[OpenRouter] "openrouter/auto" is set as the default model and unexpected request is sent using this model

[limingchina]

Reproduction steps

[Prerequisit]: OpenRouter key is set and it can be used by Zed Agent.

1. Start zed
2. In the AI assistant chat panel, select a free OpenRouter model, e.g. Stepfun 3.5 Flash( free )
3. Type some test message like "hi"
4. Check the OpenRouter activity log. It will show two requests. One is from the selected model "Stepfun 3.5 Flash( free )" and the other is from the "openrouter/auto" model. In my case, I set it to "Mistral Small 3.2 24B", which is specified using a filter setting at https://openrouter.ai/settings/routing. If I don't set this, it will choose "Claude Opus 4.6".

Note, this is not sent with every message, it happens at the beginning. However, it has small amount of unexpected cost on my openrouter credit.

Extra info: The "openrouter/auto" seems to be used In the "Model"'s constructor.

zed/crates/open_router/src/open_router.rs

Line 87 in a8043dc

"openrouter/auto",

Current vs. Expected behavior

Current behavior: Unexpected request is sent using "openrouter/auto" model shown as the screenshot:

Expected behavior: No request should be sent using "openrouter/auto" model

Zed version and system specs

Zed: v0.224.11+stable.175.e4cabf49a18ed03969d84ee15643e9ec81857e97 (Zed)
OS: macOS 26.3
Memory: 18 GiB
Architecture: aarch64

Attach Zed log file

Zed.log

Relevant Zed settings

settings.json

Relevant Keymap

keymap.json

(for AI issues) Model provider details

• Provider: OpenRouter
• Model name: "openrouter/auto"
• Mode: Agent pannel

If you are using WSL on Windows, what flavor of Linux are you using?

None

[mchisolm0]

Thanks for the report. Can you confirm I have setup the "openrouter/auto" the way you described? If so, I have not been able to reproduce it yet.

Screenshot of openrouter settings

Steps I've taken

1. Set the "Auto Router" setting at https://openrouter.ai/settings/routing to mistralai/mistral-small-3.2-24b-instruct-2506
2. In Zed, configured an openrouter API key
3. Open an agent thread
4. Select the Stepfun 3.5 Flash( free ) model on openrouter
5. Send a request using the model
6. Observe https://openrouter.ai/logs and only saw requests for the Stepfun 3.5 Flash( free ) model

Please let me know if I have missed anything.

Zed: v0.226.0+nightly.2224.d9b7d77d7a9c914fbf29d3007db4d550d9e75800 (Zed Nightly d9b7d77)
OS: Linux Wayland cachyos unknown
Memory: 15.5 GiB
Architecture: x86_64
GPU: NVIDIA GeForce RTX 3050 || NVIDIA || 590.48.01

[limingchina]

@hshahrokni2 , I set it to a smaller model, otherwise it defaults to "Claude Opus 4.6" which is much more expensive. BTW, are you able to reproduce the problem, since @mchisolm0 can't reproduce the issue.

[limingchina]

@mchisolm0 , I tried the step on my old linux box. With new zed install. It still behaves the same. I noticed what you have tested is the nightly version, which is a bit newer than what I have. Could that be the reason?

Zed: v0.224.11+stable.175.e4cabf49a18ed03969d84ee15643e9ec81857e97 (Zed)
OS: Linux Wayland ubuntu 24.04
Memory: 7.7 GiB
Architecture: x86_64
GPU: Intel(R) HD Graphics 4600 (HSW GT2) || Intel open-source Mesa driver || Mesa 25.0.7-0ubuntu0.24.04.2

[limingchina]

I've checked the file history of openrouter.rs and find out it might have been fixed with
#47475

I think I can confirm that from the code point of view: in v0.224.11 tag one can see

zed/crates/language_models/src/provider/open_router.rs

Line 192 in e4cabf4

Some(self.create_language_model(open_router::Model::default_fast()))

        Some(self.create_language_model(open_router::Model::default_fast()))

This got removed from the the PR:
https://github.com/zed-industries/zed/pull/47475/changes#diff-9c4be6fd1f175935d0dfda7388455462548381b279dc82c25ccb7375893eab51

[limingchina]

I saw in the tag 0.225.8, that line already gets removed. I've tried the preview version 0.225.8. As I expected. It doesn't invoke the openrouter/auto model any longer.