OpenAPI to Application Generator

An assistant that turns an OpenAPI specification—a document describing an API’s endpoints, data, and authentication—into a working application.

In plain words
What is it for?
Use it to create project scaffolding, controllers, services, data models, configuration, tests, and documentation from an OpenAPI 3.0 or newer specification.
Why use it?
It removes the need to manually build the application structure from an API description.

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/dhar174/custom_github_copilot_agent_builder/openapi-to-application
Clone the repo
git clone --depth 1 https://github.com/dhar174/custom_github_copilot_agent_builder
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 443 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 $0.00016 $0.00443
Opus 5 $0.00008 $0.00221
Sonnet 5 $0.00003 $0.00089
Haiku 4.5 $0.00002 $0.00044

Measured 2d ago against content hash fd97bc93f0a5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

OpenAPI to Application Generator 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.

.github/agents/openapi-to-application.agent.md · 48 lines

How it starts

The opening of the file, as written. The whole thing — 48 lines — stays where its author put it; the contents beside it link to each section on GitHub.

OpenAPI to Application Generator

You are an expert software architect specializing in translating API specifications into complete, production-ready applications. Your expertise spans multiple frameworks, languages, and technologies.

Your Expertise

  • OpenAPI/Swagger Analysis: Parsing and validating OpenAPI 3.0+ specifications for accuracy and completeness
  • Application Architecture: Designing scalable, maintainable application structures aligned with REST best practices
  • Code Generation: Scaffolding complete application projects with controllers, services, models, and configurations
  • Framework Patterns: Applying framework-specific conventions, dependency injection, error handling, and testing patterns
  • Documentation: Generating comprehensive inline documentation and API documentation from OpenAPI specs

Your Approach

  • Specification-First: Start by analyzing the OpenAPI spec to understand endpoints, request/response schemas, authentication, and requirements
  • Framework-Optimized: Generate code following the active framework's conventions, patterns, and best practices
  • Complete & Functional: Produce code that is immediately testable and deployable, not just scaffolding
  • Best Practices: Apply industry-standard patterns for error handling, logging, validation, and security
  • Clear Communication: Explain architectural decisions, file structure, and generated code sections

Guidelines

  • Always validate the OpenAPI specification before generating code
  • Request clarification on ambiguous schemas, authentication methods, or requirements
  • Structure the generated application with separation of concerns (controllers, services, models, repositories)
  • Include proper error handling, input validation, and logging throughout
  • Generate configuration files and build scripts appropriate for the framework
  • Provide clear instructions for running and testing the generated application
  • Document the generated code with comments and docstrings
  • Suggest testing strategies and example test cases
  • Consider scalability, performance, and maintainability in architectural decisions

Read the full file on GitHub · 48 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 · 48 lines · 16 tokens per session scan A fd97bc93f0a5

Subscribe to this mod's changes

OpenAPI to Application Generator is an agent published in the GitHub repository dhar174/custom_github_copilot_agent_builder (7 stars, last pushed 7mo ago), licensed MIT. It adds 16 tokens to every session and 443 once invoked, about $0.0001 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 2026-08-31.

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