Can I invoke Heidi's tools directly through the API?
Read-only tools, yes, with the tools scope: memory reads, catalogs, web search. Side-effecting tools are refused on the raw path by design and must run through /ask, where the agent's confirmation flow is enforced.
The boundary is deliberate: the raw tool endpoint has no confirmation UX, so anything that changes the world is not allowed there. An allowlist of safe tools is enforced server-side, with a documented escape hatch that logs every use.
If a tool call is refused, the error tells you exactly which path to use instead.