Where does the bug appear (feature/product)? Cursor IDE Describe the Bug Same issue as Opus 4.7 via AWS Bedrock. Opus v4.8 is broken with this API Error: The model returned the following errors: temperature is deprecated for this model. Steps to Reproduce Try to use Opus v4.8 via AWS Bedrock Ope…

Hi @mjnowen Thanks for reporting, and I apologize for the inconvenience. This is a confirmed regression unfortunately. We fixed it with 4.7 but it has re-appeared with 4.8 We have a bug report raised for this and I’ll let you know when it is sorted out.

Where does the bug appear (feature/product)? Cursor IDE Describe the Bug just like in 4.7: Opus 4.7 not functioning on Bedrock because of Temperature deprecation / 400 - #12 . switching to 4.7 works. Steps to Reproduce use aws bedrock credentials enable us.anthropic.claude-opus-4-8 try to send a …

Having same issue with opus-4-8

Hi @here We just merged a fix for this, you should see 4.8 requests going thru Bedrock successfully soon. Please give it a shot and let us know if all is well. This is a server-side change, so no client update is required (although we always encourage you to keep Cursor up to date!)

Awesome! @Oguz_Akkas Thanks for confirming!

Yes, it works, but I also upgraded to Cursor v3.6.21 and now I have a new bug. Oh dear… [image] Cursor v3.6.21 - caught in loop for "cursor-agent-worker" Reload Window Bug Reports Where does the bug appear (feature/product)? Cursor IDE Describe the Bug “curs…

Ok thank you for highlighting! We’ve got a bug report open for this I’ll follow up on the other thread and let you know when any updates.

Opus 4.8 via Bedrock: "temperature" is deprecated for this model

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mjnowen May 29, 2026, 8:06pm 14

Yes, it works, but I also upgraded to Cursor v3.6.21 and now I have a new bug. Oh dear…

Topic		Replies	Views
Opus 4.8 on AWS Bedrock does not work Bug Reports byok , anthropic	9	573	May 29, 2026
Opus 4.7 not functioning on Bedrock because of Temperature deprecation / 400 Bug Reports nightly , byok , anthropic	4	1864	April 16, 2026
Opus 4.8 with bedrock errors out saying `temperature` is deprecated Bug Reports byok , anthropic	1	134	May 29, 2026
Crash oder Verbindungsproblem von Opus 4.7 Bug Reports anthropic	2	72	April 27, 2026
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Opus 4.8 via Bedrock: "temperature" is deprecated for this model

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