[Claude Sonnet 4.5] invalid request format to OpenRouter's API: Provider returned error

### Reproduction steps

1. Create API key in OpenRouter admin screen
2. Setup the same key in Zed config (LLM Providers)
3. Make sure the API key configured icon is green
4. Select Claude Sonnet 4.5 via OpenRouter as LLM
5. Start a new thread

### Current vs. Expected behavior

<img width="936" height="86" alt="Image" src="https://github.com/user-attachments/assets/133e204a-3cf0-4d64-b396-a101c5b30414" />

### Zed version and system specs

Zed: v0.214.7 (Zed) 
OS: Linux Wayland arch unknown
Memory: 31.2 GiB
Architecture: x86_64
GPU: NVIDIA GeForce RTX 3060 || NVIDIA || 580.105.08

### Attach Zed log file

<details><summary>Zed.log</summary>

Caused by:
    oneshot canceled
2025-12-03T06:55:53+08:00 INFO  [agent] Received prompt request for session: a8ae35d2-ee9e-4398-bda8-a201d7a31ce4
2025-12-03T06:55:53+08:00 INFO  [agent::thread] Thread::send called with model: Claude Sonnet 4.5
2025-12-03T06:56:59+08:00 ERROR [agent::thread] Turn execution failed: invalid request format to OpenRouter's API: Provider returned error
2025-12-03T06:56:59+08:00 ERROR [agent] Error in model response stream: invalid request format to OpenRouter's API: Provider returned error
2025-12-03T06:58:24+08:00 INFO  [agent] Cancelling on session: a8ae35d2-ee9e-4398-bda8-a201d7a31ce4
2025-12-03T07:01:53+08:00 ERROR [crates/acp_thread/src/acp_thread.rs:1703] failed to get old checkpoint

Caused by:
    oneshot canceled
2025-12-03T07:01:53+08:00 INFO  [agent] Received prompt request for session: a8ae35d2-ee9e-4398-bda8-a201d7a31ce4
2025-12-03T07:01:53+08:00 INFO  [agent::thread] Thread::send called with model: Claude Sonnet 4.5
2025-12-03T07:02:43+08:00 INFO  [agent] Cancelling on session: a8ae35d2-ee9e-4398-bda8-a201d7a31ce4
2025-12-03T07:02:50+08:00 INFO  [zbus::proxy] new;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::proxy] keep_updated;
2025-12-03T07:02:50+08:00 INFO  [zbus::proxy] new;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:02:50+08:00 INFO  [zbus::connection::socket_reader] read_socket;
2025-12-03T07:07:38+08:00 ERROR [crates/acp_thread/src/acp_thread.rs:1703] failed to get old checkpoint

Caused by:
    oneshot canceled
2025-12-03T07:07:38+08:00 INFO  [agent] Received prompt request for session: a8ae35d2-ee9e-4398-bda8-a201d7a31ce4
2025-12-03T07:07:38+08:00 INFO  [agent::thread] Thread::send called with model: Claude Sonnet 4.5
2025-12-03T07:08:45+08:00 ERROR [agent::thread] Turn execution failed: invalid request format to OpenRouter's API: Provider returned error
2025-12-03T07:08:45+08:00 ERROR [agent] Error in model response stream: invalid request format to OpenRouter's API: Provider returned error

```log

```

</details>


### Relevant Zed settings

<details><summary>settings.json</summary>

```jsonc
// Zed settings
//
// For information on how to configure Zed, see the Zed
// documentation: https://zed.dev/docs/configuring-zed
//
// To see all of Zed's default settings without changing your
// custom settings, run `zed: open default settings` from the
// command palette (cmd-shift-p / ctrl-shift-p)
{
  "agent": {
    "always_allow_tool_actions": true,
    "profiles": {
      "write": {
        "name": "Write",
        "tools": {
          "copy_path": true,
          "create_directory": true,
          "delete_path": true,
          "diagnostics": true,
          "edit_file": true,
          "fetch": true,
          "list_directory": true,
          "project_notifications": false,
          "move_path": true,
          "now": true,
          "find_path": true,
          "read_file": true,
          "open": true,
          "grep": true,
          "terminal": true,
          "thinking": true,
          "web_search": true
        },
        "enable_all_context_servers": true,
        "context_servers": {}
      }
    },
    "default_profile": "write",
    "inline_assistant_model": {
      "provider": "openrouter",
      "model": "google/gemini-3-pro-preview"
    },
    "default_model": {
      "provider": "openrouter",
      "model": "anthropic/claude-sonnet-4.5"
    },
    "model_parameters": []
  },
  "context_servers": {
    "serena-context-server": {
      "enabled": true,
      "command": "uv",
      "args": [
        "run",
        "--directory",
        "/home/bob/Code/serena",
        "serena",
        "start-mcp-server"
      ],
      "env": {}
    },
    "mcp-server-context7": {
      "enabled": true,
      "settings": {
        "context7_api_key": "ctx7sk-xxxx-xxxx-xxxx-xxxx-xxx-xxx-yyyy"
      }
    },
    "Ref": {
      "enabled": false,
      "command": "npx",
      "args": ["ref-tools-mcp@latest"],
      "env": {
        "REF_API_KEY": "ref-77777yyyd77d7d"
      }
    }
  },
  "telemetry": {
    "diagnostics": false,
    "metrics": false
  },
  "ui_font_size": 16,
  "buffer_font_size": 15,
  "theme": {
    "mode": "system",
    "light": "One Light",
    "dark": "One Dark"
  }
}

```jsonc

</details>


### (for AI issues) Model provider details

- Provider OpenRouter, model Claude Sonnet 4.5

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

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Uh oh!

[Claude Sonnet 4.5] invalid request format to OpenRouter's API: Provider returned error #44032

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Uh oh!

[Claude Sonnet 4.5] invalid request format to OpenRouter's API: Provider returned error #44032

Description

Reproduction steps

Current vs. Expected behavior

Zed version and system specs

Attach Zed log file

Relevant Zed settings

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions