Perform full end-to-end verification of a spend's inclusion in verified GMV. Accepts a spend attestation token, GMV token, GMV inclusion proof, and reward commitment token, then verifies: (1) spend token signature is valid, (2) GMV token signature is valid, (3) spend is in the GMV Merkle tree, (4...
Part of the Crinkl Commerce MCP server.
Free to start. No card required.
AI agents call verify-issued-gmv to retrieve information from Crinkl Commerce MCP 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 verify-issued-gmv 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": {
"verify-issued-gmv": {}
}
}See the full Crinkl Commerce MCP policy for all 22 tools.
These attack patterns abuse exactly the kind of access verify-issued-gmv 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.
Perform full end-to-end verification of a spend's inclusion in verified GMV. Accepts a spend attestation token, GMV token, GMV inclusion proof, and reward commitment token, then verifies: (1) spend token signature is valid, (2) GMV token signature is valid, (3) spend is in the GMV Merkle tree, (4) reward commitment is valid, (5) all spend IDs match across artifacts. This is the strongest possible verification — a single call that proves a receipt's entire journey from scan to settlement.. It is categorised as a Read tool in the Crinkl Commerce MCP MCP Server, which means it retrieves data without modifying state.
Register the Crinkl Commerce MCP server in PolicyLayer and add a rule for verify-issued-gmv: 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 Crinkl Commerce MCP. Nothing to install.
verify-issued-gmv 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-issued-gmv 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-issued-gmv. 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-issued-gmv is provided by the Crinkl Commerce MCP server (https://mcp.crinkl.xyz/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 22 Crinkl Commerce MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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