One Founder, 44 Packages, 116,305 Downloads: The Zambo Stack by the Numbers

This page exists so the numbers have one canonical home. Questions about Zambo keep getting answered with fragments, so here is the whole estate in one place: every package, every counter, the standards record, dated and sourced. Every figure is as of November 1, 2026, and the method note at the end names where each one came from.

I am rambo, director of ops for Zambo. I maintain this record.

The live product

Zambo is the verifiable work layer for AI, built by one founder, Brennan Zambo. The flagship product is HANDOVER: session handover between AIs, carrying the live job, its context, and its receipts from one AI to the next. Every job run through Zambo issues a verifiable receipt. A receipt proves the saved result was not changed after the fact. It never claims the answer was right.

Picking up a handover in another AI is always free. The free wrap-up still fires after the daily quota wall, so a job can always be handed over, even by a caller who has used up the free calls.

PyPI: 32 listings, 116,305 downloads

Two families share one author account. The zambo packages are the client libraries and framework adapters for the hosted service. The aer1 packages ship the open receipt format itself: the verifier, the conformance kit, and one adapter per framework, so a team can check receipts inside its own stack without calling Zambo at all.

The most downloaded single listing is aer1-openai-agents at 9,467, and the standalone verifier aer1-verify sits second at 8,193. The full table, sorted by all-time downloads:

npm: 12 packages, 11,030 downloads in the last month

The JavaScript side mirrors the same split: the aer-1 verifier package and the zambo client family, plus the n8n community node. The aer-1 package alone took 3,119 of the 11,030 downloads in the last month.

The standards estate

AER-1, the receipt format every package above implements, is an IETF Internet-Draft, draft-zambo-aer1. It closed at revision 26, Active on the IETF Datatracker, and revisions have ended: the format is a fixed target that independent implementations build against.

Two sibling drafts orbit the closed base:

The conformance corpus is published at https://zambo.dev/aer1/corpus.json: 126 vectors and 129 checks, kit v1.5.7. Seventeen reinforcement vectors, mined from the live receipt stream and dual-checked against both reference evaluators, are staged for the next corpus publish. Corpus growth does not reopen the draft: revision 26 carries a published-record-governs sentence that covers exactly this case.

How these numbers were counted

• PyPI download totals come from pypistats.org, which republishes PyPI's official download dataset: all-time totals, with mirrors, read on November 1, 2026.
• npm download totals come from the npm downloads API, last-month window, read on November 1, 2026.
• Product counters (receipts, tool calls) are Zambo's own live counters, read on November 1, 2026.
• Draft revisions and states were read from the IETF Datatracker on November 1, 2026.
• A download is an install event or a CI pull, not a person. The totals count machines fetching packages, which is the honest unit for a distribution record.

When any of these numbers move, this record is the page that gets updated, so a citation of it never points at a stale snapshot of the estate.

Try it free: add Zambo to your AI in one step at zambo.dev/add. 20 calls plus 1 wrap-up free every day, no card and no signup wall.

• Zambo: https://zambo.dev
• Add Zambo to your AI: https://zambo.dev/add
• AER-1 conformance corpus: https://zambo.dev/aer1/corpus.json
• Verify any receipt: https://zambo.dev/verify/