Tenso

Tenso is an HTTP REST API framework, that will handle the serialization & creation of hypermedia links; all you have to do is give it Arrays or Objects.

Example

Creating an API with Tenso can be this simple:

import {tenso} from "tenso";

export const app = tenso();

app.get("/", "Hello, World!");
app.start();

Creating Routes

Routes are loaded as a module, with each HTTP method as an export, affording a very customizable API server.

You can use res to res.send(body[, status, headers]), res.redirect(url), or res.error(status[, Error]).

The following example will create GET routes that will return an Array at /, an Error at /reports/tps, & a version 4 UUID at /uuid.

As of 10.3.0 you can specify always as a method to run middleware before authorization middleware, which will skip always middleware registered after it (via instance methods).

As of 17.2.0 you can have routes exit the middleware pipeline immediately by setting them in the exit Array. This differs from unprotect as there is no request body handling.

Example

Routes

import {randomUUID as uuid} from "crypto";

export const initRoutes = {
	"get": {
		"/": ["reports", "uuid"],
		"/reports": ["tps"],
		"/reports/tps": (req, res) => res.error(785, Error("TPS Cover Sheet not attached")),
		"/uuid": (req, res) => res.send(uuid(), 200, {"cache-control": "no-cache"})
	}
};

Server

import {tenso} from "tenso";
import {initRoutes} from "./routes";

export const app = tenso({initRoutes});

app.start();

Protected Routes

Protected routes are routes that require authorization for access, and will redirect to authentication end points if needed.

Unprotected Routes

Unprotected routes are routes that do not require authorization for access, and will exit the authorization pipeline early to avoid rate limiting, csrf tokens, & other security measures. These routes are the DMZ of your API! You must secure these end points with alternative methods if accepting input!

Reserved Route

The /assets/* route is reserved for the HTML browsable interface assets; please do not try to reuse this for data.

Request Helpers

Tenso decorates req with "helpers" such as req.allow, req.csrf, req.ip, req.parsed, & req.private. PATCH, PUT, & POST payloads are available as req.body. Sessions are available as req.session when using local authentication.

Tenso decorates res with "helpers" such as res.send(), res.status(), & res.json().

Extensibility

Tenso is extensible, and can be customized with custom parsers, renderers, & serializers.

Parsers

Custom parsers can be registered with server.parser('mimetype', fn); or directly on server.parsers. The parameters for a parser are (arg).

Tenso has parsers for:

• application/json
• application/x-www-form-urlencoded
• application/jsonl
• application/json-lines
• text/json-lines

Renderers

Custom renderers can be registered with server.renderer('mimetype', fn);. The parameters for a renderer are (req, res, arg).

Tenso has renderers for:

• application/javascript
• application/json
• application/jsonl
• application/json-lines
• text/json-lines
• application/yaml
• application/xml
• text/csv
• text/html

Serializers

Custom serializers can be registered with server.serializer('mimetype', fn);. The parameters for a serializer are (arg, err, status = 200, stack = false).

Tenso has two default serializers which can be overridden:

• plain for plain text responses
• custom for standard response shape

{
  "data": "`null` or ?",
  "error": "`null` or an `Error` stack trace / message",
  "links": [],
  "status": 200
}

Responses

Responses will have a standard shape, and will be utf-8 by default. The result will be in data. Hypermedia (pagination & links) will be in links:[ {"uri": "...", "rel": "..."}, ...], & also in the Link HTTP header.

Page size can be specified via the page_size parameter, e.g. ?page_size=25.

Sort order can be specified via then order-by which accepts [field ]asc|desc & can be combined like an SQL 'ORDER BY', e.g. ?order_by=desc or ?order_by=lastName%20asc&order_by=firstName%20asc&order_by=age%20desc

REST / Hypermedia

Hypermedia is a prerequisite of REST, and is best described by the Richardson Maturity Model. Tenso will automagically paginate Arrays of results, or parse Entity representations for keys that imply relationships, and create the appropriate Objects in the link Array, as well as the Link HTTP header. Object keys that match this pattern: /_(guid|uuid|id|uri|url)$/ will be considered hypermedia links.

For example, if the key user_id was found, it would be mapped to /users/:id with a link rel of related.

Tenso will bend the rules of REST when using authentication strategies provided by passport.js, or CSRF if is enabled, because they rely on a session. Session storage is in memory, or Redis. You have the option of a stateless or stateful API.

Hypermedia processing of the response body can be disabled as of 10.2.0, by setting req.hypermedia = false and/or req.hypermediaHeader via middleware.

Configuration

This is the default configuration for Tenso, without authentication or SSL. This would be ideal for development, but not production! Enabling SSL is as easy as providing file paths for the two keys.

