HTTP Endpoints

Overview

ngrok's HTTP endpoints enable you to serve APIs, web services, websocket servers, websites and more.

Serving a web application is as simple as ngrok http 80. You can also layer on additional capabilities like auth, observability, load balancing and more.

Example Usage

Basic usage

Create an HTTPS endpoint on a randomly assigned ngrok domain.

Agent CLI

ngrok http 8080

Agent Config

tunnels:
  example:
    proto: http
    addr: 8080

SSH

ssh -R 443:localhost:80 v2@connect.ngrok-agent.com http

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func ngrokListener(ctx context.Context) (net.Listener, error) {
	return ngrok.Listen(ctx,
		config.HTTPEndpoint(),
		ngrok.WithAuthtokenFromEnv(),
	)
}

Go Package Docs:

• https://pkg.go.dev/golang.ngrok.com/ngrok/config#HTTPEndpoint

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: 8080,
		authtoken_from_env: true,
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html
• https://ngrok.github.io/ngrok-javascript/classes/Session.html#httpEndpoint
• https://ngrok.github.io/ngrok-javascript/functions/connect.html

Python

import ngrok

listener = ngrok.forward("localhost:8080", authtoken_from_env=True)

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/http_listener_builder.html
• https://ngrok.github.io/ngrok-python/session.html#ngrok.Session.http_endpoint
• https://ngrok.github.io/ngrok-python/module.html#ngrok.connect

Rust

use ngrok::prelude::*;

async fn listen_ngrok() -> anyhow::Result<impl Tunnel> {
    let sess = ngrok::Session::builder()
        .authtoken_from_env()
        .connect()
        .await?;

    let tun = sess
        .http_endpoint()
        .listen()
        .await?;

    println!("Listening on URL: {:?}", tun.url());

    Ok(tun)
}

Rust Crate Docs:

• https://docs.rs/ngrok/latest/ngrok/session/struct.Session.html#method.http_endpoint

Kubernetes Controller

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    k8s.ngrok.com/modules: ngrok-module-set
spec:
  ingressClassName: ngrok
  rules:
    - host: example.ngrok.app
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: example-service
                port:
                  number: 80

Static domain

Create an HTTPS endpoint on example.ngrok.app

Agent CLI

ngrok http 80 --domain example.ngrok.app

Agent Config

tunnels:
  example:
    proto: http
    addr: 8080
    domain: example.ngrok.app

SSH

ssh -R example.ngrok.app:443:localhost:80 v2@connect.ngrok-agent.com http

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func ngrokListener(ctx context.Context) (net.Listener, error) {
	return ngrok.Listen(ctx,
		config.HTTPEndpoint(
                        config.WithDomain("example.ngrok.app"),
                ),
		ngrok.WithAuthtokenFromEnv(),
	)
}

Go Package Docs:

• https://pkg.go.dev/golang.ngrok.com/ngrok/config#WithDomain

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: 8080,
		authtoken_from_env: true,
		domain: "example.ngrok.app",
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#domain
• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html#domain

Python

import ngrok

listener = ngrok.forward("localhost:8080", authtoken_from_env=True,
    domain="example.ngrok.app")

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.domain
• https://ngrok.github.io/ngrok-python/index.html#full-configuration

Rust

use ngrok::prelude::*;

async fn listen_ngrok() -> anyhow::Result<impl Tunnel> {
    let sess = ngrok::Session::builder()
        .authtoken_from_env()
        .connect()
        .await?;

    let tun = sess
        .http_endpoint()
        .domain("example.ngrok.app")
        .listen()
        .await?;

    println!("Listening on URL: {:?}", tun.url());

    Ok(tun)
}

Rust Crate Docs:

• https://docs.rs/ngrok/latest/ngrok/config/struct.HttpTunnelBuilder.html#method.domain

Kubernetes Controller

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    k8s.ngrok.com/modules: ngrok-module-set
spec:
  ingressClassName: ngrok
  rules:
    - host: example.ngrok.app
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: example-service
                port:
                  number: 80

Bring your own domain

Create an HTTPS endpoint on app.example.com.

