PreClick MCP Server

PreClick — An MCP-native URL preflight scanning service for autonomous agents. It scans links for threats and confirms they match the intended task before execution. Built for agentic workflows, it provides high-accuracy, context-aware browsing governance with adaptive learning.

Publisher: CybrLab.ai | Service: PreClick

Hosted Trial Tier: No API key required for up to 100 requests/day. For higher limits and stable quotas, use an API key (contact contact@cybrlab.ai).

Overview

PreClick is an MCP server that enables AI agents and any MCP-compatible client to analyze URLs for malicious content and security threats before navigation.

Integrations

PreClick works with any MCP-compatible client. For framework-specific adapters:

For manual MCP bridge configuration (any client), see Quick Start below.

Authentication Modes

Important Notice

This tool is intended for authorized security assessment only. Use it solely on systems or websites that you own or for which you have got explicit permission to assess. Any unauthorized, unlawful, or malicious use is strictly prohibited. You are responsible for ensuring compliance with all applicable laws, regulations, and contractual obligations.

Use Cases

• Pre-flight URL validation for AI agents
• Automated URL security scanning in workflows
• Malicious link detection in emails/messages

Quick Start

1. Configure Your MCP Client

Choose one option:

Trial (hosted, up to 100 requests/day without API key):

{
  "mcpServers": {
    "preclick-mcp": {
      "transport": "streamable-http",
      "url": "https://preclick.ai/mcp"
    }
  }
}

Authenticated (recommended for stable and higher-volume usage):

{
  "mcpServers": {
    "preclick-mcp": {
      "transport": "streamable-http",
      "url": "https://preclick.ai/mcp",
      "headers": {
        "X-API-Key": "YOUR_API_KEY"
      }
    }
  }
}

2. Optional: Initialize Session (stateful mode only)

Default hosted usage is stateless. Clients send JSON-RPC messages with POST /mcp. Some Streamable HTTP clients may also probe GET /mcp for an SSE stream. On the stateless hosted deployment, /mcp does not offer an SSE stream and returns HTTP 405 Method Not Allowed. Clients should treat 405 as "no SSE stream on this endpoint" and continue using POST /mcp.

Clients should still send the standard MCP HTTP headers:

• Accept: application/json, text/event-stream on POST
• MCP-Protocol-Version on all non-initialize requests

The hosted deployment currently normalizes missing or incomplete POST Accept headers for compatibility. It also allows missing MCP-Protocol-Version on discovery-only POST list requests (tools/list, resources/list, prompts/list) for registry compatibility. Clients should not rely on either behavior.

# Only required if the server is running in stateful mode
curl -X POST https://preclick.ai/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
      "protocolVersion": "2025-06-18",
      "capabilities": {},
      "clientInfo": {"name": "my-client", "version": "1.0"}
    }
  }'
# Response includes Mcp-Session-Id header - save it for subsequent requests

3. Start a Scan

url_scanner_scan supports two execution modes (the same modes apply to url_scanner_scan_with_intent):

• Task-augmented (recommended): Include the task parameter for async execution
• Direct: Omit the task parameter for synchronous execution

curl -X POST https://preclick.ai/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "MCP-Protocol-Version: 2025-06-18" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "id": 2,
    "method": "tools/call",
    "params": {
      "name": "url_scanner_scan",
      "arguments": {
        "url": "https://example.com"
      },
      "task": {
        "ttl": 720000
      }
    }
  }'
# If stateful mode is enabled, include: -H "Mcp-Session-Id: YOUR_SESSION_ID"

Response (task submitted):

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "task": {
      "taskId": "550e8400-e29b-41d4-a716-446655440000",
      "status": "working",
      "statusMessage": "Queued for processing",
      "createdAt": "2026-01-18T12:00:00Z",
      "lastUpdatedAt": "2026-01-18T12:00:00Z",
      "ttl": 720000,
      "pollInterval": 2000
    }
  }
}

Optional: Provide an url visiting intent for additional context (recommended but not required):

curl -X POST https://preclick.ai/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "MCP-Protocol-Version: 2025-06-18" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "id": 3,
    "method": "tools/call",
    "params": {
      "name": "url_scanner_scan_with_intent",
      "arguments": {
        "url": "https://example.com",
        "intent": "Book a hotel room"
      },
      "task": {
        "ttl": 720000
      }
    }
  }'

Recommendation: Use url_scanner_scan_with_intent when you can state your purpose (login, purchase, booking, payments, file download) so intent/content mismatch can be considered as an additional signal. Otherwise use url_scanner_scan. Max intent length: 248 characters. Low-information or instruction-like intent strings are treated as not provided. Result includes intent_alignment (misaligned, no_mismatch_detected, inconclusive, or not_provided). no_mismatch_detected is only returned when intent analysis had sufficient evidence; if intent analysis is unavailable or evidence is limited, result is inconclusive. When intent_alignment is misaligned and confirmed by successful high-confidence analysis, the response directive is DENY with reason intent_inconsistent_destination (policy gate; risk score is unchanged). When high-confidence analysis confirms an unverified high-impact service claim with weak identity corroboration in a low-confidence context, the response directive is also DENY with reason insufficient_service_verification (policy gate; risk score is unchanged). In additional contextual low-evidence policy cases, responses may return DENY with reasons such as insufficient_service_verification or insufficient_trust_signals (policy gate; risk score is unchanged).

Direct-call timeout note: synchronous tool calls use a bounded server wait window sized for direct-only clients (hosted default 90s). If timeout is reached, the server returns JSON-RPC -32603 with error.data.taskId and error.data.pollInterval so you can continue via tasks/get / tasks/result.

Compatibility note: if your MCP client cannot call native Tasks methods (tasks/get / tasks/result), use url_scanner_async_scan or url_scanner_async_scan_with_intent to submit work and then poll with url_scanner_async_task_status / url_scanner_async_task_result. Call these compatibility tools as ordinary tools only; do not include a native MCP task parameter.

4. Poll for Results

tasks/result uses a shorter hosted blocking wait (default 30s). If this wait is exceeded, the server returns JSON-RPC -32603 with error.data.taskId and error.data.pollInterval. Native Tasks clients should prefer polling with tasks/get until status is completed, then call tasks/result to retrieve the final result immediately.

curl -X POST https://preclick.ai/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "MCP-Protocol-Version: 2025-06-18" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "id": 3,
    "method": "tasks/result",
    "params": {
      "taskId": "550e8400-e29b-41d4-a716-446655440000"
    }
  }'
# If stateful mode is enabled, include: -H "Mcp-Session-Id: YOUR_SESSION_ID"

Response (completed task — CallToolResult shape, same as synchronous tools/call):

{
  "jsonrpc": "2.0",
  "id": 3,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "{\"risk_score\":0.05,\"confidence\":0.95,\"analysis_complete\":true,\"agent_access_directive\":\"ALLOW\",\"agent_access_reason\":\"no_immediate_risk_detected\",\"intent_alignment\":\"not_provided\"}"
      }
    ],
    "isError": false
  }
}

Available Tools

See Full API Documentation for detailed schemas and examples.

Authentication

Authentication requirements depend on deployment mode:

• Hosted endpoint (https://preclick.ai/mcp): API key is optional for up to 100 requests/day.
• Hosted endpoint above trial quota: API key required.

See Authentication Guide for details on getting API keys.

Technical Specifications

Support

• Publisher: CybrLab.ai
• Service: PreClick
• Email: contact@cybrlab.ai

License

Apache License 2.0 - See LICENSE for details.

Copyright CybrLab.ai