A2A Agent-Card Trust-Chain Validator — OpenChainGraph compute node (compliance_mandate). Regulatory deadline: 2026-08 (A2A at Linux Foundation (150+ orgs); EU AI Act Aug 2026 pushes agent KYA toward requirement.). Runs deterministically in-browser; zero PII, zero egress. Exports an AP2 artifact w...
AI agents call validate_a2a_trust_chain to retrieve information from Ainumbers Mcp Apps without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
compute | string | — | Compute mode (v0.4 Compute Binding). "auto" (default) = server for gpu:false nodes with registered kernels; "server" = force server-side; "browser" = always ret |
parent_hashes | array | — | execution_hash values from upstream ChainGraph AP2 artifacts to chain from (sets chain.parent_hashes in the export). |
parent_tool_ids | array | — | tool_id values matching parent_hashes, in the same order. |
policy_parameters | object | — | Input parameters for this tool's decision function. For gpu:false nodes with a registered kernel, these are computed server-side when compute is "auto" or "serv |
Parameters from the server's own tool schema.
This is a read-only validator that checks regulatory compliance of A2A trust chains and exports attestation artifacts. The tool performs deterministic validation and outputs cryptographic hashes for audit purposes—characteristic of Read operations.
From the tool's definition 'Validator' tool that 'Runs deterministically in-browser; zero PII, zero egress' and 'Exports an AP2 artifact with execution_hash for chain provenance.' The tool retrieves and validates trust chain compliance data without modifying state, deleting records,…
Attacks that exploit this kind of access
A2A Agent-Card Trust-Chain Validator — OpenChainGraph compute node (compliance_mandate). Regulatory deadline: 2026-08 (A2A at Linux Foundation (150+ orgs); EU AI Act Aug 2026 pushes agent KYA toward requirement.). Runs deterministically in-browser; zero PII, zero egress. Exports an AP2 artifact with execution_hash for chain provenance. Output feeds: art-04-agent-identity-attestation-checker, art-02-agent-spend-policy-simulator, ptg-01-ap2-prompt-template-generator. Open at: https://ainumbers.co/chaingraph/art-32-a2a-agent-card-trust-chain-validator.html. It is categorised as a Read tool in the Ainumbers Mcp Apps MCP Server, which means it retrieves data without modifying state.
validate_a2a_trust_chain accepts 4 parameters: compute, parent_hashes, parent_tool_ids, policy_parameters. The full parameter table on this page comes from the server's own tool schema.
Register the Ainumbers Mcp Apps MCP server in PolicyLayer and add a rule for validate_a2a_trust_chain: 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 Ainumbers Mcp Apps. Nothing to install.
validate_a2a_trust_chain 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 validate_a2a_trust_chain 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 validate_a2a_trust_chain. 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.
validate_a2a_trust_chain is provided by the Ainumbers Mcp Apps MCP server (postoaklabs/ainumbers-mcp-apps). 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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