mixins

mixins is a skill for Claude Code from finom/vovk. It costs 275 tokens per session (4,239 once invoked), scanned A, original, MIT.

A code-generation feature that turns an OpenAPI 3.x document—a description of an HTTP API—into typed client modules for Vovk.ts applications. The generated modules use the same calling style as Vovk’s own remote-procedure modules.

In plain words
What is it for?
Use it to import third-party APIs into a Vovk.ts app, generate typed calls from an OpenAPI specification, or expose those calls to OpenAI, Anthropic, or Vercel function-calling tools.
Why use it?
It reduces manual work when connecting an application to an external service described by an OpenAPI document. It can also provide parameter schemas for some AI function-calling integrations.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the vovk plugin — 15 skills shipped together

Good fit Use it to import third-party APIs into a Vovk.ts app, generate typed calls from an OpenAPI specification, or expose those calls to OpenAI, Anthropic, or Vercel function-calling tools.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/finom/vovk/mixins
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.

Any agent
npx skills add finom/vovk --skill mixins
Clone the repo
git clone --depth 1 https://github.com/finom/vovk

Made for: Claude Code.

Or install vovk, the plugin that ships this one along with the rest of its 15 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 mixins

README.md
[![agentmods](https://agentmods.dev/badge/skills/finom/vovk/mixins.svg)](https://agentmods.dev/skills/finom/vovk/mixins)
Your own site
<a href="https://agentmods.dev/skills/finom/vovk/mixins"><img src="https://agentmods.dev/badge/skills/finom/vovk/mixins.svg" alt="Measured on agentmods" height="20"></a>
Per session 275 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,239 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 warn 7 Sept 2026
SkillSpector: 3 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium MCP Rug Pull · line 74
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 285
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 317
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
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 $0.00275 $0.04239
Opus 5 $0.00138 $0.02119
Sonnet 5 $0.00055 $0.00848
Haiku 4.5 $0.00028 $0.00424

Measured 8d ago against content hash f56a1c620bf4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

mixins 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 8d 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/mixins/SKILL.md · 318 lines

How it starts

The opening of the file, as written. The whole thing — 318 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Vovk.ts OpenAPI mixins

Mixins turn any OpenAPI 3.x spec into typed client module behaving exactly like native Vovk RPC module — same { params, query, body } call shape, same client surface, same type-inference helpers (VovkBody, VovkOutput, …). Can run mixins standalone (no Next.js) as pure codegen tool.

One caveat not obvious from call shape: mixins work with deriveTools for OpenAI / Anthropic / Vercel function-calling — parameters (JSON Schema) populates from the mixin's validation. Exception: the mcp-handler path reads inputSchemas (Standard Schemas), which mixins don't carry — for MCP servers, wrap mixin calls in createTool instead. Verified in packages/vovk/src/client/create-rpc.ts:178-193 (no definition) vs packages/vovk/src/tools/derive-tools.ts:113-115 (reads definition for inputSchemas) and packages/vovk/src/validation/with-validation-library.ts:281 (definition set only by procedure({...}).handle(...)). See tools skill for createTool wrapper pattern.

Prefer the official SDK when one exists

Recommend official client library first. Hand-maintained SDKs like stripe, @octokit/rest, @aws-sdk/*, @google-cloud/* ship with auth flows, retries, pagination helpers, webhook signature verification, edge-case handling that generated client can't match — and track upstream API changes faster than any spec snapshot. If vendor publishes official SDK, use it.

Mixins right tool when:

  • No official SDK exists — internal services, niche vendors, legacy APIs that only publish OpenAPI document.
  • LLM tool exposurederiveTools works directly for OpenAI / Anthropic / Vercel function-calling. For MCP, wrap mixin calls in createTool({...}) (see caveat at top). For GitHub-style APIs @octokit/rest still better tool body, but mixin remains useful when third-party API has no official SDK.
  • Spec-as-source-of-truth — internal microservices where OpenAPI doc is generated and you want client drift to surface as TypeScript error at build time.

Read the full file on GitHub · 318 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. 8d ago First seen · 318 lines · 275 tokens per session scan A f56a1c620bf4

Subscribe to this mod's changes

mixins is a skill published in the GitHub repository finom/vovk (52 stars, last pushed 11d ago), licensed MIT. It adds 275 tokens to every session and 4,239 once invoked, about $0.0014 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.

Related

Other skills, from other repositories

client-setup

Create a vanilla tRPC client with createTRPCClient (), configure link chain with httpBatchLink/httpLink, dynamic headers for auth, transformer on links (not client constructor). Infer types with inferRouterInputs and inferRouterOutputs. AbortController signal support. TRPCClientError typing.

trpc/trpc · 63 tokens

adapter-express

Mount tRPC as Express middleware with createExpressMiddleware() from @trpc/server/adapters/express. Access Express req/res in createContext via CreateExpressContextOptions. Mount at a path prefix like app.use('/trpc', ...). Avoid global express.json() conflicting with tRPC body parsing for FormData.

trpc/trpc · 67 tokens

trpc-router

Entry point for all tRPC skills. Decision tree routing by task: initTRPC.create(), t.router(), t.procedure, createTRPCClient, adapters, subscriptions, React Query, Next.js, links, middleware, validators, error handling, caching, FormData.

trpc/trpc · 59 tokens

ocli-api

Turn any OpenAPI/Swagger API into CLI commands and call them. Search endpoints with BM25, check parameters, execute — no MCP server needed.

EvilFreelancer/openapi-to-cli · 34 tokens

nestjs

Use when building or structuring a NestJS backend — feature modules, providers and DI wiring, provider scopes and request-lifecycle order, where to bind guards/pipes/interceptors/filters, and testing with Test.createTestingModule. NOT a bare Express/Fastify service with no DI (that is nodejs), NOT framework-agnostic…

ericrisco/rsc-harness · 81 tokens

webiny-api-cms-custom-field-type

How to implement a custom CMS field type that integrates with the model builder's fluent API. Covers extending DataFieldBuilder, composing validator interfaces, creating a FieldTypeFactory, registering via DI, and module augmentation for TypeScript autocomplete on the fields() registry.

webiny/webiny-js · 60 tokens