Runtime tools are tool definitions passed inline with a dispatch API request, without saving them to the platform first. They support the same execution types as saved tools.
Runtime tools support four types:
Call any HTTP API. Configure the URL, method, headers, and body with {{parameter}} template variables.
Execute sandboxed JavaScript, TypeScript, or Python code.
Execute another saved Runtype Flow as a tool.
Spawn a focused child agent with its own context window and a restricted tool subset.
The child agent runs in isolation and only its final result returns to the parent. allowedTools is intersected with the parent’s available tools so the child cannot escalate privileges.
Include runtime tools in the tools.runtimeTools array on a prompt step:
Runtime tools can be combined with saved tools and built-in tools in the same step:
Runtime tools can reference credentials passed in the secrets field of the dispatch request. Secrets are never logged or returned in responses.
Reference them in tool configs with {{secrets.key_name}}.