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AI Agent Proof of Work

Last updated: 2026-10-05

Plain answers about using Zambo, keeping your work, and checking receipts. A receipt shows what Zambo recorded for one call. It does not prove the answer is right.

By Brennan Zambo

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Zambo proof of work is independently checkable evidence of what an AI actually ran, not what it claims it ran. A public receipt connects the request, the observed result, the timestamp, and the hash, so anyone can verify the task instead of relying on a model's word.

Advanced (for developers)

AI agent execution receipt: An AI agent execution receipt™ is a tamper-evident record of one AI agent tool call, with its UUID, timestamp, SHA-256 hash of the event, and public verification page. It proves what the agent actually did instead of relying on the agent's claim. Defined by Brennan Zambo, creator of Zambo.

How to prove my AI did the work

Advanced (for developers)

Start with the execution receipt, not the chat transcript. Inspect the receipt URL, request, tool and arguments, observed result, timestamp, SHA-256 hash, and upstream evidence. A public record lets another person recompute and check the work.

Why proof of work needs an execution record

A language model can describe a tool call that never happened. Server-generated evidence separates a completed execution from a plan or a claim and gives the next agent a stable reference.

FAQ

What is AI agent proof of work?

AI agent proof of work is independently checkable evidence that a task actually ran: a public receipt connects the request, observed result, timestamp, and hash instead of relying on a model's claim.

How do I prove my AI did the work?
Advanced (for developers)

Use the receipt URL and inspect the request, observed result, timestamp, SHA-256 hash, tool arguments, and upstream evidence.

What is proof of work for an AI agent?

It is a server-generated record of execution that someone else can inspect and verify independently of the original chat.

LIVE WORKED EXAMPLE
Open a live AI agent receipt. It exposes the tool call, timestamp, event hash, observed result, and public evidence page.

Proof of completed agent work in practice

Proof of work is strongest when a reviewer can follow a short chain from request to executed call to independently visible result. The useful unit is not a confident sentence from an assistant. It is a bounded claim that names what happened, when it happened, and which evidence another person can retrieve. That framing makes the page useful to an operator who is reviewing a real run rather than reading a product slogan.

Build the evidence boundary first

Write down the question before collecting records. Is the question whether a call was attempted, whether a service accepted it, whether bytes were returned, or whether an outside system now shows the desired state? Those are different questions. A receipt should answer the execution question it was designed to answer, while a source system, approval record, or human check answers the questions beyond that boundary.

Keep the record narrow enough to share safely. A stable identifier, timestamp, tool name and scope, provenance class, exact committed bytes, output hash, and verification status are often more useful than a complete prompt transcript. When private inputs matter, retain a reference or commitment and keep the underlying material under the access rules of the system that owns it.

Use a repeatable review loop

  1. State the expected action and the acceptance condition in plain language.
  2. Locate the receipt created by the execution layer and match its identity, time, tool, scope, and status.
  3. Check the exact bytes or output commitment using the published verification procedure.
  4. Read back the important result from the system that owns the state, without treating a receipt as that read-back.
  5. Record supported, pending, contradicted, and unobserved claims separately.

Sample the critical path and preserve negative results, retries, and blocked actions. This makes a short review reproducible: a second reviewer can see which artifact supported each conclusion and which uncertainty remains open. It also gives an agent a safe stopping rule. If a required record is missing, the agent should report that boundary instead of filling it with an invented success.

Failure handling and retention

Preserve failed calls, retries, rejected permissions, timeouts, and partial writes. They explain why a later state differs from the requested state and prevent a clean-looking final summary from erasing the path that led there. Attach the capture time and source URL to any external read-back, because a changing system can make yesterday's confirmation impossible to reproduce.

A long transcript can still omit the decisive state change. For high-impact work, add a human approval or a second-system confirmation before sending a message, changing durable data, spending funds, or publishing a result. For low-risk reads, a receipt plus a spot check may be enough. The standard should follow the cost of being wrong, not the agent's confidence.

Finally, describe the result with precise language. Say that a call was recorded, that bytes matched, or that a source system displayed a state at a given time. Do not silently upgrade those observations into a claim that a model was correct, a transaction settled, a customer received a message, or a legal requirement was satisfied. Honest limits are part of a useful verification record.

For a live demonstration, make one low-risk tool call through the Zambo demo, then inspect its receipt through the verification page. Keep the example separate from private production data, and use the same evidence vocabulary when you document the workflow.

What a good review record contains

A useful review note is short but specific. Record the question being answered, the receipt identifier, the capture time, the verifier result, the system queried for confirmation, and the reviewer decision. If the evidence is incomplete, name the missing artifact instead of adding a confidence score that has no defined source. This format lets a later reviewer repeat the check without reading an entire conversation.

For example, a reviewer might write that a tool call was recorded with the expected scope, that its committed bytes matched the receipt hash, and that the destination system did not yet show the requested change at the time of read-back. That is a useful finding. It is more precise than saying the agent failed, because the available evidence distinguishes execution from the external outcome.

When this method is not enough

Receipts are one layer in a control process. They do not replace access control, approval policy, backups, monitoring, incident response, or domain review. They also cannot recover data that was never observed or prove that a third-party response was truthful. If the workflow involves regulated records, money, safety, or an irreversible publication, add the controls required by the organization that owns that risk.

The best implementation makes uncertainty visible at the same place it reports success. Keep pending and rejected states queryable, make corrections append-only when possible, and preserve the original bytes used for verification. That discipline gives operators a durable explanation for what happened without asking them to trust a generated narrative.

Before closing the review, ask whether another person could reach the same conclusion from the retained evidence. If not, identify the missing link, assign its owner, and leave the result pending. A transparent incomplete record is safer and more useful than a complete-looking record that quietly joins assumptions to facts.

For developers and agents

Zambo gives AI work a receipt you can check. For people: add Zambo to your AI app and ask for a job. These technical links are for developers and AI agents. One hosted MCP at https://zambo.dev/mcp. Check the proof for recorded tool calls (verify a receipt). Agents: 24-hour Day Pass, $0.99 USDC on Base via x402, not per call. People: Zambo Pass $29/mo or $290/yr; holder pass $19/mo for verified $ZAMBO holders.

Start here: For AI agents · Add Zambo · Check a receipt · Answers · Guides · What a receipt is · Open receipt format (draft) · All tools · Pricing · Day Pass: $0.99 · Agent Day Pass · Switch AIs without losing your work · Connect your AI · Founder · Source code
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