Diff Checker API

Compare two texts line-by-line. Returns structured diff with additions, deletions, unchanged lines, and summary stats. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

{
  "mcpServers": {
    "diff-checker": {
      "url": "https://diff-checker.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

curl -X POST "https://diff-checker.api.klymax402.com/api/diff" \
  -H "Content-Type: application/json" \
  -d '{"text1":"...","text2":"..."}'
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

Tool	Method	Path	Price	Description
text_compare_diff	POST	/api/diff	$0.005	Compare two texts and show line-by-line differences

text_compare_diff

Use this when you need to compare two pieces of text and identify exactly what changed between them. Returns a structured line-by-line diff with summary statistics.

Parameters

Name	Type	Required	Description
text1	string	yes	The original text (base)
text2	string	yes	The modified text to compare against

Example response:

{"changes":[{"type":"unchanged","content":"line 1"},{"type":"removed","content":"old line 2"},{"type":"added","content":"new line 2"}],"linesAdded":1,"linesRemoved":1,"linesUnchanged":1,"similarity":66.7}

When to use: code review (comparing before/after), tracking document revisions, verifying config file changes, or auditing template modifications. Use this BEFORE deploying config changes to understand what differs.

Not for: text classification (use text_classify_content), sentiment analysis (use text_analyze_sentiment), word counting (use text_count_words).

Example agent prompts

• "Compare two pieces of text and identify exactly what changed between them"

Payment

• Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
• Network: Base L2 (eip155:8453)
• Asset: USDC
• Facilitator: Coinbase CDP (primary), PayAI (fallback)
• Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

• Catalog: https://klymax402.com/llms.txt
• Full API reference: https://klymax402.com/llms-full.txt
• Live stats: https://klymax402.com/stats

License

MIT