Claim the next pending mock batch for processing. This acquires a lease on the batch. You MUST call this before provide_batch_mock_data. The batch will be locked for 30 seconds (configurable via leaseMs). If you don
AI agents use claim_next_batch to create or update resources in Mock — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mock environment.
This tool claims and locks a batch resource, which is a stateful write/reservation operation. It modifies the state of the batch (from pending to locked/claimed) in a reversible way (lease expires after 30 seconds). It does not delete data or execute arbitrary code, making Write the most appropriate category. Misuse could cause processing delays by locking batches unnecessarily.
From the tool's definition Claim the next pending mock batch for processing. This acquires a lease on the batch. The batch will be locked for 30 seconds
Documented attack patterns abuse exactly the kind of access claim_next_batch gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mock, and nothing reaches the server without passing your rules. This is the rule we recommend for claim_next_batch:
{
"version": "1",
"default": "deny",
"tools": {
"claim_next_batch": {
"limits": [
{
"counter": "claim_next_batch_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}claim_next_batch stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Claim the next pending mock batch for processing. This acquires a lease on the batch. You MUST call this before provide_batch_mock_data. The batch will be locked for 30 seconds (configurable via leaseMs). If you don. It is categorised as a Write tool in the Mock MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mock MCP server in PolicyLayer and add a rule for claim_next_batch: 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 Mock. Nothing to install.
claim_next_batch is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the claim_next_batch 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 claim_next_batch. 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.
claim_next_batch is provided by the Mock MCP server (mcpland/mock-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mock, 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.
6 Mock tools catalogued and risk-classified — across an index of 43,000+ MCP servers.