The substrate's read and write surfaces are end-to-end-tested
internally; this slice answers the harder question — "is the
substrate actually usable from the outside?" — by writing the
smallest standalone program that consumes it. agent-probe walks
the discovery → triage → depth → push flow against a running
Pulse instance using only the Go standard library, so it doubles
as a reference implementation for anyone building MCP servers,
Claude Code integrations, or custom agents on top of Pulse.
It resolves every path from the manifest rather than hardcoding
them — if discovery moves a path, the probe follows
automatically — and branches on the stable error envelope's
"error" code field, never on human-readable messages. The focus
rule (severity-lex-ordered) is intentionally simple so a reader
can predict what the probe will pick; real agents will have
richer policies.
This is documentation as code: the program is short enough to
read top-to-bottom and reads like the agent's own narration of
what it's doing. The unit test pins the focus rule's lex
ordering so a refactor that swaps it for a weighted score (which
allowed many warnings to outrank one critical) cannot regress
silently.
