Gemini HTTP 400 (INVALID_ARGUMENT): Function call is missing a thought_signature | Nous Research | Page 1

grizzled wave Apr 23, 2026, 12:25 PM

#

I'm unable to use Gemini 3.1 Pro (API) today
(it was working fine previously)

I'm getting an error when running a simple command like hermes skills list.

Here is the error message:

  ┊ :books: skills    list all  0.2s
:warning:  API call failed (attempt 1/3): GeminiAPIError [HTTP 400]
   :electric_plug: Provider: gemini  Model: gemini-3.1-pro-preview
   :globe_with_meridians: Endpoint: https://generativelanguage.googleapis.com/v1beta
   :pencil: Error: HTTP 400: Gemini HTTP 400 (INVALID_ARGUMENT): Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call `default_api:skills_list` , position 2. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.
:warning: Non-retryable error (HTTP 400) — trying fallback...
:x: Non-retryable error (HTTP 400): HTTP 400: Gemini HTTP 400 (INVALID_ARGUMENT): Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance. Additional data, function call `default_api:skills_list` , position 2. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.
:x: Non-retryable client error (HTTP 400). Aborting.
   :electric_plug: Provider: gemini  Model: gemini-3.1-pro-preview
   :globe_with_meridians: Endpoint: https://generativelanguage.googleapis.com/v1beta
   :bulb: This type of error won't be fixed by retrying.
 ─  ⚕ Hermes  ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 
                                                                                                                                                                                    
     Error: Gemini HTTP 400 (INVALID_ARGUMENT): Function call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing       
     thought_signature may lead to degraded model performance. Additional data, function call default_api:skills_list , position 2. Please refer to                                 
     https://ai.google.dev/gemini-api/docs/thought-signatures for more details. ```

toxic agate Apr 23, 2026, 12:27 PM

#

When was your last

hermes update

this looks a lot like an error that was patched recently

normal bison Apr 23, 2026, 12:30 PM

#

This is the wrong place for your error please create a different #1485307775444844625

normal bison Apr 23, 2026, 12:30 PM

#

grizzled wave I'm unable to use Gemini 3.1 Pro (API) today (it was working fine previously) I...

hermes skills list is for the main terminal not in the TUI

#

Can you run /debug and share the output of it here

grizzled wave Apr 23, 2026, 12:34 PM

#

toxic agate When was your last hermes update this looks a lot like an error that was patc...

I updated to the latest version a few days ago
It works fine when I switch to model 2.5, but it doesn't work when using the 3. model

toxic agate Apr 23, 2026, 12:34 PM

#

A few days is out of date
please run

hermes update

and le's get a clean slate

#Gemini HTTP 400 (INVALID_ARGUMENT): Function call is missing a thought_signature