oc-api-dev

oc-api-dev is a skill for Claude Code, Codex from asfbay-bit/opchain-skills. It costs 171 tokens per session (6,432 once invoked), scanned A, original, Apache-2.0.

A workflow for designing and building an API, the interface through which other software communicates with your application. It creates an OpenAPI or GraphQL contract, builds typed handlers and an SDK, and tests the running service against that contract.

In plain words
What is it for?
Use it to design or update an API specification, scaffold handlers and validation, generate an SDK, test a running server, and check changes against the previously released API.
Why use it?
It keeps the API description, implementation, and generated client code aligned, while helping identify breaking changes before they surprise users.

Skill for Claude CodeCodex

Part of the opchain plugin — 33 skills, 12 commands, 3 hooks shipped together

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 skills/asfbay-bit/opchain-skills/oc-api-dev
Any agent
npx skills add asfbay-bit/opchain-skills --skill oc-api-dev
Clone the repo
git clone --depth 1 https://github.com/asfbay-bit/opchain-skills

Made for: Claude Code, Codex.

Or install opchain, the plugin that ships this one along with the rest of its 33 skills, 12 commands, 3 hooks.

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 oc-api-dev

README.md
[![agentmods](https://agentmods.dev/badge/skills/asfbay-bit/opchain-skills/oc-api-dev.svg)](https://agentmods.dev/skills/asfbay-bit/opchain-skills/oc-api-dev)
Your own site
<a href="https://agentmods.dev/skills/asfbay-bit/opchain-skills/oc-api-dev"><img src="https://agentmods.dev/badge/skills/asfbay-bit/opchain-skills/oc-api-dev.svg" alt="Measured on agentmods" height="20"></a>
Per session 171 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,432 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 5.1 $0.00171 $0.06432
Opus 5 $0.00086 $0.03216
Sonnet 5 $0.00034 $0.01286
Haiku 4.5 $0.00017 $0.00643

Measured yesterday against content hash c03ebd64c061, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

oc-api-dev 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 yesterday.

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/opchain/skills/oc-api-dev/SKILL.md · 640 lines

How it starts

The opening of the file, as written. The whole thing — 640 lines — stays where its author put it; the contents beside it link to each section on GitHub.

API Developer

On first invocation, read references/orchestrator.md and follow its welcome protocol.

Tri-agent first-party API harness: Designer authors the contract (OpenAPI / GraphQL schema) → Builder scaffolds typed handlers, validation, and an SDK against it → Conformance hits the running server, validates responses against the spec, and diffs the new spec against the previously-shipped one to flag undeclared breaking changes.

This is the producer-side counterpart to oc-integrations-engineer. If you're consuming someone else's API (Stripe, Slack, Salesforce, OAuth providers), use oc-integrations-engineer. If you're designing/building the API your own clients, customers, or partners consume, use this skill.


/oc-api — Command Reference

API DEVELOPER COMMANDS
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  TRI-AGENT HARNESS
  /oc-api design         Author the API contract (Designer agent)
  /oc-api build          Scaffold + conformance loop (Builder → Conformance)
  /oc-api test           Run Conformance against an existing server

  AUTHOR
  /oc-api spec           Generate / update OpenAPI or GraphQL schema from data model
  /oc-api scaffold       Generate typed handlers + validation middleware from spec
  /oc-api lint           Run spectral / redocly lint on the spec

  LIFECYCLE
  /oc-api version        Plan a new version (URL or header strategy)
  /oc-api deprecate      Mark endpoints deprecated; emit Sunset/Deprecation headers
  /oc-api docs           Render human-readable docs from the spec
  /oc-api sdk            Generate TypeScript / Python / Go SDK from the spec

  UTILITIES
  /oc-api list           Show all endpoints with version + deprecation status
  /oc-api drift          Compare spec to running code; report mismatches
  /checkpoint         Show checkpoint status

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
  Type any command to begin. /oc-api to see this again.

Tri-Agent Architecture

API DESIGN INTENT
(from oc-app-architect 02-architecture.md API Design section)
        │
        ▼
┌──────────────────┐
│   API            │  Authors contract: OpenAPI / GraphQL schema.
│   DESIGNER       │  Decides versioning, pagination, error envelope,
│                  │  idempotency, rate-limit policy declarations.
└────────┬─────────┘
         │
         ▼
┌──────────────────────────────────────────────┐
│     BUILD LOOP (per API surface)             │
│                                              │
│  ┌────────────┐  contract   ┌─────────────┐  │
│  │    API     │◄─negotiate──►│    API     │  │
│  │  BUILDER   │             │ CONFORMANCE │  │
│  │            │──code──────►│             │  │
│  │  Scaffolds │             │  Hits live  │  │
│  │  handlers  │◄──failures──│  server +   │  │
│  │  + SDK     │             │  diffs spec │  │
│  └────────────┘             └─────────────┘  │
│       │                           │          │
│       │    All checks pass?       │          │
│       └───────────────────────────┘          │
└──────────────────────────────────────────────┘
         │
         └──► Drift monitoring (ongoing)

Read the full file on GitHub · 640 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. yesterday Changed · +2 lines · +17 tokens per session c03ebd64c061
  2. 4d ago First seen · 638 lines · 154 tokens per session scan A b69c584ab9c9

Subscribe to this mod's changes

oc-api-dev is a skill published in the GitHub repository asfbay-bit/opchain-skills (0 stars, last pushed 2d ago), licensed Apache-2.0. It adds 171 tokens to every session and 6,432 once invoked, about $0.0009 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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