Zambo This document specifies AER-1, a small vocabulary for recording one AI agent tool call as a portable, independently checkable execution receipt. A receipt identifies the execution, records when it happened, preserves the canonical bytes used for the output commitment, names the tool and caller scope, carries a provenance class, and resolves at a stable public URL. The format separates what the system observed from claims about the outside world, and it separates provenance (who ran or reported the action) from the record itself. A reference implementation is deployed, and its receipts are publicly verifiable without an account or token. This revision adds workflow receipts: a verifiable record that binds an ordered sequence of step receipts to a single goal, with a Merkle root over the step sequence for tamper evidence. The worked workflow example's Merkle root is computed with the Section 8.1 leaf construction. This revision hardens the Section 7 hash-chain entry digest: the digest now binds the entry's sequence number, job identifier, closing flag, receipt identifier, tool name, and provenance class alongside the output commitment, so relabeling or splicing attacks against chain metadata are detectable by recomputation. The revision also states the honest limit of chain mechanics: truncation with re-linking is not detectable by the chain alone and needs an anchored endpoint commitment.