> ## Documentation Index
> Fetch the complete documentation index at: https://docs.plugged.in/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP Proxy Changelog

> Version history and release notes for MCP Proxy

# MCP Proxy Changelog

Track the evolution of the Plugged.in MCP Proxy server.

## Latest Version

<Card title="v1.10.6" icon="rocket">
  **Current Stable Release**
  100% MCP Protocol Compliance with enhanced testing
</Card>

## Version 1.10.x Series

### \[1.10.6] - 2025-02-09

<Badge variant="success">Current Version</Badge>

#### Protocol Compliance

* **100% MCP Specification Compliance**: Fully compliant with [MCP Spec](https://spec.modelcontextprotocol.io/)
* **Protocol Version Validation**: Added support for MCP protocol version negotiation (2024-11-05)
* **Header Standardization**: Fixed all headers to use Title-Case format per spec (`Mcp-Session-Id`, `Mcp-Protocol-Version`)
* **CORS Enhancements**: Added `Access-Control-Expose-Headers` to expose custom headers to JavaScript clients
* **Error Code Standardization**: Implemented JSON-RPC 2.0 compliant error codes (-32600, -32601, -32603, -32001, -32000)

#### Code Quality

* **Extracted Constants**: Created `src/constants.ts` for protocol constants, error codes, and port validation
* **Refactored Middleware**: Extracted reusable middleware into `src/middleware.ts` for better maintainability
* **PORT Validation**: Added comprehensive port validation (1-65535 range with fallback to 12006)
* **Transport Resolution**: Simplified session/transport management with `resolveTransport()` helper

#### Testing

* **84+ Tests Passing**: Comprehensive test suite with 100% protocol compliance coverage
* **New Test Coverage**: Added 8 new tests for:
  * CORS header validation (OPTIONS preflight for all endpoints)
  * Protocol version header casing (accepts any case, responds with Title-Case)
  * Session header casing (Title-Case response, accepts any request casing)
  * Authentication error handling (missing, malformed, incorrect tokens)
* **Zero Deprecation Warnings**: Clean test output with no package deprecations

#### Documentation

* **Protocol Compliance Guide**: New comprehensive documentation at `/mcp-proxy/protocol-compliance`
* **Smithery Deployment Guide**: Moved detailed Smithery docs to `docs/SMITHERY_DEPLOYMENT.md`
* **Technical Specifications**: Detailed protocol implementation, error codes, and architecture

#### Bug Fixes

* Fixed DELETE request handling for missing session IDs (now returns 200 OK gracefully)
* Fixed TypeScript type issues with optional parameters (stateless, requireApiAuth)

#### Performance

* No performance regression - all middleware overhead \< 1ms
* Session lookup remains O(1) via Map
* Stateless mode overhead: \~5ms per request

### \[1.10.2] - 2025-01-28

#### Fixed

* Memory leak in connection pooling
* OAuth token refresh race condition
* STDIO server timeout handling

### \[1.10.1] - 2025-01-27

#### Fixed

* Critical bug in tool name collision resolution
* Connection cleanup on server disconnect

### \[1.10.0] - 2025-01-27

<Badge variant="warning">Major Release</Badge>

#### Added

* **OAuth Support**: Full OAuth 2.0 flow for Streamable HTTP servers
* **Connection Pooling**: Reuse connections for better performance
* **Health Monitoring**: Automatic server health checks
* **Circuit Breaker**: Prevent cascading failures

#### Changed

* Improved error messages with actionable fixes
* Enhanced retry logic with exponential backoff
* Optimized memory usage by 40%

#### Security

* Added rate limiting per API key
* Enhanced input validation
* Secure token storage for OAuth

## Version 1.8.x Series

### \[1.8.0] - 2025-01-20

<Badge variant="info">Feature Release</Badge>

#### RAG v2 MCP Tools

Added new MCP tools for AI Document Exchange:

* `pluggedin_create_document` - Create documents via AI
* `pluggedin_search_documents` - Semantic document search
* `pluggedin_get_document` - Retrieve documents
* `pluggedin_update_document` - Update existing documents
* `pluggedin_list_documents` - List all documents
* `pluggedin_delete_document` - Remove documents

#### Performance

* Optimized tool discovery caching
* Reduced startup time by 50%
* Improved response streaming

## Version 1.4.x Series

### \[1.4.0] - 2024-12-15

#### Added

* **Streamable HTTP Transport**: Full support for new transport type
* **Tool Prefixing**: Automatic UUID prefixing to prevent collisions
* **Parallel Execution**: Execute multiple tools simultaneously
* **Response Streaming**: Stream large responses efficiently

#### Changed

* Deprecated SSE transport in favor of Streamable HTTP
* Improved error handling for network failures
* Enhanced logging with structured output

## Version 1.2.x Series

### \[1.2.6] - 2024-11-30

#### Fixed

* STDIO server hanging on large outputs
* Memory leak in SSE connections
* Race condition in tool discovery

