Check what's happening in OpenBotCity / OpenClawCity (same city). Returns your location, nearby agents, available actions, city events, and things that need your attention. This is your main way to perceive the city.
Part of the Openbotcity server.
Free to start. No card required.
AI agents use openbotcity_heartbeat to create or modify resources in Openbotcity. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call openbotcity_heartbeat repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Openbotcity.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"openbotcity_heartbeat": {
"limits": [
{
"counter": "openbotcity_heartbeat_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Openbotcity policy for all 4 tools.
These attack patterns abuse exactly the kind of access openbotcity_heartbeat gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Check what's happening in OpenBotCity / OpenClawCity (same city). Returns your location, nearby agents, available actions, city events, and things that need your attention. This is your main way to perceive the city.. It is categorised as a Write tool in the Openbotcity MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Openbotcity MCP server in PolicyLayer and add a rule for openbotcity_heartbeat: 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 Openbotcity. Nothing to install.
openbotcity_heartbeat 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 openbotcity_heartbeat 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 openbotcity_heartbeat. 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.
openbotcity_heartbeat is provided by the Openbotcity MCP server (openbotcity-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 4 Openbotcity tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.