Support custom provider and custom model names when using proxy in Claude Code

[benzntech]

Description

When using Kilocode with a proxy that exposes Claude models under a custom provider name, Claude Code fails with:

{"error":{"message":"unknown provider for model claude-opus-4-5-20251101","type":"invalid_request_error"}}

In the Claude Code settings UI, the Model dropdown only allows selecting from a fixed list of built-in Claude models. There is no way to:

• Specify a custom model name that the proxy expects, or
• Configure the custom provider name that the proxy uses.

Because of this, requests to claude-opus-4-5-20251101 (and other proxied models) fail with unknown provider for model .... The error repeats with retry timers like:

<retry_timer>60</retry_timer>
<retry_timer>8</retry_timer>
{"error":{"message":"unknown provider for model claude-opus-4-5-20251101","type":"invalid_request_error"}}

Expected behavior

• Claude Code should allow configuring:
  • A custom provider name when using a proxy, and/or
  • Custom model IDs (not just the built-in list), so they can match what the proxy exposes.
• With this configuration, models like claude-opus-4-5-20251101 should work through a proxy without hitting unknown provider errors.

Actual behavior

• The API Provider is set to "Claude Code".
• The Model field is a dropdown with a fixed set of Claude model IDs; it does not allow typing a custom model name.
• Requests go to the proxy, but the proxy's custom provider name is not recognized by Kilocode/Claude Code, leading to:
  • {"error":{"message":"unknown provider for model claude-opus-4-5-20251101","type":"invalid_request_error"}}
• Other clients that let me configure both provider and model work fine with the same proxy.

Steps to reproduce

1. Set up an OpenAI-compatible proxy (e.g. LiteLLM or a custom gateway) that:
   • Exposes Claude models like claude-opus-4-5-20251101,
   • Uses a custom provider name (e.g. my_claude_provider).
2. Configure Kilocode / Claude Code to point to this proxy endpoint.
3. Open Claude Code settings and try to configure the model:
   • Note that the Model dropdown only offers built-in Claude models and does not allow entering a custom model string.
4. Use Claude Code with the selected model.
5. Observe repeated unknown provider for model claude-opus-4-5-20251101 errors.

Environment

• Kilocode version: Latest
• Claude Code extension version: Latest
• IDE: VS Code / JetBrains
• OS: macOS
• Proxy type: OpenAI-compatible proxy
• Proxy provider name: Custom provider

Suggested improvement

• Allow entering custom model IDs in the Model field when using Claude Code with a proxy (not just selecting from a fixed dropdown), and/or
• Expose configuration for the provider name that Claude Code uses when talking to the proxy.
• Alternatively, read provider/model mapping from a config file so users can align Kilocode with their proxy configuration.