Reconstruct the full 4W audit trail for a contested agent action. Returns WHO (agent identity + SIGIL), WHAT (SHA-256 hash on-chain), WHEN (MultiversX block timestamp), WHY (decision chain anchored before acting). Includes verification summary with intent_preceded_execution flag, chronological ti...
Part of the xProof server.
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AI agents call investigate_proof to retrieve information from xProof without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though investigate_proof only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"investigate_proof": {}
}
}See the full xProof policy for all 10 tools.
These attack patterns abuse exactly the kind of access investigate_proof gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Reconstruct the full 4W audit trail for a contested agent action. Returns WHO (agent identity + SIGIL), WHAT (SHA-256 hash on-chain), WHEN (MultiversX block timestamp), WHY (decision chain anchored before acting). Includes verification summary with intent_preceded_execution flag, chronological timeline of WHY/WHAT proofs, and session heartbeat anchor. Requires x402 payment ($0.05 USDC on Base via X-PAYMENT header) or API key authentication. Without payment, returns payment requirements with USDC address and amount.. It is categorised as a Read tool in the xProof MCP Server, which means it retrieves data without modifying state.
Register the xProof MCP server in PolicyLayer and add a rule for investigate_proof: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches xProof. Nothing to install.
investigate_proof is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the investigate_proof rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for investigate_proof. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
investigate_proof is provided by the xProof MCP server (https://xproof.app/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 10 xProof tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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