Everything is optional! You can provide as much, or as little configuration as you like.

{
	auth: {
		delay: 0,
		protect: [],
		unprotect: [],
		basic: {
			enabled: false,
			list: []
		},
		bearer: {
			enabled: false,
			tokens: []
		},
		jwt: {
			enabled: false,
			auth: null,
			audience: EMPTY,
			algorithms: [
				"HS256",
				"HS384",
				"HS512"
			],
			ignoreExpiration: false,
			issuer: "",
			scheme: "bearer",
			secretOrKey: ""
		},
		msg: {
			login: "POST 'username' & 'password' to authenticate"
		},
		oauth2: {
			enabled: false,
			auth: null,
			auth_url: "",
			token_url: "",
			client_id: "",
			client_secret: ""
		},
		uri: {
			login: "/auth/login",
			logout: "/auth/logout",
			redirect: "/",
			root: "/auth"
		},
		saml: {
			enabled: false,
			auth: null
		}
	},
	autoindex: false,
	cacheSize: 1000,
	cacheTTL: 300000,
	catchAll: true,
	charset: "utf-8",
	corsExpose: "cache-control, content-language, content-type, expires, last-modified, pragma",
	defaultHeaders: {
		"content-type": "application/json; charset=utf-8",
		"vary": "accept, accept-encoding, accept-language, origin"
	},
	digit: 3,
	etags: true,
	exit: [],
	host: "0.0.0.0",
	hypermedia: {
		enabled: true,
		header: true
	},
	index: [],
	initRoutes: {},
	jsonIndent: 0,
	logging: {
		enabled: true,
		format: "%h %l %u %t \"%r\" %>s %b",
		level: "debug",
		stack: true
	},
	maxBytes: 0,
	mimeType: "application/json",
	origins: ["*"],
	pageSize: 5,
	port: 8000,
	prometheus: {
		enabled: false,
		metrics: {
			includeMethod: true,
			includePath: true,
			includeStatusCode: true,
			includeUp: true,
			buckets: [0.001, 0.01, 0.1, 1, 2, 3, 5, 7, 10, 15, 20, 25, 30, 35, 40, 50, 70, 100, 200],
			customLabels: {}
		}
	},
	rate: {
		enabled: false,
		limit: 450,
		message: "Too many requests",
		override: null,
		reset: 900,
		status: 429
	},
	renderHeaders: true,
	time: true,
	security: {
		key: "x-csrf-token",
		secret: "",
		csrf: true,
		csp: null,
		xframe: "",
		p3p: "",
		hsts: null,
		xssProtection: true,
		nosniff: true
	},
	session: {
		cookie: {
			httpOnly: true,
			path: "/",
			sameSite: true,
			secure: "auto"
		},
		name: "tenso.sid",
		proxy: true,
		redis: {
			host: "127.0.0.1",
			port: 6379
		},
		rolling: true,
		resave: true,
		saveUninitialized: true,
		secret: "tensoABC",
		store: "memory"
	},
	silent: false,
	ssl: {
		cert: null,
		key: null,
		pfx: null
	},
	webroot: {
		root: "process.cwd()/www",
		static: "/assets",
		template: "template.html"
	}
}

Authentication

The protect Array is the endpoints that will require authentication. The redirect String is the end point users will be redirected to upon successfully authenticating, the default is /.

Sessions are used for non Basic or Bearer Token authentication, and will have /login, /logout, & custom routes. Redis is supported for session storage.

Multiple authentication strategies can be enabled at once.

Authentication attempts have a random delay to deal with "timing attacks"; always rate limit in production environment!

Basic Auth

{
	"auth": {
		"basic": {
			"enabled": true,
			"list": ["username:password", ...],
		},
		"protect": ["/"]
	}
}

JSON Web Token

JSON Web Token (JWT) authentication is stateless and does not have an entry point. The auth(token, callback) function must verify token.sub, and must execute callback(err, user).

This authentication strategy relies on out-of-band information for the secret, and other optional token attributes.

{
	"auth": {
		"jwt": {
			"enabled": true,
			"auth": function (token, cb) { ... }, /* Authentication handler, to 'find' or 'create' a User */
			"algorithms": [], /* Optional signing algorithms, defaults to ["HS256", "HS384", "HS512"] */
			"audience": "", /* Optional, used to verify `aud` */
			"issuer: "", /* Optional, used to verify `iss` */
			"ignoreExpiration": false, /* Optional, set to `true` to ignore expired tokens */
			"scheme": "Bearer", /* Optional, set to specify the `Authorization` scheme */
			"secretOrKey": ""
		}
		"protect": ["/private"]
	}
}

OAuth2

OAuth2 authentication will create /auth, /auth/oauth2, & /auth/oauth2/callback routes. auth(accessToken, refreshToken, profile, callback) must execute callback(err, user).