You will need to create a CNAME DNS record to bring your own domain. Create a Domain record on your ngrok dashboard and follow the instructions.

Consult the documentation about setting up branded domains for additional details.

Agent CLI

ngrok http 80 --domain app.example.com

Agent Config

tunnels:
  example:
    proto: http
    addr: 8080
    domain: app.example.com

SSH

ssh -R app.example.com:443:localhost:80 v2@connect.ngrok-agent.com http

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func ngrokListener(ctx context.Context) (net.Listener, error) {
	return ngrok.Listen(ctx,
		config.HTTPEndpoint(
                        config.WithDomain("app.example.com"),
                ),
		ngrok.WithAuthtokenFromEnv(),
	)
}

Go Package Docs:

• https://pkg.go.dev/golang.ngrok.com/ngrok/config#WithDomain

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: 8080,
		authtoken_from_env: true,
		domain: "example.ngrok.app",
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#domain
• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html#domain

Python

import ngrok

listener = ngrok.forward("localhost:8080", authtoken_from_env=True,
    domain="example.ngrok.app")

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.domain
• https://ngrok.github.io/ngrok-python/index.html#full-configuration

Rust

use ngrok::prelude::*;

async fn listen_ngrok() -> anyhow::Result<impl Tunnel> {
    let sess = ngrok::Session::builder()
        .authtoken_from_env()
        .connect()
        .await?;

    let tun = sess
        .http_endpoint()
        .domain("example.ngrok.app")
        .listen()
        .await?;

    println!("Listening on URL: {:?}", tun.url());

    Ok(tun)
}

Rust Crate Docs:

• https://docs.rs/ngrok/latest/ngrok/config/struct.HttpTunnelBuilder.html#method.domain

Kubernetes Controller

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    k8s.ngrok.com/modules: ngrok-module-set
spec:
  ingressClassName: ngrok
  rules:
    - host: app.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: example-service
                port:
                  number: 80

Basic auth

Adds a username and password with the Basic Auth Module.

Agent CLI

ngrok http 80 --basic-auth "username1:password1" --basic-auth "username2:password2"

Agent Config

tunnels:
  example:
    proto: http
    addr: 80
    basic_auth:
      - username1:password1
      - username2:password2

SSH

ssh -R 443:localhost:80 v2@connect.ngrok-agent.com http \
  --basic-auth "username1:password1" \
  --basic-auth "username2:password2"

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func ngrokListener(ctx context.Context) (net.Listener, error) {
	return ngrok.Listen(ctx,
		config.HTTPEndpoint(
			config.WithBasicAuth("username1", "password1"),
			config.WithBasicAuth("username2", "password2"),
		),
		ngrok.WithAuthtokenFromEnv(),
	)
}

Go Package Docs:

• https://pkg.go.dev/golang.ngrok.com/ngrok/config#WithBasicAuth

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: 8080,
		authtoken_from_env: true,
		basic_auth: ["username1:password1", "username2:password2"],
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#basic_auth
• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html#basicAuth

Python

import ngrok

listener = ngrok.forward("localhost:8080", authtoken_from_env=True,
    basic_auth=["username1:password1", "username2:password2"])

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.basic_auth
• https://ngrok.github.io/ngrok-python/index.html#full-configuration

Rust

use ngrok::prelude::*;

async fn listen_ngrok() -> anyhow::Result<impl Tunnel> {
    let sess = ngrok::Session::builder()
        .authtoken_from_env()
        .connect()
        .await?;

    let tun = sess
        .http_endpoint()
        .basic_auth("username1", "password1")
        .basic_auth("username2", "password2")
        .listen()
        .await?;

    println!("Listening on URL: {:?}", tun.url());

    Ok(tun)
}

Rust Crate Docs:

• https://docs.rs/ngrok/latest/ngrok/config/struct.HttpTunnelBuilder.html#method.basic_auth

Kubernetes Controller

info

This module is not supported by the Kubernetes Ingress Controller.

