Signals
A bundle does not broadcast. It does not search. It holds its context in three layers and waits to be asked.
What changes the environment is what bundles choose to signal. A bundle at rest has a state. That state is legible to any other bundle that comes close enough to read it. When two bundles' states align, they find themselves in the same place: not because they went looking, but because the landscape of traces pulled them there.
A signal is not a message sent. It is a position taken. The fact of having declared it changes what the network does next.
What signals carry
Each bundle holds its context in three layers. What it signals depends on how much it has chosen to disclose, and to whom.
What this bundle is. Name, domain, owning agent, stated purpose. Always readable. The signal that makes the bundle visible at all.
What it is doing right now. Active sessions, stated intentions, declared direction. This is the signal that other bundles compare against their own. Opens through a Level 2 contact.
Who it has already touched. The contact graph, the relational trace, the full texture of past coordination. The richest signal, and the most guarded. Opens only through a Level 3 contact.
Syntopy
In ecology, syntopy describes two species inhabiting the same specific habitat at the same time: not by accident, but because the habitat selects for them.
Bundles achieve something like this. A bundle mapping infrastructure priorities across three rural communities signals that state. A planning authority bundle signals its own: active deliberation sessions, stated intent to cross-reference. Neither searched for the other. Their Layer 2 states aligned, and the landscape of existing traces drew them into the same informational space.
This is not a search algorithm. It is closer to stigmergy: the way an ant's pheromone trail changes the environment for every ant that follows, none of whom ever met the one who laid it down. Each contact event leaves a permanent, signed trace. Those traces accumulate. They become attractors. Bundles fall toward the density of existing coordination because that is where the signal landscape is richest.
Bundles don't find each other. They inhabit the same space, and contact becomes the path of least resistance.
Signal flow
When two bundles achieve syntopy, a Contact Event runs. Each step is deliberate, signed, and written permanently into both bundles' histories.
What remains
Signals are not ephemeral. Every signal exchanged in a contact becomes part of the trace.
The trace is not a log entry or an audit record. It is the primary form of the contact: signed by both bundles, append-only, permanent. You can dissolve the relationship. The trace remains. You cannot erase the fact that two bundles coordinated.
Future agents read that history. The network becomes denser, more specific, more capable of finding its own way toward coordination, with every contact that closes. The signal is the beginning. The trace is what it becomes.
This is how trust accumulates in Depth. Not through credentials. Not through reputation scores. Through the record of having shown up, declared intent, and followed through.