Multi-Agent Topologies and Collaboration Contracts
Select and govern multiple agents only when specialization, parallelism, or independent assurance creates measurable value.
A focused view of boundaries, contracts, state, authority, failure paths, and tradeoffs drawn from this chapter.
3. Collaboration contract
Every delegated assignment declares parent work, delegator identity, delegate profile/version, purpose, owned scope, allowed tools and data, maximum delegation depth, input package, expected output schema, completion criteria, deadline, budget, evidence requirement, failure policy, and return channel. The delegate cannot widen scope, re-delegate unless explicitly allowed, or claim acceptance.
delegation:
id: delegation-204
parent_attempt: attempt-31
delegator: agent:supervisor@7
delegate: agent:security-reviewer@4
purpose: "Review changed authorization paths"
scope: [files:security/**]
authority: [repository-read, test-run]
context_package: context:sec-review-88
completion: schema:security-findings@3
deadline: 2026-08-30T19:00:00Z
budget: {model_calls: 6, cost_usd: 3}
on_failure: return-partial-and-escalate
4. Context and shared state
Use private context when independence or least privilege matters. Use shared state only through versioned records with ownership and merge rules. Never pass an unbounded transcript as the only handoff. Summaries identify source, author, confidence, unresolved questions, and exact artifacts. Governing contracts are immutable; a delegate's observation cannot overwrite them.
8. Failure containment
| Failure | Containment | Recovery |
|---|---|---|
| Delegate exceeds scope | Gateway denies and supervisor pauses branch | Review attempted calls; reissue narrower assignment if safe |
| Child fails after mutation | Stop sibling work on dependent state | Reconcile effect, compensate or replan |
| Supervisor fails | Durable graph and delegation ledger preserve state | New controller reconciles leases and child results |
| Conflicting edits | Ownership/merge conflict blocks aggregation | Rebase or deterministic conflict owner decides |
| Correlated reviewers miss defect | Independence monitor and injected fault | Replace review path and rerun affected evidence |
| Budget fan-out | Parent reservation denies new child | Return partial results and escalate |
10. Versioning, tradeoffs, and nonclaims
Topology, role profiles, collaboration schemas, and join policies are versioned as part of the workflow. Changing authority or merge semantics is breaking. Multi-agent systems can improve specialization and latency but usually cost more and are harder to reproduce. This review-ready reference does not prove that any multi-agent topology beats a simpler baseline.
Review this chapter.
Challenge a claim, boundary, missing failure mode, unclear term, or unsupported evidence statement.
- Claim
- Boundary
- Failure
- Evidence