IndieAuth is a federated login protocol for Web sign-in, enabling users to use their own domain to sign in to other sites and services. IndieAuth can be used to implement OAuth2 login AKA OAuth-based login.
IndieAuth is built on ideas and technology from existing proven technologies like OAuth and OpenID but makes it easier for users as well as developers. It decentralizes much of the process so completely separate implementations and services can be used for each part.
If you’re familiar with writing an OAuth client, then you're familiar with the problem of having to register your client manually with each OAuth provider. IndieAuth uses DNS as a replacement for client registration, thereby eliminating the need for any manual registration with providers.
⚠️ Note: IndieAuth is often conflated with the IndieAuth.com service provider. The first is the subject of this page: the way the IndieAuth protocol works. The second is a service that provides an authorization endpoint, and was also previously used by this wiki until the wiki switched to using indielogin.com.
Why
By choosing your IndieAuth provider, you can tell applications where to send you to sign in. This gives you more control over the privacy and security of your logins.
Most Micropub clients use IndieAuth to log you in, obtaining your authorization by directing you to your chosen IndieAuth server. This allows you to use your own website to log in to the tools you use to post content.
IndieAuth is part of taking back control of your online identity. Instead of logging in to websites as “you on Twitter” or “you on Facebook”, you should be able to log in as just “you”. We should not be relying on silos to provide our authenticated identities, we should be able to use our own personal domains to log in to sites everywhere.
You can use it right now to log in to this wiki and contribute to the community, including doing common things like:
The user fills in their personal URL This is called Web sign-in.
The app fetches the URL, looking for an authorization endpoint. For this, the user can use IndieAuth.com, but it can also be at their own domain. The app redirects the User to their authorization endpoint.
The user authenticates at their own authorization endpoint. IndieAuth.com uses RelMeAuth to authenticate users, but if a user uses an authorization endpoint on their own site, it can be a password, e-mail link, or any other authentication mechanism the authorization endpoint provides. They prove their identity to their authorization endpoint while the app waits for them to complete.
The authorization endpoint issues a temporary authorization code, and sends it to the app by redirecting the user's browser back to the app.
The app checks the code with the authorization endpoint, and if the code is valid and if the user’s identifier matches the identifier the authorization endpoint gives, the login is completed, and the user can enter and use the app.
How to
If all you're trying to do is log in to the wiki, then you may not need to set up IndieAuth at all! Instead, you can just link to your existing Twitter or GitHub accounts and the wiki will use those to authenticate you! See indielogin.com/setup for more details.
If you use WordPress, you can install the Wordpress IndieAuth Plugin which provides a built-in IndieAuth server. If you have problems with the authentication header being stripped off by Apache (a common problem on hosting services like Bluehost.com), the IndieAuth plugin should be disabled or removed, and the Micropub plugin should be used to provide authentication through IndieAuth.com.
Set up using IndieAuth.com
IndieAuth.com is a service that allows you to sign in as your site by using your social media profiles. This is aimed at those who want to experiment with IndieAuth, and is not preferred as a long-term solution due its dependence on logging in via third-parties.
Your homepage and social media profiles need to link to each other for verification. Instead of registering for an account at indieauth.com, it uses your existing social media accounts to verify you own the URL you're signing in as.
Add rel-me links to your homepage for various ways to reach you, e.g. <a href="https://github.com/aaronpk" rel="me">GitHub</a>.
Make sure any social media profiles you linked to have a link back to your homepage.
Finally, include <link rel="authorization_endpoint" href="https://indieauth.com/auth"> on your homepage.
You are done! Try to log in to a site that supports IndieAuth, such as:
Sebastiaan Andeweg has an authorization endpoint at https://seblog.nl/auth as of IndieWebWeek 2017 in Düsseldorf and Nürnberg. Since IndieWebCamp Düsseldorf 2021, he uses a rewritten version at the same URL.
