jimjam-0.0.2 is not a library.

jimjam 🎭

A configurable HTTP mock server that serves responses based on YAML-defined rules. Perfect for API mocking, testing, and development.

Features

YAML-based configuration - Define mock responses in simple YAML files
Multiple response scenarios - Define different responses for the same endpoint based on conditions
Path parameters - Support for dynamic URL segments like /users/{id}
Response delays - Simulate slow APIs with configurable delays
File-based bodies - Load large response bodies from external files

Quick Start

Build

cargo build --release

Run

cargo run

The server starts on http://127.0.0.1:8080 by default.

Test

curl http://127.0.0.1:8080/api/health
# → {"status": "ok", "service": "jimjam"}

Configuration

Main Config (`config/config.yaml`)

# jimjam main configuration

server:
  host: "127.0.0.1"
  port: 8080

# Location of mock response definition files
mock_files:
  directory: "./mocks"
  patterns:
    - "**/*.yaml"
    - "**/*.yml"
  hot_reload: true

mocks:

path: "/api/users/{id}" id: "1" status: 200 {"id": 1, "name": "Alice"}

Fallback response (no conditions)

Condition	Description	Example
`path_params`	Match URL path parameters	`id: "123"`
`query_params`	Exact query parameter match	`sort: "asc"`
`query_contains`	Query string substring	`"category=books"`
`headers`	Exact header match	`Authorization: "Bearer token"`
`header_contains`	Header substring	`Authorization: "Bearer"`
`body_contains`	Body substring	`'"role": "admin"'`
`body_json`	JSON field match	`name: "test"`
`body_regex`	Regex pattern	`'"email":\\s".@test\\.com"'`

Response Options

- status: 201                    # HTTP status code
  headers:                       # Response headers
    Content-Type: "application/json"
    X-Custom-Header: "value"
  body: |                        # Inline response body
    {"created": true}
  body: "@./data/large.json"     # Or use @ prefix to load from file
  body_file: "./data/large.json" # Alternative: explicit file reference
  delay_ms: 2000                 # Simulate slow response

Body Content Options

Inline body - Write content directly in YAML
```
body: '{"name": "example"}'
```
File reference with @ - Prefix path with @ (recommended)
```
body: "@./mocks/data/users.json"
```
Explicit body_file - Use separate field
```
body_file: "./mocks/data/users.json"
```

Directory Structure

jimjam/
├── config/
│   └── config.yaml       # Server configuration
├── mocks/
│   ├── users.yaml        # User API mocks
│   ├── products.yaml     # Product API mocks
│   └── data/
│       └── products.json # Large response bodies
└── src/
    └── ...

Running Tests

cargo test

How jimjam works

See how-jimjam-works.md for schema, matching, and advanced usage.

jimjam 0.0.2