8bd3826462

Subscribe to this mod's changes

api-architect is an agent published in the GitHub repository nodnarbnitram/claude-code-extensions (16 stars, last pushed 4mo ago), licensed MIT. It adds 74 tokens to every session and 658 once invoked, about $0.0004 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 2026-08-30.

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