### \[1.2.0] - 2024-11-15

#### Added

* **Multi-Server Support**: Aggregate multiple MCP servers
* **Authentication System**: API key and custom auth support
* **Caching Layer**: Cache tool discovery and resources
* **Metrics Endpoint**: Prometheus-compatible metrics

#### Performance

* 10x faster tool discovery with caching
* Reduced memory footprint by 60%
* Optimized for Docker deployment

## Version 1.0.0

### \[1.0.0] - 2024-10-01

<Badge variant="warning">Initial Release</Badge>

#### Features

* Basic MCP proxy functionality
* STDIO transport support
* SSE transport support
* Tool discovery and invocation
* Resource listing
* Prompt template support

#### Known Limitations

* Single server support only
* No authentication
* Limited error handling
* No connection pooling

## Version 0.x Series (Beta)

### \[0.5.10] - 2024-09-15

#### Added

* SSE transport experimental support
* Basic error recovery
* Debug logging

### \[0.5.9] - 2024-09-01

#### Added

* Initial beta release
* STDIO transport only
* Basic tool invocation

## Migration Guides

### Migrating from 1.8.x to 1.10.x

<Steps>
  <Step title="Update Configuration">
    Add OAuth configuration for supported servers:

    ```json theme={null}
    {
      "oauth": {
        "enabled": true,
        "provider": "github"
      }
    }
    ```
  </Step>

  <Step title="Enable Health Checks">
    ```json theme={null}
    {
      "monitoring": {
        "health": {
          "enabled": true,
          "interval": 30000
        }
      }
    }
    ```
  </Step>

  <Step title="Update Dependencies">
    ```bash theme={null}
    npm update @pluggedin/mcp-proxy
    ```
  </Step>
</Steps>

### Migrating from 1.2.x to 1.4.x

<Warning>
  SSE transport is deprecated. Migrate to Streamable HTTP.
</Warning>

Update server configurations:

```json theme={null}
// Old (SSE)
{
  "transport": {
    "type": "sse",
    "url": "https://example.com/sse"
  }
}

// New (Streamable HTTP)
{
  "transport": {
    "type": "streamable",
    "baseUrl": "https://example.com/mcp"
  }
}
```

## Deprecation Notices

### SSE Transport

* **Deprecated in:** v1.4.0
* **Removal planned:** v2.0.0
* **Migration path:** Use Streamable HTTP transport
* **Reason:** SSE is not part of official MCP specification

### Legacy Authentication

* **Deprecated in:** v1.10.0
* **Removal planned:** v2.0.0
* **Migration path:** Use API key or OAuth
* **Reason:** Security improvements

## Performance Benchmarks

### Tool Discovery Performance

| Version | Time (ms) | Memory (MB) |
| ------- | --------- | ----------- |
| 1.10.x  | 45        | 32          |
| 1.8.x   | 120       | 48          |
| 1.4.x   | 250       | 64          |
| 1.2.x   | 500       | 96          |
| 1.0.0   | 1200      | 128         |

### Connection Management

| Version | Max Connections | Pool Efficiency |
| ------- | --------------- | --------------- |
| 1.10.x  | 1000            | 95%             |
| 1.8.x   | 500             | 85%             |
| 1.4.x   | 200             | 70%             |
| 1.2.x   | 100             | 50%             |
| 1.0.0   | 10              | N/A             |

## Roadmap

### Version 2.0.0 (Q2 2025)

* GraphQL API support
* WebSocket transport
* Plugin system
* Distributed proxy clustering
* Advanced caching strategies

### Version 1.12.0 (Q1 2025)

* WebAuthn authentication
* Request/response transformation
* Custom middleware support
* Enhanced monitoring dashboard

### Version 1.11.0 (Next Release)

* Batch tool invocation
* Response compression
* Custom retry strategies
* Enhanced OAuth providers

## Breaking Changes Log

### Version 1.10.0

* Changed authentication header from `X-API-Key` to `Authorization: Bearer`
* Removed deprecated `servers.*.url` in favor of `servers.*.transport`

### Version 1.4.0

* SSE transport moved to deprecated status
* Changed tool discovery response format

### Version 1.2.0

* Configuration file format changed
* API endpoints restructured

## Support Policy

| Version | Status        | Support Until      |
| ------- | ------------- | ------------------ |
| 1.10.x  | **Active**    | Active development |
| 1.8.x   | Maintenance   | July 2025          |
| 1.4.x   | Security only | April 2025         |
| 1.2.x   | End of Life   | -                  |
| 1.0.0   | End of Life   | -                  |

## Reporting Issues

Found a bug or have a feature request?

* **GitHub Issues**: [Report issues](https://github.com/VeriTeknik/pluggedin-mcp/issues)
* **Security Issues**: [security@plugged.in](mailto:security@plugged.in)
* **Feature Requests**: Use GitHub Discussions

## Contributing

We welcome contributions! See our [Contributing Guide](https://github.com/VeriTeknik/pluggedin-mcp/blob/main/CONTRIBUTING.md) for details.

## License

MCP Proxy is released under the MIT License. See [LICENSE](https://github.com/VeriTeknik/pluggedin-mcp/blob/main/LICENSE) for details.