4X_Pro in February 2021 implemented authorization endpoint on http://4xpro.ru, which is powered by Intellect Board forum/blog engine.
capjamesg has an authorization endpoint at https://auth.jamesg.blog as of October, 2021. His endpoint supports Twitter, GitHub, and passwordless authentication via a mobile push notification. The push notification is developed with use of Okta's Verify product.
IndieAuth.com is an implementation of Web sign-in/RelMeAuth with an HTTP API, used by many people as a quick way of adding IndieAuth support to their site by linking to existing silo accounts
commentpara.de provides IndieAuth identities to anyone wishing to log in to a website anonymously.
indieauth-openid converts an existing OpenID setup to work with IndieAuth
Most Micropub apps use IndieAuth to allow the app to post to your site
Hosted services which make developing IndieAuth-based applications easier.
IndieLogin.com
IndieLogin.com is a service that consumes IndieAuth. It authenticates users using IndieAuth, RelMeAuth, email and PGP, wrapping all the logic in a simple API. It is used by the indieweb.org wiki as well as other related projects to sign users in.
The IndieAuth.com service provides an authorization endpoint to bootstrap your Micropub server development. It lets you authenticate via GitHub, email, and PGP. Eventually this will be replaced with a new service, MyIndieAuth.com, although development of that service has not yet begun.
Historically, IndieAuth.com also provided an API for developers to use to authenticate users, tho this is being phased out in favor of IndieLogin.com.
Software libraries and plugins which allow developers to add IndieAuth server functionality to their apps, and CMSes which provide a IndieAuth server by default.
Acquiescence is a simple IndieAuth authorization and token endpoint. It is currently limited to GitHub for authorization. Barry Frost uses Acquiescence on his website.
The Drupal IndieWeb module provides a self-contained IndieAuth server for Drupal
Microblog.pub implements IndieAuth endpoints (authorization and token endpoint) with U2F support and you can use your ActivityPub identity to login to other websites/app
selfauth is a single-user authorization endpoint implemented in a single PHP file
taproot/indieauth is a PHP library for quickly adding well-tested, flexible, extensible, templatable IndieAuth Server functionality to any PSR-7 compatible app
Belding is a self-hostable standalone PHP app built around taproot/indieauth that provides authentication, token, introspection, and metadata endpoints for a single user / site.
reiterate-app/authorio is a Rails Engine (plug-in) that will enable IndieAuth authentication endpoint functionality for any Rails-based site.
Install the gem into your Gemfile and follow the instructions in the README. The engine installs with minimal changes needed to your existing site.
spruce/indieLogin is a NodeJs implementation of indieLogin.com which is intended for JavaScript Developers to implement RelMeAuth authentication functionality.
indielib (go.hacdias.com/indielib) is a Go library that provides a toolkit to implement both Server and Client IndieAuth authentication.
Owncast uses IndieAuth as an optional way to authenticate themselves with live stream chat as of v0.0.12. [1]
IndieAuth for ProcessWire adds authorization endpoint and token endpoint functionality to your ProcessWire site.
SnackAuth is an IndieAuth authorization and token endpoint developed in Python.
IndieAuth clients (AKA IndieAuth consuming sites) are sites that let you login using your IndieAuth identity. In identity terms, a site that consumes an IndieAuth identity is a relying party (RP), and as a set they are relying parties (RPs).
There are a growing number of web sites that you can log in to using IndieAuth and gain additional functionality:
IndieWeb.org — this site! Signing-in with IndieAuth enables you to edit the wiki, and authenticates you for its subdomains also like:
imoxia toolbox — a web-app developed by David Somers [omz13] – to test various IndieWeb and related things (profile discovery, endpoint discovery, authorization server metadata discovery, etc.)
hacdias/indieauth — Go library that provides a toolkit to implement both Server and Client IndieAuth authentication.
...
IndieAuth Protocol
This section is a high-level overview of the protocol. See The IndieAuth Specification for in-depth technical information
A user should only have to communicate their own homepage URL to the website they are trying to log in to. This is the core idea of Web sign-in. This means a developer should in their turn be able to find everything they need on that one user supplied URL.
