Multi-Agent Coordination: Sequential State-Passing vs a Shared Blackboard
Compare the custom runtime's current coordination model, where agents run in rounds and pass a handoff envelope, with a blackboard model where agents read and write a shared workspace, on convergence, token use, cost and latency.
Hypothesis
A shared blackboard should cut contradictions before reconciliation, because each agent sees others' commitments as they are made, but it will raise token use, because every agent reads more context. Sequential state-passing should stay cheaper and more predictable.
Problem
In the executive-team run, specialists build on each other in fixed rounds, and the CEO agent finds and resolves conflicts at the end. That works, but conflicts are only caught late, and every revision round costs extra calls.
Setup
Baseline: the current seven-round run. The CEO writes sub-briefs, the CMO sets the foundation, Creative and Sales work in parallel on it, the PM builds the roadmap, the CEO scans for conflicts, flagged agents revise, and the CEO writes one strategy. State moves only through the handoff envelope. Variant: a blackboard of typed entries (positioning, price points, channels, dates, risks) that every specialist reads before writing and appends to after. The CEO reconciles at the end as before. Metrics: conflicts flagged by the CEO's scan, revision rounds needed, total tokens, LLM calls, cost per run and wall-clock time.
Two ways for agents to coordinate
flowchart TD
subgraph SP[Sequential state-passing]
C1[CEO sub-briefs] --> M1[CMO foundation]
M1 --> X1[Creative + Sales]
X1 --> P1[PM roadmap]
P1 --> K1{CEO conflict scan}
K1 --> R1[Revisions]
R1 --> S1([Strategy])
end
subgraph BB[Shared blackboard]
B[(Blackboard: positioning, prices, channels, dates, risks)]
M2[CMO] <--> B
X2[Creative] <--> B
Y2[Sales] <--> B
P2[PM] <--> B
B --> K2{CEO reconcile}
K2 --> S2([Strategy])
endInput
A fixed set of representative briefs (launch plans, campaigns, event decisions), run several times through each variant with the same models and temperatures.
Output
Per-variant averages for each metric, and examples of conflicts each model caught or missed.
Decision
Status: designed, not run. The baseline runtime is in production; the blackboard variant is not built yet.
Next Step
Implement the blackboard as an alternative workflow behind a setting, run the brief set through both, and publish the comparison here.
Use Cases
- ▸Choosing a coordination model for multi-agent systems
- ▸Reducing late-stage conflict resolution cost