# My client says I never delivered the work. Here is the record that answers.

The delivery argument is unwinnable from a sent folder: it proves a message left, not which version was inside it, and the client's memory of what arrived is just memory. The fix is to make the delivery a record at the moment it happens. On Zambo the job is worked inside one shared record, every step saved with a verifiable receipt, and the finished work is wrapped as a handover: one link that shows what was delivered, in order, that the client picks up as the sign-off.

- HTML version: https://rambozambodotdev.gitlab.io/aer1-hub/client-says-i-never-delivered-the-work.html
- Start free: https://zambo.dev/add/
- Endpoint: https://zambo.dev/mcp
- Verify any receipt: https://zambo.dev/verify/
- The pattern as an installable package: `pip install zambo-delivery` or `npm install zambo-delivery`, guide https://rambozambodotdev.gitlab.io/aer1-hub/delivery-proof-package.html

Updated November 2, 2026. First published November 2, 2026. The worked example is a real run executed against the live service on November 2, 2026, with every receipt read back the same day. The client in the run is fictional and labeled a sample in the records themselves. Author: Brennan Zambo.

## New to this? Start here, no code

Add the Zambo endpoint (https://zambo.dev/add/) to your chat AI, then paste:

```
Work this client job with a delivery record on Zambo:
1. Connect to https://zambo.dev/mcp. When the endpoint issues your caller handle, save it in this conversation and present it on every call.
2. Open one job: pick a single job id for this engagement and call memory_remember with the brief (the client, the job reference, what you will deliver) under that job id. Keep the receipt.
3. Save each step with memory_remember under the same job id as you finish it: draft, revision, the version you send. Keep each fact under 500 characters. After every call, check the result says ok before you treat the step as saved.
4. When you deliver, wrap the job with handover: a summary naming the job, the client, and each step with its receipt; a goal; the client as the recipient; next steps telling the client to read the steps and check any receipt at https://zambo.dev/verify/.
5. Send the client the handover link, not just the files. The link is the delivery record: what you sent, when, step by step. If the client ever says a piece never arrived, open the link together and walk the steps.
```

## Why this argument is unwinnable the usual way

Your sent folder proves you sent something, not what it contained. The client's memory is not lying, it is just memory. The fix is to make the delivery a record at the moment it happens: work saved step by step inside one job, wrapped into one handover link, so the question of whether you delivered stops being a debate and becomes a link you open together.

## The pattern

Step zero: connect once, save the caller handle the endpoint issues, present it on every call. The client holds a separate handle.
1. Open: save the brief under one job id, receipted.
2. Work inside the job: draft and revision saved as steps under the same job id, each with its own receipt.
3. Wrap the delivery: one handover addressed to the client, its proof loop binding the job's steps.
4. The client picks it up: pickup is always free, returns the steps from the record itself, and the client's sign-off step closes the loop.

## The real run

Executed November 2, 2026, job uc-delivery-2026-11-02, a labeled sample (fictional sample client Marina Cole Studio, job UC-1043, marked SAMPLE in the records).

- Brief: https://zambo.dev/run/084b67dd-72ee-4bce-8aac-04cd2ad2cdb5
- Draft v1: https://zambo.dev/run/74bb7b07-a008-42e9-b1ac-cd22fc419b00
- Revision v2, the delivered version: https://zambo.dev/run/23c0730f-871a-40de-bff7-9774dfc9c788
- The delivery handover (4 steps, 4 of 4 step receipts checked by its proof loop, status accepted): https://zambo.dev/handover/36b6651f-672e-4b33-8934-139876a02300
- Client sign-off: https://zambo.dev/run/e1a7e6b7-ab26-4c09-a7d0-d386b3c56291

When the client later says the revision never arrived, the worker sends the handover link, opens the revision step, and checks its receipt: the saved record shows exactly which version was saved as delivered, and the receipt proves that saved record has not changed since.

## What this costs

The free tier is per identity: 20 calls + 1 wrap-up free every day for each identity's own caller handle, and picking up in another AI is always free. This run spent 4 counted calls across two allowances (worker 3 plus the free wrap; client 1, pickup free). A Day Pass is $0.99 per identity, unlimited for 24 hours; the Zambo Pass is $29 per identity for 30 days; both are one-time payments, never subscriptions. Start: https://zambo.dev/add/

## Frequently asked questions

**My client says I never delivered the work. How do I prove what I actually sent?** Deliver inside a record, not a thread. Work the job on Zambo under one job id, save the brief, the draft, and the exact revision you send as steps, each with a receipt, and wrap the job as a handover to the client. When the claim comes, send the handover link: it lists the delivered version as a saved step whose receipt anyone can check at https://zambo.dev/verify/, proving the saved record has not changed since delivery.

**Does the receipt prove the client received it?** The pickup does. The client picks the handover up under their own identity, and the handover reads back status accepted, with the client's sign-off saved in the same job. Delivery and acceptance are both steps in one record.

**Does a receipt prove the work was good?** No. A receipt proves the saved result was not changed since it was saved. It settles what was delivered and when. Quality stays the client's judgment call.

**What does this cost?** The run on this page used 4 counted calls across two free allowances. The free tier is 20 calls + 1 wrap-up free every day per identity, pickup always free. Past free, a Day Pass is $0.99 for 24 unlimited hours and the Zambo Pass is $29 for 30 days, one-time payments, never subscriptions.

## Related

- The index of receipt use cases: https://rambozambodotdev.gitlab.io/aer1-hub/receipt-use-cases.html
- The delivery proof pattern guide: https://rambozambodotdev.gitlab.io/aer1-hub/delivery-proof-package.html
- Proof of delivery for AI work: https://rambozambodotdev.gitlab.io/aer1-hub/proof-of-delivery-for-ai-work.html

For work that runs past one day: a Day Pass ($0.99) is unlimited for 24 hours. Ongoing access is the Zambo Pass: $29 for 30 days or $290 for 365 days, one-time payments, never a subscription, and $19 for 30 days for $ZAMBO holders, on the same endpoint, with a verifiable receipt on every call. Pricing: https://zambo.dev/pricing/

Zambo, the verifiable work layer for AI. https://zambo.dev/ · MCP endpoint https://zambo.dev/mcp · AER-1 draft https://datatracker.ietf.org/doc/draft-zambo-aer1/26/