IndieAuth uses the indieauth-metadata link rel value to allow clients to discover the location of an IndieAuth Server Metadata endpoint from a user’s homepage, which they can then fetch to discover all information necessary for the rest of the IndieAuth flow.
A user can link to their metadata endpoint from the <head> of their homepage, add the correct rel value and be done.
Previous versions of IndieAuth defined two separate rel values for discovery of the authorization and token endpoints, which can be used for back-compat with older clients in addition to indieauth-metadata.
The authorization endpoint is a page where applications can send users to and asking them to identify themselves. Because the user defines their own endpoint on their homepage, this can be part of their own website or a completely separate service. This is how the user provides proof they really operate the homepage URL they provided.
An application can also ask the user to grant it certain rights by requesting them through the authorization endpoint. A Micropub client might ask to be allowed create rights. The user can then either accept these or not when they have been redirected to their endpoint.
For developers, the authorization endpoint also functions as a verification service. If they get a code from a user they can check its validity with the endpoint to make sure it was truly issued by the user.
The token endpoint is a service that creates access tokens for applications to store and use in Micropub requests. After authorizing the application, the token endpoint creates a token that the application stores. The application will send it in a header when making a Micropub request, and the Micropub endpoint is expected to be able to validate the token while processing the request.
Q: Do I need to enter my URL every time I log in to an app that uses IndieAuth?
Yes, like traditional username/password forms, you need to enter your URL when you log in to an app. Browsers will remember your URL you enter and will suggest it using their normal autofill mechanisms as well.
Can anyone supply the URL as the client ID when they make the request?
Yes, just like you can find someone's client ID and supply that in the request with public client in OAuth 2.0.
In OAuth 2.0 there is the idea of public vs. confidential clients, public clients are when things can't be kept secret, like native apps.
A secret already can't be used when it is deployed in native apps in traditional OAuth 2.0, so we're just taking the idea of public clients and doing all the protections that you would have to do with public clients and extending that to all clients.
Should I use HTTPS?
The IndieAuth specification is an extension of OAuth 2.0, and OAuth 2.0 recommends using https URLs for everything. IndieAuth doesn't provide any new reason to require or not require https so delegates this recommendation to OAuth 2.0.
Why do I see form-encoded responses?
IndieAuth originally used standard form-encoding for requests and responses, since it has been a standard encoding format since the beginning of the web.
Over time, implementations added support for sending JSON responses as well as form-encoded. When IndieAuth was written up as a formal OAuth 2.0 extension, it documented only the JSON responses in order to be compatible with OAuth 2.0. At that point, most implementations already supported JSON responses, or did content negotiation to support both formats.
How can an application get additional information about the user?
The IndieAuth specification offers the user’s profile page where further public information about the user can be found, e.g. by parsing an h-card. There is currently no common way of retrieving private information.
How is this any different than OpenID 1.0?
OpenID 1.0 solved a lot of the same problems as this, and then those problems kind of got push by the wayside when OpenID Connect came around.
With OpenID 1.0, the whole idea was bring your own identity. In fact, it was only the "prove the identity" aspect. It didn't include anything around OAuth which is about the ability to get something that can be used to access an API. OpenID 1.0 only solved half of that first of it all.
So yes, the original goals of OpenID 1 absolutely apply. OpenID Connect chose to ignore individual identity and instead, switched to where enterprises issue identities and everybody is siloed off and the issuer controls the identity.
Does this use Webfinger for discovery?
IndieAuth uses even less steps than Webfinger. Currently all IndieAuth applications a user enters their full URL which then fetchs HTTP and HTML link rels to find the appropriate endpoints.
If you wanted to have a user type in an email address to start out with, you would then need to use something like WebFinger to turn that into URL first.
We don't see a lot of that being done right now in the things that are running today.
If you have no pre-existing registration, how are you identifying yourself?
