autoreply MCP Server & CLI (Rust)

A dual-mode application for Bluesky profile and post search functionality, written in Rust.

Overview

This application supports two operational modes:

1. MCP Server Mode (default): Model Context Protocol server using stdio
2. CLI Mode: Command-line utility for direct tool execution

Both modes implement the same tools:

• profile(account) - Retrieve user profile information
• search(account, query) - Search posts within a user's repository
• feed - Get the latest feed from BlueSky (Discovery feed or curated feeds)
• thread(postURI) - Fetch a complete thread with all replies
• post(postAs, text, replyTo) - Create posts and replies to the BlueSky network
• react(reactAs, like, unlike, repost, delete) - Interact with posts (likes, reposts, deletions)
• login(...) - Authenticate accounts and manage stored credentials (OAuth + app password)
  • Supports interactive elicitation for missing credentials when used via MCP clients that support the elicitation capability
  • Falls back to clear error messages with instructions for non-supporting clients

Authentication support via app passwords allows storing and managing credentials for future authenticated operations.

Features

✅ Complete MCP Protocol Implementation

• JSON-RPC 2.0 compliant
• Stdio communication
• Proper error handling with MCP error codes
• Bidirectional RPC support for server-to-client requests (elicitation)
• Client capability detection and negotiation

✅ Authentication & Credential Management

• OAuth Browser Flow - Interactive OAuth with PKCE and callback server
• App password authentication via AT Protocol
• Secure credential storage (OS keyring with file fallback)
• Multi-account support with default selection
• Token refresh and lifecycle management
• CLI commands: login (with subcommands: list, default <handle>, delete)
• MCP login tool with interactive elicitation for handles and app passwords
  • Automatically prompts for missing credentials when MCP client supports elicitation
  • Provides clear instructions when elicitation is not available
• Defaults to OAuth and allows for app passwords

✅ Bluesky Integration

• DID resolution (handle → DID)
• CAR file caching with atomic operations
• Fast streaming CAR file parsing with iterator-based processing
• AT Protocol record parsing and filtering
• Profile and post extraction

✅ Advanced Functionality

• Streaming CAR reader (20-80x times faster than atrium-repo)
• Text search with highlighting
• Unicode normalization (NFKC)
• Comprehensive input validation
• Atomic file operations with locking
• System proxy support via environment variables (HTTP(S)_PROXY, NO_PROXY)

✅ Quality Assurance

• Comprehensive test suite with 124+ tests (including 15+ tests for elicitation)
• Full error handling and edge case coverage
• Performance optimized for ~2s repo processing
• Clean builds with zero clippy warnings (default features)

🧪 Experimental Features (opt-in via feature flags)

• SentencePiece tokenization support (experimental-sentencepiece)
• Quantized embedding table support for semantic search prototypes
• Not production-ready - for research and experimentation only

Building

cd rust-server
cargo build --release

Building with Experimental Features

# Build with SentencePiece support (requires protobuf compiler)
cargo build --release --features experimental-sentencepiece

Note: Experimental features require additional dependencies and are not recommended for production use.

Usage

MCP Server Mode (Default)

The server communicates via stdio using the MCP protocol:

./target/release/autoreply

CLI Mode

When invoked with arguments, the binary operates as a command-line utility:

# Get profile information
autoreply profile --account alice.bsky.social

# Search posts
autoreply search --account bob.bsky.social --query "rust programming" --limit 10

# Authentication commands

# OAuth browser flow (default - recommended!)
autoreply login --handle alice.bsky.social

# App password authentication
autoreply login --handle alice.bsky.social --password app-password-here

# Account management
autoreply login list
autoreply login default alice.bsky.social
autoreply login delete --handle alice.bsky.social

# Get help
autoreply --help
autoreply profile --help
autoreply search --help
autoreply login --help

For complete CLI usage documentation, see CLI-USAGE.md.

For authentication details and examples, see src/auth/README.md.

Proxy support

This server honors system proxy environment variables via reqwest’s system proxy detection:

• HTTP_PROXY / http_proxy
• HTTPS_PROXY / https_proxy
• ALL_PROXY / all_proxy
• NO_PROXY / no_proxy

Examples:

# HTTPS over an HTTP proxy (CONNECT):
export HTTPS_PROXY=http://application-proxy.blackrock.com:9443

# Exclude local addresses or specific hosts:
export NO_PROXY=localhost,127.0.0.1,::1

# Run the server
./target/release/autoreply

Notes:

• Credentials (if required) may be provided in the proxy URL, e.g. http://user:pass@proxy.example.com:8080
• TLS uses the OS trust store (native TLS). If your proxy performs TLS interception, ensure your corporate root CA is installed in the OS trust store.

Example MCP Requests

List available tools:

{"jsonrpc": "2.0", "id": 1, "method": "tools/list"}

Get user profile:

{"jsonrpc": "2.0", "id": 2, "method": "tools/call", "params": {"name": "profile", "arguments": {"account": "alice.bsky.social"}}}

Search user's posts:

{"jsonrpc": "2.0", "id": 3, "method": "tools/call", "params": {"name": "search", "arguments": {"account": "alice.bsky.social", "query": "hello world"}}}

Create a post:

{"jsonrpc": "2.0", "id": 4, "method": "tools/call", "params": {"name": "post", "arguments": {"postAs": "alice.bsky.social", "text": "Hello from MCP!"}}}

Reply to a post:

{"jsonrpc": "2.0", "id": 5, "method": "tools/call", "params": {"name": "post", "arguments": {"postAs": "alice.bsky.social", "text": "Great point!", "replyTo": "at://did:plc:z72i7hdynmk6r22z27h6tvur/app.bsky.feed.post/3l47qoztfqi2w"}}}

React to posts:

{"jsonrpc": "2.0", "id": 6, "method": "tools/call", "params": {"name": "react", "arguments": {"reactAs": "alice.bsky.social", "like": ["at://did:plc:z72i7hdynmk6r22z27h6tvur/app.bsky.feed.post/3l47qoztfqi2w"]}}}

Get feed:

{"jsonrpc": "2.0", "id": 7, "method": "tools/call", "params": {"name": "feed", "arguments": {"limit": 20}}}

Note: Omit the feed argument to use the default "What's Hot" feed, or provide a feed URI like at://did:plc:z72i7hdynmk6r22z27h6tvur/app.bsky.feed.generator/whats-hot

Get thread:

{"jsonrpc": "2.0", "id": 8, "method": "tools/call", "params": {"name": "thread", "arguments": {"postURI": "at://did:plc:z72i7hdynmk6r22z27h6tvur/app.bsky.feed.post/3l47qoztfqi2w"}}}

Note: The postURI should be in at:// format, e.g., at://{did}/app.bsky.feed.post/{postId}

Login / manage credentials:

{"jsonrpc": "2.0", "id": 9, "method": "tools/call", "params": {"name": "login", "arguments": {"handle": "alice.bsky.social"}}}

**Login / manage credentials:**
```json
{"jsonrpc": "2.0", "id": 6, "method": "tools/call", "params": {"name": "login", "arguments": {"handle": "alice.bsky.social"}}}