Temba

Get a simple REST API with zero coding in less than 30 seconds (seriously).

For developers that need a quick NodeJS backend for small projects.

No need for any coding, unless you want to opt-out of the defaults, or want to do more customization.

Data is kept in memory, but you can also store it in a JSON file or MongoDB database.

Table of contents

Temba?

Getting Started

What Temba does

Usage

Config settings overview

Temba?

"Temba, at REST"

A metaphor for the declining of a gift, from the Star Trek - The Next Generation episode "Darmok".

In the fictional Tamarian language the word "Temba" means something like "gift".

Getting Started

Prerequisites you need to have:

• Node
• NPM

• Optional: A MongoDB database, either locally or in the cloud

Use the starter with npx

Create your own Temba server with the following command and you are up and running!

npx create-temba-server@latest my-rest-api
cd my-rest-api
npm start

This command clones the Temba-starter repository, installs all dependencies, and starts the server.

In your console you'll see:

✅ Server listening on port 3000

Now you can issue any HTTP request, to any resource.

Adding to an existing app

Alternatively, add Temba to your app manually:

1. npm i temba

2. Example code to create a Temba server:

import { create } from "temba"
const server = create()
server.start()

3. In your console you'll see:

✅ Server listening on port 3000

Configuration

To opt-out or customize Temba's workings, pass a config object to the create function. Learn more in the Usage section, or check out the config settings.

What Temba does

Out of the box, Temba gives you a CRUD REST API to any resource name you can think of.

Whether you GET either /people, /movies, /pokemons, or whatever, it all returns a 200 OK with a [] JSON response. As soon as you POST a new resource, followed by a GET of that resource, the new resource will be returned. You can also DELETE, PATCH, or PUT resources by its ID.

For every resource (movies is just an example), Temba supports the following requests:

• GET /movies - Get all movies
• GET /movies/:id - Get a movie by its ID
• POST /movies - Create a new movie
• PATCH /movies/:id - Partially update a movie by its ID
• PUT /movies/:id - Fully replace a movie by its ID
• DELETE /movies - Delete all movies (if configured)
• DELETE /movies/:id - Delete a movie by its ID
• HEAD /movies - Get all movies, but without the response body
• HEAD /movies/:id - Get a movie by its ID, but without the response body

Supported HTTP methods

The HTTP methods that are supported are GET, POST, PATCH, PUT, DELETE, and HEAD.

On the root URI (e.g. http://localhost:8080/) only a GET request is supported, which shows you a message indicating the API is working. All other HTTP methods on the root URI return a 405 Method Not Allowed response.

The OPTIONS method also works, but because Temba uses Express' default implementation for that, the Access-Control-Allow-Methods response header might not always be correct.

JSON

Temba supports JSON only.

Request bodies sent with a POST, PATCH, and PUT requests are valid when the request body is either empty, or when it's valid formatted JSON. If you send a request with invalid formatted JSON, a 400 Bad Request response is returned.

Any valid formatted JSON is accepted and stored. If you want to validate or even change the JSON in the request bodies, check out JSON Schema request body validation and the requestInterceptor.

IDs are auto generated when creating resources.

Providing IDs in the request body of POST, PUT, or PATCH requests is not allowed and will return a 400 Bad Request response. The same applies to adding an ID in a POST request URL, or omitting an ID in a PUT or PATCH request URL.

Usage

Data persistency

By default data is stored in memory. This means the data is flushed when the server restarts. To persist your data, provide the connectionString config setting for your JSON file or MongoDB database.

JSON file

const config = {
  connectionString: 'data.json',
}
const server = create(config)

All resources are saved in a single JSON file. The file is not created or updated unless you create, update, or delete resources.

MongoDB

const config = {
  connectionString: 'mongodb://localhost:27017/myDatabase',
}
const server = create(config)

For every resource you use in your requests, a collection is created in the database. However, not until you actually create a resource with a POST.

Allowing specific resources only

If you only want to allow specific resource names, configure them by providing a resources key in the config object when creating the Temba server:

const config = {
  resources: ['movies', 'actors'],
}
const server = create(config)

Requests on these resources only give a 404 Not Found if the ID does not exist. Requests on any other resource will always return a 404 Not Found.

Static assets

If you want to host static assets, for example next to the API, a web app consuming it, you can configure a staticFolder:

const config = {
  staticFolder: 'build',
}
const server = create(config)

With this setting, sending a GET request to the root URL, returns the content that is in the './build' folder in your project.

Without configuring a staticFolder, a GET to the root URL returns "It works! ツ". When the staticFolder is configured, it returns whatever is in the build folder in your project, for example an HTML page.

However, this might cause conflicts between the API resources and the web app routes: If the web app in the build folder has a route to /products, but there is also a /products API resource, the web app route is returned.

