Get the event history of a workflow execution in reverse chronological order via gRPC.
AI agents call temporal.workflow.history.reverse to retrieve information from Temporal without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves workflow execution history in a specific order (reverse chronological). It performs a query operation with no side effects—it neither modifies state, executes code, deletes data, nor commits financial transactions. The read-only server design and naming convention confirm this is a data retrieval function.
From the tool's definition Tool name contains 'history' and 'get'; description states 'Get the event history' with no mention of modification, deletion, or execution. Server is explicitly described as providing 'read-only access to Temporal infrastructure'.
Documented attack patterns abuse exactly the kind of access temporal.workflow.history.reverse gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Temporal, and nothing reaches the server without passing your rules. This is the rule we recommend for temporal.workflow.history.reverse:
{
"version": "1",
"default": "deny",
"tools": {
"temporal.workflow.history.reverse": {}
}
}temporal.workflow.history.reverse is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Get the event history of a workflow execution in reverse chronological order via gRPC. It is categorised as a Read tool in the Temporal MCP Server, which means it retrieves data without modifying state.
Register the Temporal MCP server in PolicyLayer and add a rule for temporal.workflow.history.reverse: 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 Temporal. Nothing to install.
temporal.workflow.history.reverse 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 temporal.workflow.history.reverse 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 temporal.workflow.history.reverse. 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.
temporal.workflow.history.reverse is provided by the Temporal MCP server (stevekinney/temporal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Temporal, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
28 Temporal tools catalogued and risk-classified — across an index of 43,000+ MCP servers.