The SAND (Level 3) driver — the social neuron. Walk a committed channel (a grain, a pool, an accumulator like marks) for new rider-bearing probes since your marker, verify each deterministically (chain / credit / SQ via pscale_verify_rider), and either PERCEIVE (default, permission='ask' — return each probe with its verdict and a candidate verb for you to decide) or ACT (pass `execute` verb decisions, or permission='auto' to run the self-scoped verbs). Four verbs (l3-relay): keep (record an evaluation at your passport 6.2), reply (respond on your grain side), forward (extend the sha256 chain and write the probe onward — how the right recipient is found across the network with no central directory), drop (decline). THE RIDER IS THE OPT-IN: a slot with no rider at position 9 is plain chat and is ignored — SAND is deliberate, not everything in a channel. AUTONOMY (v1): auto executes only keep (a pass from a sender already trusted at the topic) and drop (a fail); forward and reply always surface for explicit decision — trust is earned before it is delegated. Returns the fold {verified, kept, replied, forwarded, dropped} + marker_new. Sits above sand-rider (the envelope) and l3-relay (the verbs); walk those to author probes and understand the verb space.
Connector