Verify a contract by its SHA-256 content hash. Returns whether the hash is registered, its on-chain Polygon transaction id, and the signedBy[] array — for agent-signed contracts this includes the DID and the externally-verifiable Ed25519 signature payload.
AI agents call verify_hash to retrieve information from QuickContract MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
verify_hash performs a read-only query operation that checks and returns verification status of a contract hash on-chain. It retrieves existing data (transaction IDs, signature payloads) without modifying state, executing commands, deleting data, or committing financial transactions. The low severity reflects minimal blast radius — an agent could only query verification status, not manipulate contracts or escrow.
From the tool's definition Tool description states it 'Verify a contract by its SHA-256 content hash. Returns whether the hash is registered, its on-chain Polygon transaction id, and the signedBy[] array' — purely retrieval of verification data with no modification, creation, deletion,…
Attacks that exploit this kind of access
Verify a contract by its SHA-256 content hash. Returns whether the hash is registered, its on-chain Polygon transaction id, and the signedBy[] array — for agent-signed contracts this includes the DID and the externally-verifiable Ed25519 signature payload. It is categorised as a Read tool in the QuickContract MCP MCP Server, which means it retrieves data without modifying state.
Register the QuickContract MCP server in PolicyLayer and add a rule for verify_hash: 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 QuickContract MCP. Nothing to install.
verify_hash 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 verify_hash 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 verify_hash. 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.
verify_hash is provided by the QuickContract MCP server (quickcontractio/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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