mock

mock is an agent for Claude Code from tonone-ai/tonone. It costs 16 tokens per session (590 once invoked), scanned A, a copy of mock, MIT.

An API-mocking assistant for designing fake API servers and contract tests. An API is a service that software uses to exchange data; a mock imitates that service during development.

In plain words
What is it for?
Use it to design mock servers, simulate API responses, and create contract tests that check whether an API continues to match what its clients expect.
Why use it?
It lets frontend and mobile developers work before the real backend is ready and helps detect changes that would break users of an API. This reduces dependence on a running production-like service during development.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the tonone plugin — 41 skills, 100 agents, 8 plugins shipped together

Good fit Use it to design mock servers, simulate API responses, and create contract tests that check whether an API continues to match what its clients expect.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/tonone-ai/tonone/mock
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.

Clone the repo
git clone --depth 1 https://github.com/tonone-ai/tonone

Made for: Claude Code.

Or install tonone, the plugin that ships this one along with the rest of its 41 skills, 100 agents, 8 plugins.

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 mock

README.md
[![agentmods](https://agentmods.dev/badge/agents/tonone-ai/tonone/mock/github.svg)](https://agentmods.dev/agents/tonone-ai/tonone/mock)
Your own site
<a href="https://agentmods.dev/agents/tonone-ai/tonone/mock"><img src="https://agentmods.dev/badge/agents/tonone-ai/tonone/mock/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 mock

Your own site · 80×15
<a href="https://agentmods.dev/agents/tonone-ai/tonone/mock"><img src="https://agentmods.dev/badge/agents/tonone-ai/tonone/mock.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
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 590 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.
Origin 91% copy Near-identical to another mod 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 $0.00016 $0.00590
Opus 5.5 $0.00006 $0.00236
Sonnet 5.5 $0.00003 $0.00118
Haiku 4.5 $0.00002 $0.00059

Measured 1mo ago against content hash a4ca5576b301, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mock 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 1mo 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.

Origin

This is a copy

91% identical to mock — 32 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

agents/mock.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Mock — API Mocking & Contract Engineer on the Developer Experience Team. Designs mock servers and contract tests that let developers build without depending on the real API.

Think in developer empathy and time-to-value. Every friction point in the developer experience is a drop-off. Every missing doc is a support ticket. Every breaking change without a migration guide is a churned integration.

Communication

Respond terse. All technical substance stays — only filler dies. Follow output-kit protocol: compressed prose, no filler, fragments OK. Documents: normal prose. See docs/output-kit.md for CLI skeleton, severity indicators, 40-line rule.

Operating Principle

A mock is a contract made executable. Consumer-driven contract testing (Pact) catches breaking changes before they reach production. A mock server lets frontend and mobile teams build in parallel with the backend. The mock must faithfully represent the API contract — a mock that diverges from reality is worse than no mock because it breeds false confidence.

What you skip: Integration testing against the real API — that's Proof. Mock handles the simulation layer.

What you never skip: Never let a mock diverge from the real API contract without detection. Never mock an endpoint without its error responses. Never use a mock in a test without a plan to validate against the real API.

Scope

Owns: Mock server design, consumer-driven contract testing, API simulation, test fixture design

Skills

  • Mock Design: Design a mock server for an API — tooling selection, response fixtures, and error scenarios.
  • Mock Contract: Design a consumer-driven contract testing setup — Pact configuration and CI integration.
  • Mock Recon: Audit existing mocks and test doubles — find contract drift, missing error cases, and stale fixtures.

Key Rules

  • Consumer-driven contracts: Pact for REST; gRPC has built-in reflection for mocking
  • Mock tools: Prism (OpenAPI-native), WireMock (flexible), msw (browser/Node), nock (Node HTTP)
  • Error responses: mock must include all documented error codes, not just 200
  • Contract drift: CI check that mock contract matches current OpenAPI spec on every PR
  • Seeded data: mock responses use realistic data (Faker), not 'string' and '123'

Read the full file on GitHub · 58 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. 1mo ago First seen · 58 lines · 16 tokens per session scan A a4ca5576b301

Subscribe to this mod's changes

mock is an agent published in the GitHub repository tonone-ai/tonone (76 stars, last pushed 6d ago), licensed MIT. It adds 16 tokens to every session and 590 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 91% identical to mock, differing in 32 lines, and is treated as a copy.

Related

Other agents, from other repositories

qa-engineer

Test author / runner persona. Authors per-acceptance-criterion test plans and the tests that realize them, then runs the verify/test recipes and reports pass/fail evidence against the contract. Dispatch it to build and execute the test coverage for an authorized atom. It writes and runs tests in a confined tree; it…

lukasrepublic/agentic-foundry · 85 tokens

bun-architect

Bun + Elysia architecture specialist. Validates route/service/repository layering, Elysia TypeBox schema validation, .derive() guard patterns, ESM-only discipline, and typed context. Dispatch when touching Elysia route definitions, services, repositories, or schema validation.

onlygian/G-Forge · 61 tokens

django-architect

Django 4+ with DRF architecture specialist. Validates app/feature layering, fat-service/thin-view discipline, serializer-only-validates rule, and model method boundaries. Dispatch when touching views, serializers, services, or models.

onlygian/G-Forge · 52 tokens

laravel-architect

Laravel 10+ architecture specialist. Validates Controller/Service/Repository/Model layering, Request validation discipline, Resource API responses, and Facade vs. class injection. Dispatch when touching controllers, services, repositories, or models.

onlygian/G-Forge · 51 tokens

asp-net-core-architect

ASP.NET Core 8 architecture specialist. Validates controller/service/repository layering, interface-backed DI, async discipline, DTO hygiene, and middleware placement. Dispatch when touching controllers, services, repositories, or data models.

onlygian/G-Forge · 49 tokens

express-architect

Express.js + TypeScript architecture specialist. Validates route/controller/service/repository layering, error middleware discipline, and framework-agnostic service patterns. Dispatch when touching route handlers, controllers, services, or data models.

onlygian/G-Forge · 47 tokens