Auth with Google

Enforce a browser-based OAuth flow in front of your HTTP endpoints to an identity provider like Google with the OAuth Module.

Agent CLI

ngrok http 80 --oauth google

Agent Config

tunnels:
  example:
    proto: http
    addr: 80
    oauth:
      provider: "google"

SSH

ssh -R 443:localhost:80 v2@connect.ngrok-agent.com http --oauth=google

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func ngrokListener(ctx context.Context) (net.Listener, error) {
	return ngrok.Listen(ctx,
		config.HTTPEndpoint(
			config.WithOAuth("google"),
		),
		ngrok.WithAuthtokenFromEnv(),
	)
}

Go Package Docs:

• https://pkg.go.dev/golang.ngrok.com/ngrok/config#WithOAuth
• https://pkg.go.dev/golang.ngrok.com/ngrok/config#OAuthOption

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: 8080,
		authtoken_from_env: true,
		oauth_provider: "google",
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#oauth_provider
• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html#oauth

Python

import ngrok

listener = ngrok.forward("localhost:8080", authtoken_from_env=True,
    oauth_provider="google")

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.oauth
• https://ngrok.github.io/ngrok-python/index.html#full-configuration

Rust

use ngrok::prelude::*;

async fn listen_ngrok() -> anyhow::Result<impl Tunnel> {
    let sess = ngrok::Session::builder()
        .authtoken_from_env()
        .connect()
        .await?;
    let tun = sess
        .http_endpoint()
        .oauth(OauthOptions::new("google"))
        .listen()
        .await?;
    println!("Listening on URL: {:?}", tun.url());
    Ok(tun)
}

Rust Crate Docs:

• https://docs.rs/ngrok/latest/ngrok/config/struct.HttpTunnelBuilder.html#method.oauth
• https://docs.rs/ngrok/latest/ngrok/config/struct.OauthOptions.html

Kubernetes Controller

---
kind: NgrokModuleSet
apiVersion: ingress.k8s.ngrok.com/v1alpha1
metadata:
  name: ngrok-module-set
modules:
  oauth:
    google:
      optionsPassthrough: false
      inactivityTimeout: 4h
      maximumDuration: 24h
      authCheckInterval: 1h
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    k8s.ngrok.com/modules: ngrok-module-set
spec:
  ingressClassName: ngrok
  rules:
    - host: your-domain.ngrok.app
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: example-service
                port:
                  number: 80

Forward to HTTPS

Use a URL with an https:// scheme to make ngrok speak HTTPS to your upstream service.

Agent CLI

ngrok http https://localhost:8443

Agent Config

tunnels:
  example:
    proto: http
    addr: https://localhost:8443

SSH

info

Forwarding to an upstream HTTPS service is not supported via SSH.

Go

info

Forwarding to an upstream service is not supported by the Go SDK

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: "https://localhost:8443",
		authtoken_from_env: true,
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#addr
• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html#listenAndForward

Python

import ngrok

listener = ngrok.forward("https://localhost:8443", authtoken_from_env=True)

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/module.html#ngrok.connect
• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.listen_and_forward

Rust

info

Forwarding to an upstream service is not supported by the Rust SDK

Kubernetes Controller

Add the k8s.ngrok.com/app-protocols label to the Service definition targeted by your ingress backend to instruct the Ingress Controller to use https when forwarding connections.

apiVersion: v1
kind: Service
metadata:
  name: example-service
  annotations:
    k8s.ngrok.com/app-protocols: '{"example-https-port":"HTTPS"}'
spec:
  ports:
    - name: example-https-port
      port: 443
      protocol: TCP
      targetPort: 8443
  selector:
    app-name: some-example-app-label
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    k8s.ngrok.com/modules: ngrok-module-set
spec:
  ingressClassName: ngrok
  rules:
    - host: app.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: example-service
                port:
                  number: 443

Rewrite Host header

Rewrite the Host header to the value localhost using the Request Headers module. Adding the Host header is a special case that replaces the existing Host header instead of appending a second value.

