<!-- mobian-agent-page publisher="dailydev" canonical="https://daily.dev/posts/medium-tpgjrsou1" -->

---
title: Medium | daily.dev
description: A comprehensive guide to integrating Keycloak for Identity and Access Management with both FastAPI (Python) and Go backends. Covers core OIDC concepts,...
canonical: https://daily.dev/posts/medium-tpgjrsou1
twitter:card: summary_large_image
twitter:site: @dailydotdev
og:type: website
og:site_name: daily.dev
og:title: Medium | daily.dev
og:description: A comprehensive guide to integrating Keycloak for Identity and Access Management with both FastAPI (Python) and Go backends. Covers core OIDC concepts,...
og:url: https://daily.dev/posts/medium-tpgjrsou1
og:image: https://api.daily.dev/og/posts/tPgJRsoU1.png
og:image:alt: Medium
og:image:width: 1200
og:image:height: 630
og:locale: en
---

> ## Documentation Index
> Fetch the complete documentation index at: https://daily.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Medium

**[Medium](https://daily.dev/sources/medium_js)** · 10 min read · 1 upvotes · 0 comments

## Summary

A comprehensive guide to integrating Keycloak for Identity and Access Management with both FastAPI (Python) and Go backends. Covers core OIDC concepts, Docker-based Keycloak setup, JWT validation, RBAC with realm and client roles, and production best practices including TLS configuration, token lifetimes, JWKS key rotation, and proper OAuth flows.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://mjmichael.medium.com/keycloak-the-complete-guide-to-open-source-identity-and-access-management-with-fastapi-golang-182d042c9fef>

## Questions this post answers

### How do I validate a Keycloak-issued JWT in a FastAPI application?

Fetch Keycloak's JWKS from the realm's certs endpoint, match the token's 'kid' header to a public key, then decode the JWT with python-jose using RS256, checking issuer and audience claims. A dependency function like get_current_user can perform this validation and return the decoded claims for use in route handlers, with role checks handled by a separate require_role dependency factory.

_daily.dev surfaces backend security practices for developers wiring JWT validation into FastAPI services._

### How do I verify Keycloak JWTs in a Go net/http service without manually parsing tokens?

Use the coreos/go-oidc library, which fetches the OIDC discovery document and JWKS automatically via oidc.NewProvider, then create a verifier with provider.Verifier(&oidc.Config{ClientID: "account"}) to validate signature, issuer, and expiry on each request. This avoids manual JWKS caching and automatically re-fetches keys when Keycloak rotates its signing keys, unlike a naive manual JWT parsing approach with golang-jwt/jwt.

_Go developers comparing JWT libraries can track integration patterns like this on daily.dev._

### Why should I avoid the OAuth2 Resource Owner Password Credentials grant with Keycloak in production?

The password grant is deprecated in OAuth 2.1 because it requires the client to handle raw user credentials directly, defeating the purpose of delegated authentication. For production Keycloak deployments, use Authorization Code Flow with PKCE for user-facing applications and Client Credentials flow for service-to-service calls instead, reserving the password grant only for quick local testing.

_daily.dev helps developers weigh OAuth2 flow trade-offs before locking in a production auth design._

## Similar posts on daily.dev

- [Integrate Keycloak with ASP.NET Core Using OAuth 2.0](https://daily.dev/posts/integrate-keycloak-with-asp-net-core-using-oauth-2-0-w348tdawg) · Milan Jovanović · 11 upvotes · 1 comments
- [Authentication Microservices Using Keycloak, Apache APISIX, and OpenID Connect](https://daily.dev/posts/authentication-microservices-using-keycloak-apache-apisix-and-openid-connect-u6xi0udtu) · Medium · 2 upvotes · 0 comments
- [Apache Polaris OIDC with Keycloak and Okta](https://daily.dev/posts/apache-polaris-oidc-with-keycloak-and-okta-cjfeyusju) · Dremio Blog · 0 upvotes · 0 comments
- [Building an OIDC Provider from Scratch in Go](https://daily.dev/posts/building-an-oidc-provider-from-scratch-in-go-apjugsw4x) · Medium · 1 upvotes · 0 comments

---

Tags: [#infrastructure](https://daily.dev/tags/infrastructure), [#golang](https://daily.dev/tags/golang), [#authentication](https://daily.dev/tags/authentication), [#fastapi](https://daily.dev/tags/fastapi)

[View this post on daily.dev](https://daily.dev/posts/medium-tpgjrsou1)

```json
{"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]}
{"@context":"https://schema.org","@type":"TechArticle","headline":"Medium","url":"https://daily.dev/posts/medium-tpgjrsou1","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/medium-tpgjrsou1"},"datePublished":"2026-07-20T19:35:21.438Z","dateModified":"2026-09-13T18:51:38.152Z","description":"A comprehensive guide to integrating Keycloak for Identity and Access Management with both FastAPI (Python) and Go backends. Covers core OIDC concepts,...","image":"https://media.daily.dev/image/upload/s--OHB84bZF--/f_auto/v1722860399/public/Placeholder%2010","thumbnailUrl":"https://media.daily.dev/image/upload/s--OHB84bZF--/f_auto/v1722860399/public/Placeholder%2010","isAccessibleForFree":true,"articleSection":"Medium","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Medium","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/medium","url":"https://daily.dev/sources/medium_js"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/medium-tpgjrsou1","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"infrastructure,golang,authentication,fastapi","timeRequired":"PT10M"}
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Medium","item":"https://daily.dev/sources/medium_js"},{"@type":"ListItem","position":3,"name":"Medium"}]}
{"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/medium-tpgjrsou1#faq","mainEntity":[{"@type":"Question","name":"How do I validate a Keycloak-issued JWT in a FastAPI application?","acceptedAnswer":{"@type":"Answer","text":"Fetch Keycloak's JWKS from the realm's certs endpoint, match the token's 'kid' header to a public key, then decode the JWT with python-jose using RS256, checking issuer and audience claims. A dependency function like get_current_user can perform this validation and return the decoded claims for use in route handlers, with role checks handled by a separate require_role dependency factory. daily.dev surfaces backend security practices for developers wiring JWT validation into FastAPI services."}},{"@type":"Question","name":"How do I verify Keycloak JWTs in a Go net/http service without manually parsing tokens?","acceptedAnswer":{"@type":"Answer","text":"Use the coreos/go-oidc library, which fetches the OIDC discovery document and JWKS automatically via oidc.NewProvider, then create a verifier with provider.Verifier(&oidc.Config{ClientID: \"account\"}) to validate signature, issuer, and expiry on each request. This avoids manual JWKS caching and automatically re-fetches keys when Keycloak rotates its signing keys, unlike a naive manual JWT parsing approach with golang-jwt/jwt. Go developers comparing JWT libraries can track integration patterns like this on daily.dev."}},{"@type":"Question","name":"Why should I avoid the OAuth2 Resource Owner Password Credentials grant with Keycloak in production?","acceptedAnswer":{"@type":"Answer","text":"The password grant is deprecated in OAuth 2.1 because it requires the client to handle raw user credentials directly, defeating the purpose of delegated authentication. For production Keycloak deployments, use Authorization Code Flow with PKCE for user-facing applications and Client Credentials flow for service-to-service calls instead, reserving the password grant only for quick local testing. daily.dev helps developers weigh OAuth2 flow trade-offs before locking in a production auth design."}}]}
```