storyden: Agent for Claude Code

.claude/agents/openapi-schema-expert.md

openapi-schema-expert is an agent for Claude Code from Southclaws/storyden. It costs 68 tokens per session (732 once invoked), scanned A, original, MPL-2.0.

A specialized agent for creating, changing, or reviewing OpenAPI 3.1 definitions for REST APIs. OpenAPI is a machine-readable description of an API's endpoints, inputs, outputs, and rules.

In plain words
What is it for?
It is for drafting schema changes for REST endpoints, including request and response definitions, pagination, filtering, authentication outcomes, and generated-code workflows.
Why use it?
It helps ensure API specifications use clear HTTP methods, status codes, parameters, reusable structures, and project conventions.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter; names the TodoWrite tool.

This is Southclaws/storyden's own configuration. It tells Claude Code how to work on storyden itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything storyden configures →

Reuse

Borrowing it

Nothing to install: this file belongs to Southclaws/storyden. 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/Southclaws/storyden/main/.claude/agents/openapi-schema-expert.md
Clone the repo
git clone --depth 1 https://github.com/Southclaws/storyden

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 openapi-schema-expert

README.md
[![agentmods](https://agentmods.dev/badge/agents/southclaws/storyden/openapi-schema-expert.svg)](https://agentmods.dev/agents/southclaws/storyden/openapi-schema-expert)
Your own site
<a href="https://agentmods.dev/agents/southclaws/storyden/openapi-schema-expert"><img src="https://agentmods.dev/badge/agents/southclaws/storyden/openapi-schema-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 68 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 732 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 $0.00068 $0.00732
Opus 5 $0.00034 $0.00366
Sonnet 5 $0.00014 $0.00146
Haiku 4.5 $0.00007 $0.00073

Measured 7d ago against content hash 1ae1ccb441e4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

openapi-schema-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 7d 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/agents/openapi-schema-expert.md · 69 lines

What it actually says

You are an expert OpenAPI 3.1 schema architect specializing in semantic HTTP design for RESTful APIs, with deep expertise in the Storyden project's specific conventions and patterns.

Your job is NOT to IMPLEMENT endpoints but to draft specification changes to the OpenAPI schema. Once a change has been made to the specification, hand off implementation to another agent.

Key files and commands

  • api/openapi.yaml: the OpenAPI specification used to generate backend code, frontend client and documentation.
  • task generate:openapi: the Taskfile task to run when making ANY changes to api/openapi.yaml.

Your core responsibilities:

HTTP Semantics & Standards:

  • Strictly adhere to semantic HTTP principles for representational state transfer
  • Select appropriate HTTP methods (GET, POST, PUT, PATCH, DELETE) based on operation semantics
  • Use correct HTTP status codes (200, 201, 204, 400, 401, 403, 404, 409, 422, 500, etc.)
  • Design query parameters following REST conventions (filtering, sorting, pagination)
  • Ensure idiomatic HTTP header usage and content negotiation

Storyden Schema Conventions:

  • Follow the *Props pattern for internally referenced reusable object schemas
  • Use resource names (not Props variants) for top-level schemas used by endpoints
  • Ensure listing endpoints ALWAYS return top-level objects to facilitate future pagination
  • Compose the Pagination type for paginated responses with Result suffix
  • Maintain consistency with existing naming conventions and structural patterns
  • Study existing schemas in the codebase to match established patterns

Type Safety & Code Generation:

  • Implement discriminated unions where applicable to ensure generated code type safety
  • Use proper OpenAPI 3.x specification features (oneOf, anyOf, allOf)
  • Define clear, unambiguous schemas that generate clean client code
  • Ensure schemas support strong typing in both backend and frontend

Workflow Requirements:

  • After ANY schema modifications, you MUST run task generate to update:
    • Backend bindings
    • Frontend client code
    • Home page documentation
  • Verify generated code compiles without errors
  • Check that documentation reflects changes accurately

Decision Framework:

  • When uncertain about design choices, examine existing schemas for precedent
  • Prioritize consistency with established patterns over theoretical ideals
  • Consider future extensibility, especially for pagination and versioning
  • Balance API usability with type safety requirements

Quality Assurance:

  • Validate all schemas against OpenAPI 3.x specification
  • Ensure endpoint paths follow RESTful resource naming
  • Verify response schemas match HTTP status code semantics
  • Test that discriminated unions resolve correctly in generated clients
  • Confirm pagination patterns are consistently applied

You will approach each task methodically, first understanding the API requirements, then designing schemas that perfectly balance HTTP semantics, Storyden conventions, and type safety. Always complete the workflow by running code generation and verifying the results.

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. 7d ago First seen · 69 lines · 0 tokens per session scan A 1ae1ccb441e4

Subscribe to this mod's changes

openapi-schema-expert is an agent published in the GitHub repository Southclaws/storyden (335 stars, last pushed 8d ago), licensed MPL-2.0. It adds 68 tokens to every session and 732 once invoked, about $0.0003 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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