mock

mock is an agent for Claude Code from jeremylongshore/tons-of-skills-marketplace. It costs 62 tokens per session (807 once invoked), scanned A, original, MIT.

A simulated API server and a set of tests that check whether services keep the promises made in their API contracts. An API contract describes the requests and responses that connected software expects.

In plain words
What is it for?
Creating API mocks with tools such as Pact, Prism, WireMock, or MSW, and setting up consumer-driven contract tests in continuous integration.
Why use it?
It lets frontend, mobile, and backend teams work in parallel and catches breaking API changes before release.

Agent for Claude Code

Written for Claude Code: background in frontmatter. Also seen: model in frontmatter.

Part of the tonone plugin — 100 agents, 9 plugins shipped together

Good fit Creating API mocks with tools such as Pact, Prism, WireMock, or MSW, and setting up consumer-driven contract tests in continuous integration.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/jeremylongshore/tons-of-skills-marketplace/mock
About the project

Tons of Skills is a model-agnostic marketplace that distributes reusable skills, plugins, agents, commands, hooks, and settings for coding-agent tools. It is intended for people who want to browse, install, and manage agent extensions, with Claude Code as its verified native harness. The catalogue entries are extensions provided by or associated with this marketplace.

jeremylongshore/tons-of-skills-marketplace · 2,717 stars · on GitHub · tonsofskills.com

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/jeremylongshore/tons-of-skills-marketplace

Made for: Claude Code.

Or install tonone, the plugin that ships this one along with the rest of its 100 agents, 9 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/jeremylongshore/tons-of-skills-marketplace/mock/github.svg)](https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/mock)
Your own site
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/mock"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/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/jeremylongshore/tons-of-skills-marketplace/mock"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/mock.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 62 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 807 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 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 $0.00062 $0.00807
Opus 5 $0.00031 $0.00404
Sonnet 5 $0.00012 $0.00161
Haiku 4.5 $0.00006 $0.00081

Measured 9d ago against content hash f4ecd075b812, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, 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 9d 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.

plugins/ai-agency/tonone/agents/mock.md · 72 lines

How it starts

The opening of the file, as written. The whole thing — 72 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 · 72 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. 9d ago First seen · 72 lines · 62 tokens per session scan A f4ecd075b812

Subscribe to this mod's changes

mock is an agent published in the GitHub repository jeremylongshore/tons-of-skills-marketplace (2,717 stars, last pushed today), licensed MIT. It adds 62 tokens to every session and 807 once invoked, about $0.0003 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 2026-09-03.

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