# Keycloak (Netty) + RUM agentless (CDN) — snippet doesn't appear on login screens; OneAgent auto-injection also fails

**URL:** <https://community.dynatrace.com/t/keycloak-netty-rum-agentless-cdn-snippet-doesnt-appear-on-login-screens-oneagent-auto-injection-also-fails/53197>\
**Category:** Real User Monitoring\
**Tags:** real-user-monitoring-classic, javascript\
**Created:** [September 2, 2025, 6:06pm UTC](https://community.dynatrace.com/t/keycloak-netty-rum-agentless-cdn-snippet-doesnt-appear-on-login-screens-oneagent-auto-injection-also-fails/53197 "2025-09-02T18:06:29Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mioroo](https://avatars.discourse-cdn.com/v4/letter/m/5fc32e/32.png) [@mioroo](https://community.dynatrace.com/u/mioroo)\
**Post date:** [September 2, 2025, 6:06pm UTC](https://community.dynatrace.com/t/keycloak-netty-rum-agentless-cdn-snippet-doesnt-appear-on-login-screens-oneagent-auto-injection-also-fails/53197/1 "2025-09-02T18:06:29Z")

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**Context**  
• IdP: Keycloak (Netty technology) behind AWS CloudFront  
• Objective: Use agentless Real User Monitoring with JavaScript tag (Dynatrace CDN)  
• Desired beacon endpoint (agentless): Dynatrace SaaS/Cluster (…[bf.dynatrace.com/bf](http://bf.dynatrace.com/bf))

**What we’ve already done**  
• We inserted the CDN snippet (…\_complete.js) in the \<head\> of the realm’s login theme.  
• Network: Confirmed no blocking for [https://js-cdn.dynatrace.com](https://js-cdn.dynatrace.com).  
• Manual test (Console): By injecting \_complete.js from the CDN, the session appears in Dynatrace (beacon for /bf OK). Sometimes, the js returns a 404 when manually injected through the Dev Tools console. Symptoms Observed  
• On login screens, the CDN snippet isn’t rendered in the HTML (DevTools doesn’t display the js tag).

**Important — OneAgent Auto-Injection**  
The agentless option was chosen because automatic injection wasn’t working.  
In other words, neither agentless mode is rendering the tag in the login HTML, nor was auto-injection able to serve ruxitagentjs.

**Questions**  
In Keycloak (Netty), are there specific recommendations on where to include the tag in the login theme?  
Any specific tips or checklists for Keycloak + Netty + RUM agentless would be greatly appreciated. Thank you!

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**Author:** ![KiranSomanatti](https://avatars.discourse-cdn.com/v4/letter/k/3d9bf3/32.png) [@KiranSomanatti](https://community.dynatrace.com/u/KiranSomanatti)\
**Post date:** [September 3, 2025, 9:53am UTC](https://community.dynatrace.com/t/keycloak-netty-rum-agentless-cdn-snippet-doesnt-appear-on-login-screens-oneagent-auto-injection-also-fails/53197/2 "2025-09-03T09:53:49Z")

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Hello Mioroo,

This looks like a specific scenario where you face this issue.

especially regarding the statement:&nbsp;_ **Sometimes, the js returns a 404 when manually injected through the Dev Tools&nbsp;console.** _

This does not look like a supported way of manual injection.

Therefore, please open a support ticket with the test session HAR file and, if possible, a screenshot showing the issue so we can examine it more thoroughly.

Best Regards&nbsp;  
Kiran