Agent CLI

ngrok http 8080 --request-header-add='host: localhost'
ngrok http 9090 --request-header-add='host: example.com'

Agent Config

tunnels:
  example:
    proto: http
    addr: 8080
    request_headers:
      add: ["host: localhost"]

SSH

ssh -R 443:localhost:80 v2@connect.ngrok-agent.com http \
  --request-header-add='host: localhost'

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func ngrokListener(ctx context.Context) (net.Listener, error) {
	return ngrok.Listen(ctx,
		config.HTTPEndpoint(
			config.WithRequestHeader("host", "localhost"),
		),
		ngrok.WithAuthtokenFromEnv(),
	)
}

Go Package Docs:

• https://pkg.go.dev/golang.ngrok.com/ngrok/config#WithRequestHeader

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: 8080,
		authtoken_from_env: true,
		request_header_add: "host:localhost",
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#request_header_add
• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html#requestHeader

Python

import ngrok

listener = ngrok.forward("localhost:8080", authtoken_from_env=True,
    request_header_add="host:localhost")

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.request_header
• https://ngrok.github.io/ngrok-python/index.html#full-configuration

Rust

use ngrok::prelude::*;

async fn listen_ngrok() -> anyhow::Result<impl Tunnel> {
    let sess = ngrok::Session::builder()
        .authtoken_from_env()
        .connect()
        .await?;

    let tun = sess
        .http_endpoint()
        .request_header("host", "localhost")
        .listen()
        .await?;

    println!("Listening on URL: {:?}", tun.url());

    Ok(tun)
}

Rust Crate Docs:

• https://docs.rs/ngrok/latest/ngrok/config/struct.HttpTunnelBuilder.html#method.request_header

Kubernetes Controller

kind: NgrokModuleSet
apiVersion: ingress.k8s.ngrok.com/v1alpha1
metadata:
  name: ngrok-module-set
modules:
  headers:
    request:
      add:
        host: "localhost"
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    k8s.ngrok.com/modules: ngrok-module-set
spec:
  ingressClassName: ngrok
  rules:
    - host: your-domain.ngrok.app
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: example-service
                port:
                  number: 80

Forward to non-local

Forward traffic to a HTTP server running on your network at 192.168.1.2:80.

Agent CLI

ngrok http 192.168.1.2:80

Agent Config

tunnels:
  example:
    proto: http
    addr: 192.168.1.2:80

SSH

ssh -R 0:192.168.1.2:80 v2@connect.ngrok-agent.com http

Go

info

Forwarding to a non-local address is not supported by the Go SDK

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: "192.168.1.2:80",
		authtoken_from_env: true,
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#addr
• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html#listenAndForward

Python

import ngrok

listener = ngrok.forward("192.168.1.2:80", authtoken_from_env=True)

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/module.html#ngrok.connect
• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.listen_and_forward

Rust

info

Forwarding to a non-local address is not supported by the Rust SDK

Kubernetes Controller

The Kubernetes Ingress controller always forwards its traffic. All of our other examples show the most common forwarding case: a Service object that defines a label selector of matching pods to forward traffic to.

But you can also forward to an explicit set of IP addresses on the same network using Service and EndpointSlice objects.

apiVersion: v1
kind: Service
metadata:
  name: example-service
spec:
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
---
apiVersion: discovery.k8s.io/v1
kind: EndpointSlice
metadata:
  name: example-service-1
  labels:
    kubernetes.io/service-name: example-service
addressType: IPv4
ports:
  - name: "http"
    appProtocol: http
    protocol: TCP
    port: 80
endpoints:
  - addresses:
      - "192.168.1.2"
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    k8s.ngrok.com/modules: ngrok-module-set
spec:
  ingressClassName: ngrok
  rules:
    - host: app.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: example-service
                port:
                  number: 80

Wildcard domain

Create an endpoint on the wildcard domain, *.example.com. It will receive traffic for foo.example.com and bar.example.com. Read more about using wildcard domains.

