Coordinate Swarm

Stigmergy + local rules + quorum → coherent collective, no central ctrl.

Use When

• Distributed sys → no central bottleneck
• Self-coord teams → no mgr overhead
• Event-driven arch → shared state, not direct msg
• Works @3 agents → breaks @30 → scale
• Bootstrap new swarm domain (forage-resources, build-consensus)
• Replace fragile central orch → resilient emergent

In

• Required: Agents desc (workers, services, team)
• Required: Collective goal / target behavior
• Optional: Current coord + fail modes
• Optional: Agent count → pattern choice
• Optional: Latency tolerance (realtime vs eventual)
• Optional: Env constraints (shared state, bandwidth)

Do

Step 1: Classify Problem

1. Map: who agents, what do, where coord breaks
2. Classify:
   • Foraging → search distributed res (forage-resources)
   • Consensus → agree collective decision (build-consensus)
   • Construction → build shared structure
   • Defense → detect threats (defend-colony)
   • Division of labor → self-organize roles
3. Fail mode:
   • Single point fail (central ctrl)
   • Comm bottleneck (too many msg)
   • Coherence loss (drift, no feedback)
   • Rigidity (no adapt)

→ Clear class + fail mode → pattern choice.

If err: no single class → composite → decompose. Heterogeneous → layered coord (homogeneous clusters + inter-cluster stigmergy).

Step 2: Design Signals

Indirect comm channels.

1. Shared env (DB, queue, FS, board)
2. Signal types:
   • Trail: accumulate on success paths (ant pheromone)
   • Threshold: counter → behavior switch
   • Inhibition: repel from exhausted areas
3. Props:
   • Decay: fade rate → no stale dominance
   • Reinforce: success strengthens
   • Radius: propagation range
4. Signal → behavior map:
   • Signal X > T → action A
   • A done → deposit Y
   • No signal → default explore

Signal Design Template:
┌──────────────┬───────────────────┬──────────────┬────────────────────┐
│ Signal Name  │ Deposited When    │ Decay Rate   │ Agent Response     │
├──────────────┼───────────────────┼──────────────┼────────────────────┤
│ success-trail│ Task completed OK │ 50% per hour │ Follow toward      │
│ busy-marker  │ Agent starts task │ On completion│ Avoid / pick other │
│ help-signal  │ Agent stuck >5min │ 25% per hour │ Assist if nearby   │
│ danger-flag  │ Error detected    │ 10% per hour │ Retreat & report   │
└──────────────┴───────────────────┴──────────────┴────────────────────┘

→ Signal table: deposit conds + decay + responses. Simple + composable.

If err: too complex → 2 signals (attract/repel). Add nuance after basic works.

Step 3: Local Rules

Simple rules, local info only.

1. Perception radius (what sense?)
2. 3-7 rules, priority order:
   • Rule 1 (safety): danger-flag → flee
   • Rule 2 (response): help-signal + idle → move toward
   • Rule 3 (exploit): success-trail → follow strongest
   • Rule 4 (explore): no signal → random + unexplored bias
   • Rule 5 (deposit): task done → deposit success-trail
3. Each rule:
   • Local: only what agent perceives
   • Simple: one if-then
   • Stateless (pref): no past mem
4. Mental test → does collective behavior emerge?

→ Prioritized rules, independent exec → target behavior emerges.

If err: no emergence → feedback loop needed. Add signal for collective state + adjust rule.

Step 4: Quorum Thresholds

Trigger collective changes when enough agree.

1. Collective decisions:
   • Explore → exploit mode
   • New worksite commit / abandon
   • Normal → emergency
2. Per decision:
   • Threshold: # / % agents agreeing
   • Window: signal count period
   • Hysteresis: different on/off thresh → no osc
3. Quorum = signal accumulation:
   • Fav agent → vote-signal
   • Votes > thresh in window → activate
   • Votes < deact thresh → reverse

→ Leaderless decisions. Hysteresis gap → no rapid osc.

If err: oscillation → widen hyst gap (70/30). Never reaches quorum → lower thresh / widen window. Too slow → shrink window (beware premature).

Step 5: Test + Tune

1. Pilot 5-10 agents
2. Observe:
   • Converges on behavior?
   • How long?
   • Conditions change mid-task → what?
   • Agents fail / added → what?
3. Tune params:
   • Decay: fast → no memory; slow → stale dominates
   • Quorum: low → premature; high → paralysis
   • Explore/exploit balance: too explore → inefficient; too exploit → local optima
4. Stress:
   • Remove 30% agents → recover?
   • Double count → still coord?
   • Conflict signals → resolve / deadlock?

→ Tuned params, self-organizes, recovers, scales.

If err: stress fails → too tightly coupled. Simplify: fewer signals, faster decay, robust default. Swarm w/ zero-signal default > signal-dependent swarm.

Check

• Problem classified (foraging / consensus / construction / defense / labor)
• Signal table: deposit + decay + response
• Rules simple + local + prioritized (3-7)
• Quorum w/ hysteresis → no osc
• Small test → emergent behavior matches goal
• Stress test → graceful degradation

Traps

• Signal bloat: Too many types → confusion. Start 2 (attract/repel)
• Fake local: Rule needs global state → not local. Refactor
• No decay: Fossilized coord state. Half-life per task scale
• Zero hysteresis: Rapid osc. Deact < act always
• Homogeneity assumed: Diff caps → role-diff rules (scale-colony)

→

• forage-resources — res search + explore-exploit
• build-consensus — distrib agreement deep-dive
• defend-colony — collective defense on signal framework
• scale-colony — scaling past initial coord
• adapt-architecture — morphic arch transform
• deploy-to-kubernetes — distrib sys deploy
• plan-capacity — capacity + swarm scaling
• coordinate-reasoning — AI self-variant; stigmergy → ctx mgmt