go-openapi

go-openapi is a skill for Claude Code from eduardo-sl/go-agent-skills. It costs 149 tokens per session (2,019 once invoked), scanned A, original, MIT.

A spec-first approach to building REST APIs in Go with OpenAPI, a document that defines an API's routes, data, and expected responses.

In plain words
What is it for?
Use it when creating or extending an OpenAPI pipeline, generating Go servers and clients, validating requests, testing API contracts, or checking for breaking changes.
Why use it?
It keeps the API definition, server code, and clients aligned by generating code from one reviewed source instead of maintaining separate copies by hand.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions Claude Code.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is //go:generate go tool oapi-codegen -config oapi-codegen.yaml ../../api/openapi.yaml.

Part of the go-agent-skills plugin — 33 skills shipped together

Good fit Use it when creating or extending an OpenAPI pipeline, generating Go servers and clients, validating requests, testing API contracts, or checking for breaking changes.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/eduardo-sl/go-agent-skills
agentmods
npx agentmods add skills/eduardo-sl/go-agent-skills/go-openapi

Made for: Claude Code.

Or install go-agent-skills, the plugin that ships this one along with the rest of its 33 skills.

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 go-openapi

README.md
[![agentmods](https://agentmods.dev/badge/skills/eduardo-sl/go-agent-skills/go-openapi/github.svg)](https://agentmods.dev/skills/eduardo-sl/go-agent-skills/go-openapi)
Your own site
<a href="https://agentmods.dev/skills/eduardo-sl/go-agent-skills/go-openapi"><img src="https://agentmods.dev/badge/skills/eduardo-sl/go-agent-skills/go-openapi/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for go-openapi

Your own site · 80×15
<a href="https://agentmods.dev/skills/eduardo-sl/go-agent-skills/go-openapi"><img src="https://agentmods.dev/badge/skills/eduardo-sl/go-agent-skills/go-openapi.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 149 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,019 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00149 $0.02019
Opus 5 $0.00075 $0.01009
Sonnet 5 $0.00030 $0.00404
Haiku 4.5 $0.00015 $0.00202

Measured 10d ago against content hash 399a4e7304ba, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

go-openapi 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 10d 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.

skills/(architecture)/go-openapi/SKILL.md · 226 lines

How it starts

The opening of the file, as written. The whole thing — 226 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Go OpenAPI

The spec is the source of truth. Types, routes, and clients are generated from it — never hand-written alongside it, because two hand-maintained copies of a contract diverge within one sprint.

Operating Modes

  • Adopt — the project has hand-written handlers and no spec, or a spec nobody generates from. Introduce generation without a rewrite.
  • Extend — the pipeline exists. Change the spec, regenerate, implement.
  • Review — check that handlers, spec, and published client agree, and that the change is not silently breaking.

1. Choose the Generator Once

Tool Use it when
oapi-codegen Default. Types + server interface + client, works with net/http, chi, echo, gin
ogen You want a fully generated, strictly validating server and can accept its opinions
swaggo/swag Only for a legacy code-first project you are not converting — annotations generate the spec, so the spec cannot be reviewed before the code exists

Do not mix. A project with both annotations and a checked-in spec has two sources of truth again.

2. Wire Generation Into the Build

Pin the generator as a module tool (Go 1.24+), so every developer and CI run uses the same version:

go get -tool github.com/oapi-codegen/oapi-codegen/v2/cmd/oapi-codegen
# oapi-codegen.yaml
package: api
output: internal/api/openapi.gen.go
generate:
  models: true
  std-http-server: true   # Go 1.22+ ServeMux; use chi-server / echo-server if that is the router
  strict-server: true     # typed request/response structs instead of raw http.ResponseWriter
  embedded-spec: true     # lets the service serve its own spec
output-options:
  skip-prune: false
//go:generate go tool oapi-codegen -config oapi-codegen.yaml ../../api/openapi.yaml

Commit generated files. Reviewers need to see the diff of a contract change, and a build must not depend on a generator being installed.

CI must fail when they are stale:

go generate ./... && git diff --exit-code

Read the full file on GitHub · 226 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. 10d ago First seen · 226 lines · 149 tokens per session scan A 399a4e7304ba

Subscribe to this mod's changes

go-openapi is a skill published in the GitHub repository eduardo-sl/go-agent-skills (71 stars, last pushed 22d ago), licensed MIT. It adds 149 tokens to every session and 2,019 once invoked, about $0.0007 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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