Source Claim Proof
Verify whether a supplied public source currently supports one atomic factual claim.
Should I use this
Quality & Safety
A
Based on automated analysis of tool definitions and protocol compliance.
Context Cost
~600Tokens (tool definitions)
~7.0 KBTypical response size
Minimal attention impact (0.47% of 128k context)
This is the approximate number of tokens consumed each time the server's tools are loaded into a model's context. Higher counts reduce the attention available for other tasks.
Install
One-Click Install
Add this to your `claude_desktop_config.json` file:
{
"mcpServers": {
"verify-source-claim": {
"url": "https://source-claim-proof.mattskowronis.workers.dev/mcp"
}
}
}Remote endpoints
https://source-claim-proof.mattskowronis.workers.dev/mcpstreamable-httpWhat it can do
Tool inventory
Tools (1)
🟢 Read-only🟡 Write🔴 Delete⚪ Unknown
🟢verify_source_claim(url, claim)
Verify one atomic factual claim against one public source URL. Return supported, contradicted, or insufficient-evidence with source snippets, or explicit blocked/unreachable/unsupported states. Not a general fact checker.
Input Schema
{
"type": "object",
"properties": {
"url": {
"type": "string",
"maxLength": 2048,
"description": "Public HTTP or HTTPS source page URL to inspect."
},
"claim": {
"type": "string",
"minLength": 3,
"maxLength": 500,
"description": "One atomic factual assertion to check against that source only."
}
},
"required": [
"url",
"claim"
],
"additionalProperties": false
}Output Schema
{
"type": "object",
"properties": {
"verdict": {
"type": "string",
"enum": [
"supported",
"contradicted",
"insufficient_evidence"
],
"description": "supported, contradicted, or insufficient_evidence."
},
"claim": {
"type": "string",
"description": "The claim that was checked."
},
"source_url": {
"type": "string",
"description": "Requested source URL."
},
"final_url": {
"type": "string",
"description": "Final URL after redirects."
},
"source_status": {
"type": "string",
"enum": [
"verified",
"blocked",
"unreachable",
"unsupported",
"insufficient_evidence"
],
"description": "verified, blocked, unreachable, unsupported, or insufficient_evidence."
},
"evidence": {
"type": "array",
"maxItems": 3,
"description": "Compact source snippets used for the verdict.",
"items": {
"type": "object",
"additionalProperties": false,
"required": [
"text",
"location",
"evidence_type",
"polarity"
],
"properties": {
"text": {
"type": "string",
"maxLength": 240,
"description": "Source snippet that supports or contradicts the claim."
},
"location": {
"type": [
"string",
"null"
],
"description": "Page location of the snippet, or null if unknown."
},
"evidence_type": {
"type": "string",
"enum": [
"visible_text",
"heading",
"json_ld",
"meta",
"status"
],
"description": "Where the snippet came from on the source page."
},
"polarity": {
"type": "string",
"enum": [
"supports",
"contradicts",
"neutral"
],
"description": "Whether the snippet supports, contradicts, or is neutral."
}
}
}
},
"reasoning_summary": {
"type": "string",
"maxLength": 400,
"description": "Short machine-readable reason for the verdict."
},
"retrieval_method": {
"type": "string",
"enum": [
"direct_http",
"browser_run",
"official_api",
"unsupported"
],
"description": "How the source page was fetched."
},
"retrieved_at": {
"type": "string",
"description": "UTC timestamp of the check."
},
"content_hash": {
"type": "string",
"description": "Hash of retrieved source content."
},
"service_version": {
"type": "string",
"description": "Source Claim Proof service version."
}
},
"required": [
"verdict",
"claim",
"source_url",
"final_url",
"source_status",
"evidence",
"reasoning_summary",
"retrieval_method",
"retrieved_at",
"content_hash",
"service_version"
],
"additionalProperties": false
}Community
Evidence
Recent observations
verifiedversion not recorded1 tools
verifiedversion not recorded1 tools