MockSmith
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Describe your API.
It already exists.

One sentence is enough. MockSmith forges the spec, generates realistic data and serves complete CRUD endpoints, while your real backend does not exist yet.

Forge my first mocksee an example →

Free up to 2 projects · no credit card

  • uuid
  • fullName
  • firstName
  • lastName
  • email
  • phone
  • address
  • city
  • country
  • zipCode
  • company
  • string
  • sentence
  • paragraph
  • url
  • avatarUrl
  • boolean
  • integer
  • float
  • pastDate
  • recentDate
  • futureDate
  • enum
  • regex
  • ref

How it works

Three moves, one backend.

01

Describe

In plain language, like you would explain it to a teammate. Resources, relations, nothing else to learn.

02

Forge

By hand in the visual builder: types, ranges, regex, relations. Or with AI from a description (Pro plan).

03

Consume

Full CRUD, pagination, clean 404s. Realistic, stable data, served without any LLM.

Example

From text to endpoints, no detour.

What you write

« A shop with products, categories and reviews. Each product has a category, each review points to a product. »

What you get

  • GET/m/shop/products?page=1&limit=20
  • GET /m/shop/products/:id
  • POST /m/shop/reviews
  • PATCH /m/shop/products/:id
  • DELETE /m/shop/reviews/:id
  • … and as many for categories

# the forged spec, editable by hand

{
  "resources": [{
    "name": "products",
    "count": 40,
    "fields": [
      { "name": "id", "type": "uuid" },
      { "name": "name", "type": "string" },
      { "name": "price", "type": "float" },
      { "name": "categoryId",
        "type": "ref",
        "ref": "categories.id" }
    ]
  }, …]
}

Features

Built for the front-end day-to-day.

Full CRUD

GET, POST, PUT, PATCH, DELETE and pagination on every resource. Like a real backend.

Realistic & stable data

Plausible names, emails, dates. Seeded generation: regenerating returns the same data.

Consistent relations

Foreign keys point to real records. Your front-end joins hold up.

The spec stays yours

The LLM proposes, you decide: the JSON spec can be edited by hand and re-materialized in one click.

Deterministic at runtime

The LLM is only used at generation time. Your mock requests never touch a model: fast, predictable.

Persistent state

A POST really creates, a DELETE really deletes. Your entire app flow can be tested end to end.

Pricing

Simple as a mock.

Free

For your side projects.

€0forever

  • 2 projects
  • Visual builder, 94 data types
  • Full CRUD, pagination, persistent state
  • Bearer API keys
  • OpenAPI 3.1 import & export
  • Realistic, stable (seeded) data
Start for free
Recommended

Pro

For serious work.

€2.99/ month

  • Everything in Free, without the project limit
  • AI generation: describe your API, the spec is forged
  • Network simulation: latency and random errors
  • Pinned responses per endpoint
Create an account to start

FAQ

Frequently asked questions.

MockSmith is a mock API service: describe an API in plain language or build it visually, and get working REST endpoints (full CRUD, pagination) serving realistic fake data, instantly. Perfect for front-end development while the real backend is not ready.

Yes. The free plan includes 2 projects, the full visual builder with 94 data types, Bearer API keys and OpenAPI import/export. The Pro plan (€2.99/month) adds unlimited projects, AI generation, network simulation and pinned responses.

Yes: plausible names, emails, addresses, prices, dates, IBANs and 90+ other types. Generation is seeded, so regenerating a project returns the same data, and foreign keys always point to real records.

No. Mock endpoints are plain REST over HTTPS with open CORS: fetch, axios, curl, Postman, anything works. You can also protect a project with Bearer API keys.

Never. AI is only used at design time to turn a description into a spec (Pro). Serving requests is 100% deterministic: fast, stable, and predictable.

Yes, on every plan: import an OpenAPI 3.1 JSON document to generate a project from its schemas, and export any project back to OpenAPI 3.1 for your tooling.

Your backend can wait.
Your front-end cannot.

Create a free account, up to 2 projects included. Build your API, copy the URL: all in less time than writing a JSON file by hand.

Start for free