Agent skill

API Mock Server

by majiayu000 in majiayu000/claude-skill-registry

Generate and run mock API servers from OpenAPI specifications

Install API Mock Server

skills CLI

$ npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install majiayu000/claude-skill-registry api-mock-server --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/majiayu000/claude-skill-registry.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/api/api-mock-server .claude/skills/api-mock-server && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "api-mock-server" agent skill from https://github.com/majiayu000/claude-skill-registry/tree/main/skills/api/api-mock-server into .claude/skills/api-mock-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-mock-server", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/majiayu000/claude-skill-registry/tree/main/skills/api/api-mock-server

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install majiayu000/claude-skill-registry api-mock-server --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/majiayu000/claude-skill-registry.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/api/api-mock-server .agents/skills/api-mock-server && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "api-mock-server" agent skill from https://github.com/majiayu000/claude-skill-registry/tree/main/skills/api/api-mock-server into .agents/skills/api-mock-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-mock-server", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install majiayu000/claude-skill-registry api-mock-server --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/majiayu000/claude-skill-registry.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/api/api-mock-server .cursor/skills/api-mock-server && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "api-mock-server" agent skill from https://github.com/majiayu000/claude-skill-registry/tree/main/skills/api/api-mock-server into .cursor/skills/api-mock-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-mock-server", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/majiayu000/claude-skill-registry.git --path skills/api/api-mock-server

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install majiayu000/claude-skill-registry api-mock-server --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/majiayu000/claude-skill-registry.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/api/api-mock-server .gemini/skills/api-mock-server && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "api-mock-server" agent skill from https://github.com/majiayu000/claude-skill-registry/tree/main/skills/api/api-mock-server into .gemini/skills/api-mock-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-mock-server", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install majiayu000/claude-skill-registry api-mock-server

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/majiayu000/claude-skill-registry.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/api/api-mock-server .github/skills/api-mock-server && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "api-mock-server" agent skill from https://github.com/majiayu000/claude-skill-registry/tree/main/skills/api/api-mock-server into .github/skills/api-mock-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-mock-server", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install majiayu000/claude-skill-registry api-mock-server --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/majiayu000/claude-skill-registry.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/api/api-mock-server .opencode/skills/api-mock-server && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "api-mock-server" agent skill from https://github.com/majiayu000/claude-skill-registry/tree/main/skills/api/api-mock-server into .opencode/skills/api-mock-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "api-mock-server", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: api-mock-server
GitHub stars: 666
Used in: 1 other repo
Token cost: ~586 tokens
SKILL.md length: 64 words
Files: 2
Skills in repo: 971
Repo updated: Oct 7, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Generate and run mock API servers from OpenAPI specifications

Tasks that involve OpenAPI specifications
SKILL.md covers Overview, Capabilities, Target Processes and Input Schema, plus 2 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

API Mock Server is an agent skill from majiayu000/claude-skill-registry. Generate and run mock API servers from OpenAPI specifications

Its SKILL.md is about 590 tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file (for example `metadata.json`).

It sits in Backend & APIs, covering OpenAPI specifications. The repository describes itself as: Searchable Claude Code skills catalog with source-linked guides and generated registry artifacts. The licence is MIT.

When your agent uses it

Tasks that involve OpenAPI specifications

Example prompts

“/api-mock-server”

Requirements

Pre-approved tools (allowed-tools): Bash, Read, Write, Glob

What it can do on your machine

Read from SKILL.md and the folder at commit 000116a. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
- Bash
- Read
- Write
- Glob
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are json and javascript).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

API Mock Server loads about 586 tokens when it runs. Until then it costs about 19 tokens; SKILL.md has 64 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~19
When it runs · the whole SKILL.md, loaded when a task matches: ~586

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check: notes

The automated check noted patterns worth knowing about, such as sudo or a known installer.

NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
```
allowed-tools: Bash, Read, Write, Glob
```

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from majiayu000/claude-skill-registry at commit 000116a, republished under its MIT licence (© majiayu000). 64 words, ~586 tokens.

Download SKILL.mdSave it as .claude/skills/api-mock-server/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.

name: api-mock-server
description: Generate and run mock API servers from OpenAPI specifications
allowed-tools: Bash, Read, Write, Glob

API Mock Server Skill

Overview

Generates and runs mock API servers from OpenAPI specifications with dynamic response generation, request validation, and Prism/Mockoon integration.