{
	"auth": {
		"oauth2": {
			"enabled": true,
			"auth": function ( ... ) { ... }, /* Authentication handler, to 'find' or 'create' a User */
			"auth_url": "", /* Authorization URL */
			"token_url": "", /* Token URL */
			"client_id": "", /* Get this from authorization server */
			"client_secret": "" /* Get this from authorization server */
		},
		"protect": ["/private"]
	}
}

Oauth2 Bearer Token

{
	"auth": {
		"bearer": {
			"enabled": true,
			"tokens": ["abc", ...]
		},
		"protect": ["/"]
	}
}

SAML

SAML authentication will create /auth, /auth/saml, & /auth/saml/callback routes. auth(profile, callback) must execute callback(err, user).

Tenso uses passport-saml, for configuration options please visit it's homepage.

{
	"auth": {
		"saml": {
			"enabled": true,
			...
		},
		"protect": ["/private"]
	}
}

Sessions

Sessions can use a memory (default) or redis store. Memory will limit your sessions to a single server instance, while redis will allow you to share sessions across a cluster of processes, or machines. To use redis, set the store property to "redis".

If the session secret is not provided, a version 4 UUID will be used.

{
	"session" : {
		cookie: {
			httpOnly: true,
			path: "/",
			sameSite: true,
			secure: false
		},
		name: "tenso.sid",
		proxy: true,
		redis: {
			host: "127.0.0.1",
			port: 6379
		},
		rolling: true,
		resave: true,
		saveUninitialized: true,
		secret: "tensoABC",
		store: "memory"
	}
}

Security

Tenso uses lusca for security as a middleware. Please see it's documentation for how to configure it; each method & argument is a key:value pair for security.

{
	"security": { ... }
}

Rate Limiting

Rate limiting is controlled by configuration, and is disabled by default. Rate limiting is based on token, session, or ip, depending upon authentication method.

Rate limiting can be overridden by providing an override function that takes req & rate, and must return (a modified) rate.

{
	"rate": {
		"enabled": true,
		"limit": 450, /* Maximum requests allowed before `reset` */
		"reset": 900, /* TTL in seconds */
		"status": 429, /* Optional HTTP status */
		"message": "Too many requests",  /* Optional error message */
		"override": function ( req, rate ) { ... } /* Override the default rate limiting */
	}
}

Limiting upload size

A 'max byte' limit can be enforced on all routes that handle PATCH, POST, & PUT requests. The default limit is 20 KB (20480 B).

{
	"maxBytes": 5242880
}

Logging

Standard log levels are supported, and are emitted to stdout & stderr. Stack traces can be enabled.

{
	"logging": {
		"level": "warn",
		"enabled": true,
		"stack": true
	}
}

HTML Renderer

The HTML template can be overridden with a custom HTML document.

Dark mode is supported! The dark class will be added to the body tag if the user's browser is in dark mode.

webroot: {
    root: "full path",
    static: "folder to serve static assets",
    template: "html template"
}

Serving files

Custom file routes can be created like this:

app.files("/folder", "/full/path/to/parent");

EventSource streams

Create & cache an EventSource stream to send messages to a Client. See tiny-eventsource for configuration options:

const streams = new Map();

...

"/stream": (req, res) => {
 const id = req.user.userId;

 if (streams.has(id) === false) {
   streams.set(id, req.server.eventsource({ms: 3e4), "initialized");
 }

 streams.get(id).init(req, res);
}

...

// Send data to Clients
streams.get(id).send({...});

Prometheus

Prometheus metrics can be enabled by setting {prometheus: {enabled: true}}. The metrics will be available at /metrics.

Testing

Tenso has ~80% code coverage with its tests. Test coverage will be added in the future.

-----------|---------|----------|---------|---------|-------------------------------------------------------------------------------------------------------------------------------
File       | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
-----------|---------|----------|---------|---------|-------------------------------------------------------------------------------------------------------------------------------
All files  |   78.15 |    54.93 |   68.75 |   78.58 |                                                                                                                               
 tenso.cjs |   78.15 |    54.93 |   68.75 |   78.58 | ...85,1094,1102,1104,1115-1118,1139,1149-1175,1196-1200,1243-1251,1297-1298,1325-1365,1370,1398-1406,1412-1413,1425,1455-1456 
-----------|---------|----------|---------|---------|-------------------------------------------------------------------------------------------------------------------------------

Benchmark

1. Clone repository from GitHub.
2. Install dependencies with npm or yarn.
3. Execute benchmark script with npm or yarn.

License

Copyright (c) 2024 Jason Mulligan

Licensed under the BSD-3-Clause license.