To be able to still access the /products API resource, configure an apiPrefix:

API prefix

With the apiPrefix config setting, all resources get an extra path segment in front of them. If the apiPrefix is 'api', then /movies/12345 becomes /api/movies/12345:

const config = {
  apiPrefix: 'api',
}
const server = create(config)

A request to the apiPrefix (e.g. http://localhost:1234/api) will now return the "It works! ツ" response message.

After configuring the apiPrefix, requests to the root URL (e.g. http://localhost:1234/), instead of the "It works! ツ" response message, will now either return a 404 Not Found on GET requests, or a 405 Method Not Allowed for all other HTTP methods.

However, if you configured both an apiPrefix and a staticFolder, a GET on the root URL will return the content in the staticFolder.

JSON Schema request body validation

By default, Temba does not validate request bodies.

This means you can store your resources in any format you like. So creating the following two (very different) movies is perfectly fine:

POST /movies
{
    "title": "O Brother, Where Art Thou?",
    "description": "In the deep south during the 1930s, three escaped convicts search for hidden treasure while a relentless lawman pursues them."
}

POST /movies
{
    "foo": "bar",
    "baz": "boo"
}

You can even omit a request body when doing a POST, PATCH, or PUT. While this might be fine or even convenient when using Temba for prototyping, at some some point you might want to validate the request body.

With the schema setting, you can define a JSON Schema, per resource, and per request method. Here we define that when creating or replacing a movie, the title is required, the description is optional, and we don't allow any other fields. Updating movies has the same schema, except there are no required fields:

const schemaNewMovie = {
  type: 'object',
  properties: {
    title: { type: 'string' },
    description: { type: 'string' },
  },
  required: ['title'],
  additionalProperties: false,
}

const schemaUpdateMovie = { ...schemaNewMovie, required: [] }

const config = {
  schema: {
    movies: {
      post: schemaNewMovie,
      put: schemaNewMovie,
      patch: schemaUpdateMovie,
    },
  },
}

const server = create(config)

If a request is not valid according to the schema, a 400 Bad Request response is returned, and a message in the response body indicating the validation error.

Intercepting requests

In addition to (or instead of) validating the request using JSON Schema, you can also intercept the request before it is persisted, using the requestInterceptor setting.

It allows you to implement your own validation, or even change the request body.

const config = {
  requestInterceptor: {
    get: ({ headers, resource, id }) => {
      //...
    },
    post: ({ headers, resource, body }) => {
      // Validate, or even change the request body
    },
    put: ({ headers, resource, id, body }) => {
      // Validate, or even change the request body
    },
    patch: ({ headers, resource, id, body }) => {
      // Validate, or even change the request body
    },
    delete: ({ headers, resource, id }) => {
      //...
    },
  },
}

const server = create(config)

The requestInterceptor is an object with fields for each of the HTTP methods you might want to intercept, and the callback function you want Temba to call, before processing the request, i.e. going to the database.

Each callback function receives an object containing the request headers and the resource (e.g. "movies"). Depending on the HTTP method, also the id from the URL, and the request body are provided. body is a JSON object of the request body.

Request headers are not used by Temba internally when processing requests, so they are only passed into the requestInterceptor callback so you can do your own custom header validation.

Your callback function can return the following things:

• void: Temba will just save the request body as-is. An example of this is when you have validated the request body and everything looks fine.
• object: Return an object if you want to change the request body. Temba will save the returned object instead of the original request body.
• Throw an Error if you want to stop processing the request any further and return a 500 Internal Server Error response. Or throw the custom TembaError to provide a status code.

Example:

const config = {
  requestInterceptor: {
    post: ({ headers, resource, body }) => {      
      // Add a genre to Star Trek films:
      if (resource === 'movies' && body.title.startsWith('Star Trek'))
        return { ...body, genre: 'Science Fiction' }

      // Throw a regular error for a 500 Internal Server Error status code
      if (resource === 'foobar') {
        throw new Error('Something went foobar')
      }

      // Throw a custom error to specify the status code
      if (resource === 'pokemons') {
        throw new TembaError('You are not allowed to create new Pokemons', 400)
      }

      // If you don't return anything, the original request will just be used.
    },
  },
}

const server = create(config)

Response body interception

To change the response body of a GET request, before it's being sent to the client, configure a responseBodyInterceptor, and return the updated response body:

const config = {
  responseBodyInterceptor: ({ resource, body, id }) => {
    if (resource === 'movies') {
      if (id) {
        // response body is an object
        return {
          ...body,
          stuff: 'more stuff',
        }
      } else {
        // response body is an array
        return body.map((x) => ({
          ...x,
          stuff: 'more stuff',
        }))
      }
    }

    // If you end up here, the response body will just be returned unchanged.
  },
}

const server = create(config)

responseBodyInterceptor is a callback function that provides an object containing the resource, body, and the id. Depending on whether it's a collection or item request, the body is either an array or object, and the id can be undefined.

