WebCite MCP Server

MCP (Model Context Protocol) server for WebCite - enables any AI agent or tool to verify factual claims against authoritative sources.

Works with any MCP-compatible client including Claude Desktop, Claude Code, Cursor, Continue, Cody, Zed, Windsurf, OpenAI Agents SDK, LangChain, and more.

Features

| Tool | Description | Credits | |------|-------------|---------| | verify_claim | Full fact verification with stance analysis and verdict | 2-4 | | verify_claim_stream | Streaming verification for complex/long-running claims | 2-4 | | search_sources | Quick citation search without analysis | 2 | | list_citations | List your past verifications | Free | | get_citation | Get details of a specific verification | Free | | upload_file | Upload a document for use as verification context | - |

Installation

Claude Desktop

Add to claude_desktop_config.json:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "webcite": {
      "command": "npx",
      "args": ["-y", "webcite-mcp-server"],
      "env": {
        "WEBCITE_API_KEY": "wc_your_api_key_here"
      }
    }
  }
}

Claude Code (CLI)

# Add to Claude Code
claude mcp add webcite -- npx -y webcite-mcp-server

# Set API key
export WEBCITE_API_KEY=wc_your_api_key_here

Or add to ~/.claude/claude_settings.json:

{
  "mcpServers": {
    "webcite": {
      "command": "npx",
      "args": ["-y", "webcite-mcp-server"],
      "env": {
        "WEBCITE_API_KEY": "wc_your_api_key_here"
      }
    }
  }
}

Cursor

Add to .cursor/mcp.json in your project or ~/.cursor/mcp.json globally:

{
  "mcpServers": {
    "webcite": {
      "command": "npx",
      "args": ["-y", "webcite-mcp-server"],
      "env": {
        "WEBCITE_API_KEY": "wc_your_api_key_here"
      }
    }
  }
}

Continue

Add to ~/.continue/config.json:

{
  "experimental": {
    "modelContextProtocolServers": [
      {
        "transport": {
          "type": "stdio",
          "command": "npx",
          "args": ["-y", "webcite-mcp-server"]
        },
        "env": {
          "WEBCITE_API_KEY": "wc_your_api_key_here"
        }
      }
    ]
  }
}

Cody (VS Code)

Add to VS Code settings (settings.json):

{
  "cody.experimental.mcp.servers": {
    "webcite": {
      "command": "npx",
      "args": ["-y", "webcite-mcp-server"],
      "env": {
        "WEBCITE_API_KEY": "wc_your_api_key_here"
      }
    }
  }
}

Zed

Add to ~/.config/zed/settings.json:

{
  "context_servers": {
    "webcite": {
      "command": {
        "path": "npx",
        "args": ["-y", "webcite-mcp-server"]
      },
      "env": {
        "WEBCITE_API_KEY": "wc_your_api_key_here"
      }
    }
  }
}

Generic / Direct Usage

# Install globally
npm install -g webcite-mcp-server

# Run with API key
WEBCITE_API_KEY=wc_xxx webcite-mcp-server

# Or with npx (no install)
WEBCITE_API_KEY=wc_xxx npx webcite-mcp-server

Getting Your API Key

1. Sign up at webcite.co
2. Log in and go to API Keys in the sidebar
3. Create a new API key
4. Add it to your MCP configuration

Usage Examples

Verify a Claim

User: Verify this claim: "The Great Wall of China is visible from space"

# Fact Check: "The Great Wall of China is visible from space"

## Verdict: CONTRADICTED
Confidence: 92%
Summary: Multiple authoritative sources confirm this is a common misconception.

Source Breakdown:
- Supporting: 0
- Contradicting: 4
- Neutral: 1

## Sources

1. NASA - Great Wall of China
   URL: https://www.nasa.gov/...
   Stance: contradicts (95% confidence)
   Credibility: 98/100
   Analysis: NASA explicitly states the wall is not visible from low Earth orbit...

Verify with Thread Context

Use thread_id to group related verifications in a session:

User: Verify "Einstein won the Nobel Prize for relativity" with thread_id "research-session-1"

# The thread_id links this verification to others in the same session,
# so you can later retrieve all related fact-checks together.

