What is this?
External Capabilities let the agent call systems outside the platform — your own API, or a connected MCP tool — the same way Capabilities let it act on contacts and automations. Use this once your first agent is working and you need it to reach something the built-in capabilities don’t cover.Adding an external capability requires the
automations:edit permission.What can I do here?
Click Add External Capability and choose a Type:
Every external capability has the same core fields, whichever type you pick:
- Availability — All agents on this channel, or only this agent.
- Display Name — a short, clear name, e.g. Book Appointment.
- When should the AI use this tool? — a description of exactly when to call it. This is the same mechanism automation matching uses — write it specifically, as an instruction, not a label.
HTTP Request
- Method and URL — the endpoint to call.
- Request Body (JSON) — supports variables, e.g.
{"email": "{{input.email}}"}.
MCP Tool
- MCP Server URL — where your MCP server is reachable.
- Selected Tools — pick from the tools the server exposes, or add one manually by name.
How to use it
Write the “when to use this” field like you mean it
This one field is the entire decision surface — the same pattern that drives every other “when should this happen” choice in the builder. A vague description means the agent won’t reliably reach for the tool even when it should; a specific one (“Use this to look up a customer’s order status by email”) gets matched correctly against real customer messages.Scope Availability deliberately
If several agents on this channel should all be able to use the same external tool, set Availability to All agents on this channel rather than recreating it per agent.Troubleshooting / Technical Notes
- I don’t have permission to add one. You need
automations:edit— check with your workspace admin. - The agent never calls it. Almost always the “When should the AI use this tool?” description — make it specific to a real customer request, not a generic label.
- The tab is empty right after creating the agent. Save the agent on General first — External Capabilities only unlocks afterward.