A complete, self-contained OpenAPI toolkit for Go with minimal dependencies.
Parse, validate, fix, convert, diff, join, generate, and build OpenAPI specs (2.0–3.2) — all in one tool.
What It Does
Spec Lifecycle — parser · validator · fixer · converter
Multi-Spec Ops — joiner · differ · overlay
Code & Query — generator · builder · walker
Runtime — httpvalidator · oaserrors
12 packages covering the full OpenAPI lifecycle. See full details →
Highlights
- 📦 Minimal Dependencies — Only
go.yaml.in/yaml, golang.org/x/tools, golang.org/x/text, and the MCP Go SDK at runtime
- ✅ Battle-Tested — 8,000+ tests against 10 production APIs (Stripe, GitHub, Discord, MS Graph 34MB)
- ⚡ Performance — Pre-parsed workflows 11–150x faster; 340+ benchmarks
- 📋 OAS 2.0–3.2 — Full JSON Schema Draft 2020-12 for OAS 3.1+; automatic format detection and preservation
- 🤖 AI-Ready — Built-in MCP server exposes all capabilities to LLM agents
- 🌐 Try Online — oastools.robnrob.com — no install required
Quick Start
CLI
oastools validate openapi.yaml # Validate a spec
oastools convert -t 3.0.3 swagger.yaml -o openapi.yaml # Convert versions
oastools diff --breaking v1.yaml v2.yaml # Detect breaking changes
oastools fix api.yaml -o fixed.yaml # Auto-fix errors
oastools join -o merged.yaml base.yaml ext.yaml # Merge specs
oastools generate --client --server -o ./gen -p api openapi.yaml # Generate Go code
Library
// Parse, validate, and fix — consistent functional options API
result, _ := parser.ParseWithOptions(parser.WithFilePath("api.yaml"))
vResult, _ := validator.ValidateWithOptions(validator.WithParsed(*result))
fResult, _ := fixer.FixWithOptions(fixer.WithParsed(*result))
Full library guide →
Installation
CLI
brew install erraggy/oastools/oastools # Homebrew (macOS/Linux)
go install github.com/erraggy/oastools/cmd/oastools@latest # Go install
Pre-built binaries for macOS, Linux, and Windows on the Releases page.
Library
go get github.com/erraggy/oastools@latest
Requires Go 1.25+.
Documentation
📚 Documentation Site — Guides, examples, and package deep dives
📖 CLI Reference — All commands, flags, and output formats
🤖 MCP Server — LLM agent integration via Model Context Protocol
📦 API Reference — Go package documentation with runnable examples
Contributing
