Detailed inspection of Ethereum transactions including calldata decoding, trace analysis, and log visualization using Heimdall
AI agents call heimdall_inspect to retrieve information from Foundry MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Heimdall_inspect is purely analytical and diagnostic. It retrieves transaction details, decodes data, and visualizes traces/logs—classic Read operations with no side effects.
From the tool's definition Tool performs "inspection of Ethereum transactions including calldata decoding, trace analysis, and log visualization" — all read-only querying operations that retrieve and analyze existing onchain data without modification.
Documented attack patterns abuse exactly the kind of access heimdall_inspect gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Foundry MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for heimdall_inspect:
{
"version": "1",
"default": "deny",
"tools": {
"heimdall_inspect": {}
}
}heimdall_inspect is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Detailed inspection of Ethereum transactions including calldata decoding, trace analysis, and log visualization using Heimdall. It is categorised as a Read tool in the Foundry MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Foundry MCP Server MCP server in PolicyLayer and add a rule for heimdall_inspect: 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 Foundry MCP Server. Nothing to install.
heimdall_inspect 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 heimdall_inspect 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 heimdall_inspect. 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.
heimdall_inspect is provided by the Foundry MCP Server MCP server (praneshasp/foundry-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 16 Foundry MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
16 Foundry MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.