Agent CLI

ngrok http 80 --domain *.example.com

Agent Config

tunnels:
  example:
    proto: http
    addr: 80
    domain: *.example.com

SSH

ssh -R '*.example.com:443:localhost:80' v2@connect.ngrok-agent.com http

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func ngrokListener(ctx context.Context) (net.Listener, error) {
	return ngrok.Listen(ctx,
		config.HTTPEndpoint(
                        config.WithDomain("*.example.com"),
                ),
		ngrok.WithAuthtokenFromEnv(),
	)
}

Go Package Docs:

• https://pkg.go.dev/golang.ngrok.com/ngrok/config#WithDomain

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: 8080,
		authtoken_from_env: true,
		domain: "*.example.com",
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#domain
• https://ngrok.github.io/ngrok-javascript/classes/HttpListenerBuilder.html#domain

Python

import ngrok

listener = ngrok.forward("localhost:8080", authtoken_from_env=True,
    domain="*.example.com")

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.domain
• https://ngrok.github.io/ngrok-python/index.html#full-configuration

Rust

use ngrok::prelude::*;

async fn listen_ngrok() -> anyhow::Result<impl Tunnel> {
    let sess = ngrok::Session::builder()
        .authtoken_from_env()
        .connect()
        .await?;

    let tun = sess
        .http_endpoint()
        .domain("*.example.com")
        .listen()
        .await?;

    println!("Listening on URL: {:?}", tun.url());

    Ok(tun)
}

Rust Crate Docs:

• https://docs.rs/ngrok/latest/ngrok/config/struct.HttpTunnelBuilder.html#method.domain

Kubernetes Controller

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    k8s.ngrok.com/modules: ngrok-module-set
spec:
  ingressClassName: ngrok
  rules:
    - host: *.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: example-service
                port:
                  number: 80

Serve directory files

Serve the files in a directory on an ngrok endpoint. It works just like python3 -m http.server but built directly into the ngrok agent.

Serve files in /var/log

Agent CLI

ngrok http file://`pwd`

Agent Config

tunnels:
  example:
    proto: http
    addr: "file:///var/log"

SSH

info

Serving directory files is not supported via SSH.

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func serveFiles(ctx context.Context) error {
	l, _ := ngrok.Listen(ctx,
		config.HTTPEndpoint(),
		ngrok.WithAuthtokenFromEnv(),
	)
        http.Serve(l, http.FileServer(http.Dir("/var/log")))
}

Javascript

info

Serving directory files is not supported in the Javascript SDK.

Python

info

Serving directory files is not supported in the Python SDK.

Rust

info

Serving directory files is not supported in the Rust SDK.

Kubernetes Controller

info

Serving directory files is not supported in the Kubernetes Ingress Controller.

Serve files on Windows

Agent CLI

ngrok http "file://C:\Users\alan\Directory Name"

Agent Config

tunnels:
  example:
    proto: http
    addr: "C:\Users\alan\Directory Name"

SSH

info

Serving directory files is not supported via SSH.

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func serveFiles(ctx context.Context) error {
	l, _ := ngrok.Listen(ctx,
		config.HTTPEndpoint(),
		ngrok.WithAuthtokenFromEnv(),
	)
        http.Serve(l, http.FileServer(http.Dir("C:\Users\alan\Directory Name")))
}

Javascript

info

Serving directory files is not supported in the Javascript SDK.

Python

info

Serving directory files is not supported in the Python SDK.

Rust

info

Serving directory files is not supported in the Rust SDK.

Kubernetes Controller

info

Serving directory files is not supported in the Kubernetes Ingress Controller.

Serve files in your current working directory

Agent CLI

ngrok http "file:///var/log"

Agent Config

info

Serving the current working directory is not supported via the agent configuration file.

SSH

info

Serving directory files is not supported via SSH.

