OllamaYarpProxy

OllamaYarpProxy is an ASP.NET Core reverse proxy that emulates Ollama's API endpoints and transparently forwards requests to a configurable backend (default: http://localhost:4000). It uses YARP (Yet Another Reverse Proxy) and custom transforms to rewrite paths and adapt responses, enabling compatibility with clients expecting Ollama's API.

Features

• Ollama API Compatibility: Exposes endpoints like /api/tags, /api/show, /api/version, and /v1/chat/completions, rewriting and transforming requests/responses as needed.
• Configurable Backend: Forwards requests to a backend server, configurable via appsettings.json.
• Custom Transforms: Uses YARP's transform pipeline to rewrite paths and adapt JSON schemas for Ollama compatibility.
• Logging: Logs incoming requests, proxy destinations, and errors for easier debugging.
• Solves vscode-copilot-release#7518: Enables Copilot and similar tools to interact with Ollama-compatible endpoints even when the backend differs.

How to Run

1. Build and run the project:

   dotnet run --project src/OllamaYarpProject

2. Access the proxy:
   By default, it listens on http://localhost:11434 and forwards requests to http://localhost:4000.

Configuration

• Backend URL:
  Change the backend target in appsettings.json under the ReverseProxy section.
• Logging:
  Logging is controlled via appsettings.json or environment variables.

Endpoints

• /api/tags → /models (rewritten and response schema adapted)
• /api/show → Returns model info in Ollama format
• /api/version → Returns Ollama-compatible version info
• /v1/chat/completions → /chat/completions (rewritten)
• All other endpoints are proxied as-is

Why?

This proxy allows tools (like Copilot) that expect Ollama's API to work with alternative backends, solving integration issues such as vscode-copilot-release#7518.

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