io.github.dinosaur24/mockhero

Official9 tools

by dinosaur24 · TypeScript

MockHero

Generate realistic relational test data — 156 field types, 22 locales, JSON/CSV/SQL, free previews.

Generate realistic relational test data in JSON, CSV, or SQL formats.

Topics

apidatabasedeveloper-toolsfakermcp-servermock-datanextjsseed-datasynthetic-datatest-datatestingtypescript

Captured live from the server via tools/list.

estimate_agent_usage

Estimate MockHero agent-plan cost before generating data. No login or API key is required; include an API key only when you want the estimate to use actual daily usage.

Parameters (11)

tablesarray
promptstring
Plain-English data request. Example: 50 users and 200 orders linked to them.
formatstring
sql_dialectstring
localestring
Default locale such as en, de, fr, es, or ja.
seednumber
Seed for reproducible output.
templatestring
scalenumber
Multiplier for template record counts.
estimated_recordsinteger
Required for prompt estimates because this tool does not run prompt-to-schema conversion.
daily_used_beforeinteger
Optional assumption when no API key is supplied.
api_keystring
Optional MockHero API key for no-auth MCP clients. Prefer the Authorization header when the client supports it.

create_agent_checkout

Create a loginless Polar Checkout URL for MockHero's metered agent plan. Polar is the Merchant of Record for checkout, tax collection, and remittance. The card payment step needs a human: present the returned url to your operator together with the estimate_agent_usage cost, keep the claim_token private, then poll check_agent_checkout_status and call claim_agent_api_key once paid.

Parameters (1)

emailstringrequired
Billing email for the agent or the agent operator.

check_agent_checkout_status

Poll a Polar checkout created by create_agent_checkout using the returned claim_token.

Parameters (1)

tokenstringrequired
claim_token returned by create_agent_checkout.

claim_agent_api_key

Claim the MockHero API key after Polar marks the loginless agent checkout as paid. The key is returned once.

Parameters (1)

tokenstringrequired
claim_token returned by create_agent_checkout.

generate_test_data

Generate realistic JSON, CSV, or SQL test data from structured tables or a plain-English prompt. Explicit table schemas up to 100 records can run free as a proof-of-work preview; plain-English prompt generation, larger requests, and production usage require a MockHero API key.

Parameters (7)

tablesarray
promptstring
Plain-English data request. Example: 50 users and 200 orders linked to them.
formatstring
sql_dialectstring
localestring
Default locale such as en, de, fr, es, or ja.
seednumber
Seed for reproducible output.
api_keystring
Optional MockHero API key for no-auth MCP clients. Prefer the Authorization header when the client supports it.

generate_from_template

Generate realistic test data from a pre-built MockHero template: ecommerce, blog, saas, or social. Small template previews up to 100 records can run free; larger or production usage requires a MockHero API key.

Parameters (7)

templatestringrequired
scalenumber
localestring
formatstring
sql_dialectstring
seednumber
api_keystring
Optional MockHero API key for no-auth MCP clients. Prefer the Authorization header when the client supports it.

detect_schema

Convert SQL CREATE TABLE statements or one sample JSON object into a MockHero schema that can be passed to generate_test_data.

Parameters (2)

sqlstring
SQL CREATE TABLE statement or statements.
sample_jsonobject
Single example JSON object to infer fields from.

list_field_types

List MockHero field types, descriptions, parameters, and examples before building a schema.

No parameters.

list_templates

List MockHero's pre-built schema templates for ecommerce, blog, SaaS, and social apps.

No parameters.

README.md3 KBView on GitHub

MockHero

Synthetic test data API. Generate realistic, relational data for any database schema.

What it does

156 field types across 15+ categories (identity, location, financial, temporal, and more)
Relational data — foreign keys just work. Orders reference real user IDs, reviews link to real products. One API call seeds your entire database.
3 input modes — structured schema, plain English prompt, or pre-built templates
Auto-locale — add a country enum field and names, emails, phones match each row's nationality. 22 locales supported.
JSON, CSV, SQL output — Postgres, MySQL, SQLite dialects
Deterministic seeds — same seed + same schema = identical data every time
MCP server — use from Claude Desktop, Cursor, Windsurf, or any AI agent

Quick start

bash

curl -X POST https://mockhero.dev/api/v1/generate \
  -H "Authorization: Bearer mh_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tables": [
      {
        "name": "users",
        "count": 50,
        "fields": [
          { "name": "id", "type": "uuid" },
          { "name": "name", "type": "full_name" },
          { "name": "email", "type": "email" },
          { "name": "country", "type": "enum", "params": { "values": ["US", "DE", "FR", "JP"] } },
          { "name": "created_at", "type": "datetime" }
        ]
      },
      {
        "name": "orders",
        "count": 200,
        "fields": [
          { "name": "id", "type": "uuid" },
          { "name": "user_id", "type": "ref", "params": { "table": "users", "field": "id" } },
          { "name": "total", "type": "price" },
          { "name": "status", "type": "enum", "params": { "values": ["pending", "shipped", "delivered"] } }
        ]
      }
    ]
  }'

Or use plain English:

bash

curl -X POST https://mockhero.dev/api/v1/generate \
  -H "Authorization: Bearer mh_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "prompt": "50 users with German names and 200 orders linked to them" }'

Templates

Pre-built schemas for common patterns — no schema definition needed:

bash

curl -X POST https://mockhero.dev/api/v1/generate \
  -H "Authorization: Bearer mh_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "template": "ecommerce", "scale": 2, "locale": "de" }'

Available: ecommerce, blog, saas, social

MCP server

Use MockHero from AI agents via the Model Context Protocol.

Hosted remote MCP endpoint for agent-first clients:

text

https://mockhero.dev/mcp/agent

This endpoint exposes estimate, loginless Polar checkout, checkout status, API key claim, schema detection, templates, and generation tools.

Local stdio MCP server for agents that run npm packages:

bash

npm install -g @mockherodev/mcp-server

See @mockherodev/mcp-server for setup instructions.

Pricing

	Free	Pro	Scale
Daily records	1,000	50,000	500,000
Requests/min	10	60	200
Price	$0	$29/mo	$79/mo

Tech stack

Next.js 15 (App Router)
Supabase (Postgres)
Clerk (Auth)
Polar (Billing)
Tailwind v4

License

MIT

Install

Configuration

Environment variables

MOCKHERO_API_KEYsecret

MockHero API key (optional — without it, generation runs as a free preview up to 100 records per request; get a key at https://mockhero.dev or via the create_agent_checkout tool)

MOCKHERO_API_BASE

Base URL of the MockHero API (default https://mockhero.dev)

claude_desktop_config.json

{
  "mcpServers": {
    "mockhero": {
      "command": "npx",
      "args": [
        "-y",
        "@mockherodev/mcp-server@0.2.0"
      ],
      "env": {
        "MOCKHERO_API_KEY": "<YOUR_MOCKHERO_API_KEY>",
        "MOCKHERO_API_BASE": "<YOUR_MOCKHERO_API_BASE>"
      }
    }
  }
}