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func serveFiles(ctx context.Context) error {
	l, _ := ngrok.Listen(ctx,
		config.HTTPEndpoint(),
		ngrok.WithAuthtokenFromEnv(),
	)
        http.Serve(l, http.FileServer(http.Dir(".")))
}

Javascript

info

Serving directory files is not supported in the Javascript SDK.

Python

info

Serving directory files is not supported in the Python SDK.

Rust

info

Serving directory files is not supported in the Rust SDK.

Kubernetes Controller

info

Serving directory files is not supported in the Kubernetes Ingress Controller.

Serve HTTP and HTTPS

By default, ngrok creates an HTTPS endpoint but not an HTTP one. You can configure this behavior to create an HTTP endpoint as well.

Agent CLI

ngrok http 80 --scheme http,https

Agent Config

tunnels:
  example:
    proto: http
    addr: 80
    schemes: ["http", "https"]

SSH

When using ngrok via SSH, you can start an endpoint with either the http or https scheme, but not both.

ssh -R 80:localhost:80 v2@connect.ngrok-agent.com http --schemes http

Go

import (
	"context"
	"net"

	"golang.ngrok.com/ngrok"
	"golang.ngrok.com/ngrok/config"
)

func ngrokListener(ctx context.Context) (net.Listener, error) {
	return ngrok.Listen(ctx,
		config.HTTPEndpoint(
			config.WithSchemes("http", "https"),
		),
		ngrok.WithAuthtokenFromEnv(),
	)
}

Go Package Docs:

• https://pkg.go.dev/golang.ngrok.com/ngrok/config#WithSchemes

Javascript

const ngrok = require("@ngrok/ngrok");

(async function () {
	const listener = await ngrok.forward({
		addr: 8080,
		authtoken_from_env: true,
		schemes: "http",
	});

	console.log(`Ingress established at: ${listener.url()}`);
})();

Javascript SDK Docs:

• https://ngrok.github.io/ngrok-javascript/interfaces/Config.html#schemes

Python

import ngrok

listener = ngrok.forward("localhost:8080", authtoken_from_env=True,
    schemes="http")

print(f"Ingress established at: {listener.url()}");

Python SDK Docs:

• https://ngrok.github.io/ngrok-python/http_listener_builder.html#ngrok.HttpListenerBuilder.scheme
• https://ngrok.github.io/ngrok-python/index.html#full-configuration

Rust

use ngrok::prelude::*;

async fn listen_ngrok() -> anyhow::Result<impl Tunnel> {
    let sess = ngrok::Session::builder()
        .authtoken_from_env()
        .connect()
        .await?;

    let tun = sess
        .http_endpoint()
        .scheme("http")
        .listen()
        .await?;

    println!("Listening on URL: {:?}", tun.url());

    Ok(tun)
}

Rust Crate Docs:

• https://docs.rs/ngrok/latest/ngrok/config/struct.HttpTunnelBuilder.html#method.scheme

Kubernetes Controller

info

Creating HTTP endpoints is not supported in The Kubernetes Ingress Controller.

Behavior

ngrok is a compliant HTTP reverse proxy.

Upstream Headers

ngrok adds headers to each HTTP request with information about the client IP and original protocol.

Header	Description
X-Forwarded-For	The IP address of the client who initiated the request to your endpoint.
X-Forwarded-Proto	Either http or https, indicating the protocol the request used to access your endpoint.

Auth

Anyone can access your ngrok endpoints unless you secure them with authentication. ngrok supports many different forms of authentication. The easiest to get started with are Basic Auth and OAuth. Basic Auth lets you set a username and password for your endpoint. With OAuth, you can restrict access to a specific email address with a Google, Microsoft or GitHub account.

Examples

• Basic Auth
• OAuth

There are many other forms of auth for more advanced use cases as well:

• IP Restrictions
• Webhook Verification
• Mutual TLS
• OpenID Connect
• SAML

Domains

The Domains documentation contains details about how ngrok chooses domains, what managed based domains ngrok operates, how to set up branded domains, how wildcard domains work and more.

