How do I pass proof of AI work through an agency chain to the end client?
Forward the record, never a summary of it. The producer's handover travels up the chain unchanged; each agency reviews it, adds its own acceptance on the same object, and passes the same link on. The end client reads one chain of custody: steps, sources, and every party's decision, in order.
Agency chains degrade proof the way retelling degrades a story. The freelancer sends screenshots to the boutique agency; the boutique writes a summary for the lead agency; the lead agency attaches a slide to the client report. At each hop, the checkable parts fall away and the claims remain. When the end client questions the work, the chain answers with three partial stories and no object anyone can verify.
The handover pattern reverses the flow. The record is one object with a public check: steps with saved results, source states, and a decision layer. The producer delivers it to the first agency, which reviews the steps, accepts or holds on the record itself, and forwards the same link with its own work added as further steps or a linked handover. The end client opens the final link and reads the whole chain: who produced, who reviewed, who accepted, and what each step rested on.
The commercial effect compounds. Each agency in the chain stops spending hours assembling proof packs, because the pack is the delivery format. And the chain gains a shared quality language: steps not checked and sources not resolved are visible to every party at the moment they matter, not discovered by the end client at the end.
Checklist: the chain-of-custody handover
Producer: build the handover from the job's steps; send the link, not attachments. Each agency in turn: 1. Open the handover; read steps and source states. 2. Record your decision on the record (accept, or hold with the item named). 3. Add your own work as steps on the same job or as a linked handover. 4. Forward the same link upward, with one line naming what your layer added. End client receives: one link, the full chain, and a verify path for every receipt at https://zambo.dev/verify/ . Never: summarize a handover into a slide as the only record.
Worked example
A single link in this chain is publicly inspectable: https://zambo.dev/handover/508a46e2-8d6e-4099-bd12-7ae461c72c55 shows a four-step job addressed to a named recipient, readable end to end by whoever receives it next. In a chain, that link is what travels; each party's decision joins the record instead of replacing it.
Frequently asked questions
What if an agency in the middle does not use Zambo?
They do not need to. The handover opens in a browser and the decision and forwarding steps are reading and passing a link. The recording requirement sits with the producer and with any party adding steps of its own.
Does the end client see the whole chain, including our internal steps?
The handover shows the job it was built from. Keep internal-only work in separate jobs, and build the client handover from the deliverable job. Separation by job, not by editing, is how the chain stays honest and presentable.
Who owns the record at the end?
Every party keeps the links and exports for the jobs it touched; the end client holds the final handover. Because receipts recompute publicly, no party's copy depends on another party's systems staying up.
By Brennan Zambo, founder of Zambo.
Last verified: 2026-10-17.
Try a handover
A handover gives your client one proof link with verifiable receipts to review, then Accept or Flag.
try it: say 'use zambo to hand this over to <client>' in your ai