Stream a Complex Verification

Use verify_claim_stream for complex or multi-part claims that may take longer to process:

User: Stream-verify "The iPhone was released in 2007, was the first smartphone,
      and was designed by Steve Wozniak"

# The streaming tool collects intermediate results (sub-claim decomposition,
# per-claim verification) and returns the assembled result.

Search for Sources

User: Search for sources about "quantum computing breakthroughs 2024"

# Search Results: "quantum computing breakthroughs 2024"

Found 8 sources:

1. Nature - Quantum Error Correction Milestone
   URL: https://nature.com/...
   Credibility: 95/100
   Snippet: "Researchers achieved a significant breakthrough in..."

Upload a Document

User: Upload my research paper for verification context

# File Uploaded Successfully

File ID: f_abc123
Filename: research-paper.pdf
Type: application/pdf
Size: 245832 bytes

Review Past Verifications

User: Show my recent fact-checks

# Your Verification History

Page 1 of 3 (28 total)

1. The Earth is 4.5 billion years old
   ID: abc123...
   Date: Jan 30, 2025

2. Coffee causes cancer
   ID: def456...
   Date: Jan 29, 2025

Tool Details

verify_claim

Full fact verification with optional stance analysis and verdict generation.

Parameters:

• claim (required): The factual claim to verify
• thread_id (optional): Thread ID to group related verifications in a session
• include_stance (optional, default: true): Include stance analysis per source (+1 credit)
• include_verdict (optional, default: true): Generate overall verdict (+1 credit)
• decompose_claim (optional, default: false): Break complex claims into sub-claims

Credit Cost:

• Base search: 2 credits
• With stance: +1 credit
• With verdict: +1 credit
• Full verification: 4 credits

verify_claim_stream

Streaming verification for complex or long-running claims. Uses the SSE streaming endpoint to avoid HTTP timeouts and capture intermediate results (sub-claim decomposition, per-claim progress). Returns the same formatted output as verify_claim.

Prefer this over verify_claim when:

• The claim is complex and may take a long time to verify
• You want intermediate progress data (sub-claim decomposition, per-claim results)
• You want to avoid HTTP timeouts on long-running verifications

Parameters:

• claim (required): The factual claim to verify
• thread_id (optional): Thread ID to group related verifications in a session
• include_stance (optional, default: true): Include stance analysis per source
• include_verdict (optional, default: true): Generate overall verdict
• decompose_claim (optional, default: false): Break complex claims into sub-claims

Credit Cost: Same as verify_claim (2-4 credits)

search_sources

Quick citation search without analysis - returns raw sources.

Parameters:

• query (required): Search query or claim
• limit (optional, default: 10): Max sources to return (1-20)

Credit Cost: 2 credits

list_citations

List your past verification results.

Parameters:

• page (optional, default: 1): Page number
• limit (optional, default: 10): Results per page (max 50)
• thread_id (optional): Filter by conversation thread

Credit Cost: Free

get_citation

Get full details of a specific verification.

Parameters:

• citation_id (required): The citation ID to retrieve

Credit Cost: Free

upload_file

Upload a file to WebCite for use as verification context. Supports documents (PDF, DOCX, TXT) and other common file types.

Parameters:

• file_path (required): Absolute path to the file to upload

Environment Variables

| Variable | Description | Default | |----------|-------------|---------| | WEBCITE_API_KEY | Your WebCite API key (required) | - | | WEBCITE_API_URL | API base URL | https://api.webcite.co |

Response Format

All verification results include:

• Verdict: Overall assessment (supported/contradicted/mixed/unverifiable)
• Confidence: 0-100% confidence score
• Sources: List of authoritative citations
• Stance Analysis: Per-source support/contradict assessment
• Key Findings: Important facts extracted from sources
• Corrections: When the claim contains inaccuracies

Pricing

| Plan | Monthly Credits | Price | |------|-----------------|-------| | Free | 50 | $0 | | Builder | 500 | $20/month | | Enterprise | 10,000+ | Contact Sales |

Support

• Documentation: webcite.co/api-docs/playground
• Email: [email protected]

License

MIT