Static Domains

ngrok will randomly assign a domain when you create HTTP endpoints unless you specify one. This is okay for one-off uses, but usually you'll want to use a static domain that doesn't change.

You can ask ngrok to always use the same name with the --domain option in the agent or an equivalent option with other connectivity choices.

Example: Static Domains

Bring your own Domain

If you want to bring your own domain, you can do that as well, but you'll need to create a Domain record and set up a DNS CNAME record. Once you've set one up, you can use the following example.

Example: Bring your own Domain

Wildcard Domains

You can ask ngrok to create an endpoint which will receive traffic for all of the subdomains matching a given wildcard domain like *.example.com. Read the wildcard domains documentation to understand the matching rules.

Example: Wildcard Domain

Forwarding

The ngrok agent forwards traffic that your endpoints receive to your upstream services. You specify a URL or port number to instruct the ngrok agent how and where to forward traffic.

Upstream HTTPS servers

By default, ngrok assumes that the upstream service it is forwarding to is listening for unencrypted HTTP traffic. You can specify a URL with an https:// scheme to make ngrok speak HTTPS to your upstream service.

As a special case, ngrok assumes that if you forward to port 443 on any host that it should send HTTPS traffic and will act as if you specified an https:// URL.

ngrok assumes that the network you run the agent on is private and it does not verify the TLS certificate presented by the upstream service.

Example: Forward to HTTPS

Rewriting the Host header

Some application servers expect the Host header to match a specific value when they receive requests and others use the Host header to determine which of many sites to display. ngrok can rewrite the Host header of incoming requests so that your upstream service behaves correctly.

When you rewrite the Host header, ngrok also rewrites the Location header of HTTP responses automatically to match the hostname of your Endpoint URL.

Example: Rewrite Host header

The ngrok agent has a shortcut which rewrites the Host header to match the hostname portion of the forwarding address. The following command will rewrite the host header to foo.local.

ngrok http foo.local:80 --host-header=rewrite

It is equivalent to:

ngrok http foo.local:80 --request-header-add='foo.local'

File Serving

The ngrok agent supports the file:// scheme in a forwarding URL. When you used the file:// scheme, the ngrok agent serves local file system directories by using its own built-in file server, no separate server needed.

All paths must be specified as absolute paths, the file:// URL scheme does not understand relative paths.

Example: Serving directory files

Certificates

ngrok automatically manages all of your TLS certificates. There is nothing to setup, configure or manage.

Regardless of whether your domain is a subdomain of ngrok's managed base domains (like ngrok.app) or you brought your own domain, ngrok will automatically provision and renew TLS certificates for you. You can optionally bring your own certificates if you'd like though.

Read the TLS Certificates documentation for additional details of how ngrok automatically provisions certificates for your domains as well as how you can bring your own certificates.

Routes

When you use Edges to manage your endpoints, you can apply different modules on a per-path basis. For example, you could apply auth to /dashboard and compression to /static.

We call this primitive a Route. Each Route is defined using a path selector, which will match a path on the request to that endpoint. This can be useful for adding OAuth to specific areas of your website, or stitching multiple services together into a single website. Routes can share the same backend, or you can use a different backend for each route.

HTTP vs HTTPS

By default, ngrok only creates HTTPS endpoints for your services. You can configure ngrok to create both HTTP and HTTPS endpoints or even just HTTP only. If you are using Edges, only HTTPS endpoints are supported.

Example: Serve HTTP and HTTPS

Websockets

Websocket connections are supported. No changes or configuration is required.

Hop by hop Headers

ngrok does not forward any hop-by-hop headers to the upstream service.

As an exception to this rule, Connection: upgrade requests are forwarded to support websockets.

HTTP/1.1 Keep-Alive

When a request is transmitted over HTTP/1.1, the ngrok edge may choose to use keep-alive connections to improve the performance of future requests. This behavior is not configurable.

HTTP/2

Client to ngrok edge

ngrok's HTTP endpoints will automatically use HTTP/2 for all connections if the client supports it. HTTP/2 is used even if your upstream service does not support HTTP/2.

ngrok edge to upstream service

Requests to upstream services can be configured to continue using HTTP/2 with either the agent CLI flags or the agent SDKs.

