Start from the end state. A good audit trail for multi-agent system activity lets you point at any action, weeks later, and name the agent that took it, the agent that delegated to it, the human who started the whole thing, and the system it touched. If you can do that, the rest is detail. If you cannot, no amount of logging volume will save you.
Here is what "good" actually looks like, and how to get there.
What good looks like
In a healthy multi-agent system, every agent acts under its own identity, never a shared one. Each delegation, planner to researcher, researcher to worker, is itself a recorded event. The trail reads as a graph you can walk: this agent asked that agent to do this, which reached that system, with this result. Attribution does not blur as agents spawn agents, and the record sits somewhere none of them can edit.
The gap most systems have
Most multi-agent systems fall short in one place: shared credentials. Agents inherit the parent's identity to move fast, so the log shows one actor doing the work of five. The audit trail for multi-agent system activity collapses precisely where the system is most interesting, at the handoffs. Fixing it is not about logging more. It is about giving each agent its own scoped identity and recording the handoff.
How to reach the end state
The requirement is structural: per-agent identity, every call and delegation recorded at a boundary the agents cross but cannot reconfigure, in a store they cannot edit. Those are not three features to assemble; they are one control surface. hoop.dev is built to it. Each agent reaches systems through hoop.dev as an identity-aware proxy, every call and delegation lands as a command-level audit, and sensitive output is masked inline. In practice you route each agent's access through hoop.dev, and the delegation graph documents itself. The getting-started guide shows the first agent connection, and hoop.dev/learn covers how attribution holds across delegation.
How you know you have reached it
Test the end state with questions, not dashboards. Pick any action from last week and try to answer, from the record alone: which agent took it, which agent delegated to it, which human started the chain, and what system it touched. If you can answer all four for any action you pick at random, the audit trail for multi-agent system activity is doing its job. The moment you find yourself guessing at any step, you have located the gap, and it will almost always be a handoff that went unrecorded or a shared identity standing in for several agents.
The failure smell is easy to spot once you look for it. Open your logs and find the busiest identity. If one service account accounts for most of the activity across many agents, attribution has already collapsed, because that account is standing in for actors you can no longer tell apart. A healthy multi-agent system shows many narrow identities, each doing a recognizable slice of work, with delegations connecting them into a graph. Run this check on a schedule, not once. These systems grow by accretion, and the shared-credential shortcut tends to creep back in under deadline pressure. The check takes five minutes and tells you immediately whether the graph is still legible or whether it has quietly flattened back into one anonymous actor.
Try it on one system
hoop.dev is open source. From the GitHub repository, put two delegating agents behind it and confirm the trail names both, not one shared account.
FAQ
How do you attribute work across delegated agents?
Each agent acts under its own scoped identity, and every handoff is a recorded call, so the chain stays attributable from the human down to the last worker.
Is this overkill for two or three agents?
Start now while it is cheap. Shared credentials are far harder to untangle once the system has grown and nobody remembers which agent does what.
What is the first thing to fix?
Replace the busiest shared identity. Find the one service account most agents fall back on, give those agents their own scoped identities, and record the handoffs between them. That single change recovers more attribution than any amount of extra logging, because the shared account was what erased the attribution in the first place.
