Compose a builder URL with a fundraising link pre-filled — the URL is embedded into the GPX metadata (description, filename) so it surfaces in the runner's Strava activity after they sync. CityHeart never collects the donation; the runner's donors click straight through to JustGiving / GoFundMe /...
Part of the Heart Routes server.
Free to start. No card required.
AI agents use add_cause to create or modify resources in Heart Routes. 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 add_cause 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 Heart Routes.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"add_cause": {
"limits": [
{
"counter": "add_cause_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Heart Routes policy for all 7 tools.
These attack patterns abuse exactly the kind of access add_cause 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.
Compose a builder URL with a fundraising link pre-filled — the URL is embedded into the GPX metadata (description, filename) so it surfaces in the runner's Strava activity after they sync. CityHeart never collects the donation; the runner's donors click straight through to JustGiving / GoFundMe / Leetchi / etc.. It is categorised as a Write tool in the Heart Routes MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Heart Routes MCP server in PolicyLayer and add a rule for add_cause: 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 Heart Routes. Nothing to install.
add_cause 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 add_cause 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 add_cause. 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.
add_cause is provided by the Heart Routes MCP server (https://zhenwiaphfwetckfysod.supabase.co/functions/v1/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Heart Routes tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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