All requests to your upstream service will be transmitted over HTTP/2 Cleartext since TLS was already terminated at the ngrok edge. We cannot use TLS-ALPN at this time. We rely on HTTP/2 with Prior Knowledge currently.

HTTP/3

HTTP/3 is not yet supported.

Reference

Edges

Edges enable you to centrally manage your endpoints' Module configurations in the ngrok dashboard or API instead of defining them via an Agent or Agent SDK.

• An HTTPS Edge is attached to one or more Domains. For each Domain, it creates an HTTPS Endpoint that it listens for traffic on.
• When a Domain is associated with an HTTPS edge, agents may no longer start endpoints on that Domain. You can always detach a Domain from your Edge if you want to create Endpoints on it from an Agent or Agent SDK.
• An HTTPS Edges has one or more Routes. Routes have selectors which enable you to process traffic for paths like /app or /static differently.
• Each Route can apply different Modules. Routes can also even send traffic to different Backends.
• HTTPS Edges do not create a corresponding HTTP endpoint. Instead, all HTTP traffic to domains associated with your HTTPS edges is automatically redirected to HTTPS.
• When you create an HTTPS edge via the dashboard, it will automatically create a new Domain with a random name and assign it to your Edge. If you are on the free plan and have created your free domain, it will adopt that domain.
• When you create an HTTPS edge via the dashboard, it will automatically create a Failover Backend with two entries. First, a tunnel group backend with a unique label and second an HTTP Response backend which renders an error if there are no tunnels online in the tunnel group.

Modules

Use modules to modify the behavior of traffic flowing through your endpoints.

Module	Description
Basic Auth	Require a username and password with HTTP Basic Auth.
Circuit Breaker	Protect upstream services by rejecting traffic when they become overwhelmed.
Compression	Accelerate upstream services by compressing HTTP response bodies with gzip or deflate.
IP Restrictions	Allow or deny traffic based on the source IP of connections.
Mutual TLS	Enforce mutual TLS auth with a configured set of CAs.
OAuth	Enforce an OAuth flow to well-known IdPs like Google, optionally authorizing users by domain or email address.
OpenID Connect	Enforce an OpenID Connect flow to a federated IdP.
Request Headers	Add or remove headers from HTTP requests before they are sent to your upstream service.
Response Headers	Add or remove headers from HTTP responses before they are returned to the client.
SAML	Enforce a SAML flow to a federated IdP, optionally authorizing users by group.
TLS Termination	Customize TLS termination behavior, like the minimum supported version of TLS.
Traffic Policy	Influence and control traffic to and from your upstream service by configuring a powerful policy engine.
User Agent Filter	Block bots or browsers with rules that allow or deny HTTP requests based on User-Agent header.
Webhook Verification	Restrict access by verifying HTTP requests are signed by a webhook provider like Slack or GitHub.
Websocket TCP Converter	Convert binary websocket connections to backend TCP connections.

Observability

ngrok's events system can capture logs of HTTP requests to your endpoints. ngrok publishes both Layer 4 (connection-level) and Layer 7 (request-level) events for HTTP traffic.

When HTTP requests to your endpoints are completed, http_request_complete.v0 events are published.

When TCP connections to your HTTP endpoints are completed, tcp_connection_closed.v0 events are published.

Errors

If ngrok fails to handle an HTTP request it will set the ngrok-error-code header in the HTTP response with a unique ngrok Error Code describing the failure.

ngrok guarantees that the upstream service may never set the ngrok-error-code HTTP response header so you know reliably that it was set by ngrok.

ngrok may return an error under the following conditions:

• A configured module rejected the request
• Your upstream service timed out or rejected the connection
• Your upstream service returned a response that was not valid HTTP
• ngrok encountered an internal error

Pricing

HTTP endpoints are available on all plans.

Branded domains are available on the Pro and Enterprise plans.