In the example above we check for the id being defined, but a runtime check to determine the type of body would also suffice.

Whatever you return in this function will become the response body and will be serialized as JSON and returned to the client.

If you don't return anything, the response body will be sent as-is.

The responseBodyInterceptor will only be called when the response was successful, i.e. a 200 OK status code.

Caching and consistency with Etags

To optimize GET requests, and only send JSON over the wire when it changed, you can configure to enable Etags. Etags also prevent so-called mid-air collisions, where a client tries to update en item that has been updated by another client in the meantime:

const config = {
  etags: true,
}
const server = create(config)

After enabling etags, every GET request will return an etag response header, which clients can (optionally) send as an If-None-Match header with every subsequent GET request. Only if the resource changed in the meantime the server will return the new JSON, and otherwise it will return a 304 Not Modified response with an empty response body.

For updating or deleting items with a PUT, PATCH, or DELETE, after enabling etags, these requests are required to provide an If-Match header with the etag. Only if the etag represents the latest version of the resource the update is made, otherwise the server responds with a 412 Precondition Failed status code.

Custom router

Because Temba uses Express under the hood, you can create an Express router, and configure it as a customRouter:

// Example code of how to create an Express router, from the official Express docs at https://expressjs.com/en/guide/routing.html:
const express = require('express')
const router = express.Router()

// middleware that is specific to this router
router.use((req, res, next) => {
  console.log('Time: ', Date.now())
  next()
})
// define the home page route
router.get('/', (req, res) => {
  res.send('Birds home page')
})
// define the about route
router.get('/about', (req, res) => {
  res.send('About birds')
})

// Add the custom router to Temba config
const config = {
  customRouter: router,
}

const server = create(config)

💁 Don't overuse customRouter, as it defeats the purpose of Temba being a simple out-of-the-box solution.

A customRouter can only overrule resource routes. The root URL (with or without staticFolder) will always be handled by Temba.

So for the following router and config:

router.get('/', (req, res) => {
  res.send('Birds home page')
})
router.get('/stuff', (req, res) => {
  res.send('Some stuff')
})
router.get('api/stuff', (req, res) => {
  res.send('Some API stuff')
})

const config = {
  apiPrefix: 'api',
  customRouter: router,
  resources: ['stuff'],
  staticFolder: 'build',
}
const server = create(config)

• / will be handled by Temba, and will return the staticFolder (build) folder contents
• /stuff and /api/stuff will be handled by the custom router
• /movies will return a 404 Not Found, because of apiPrefix
• /api/movies will return movies, handled by Temba

Config settings overview

Configuring Temba is optional, it already works out of the box.

Here is an example of the config settings for Temba, and how you define them:

const config = {
  allowDeleteCollection: true,
  apiPrefix: 'api',
  connectionString: 'mongodb://localhost:27017/myDatabase',
  customRouter: router,
  delay: 500,
  etags: true,
  port: 4321,
  requestInterceptor: {
    get: ({ headers, resource, id }) => {
      //...
    },
    post: ({ headers, resource, body }) => {
      // Validate, or even change the request body
    },
    put: ({ headers, resource, id, body }) => {
      // Validate, or even change the request body
    },
    patch: ({ headers, resource, id, body }) => {
      // Validate, or even change the request body
    },
    delete: ({ headers, resource, id }) => {
      //...
    },
  },
  resources: ['movies', 'actors'],
  responseBodyInterceptor: ({ resource, body, id }) => {
    // Change the response body before it is sent to the client
  },
  returnNullFields: false,
  schema: {
    movies: {
      post: {
        type: 'object',
        properties: {
          title: { type: 'string' },
        },
        required: ['title'],
      },
    },
  },
  staticFolder: 'build',
}
const server = create(config)

These are all the possible settings:

| Config setting | Description | Default value | | :------------------------ | :----------------------------------------------------------------------------------------- | :------------ | | allowDeleteCollection | Whether a DELETE request on a collection is allowed to delete all items. | false | | apiPrefix | See API prefix | null | | connectionString | See Data persistency | null | | customRouter | See Custom router | null | | delay | The delay, in milliseconds, after processing the request before sending the response. | 0 | | etags | See Caching and consistency with Etags | false | | port | The port your Temba server listens on | 3000 | | requestInterceptor | See Request validation or mutation | noop | | resources | See Allowing specific resources only | [] | | responseBodyInterceptor | See Response body interception | noop | | returnNullFields | Whether fields with a null value should be returned in responses. | true | | schema | See JSON Schema request body validation | null | | staticFolder | See Static assets | null |

Under the hood

Temba is built with TypeScript, Node, Express, Vitest, Supertest, @rakered/mongo, and lowdb.

Contributors ✨

Thanks goes to these wonderful people (emoji key):

This project follows the all-contributors specification. Contributions of any kind welcome!