Clients are all identified by a URL. In the OAuth 2.0 world, the primary thing that client registration gives you is: it ensures that system exchanging the code is actually the same system the code was issued to.
When all clients are public clients, like JavaScript apps and mobile apps, you don't get a secret when you register, so you have to register a callback URL. The URL basically acts as authentication already in the existing OAuth 2.0 world and OpenID Connect, what we've done with IndieAuth is said that client IDs don't need to be pre-registered because the only thing it gives you is a way to put that information about the app there.
So instead of pre-registration, registration is DNS. An application will be running at example.com, that's already an identifier that's unique in the system, that is used as the identifier, and if we need to find out information about the app we can go and look it up at that URL.
Where do I get user information from?
On that last step of the authentication flow, you get a reference to the user who's been identified. You can use this to extract a h-card that'll tell you everything that the user chooses to share publicly with you. This can include their name, e-mail, photo and a username that they'd prefer to use.
Why does IndieAuth require separate authorization and token endpoints?
It’s a design decision carried over from OAuth2. The authorization endpoint is used when interacting with the user (i.e. it outputs HTML, deals with cookies and such), whereas the token endpoint is used by the application (i.e. it only responds to simple POST requests, and returns JSON).
In practice, the two endpoints will almost always be part of the same system, and be able to communicate and verify authorization codes in the same way as the authorization endpoint. Previous versions of the spec defined communication between separate auth and token endpoints, but were dropped due to confusion and lack of real-world use.
"IndieAuth is pretty slick. Feels very right to use my own domain as my identity. I spread the functionality over 8 or so cloud functions but none where more than 50 LOC. They'll scale forever up, and down. More than likely always within free tier. Pretty big upside over WP." @brianleroux June 3, 2022
Aaron Parecki at https://aaronparecki.com/auth as of 2016-04-13. As of 2017-10-04, authentication is done via a push notification to his mobile phone rather than entering a password.
Sebastiaan Andeweg has an authorization endpoint at https://seblog.nl/auth as of IndieWebWeek 2017 in Düsseldorf and Nürnberg. Since IndieWebCamp Düsseldorf 2021, he uses a rewritten version at the same URL.
Martijn van der Ven has an authorization endpoint on
Jeena Paradies has an authorization endpoint at https://jeena.net/indieauth as of IndieWebCamp 2017 in Berlin
Malcolm Blaney has an authorization endpoint on https://unicyclic.com/mal as of IndieWeb Summit 2018.
Kristof De Jaeger has an authorization endpoint on https://realize.be as of November 2018.
pmc has an authorization endpoint on https://piperswe.me, implemented with Netlify Functions.
Frank Meeuwsen has an authorization endpoint on https://diggingthedigital.com/ as of February 2019. This is powered by the WordPress IndieAuth plugin
Hammy Havoc has an authorization endpoint on https://www.hammyhavoc.com/ as of August 2022. This is powered by the WordPress IndieAuth plugin
Dmitri Shuralyov has an authorization endpoint at https://dmitri.shuralyov.com/api/indieauth/authorization as of 2019-12-22. Implemented in Go.
4X_Pro in February 2021 implemented authorization endpoint on http://4xpro.ru, which is powered by Intellect Board forum/blog engine.
capjamesg has an authorization endpoint at https://auth.jamesg.blog as of October, 2021. His endpoint supports Twitter, GitHub, and passwordless authentication via a mobile push notification. The push notification is developed with use of Okta's Verify product.
Jamie Tanna has an IndieAuth server at https://indieauth.jvt.me, built with (Java) Spring Boot.
Henrique Dias has an IndieAuth server built-in into his custom CMS. It is implemented in Go using indielib.
Barry Frost uses Acquiescence on his website.
David Somers [omz13] – to test various IndieWeb and related things (profile discovery, endpoint discovery, authorization server metadata discovery, etc.)
Manton Reece: IndieAuth for Micro.blog (archived)