Capabilities

Generate mock server from OpenAPI spec
Dynamic response generation based on schemas
Request validation against spec
Prism and Mockoon integration
Custom response scenarios
Callback and webhook simulation
Stateful mock behavior

Target Processes

api-design-specification
microservices-decomposition

Input Schema

json

{
  "type": "object",
  "required": ["specPath"],
  "properties": {
    "specPath": {
      "type": "string",
      "description": "Path to OpenAPI specification"
    },
    "port": {
      "type": "number",
      "default": 4010
    },
    "engine": {
      "type": "string",
      "enum": ["prism", "mockoon", "custom"],
      "default": "prism"
    },
    "options": {
      "type": "object",
      "properties": {
        "dynamic": {
          "type": "boolean",
          "default": true,
          "description": "Generate dynamic responses"
        },
        "validateRequest": {
          "type": "boolean",
          "default": true
        },
        "cors": {
          "type": "boolean",
          "default": true
        },
        "scenarios": {
          "type": "array",
          "description": "Custom response scenarios"
        }
      }
    }
  }
}

Output Schema

json

{
  "type": "object",
  "properties": {
    "serverUrl": {
      "type": "string"
    },
    "port": {
      "type": "number"
    },
    "endpoints": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "method": { "type": "string" },
          "path": { "type": "string" }
        }
      }
    },
    "pid": {
      "type": "number",
      "description": "Process ID of running server"
    }
  }
}

Usage Example

javascript

{
  kind: 'skill',
  skill: {
    name: 'api-mock-server',
    context: {
      specPath: 'api/openapi.yaml',
      port: 4010,
      engine: 'prism',
      options: {
        dynamic: true,
        validateRequest: true
      }
    }
  }
}

Files

SKILL.md and 1 other file in skills/api/api-mock-server of majiayu000/claude-skill-registry.

SKILL.md
metadata.json

Open the folder on GitHubat commit 000116a

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in majiayu000/claude-skill-registry, which our catalogue first saw on October 7, 2026.

a5c-ai/babysitterlibrary/specializations/software-architecture/skills/api-mock-server

Compare with similar skills

API Mock Server next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

API Mock Server compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
API Mock Server this skillmajiayu000/claude-skill-registry	666	1 repos	~586	Automated safety check: Notes	MIT	today
ToolJet Marketplace Plugin BuilderToolJet/ToolJet	41k	—	~2.1k	Automated safety check: Pass	AGPL-3.0	today
Step Partsearthtojake/text-to-cad	18k	1 repos	~1.5k	Automated safety check: Pass	MIT	today
API DesignerJeffallan/claude-skills	12k	2 repos	~2k	Automated safety check: Pass	MIT	4 days ago
OpenAPI to MCP Servermcp-use/mcp-use	11k	—	~5.2k	Automated safety check: Pass	Apache-2.0	today
Use Yaakmountain-loop/yaak	19k	—	~1.9k	Automated safety check: Pass	MIT	today

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Questions about API Mock Server

What does API Mock Server do?

Generate and run mock API servers from OpenAPI specifications. API Mock Server is an agent skill from majiayu000/claude-skill-registry.

When should I use API Mock Server?

API Mock Server fits situations like: tasks that involve OpenAPI specifications.

How do I install API Mock Server in Claude Code?

Run `npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a claude-code`. Or copy the skill folder (skills/api/api-mock-server in majiayu000/claude-skill-registry) into .claude/skills/api-mock-server in your project. Claude Code loads it when a task matches its description.

How do I install API Mock Server in Codex?

Run `npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a codex`. Or copy the skill folder (skills/api/api-mock-server in majiayu000/claude-skill-registry) into .agents/skills/api-mock-server in your project. Codex loads it when a task matches its description.

Can I use API Mock Server in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add majiayu000/claude-skill-registry --skill api-mock-server -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/api-mock-server, .gemini/skills/api-mock-server, .github/skills/api-mock-server and .opencode/skills/api-mock-server in your project.

What does API Mock Server need to run?

SKILL.md names no scripts, command-line tools or credentials: API Mock Server is instructions for the agent only. Its frontmatter pre-approves these tools: Bash, Read, Write, Glob.

Does API Mock Server access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is API Mock Server safe to install?

Our automated static check of SKILL.md found notes only (pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.

What licence does API Mock Server use?

API Mock Server is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does API Mock Server use?

About 586 tokens (SKILL.md is roughly 2.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to API Mock Server?

Skills that share tags, products or a category with API Mock Server: ToolJet Marketplace Plugin Builder (ToolJet/ToolJet, 41k stars), Step Parts (earthtojake/text-to-cad, 18k stars), API Designer (Jeffallan/claude-skills, 12k stars) and OpenAPI to MCP Server (mcp-use/mcp-use, 11k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains API Mock Server?

majiayu000 (a GitHub user) maintains it in majiayu000/claude-skill-registry, which has 666 GitHub stars. The repository holds 971 skills in this directory. The repository was last updated on October 7, 2026.

Source: majiayu000/claude-skill-registry on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install API Mock Server

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

API Mock Server Skill

Overview

Capabilities

Target Processes

Input Schema

Output Schema

Usage Example

Files

Used in 1 other repository

Compare with similar skills

Similar skills

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Related

Questions about API Mock Server