Fact Checker API
Let your coding agent verify factual claims against web sources before you ship copy, docs, or marketing that could hurt trust or AEO credibility.
Overview
Fact Checker is an MCP server for the Launch phase that verifies claims with web evidence and returns sources and a verdict for your agent.
What is this MCP server?
- Returns structured verdicts plus cited web sources for agent-driven claim review
- Remote MCP over SSE at fact-checker.api.klymax402.com—no local server to maintain
- x402 micropayment model on the hosted API (version 1.1.0)
- Useful across research drafts, validation copy, and post-launch content updates
- MCP integration for Claude Code, Cursor, and other MCP-capable agents—not a standalone skill file
- Server version 1.1.0
- Single remote MCP URL (SSE) on klymax402.com
- x402 micropayment on the hosted Fact Checker API
What problem does it solve?
Agents confidently write plausible but wrong facts into the copy you are about to ship, and manual Googling breaks your flow.
Who is it for?
Solo builders publishing marketing copy, docs, or GEO-oriented pages who already use MCP in Claude Code or Cursor.
Skip if: Teams that need certified fact-checking, paywalled corpus search only, or zero per-call API spend.
What do I get? / Deliverables
Your agent can challenge specific claims, attach sources, and accept or rewrite text before it goes live.
- Verdict on a submitted claim with supporting source URLs
- Agent-ready evidence snippets for copy edits or rejections
Recommended MCP Servers
Journey fit
Canonical shelf is Launch because solo builders most often invoke fact-checking right before publishing landing pages, changelog posts, and AI-search-facing content. GEO subphase fits content meant to be cited and surfaced in AI search—where unsourced or false claims are most costly.
How it compares
Remote verification MCP with x402 billing, not an in-repo agent skill or browser automation pack.
Common Questions / FAQ
Who is Fact Checker for?
Indie builders and agent users who want cited web checks on claims before shipping content or customer-facing answers.
When should I use Fact Checker?
Use it when drafting or revising landing copy, FAQs, changelog posts, or research notes where factual errors would damage trust or citations.
How do I add Fact Checker to my agent?
Register the remote MCP server URL https://fact-checker.api.klymax402.com/mcp (SSE) in your agent's MCP settings and ensure your client supports x402 micropayments for the API.