How does Agent Commerce Kit (ACK) compare to other pay protocols?

Agent Commerce Kit (ACK) is one of 17 standards at step 7, Pay (Settle the bill). It pairs with x402, ERC-8004: Trustless Agents, Agent Payments Protocol. Every standard at this step is listed at https://agenticweb.wiki/category/pay/.

Agent Commerce Kit (ACK) ACK

7 · Pay

Agent Commerce Kit (ACK)
Category	Pay
Governed by	Developed by Catena Labs and contributed as MIT-licensed open source (agentcommercekit/ack); no standards body
Status	Open protocols with no stated version, status or date on the concepts page; reference packages tagged up to agentcommercekit@0.11.0
Phase	draft
Implementation	prototype
Adoption	unmeasured
Version	unversioned docs; reference packages agentcommercekit@0.11.0 (2026-10-16)
Specification	https://www.agentcommercekit.com/overview/concepts
Found at	none at a fixed path; identity rests on DIDs and verifiable credentials exchanged between the parties
Acronym collisions	ACK (TCP acknowledgement, unrelated), Not one of the protocols called ACP
Last checked	2026-10-20
Freshness	current · checked 2026-10-20
Solves	Accept payments from agents, Prove an agent's identity, Let agents buy on behalf of a person

Agent Commerce Kit (ACK) is an agentic-web standard (document format) at step 7, Pay, governed by Developed by Catena Labs and contributed as MIT-licensed open source (agentcommercekit/ack); its own status is "Open protocols with no stated version, status or date on the concepts page; reference packages tagged up to agentcommercekit@0.11.0" (draft). It answers: How can an agent prove who owns it and pay another party, on any rail, with a receipt both sides can verify? Adoption is unmeasured, last verified 2026-10-20.

Pay Agent Commerce Kit (ACK) is Catena Labs' set of open patterns for agent identity and agent payments, with reference code ^[1]^[2]. ACK-ID gives an agent a DID and verifiable credentials that trace it back to its owner ^[1]. ACK-Pay covers starting a payment, issuing a verifiable receipt and settling on whichever rail the parties use, card or stablecoin among them; it supports x402 ^[1].

Overview

Catena Labs launched it in May 2025 and contributed it as MIT-licensed open source ^[1]^[3]. The docs give no version, status or date. The reference packages are tagged up to agentcommercekit@0.11.0 and the code is still active ^[2]. ACK defines nothing at a fixed path on an origin. Its payment half is filed under Pay; ACK-ID would also fit under Identify.

Discovery and probe

none at a fixed path; identity rests on DIDs and verifiable credentials exchanged between the parties

GET none — no fixed path defined
parse:     No artefact at a fixed path to parse.
on absent: Not probeable from an origin.

Not probed live: no-fixed-path. ACK identity and payment objects are exchanged between parties; no fixed path is defined.

History

2026-10-20 — added from gap scout 2026-10-20; verified against agentcommercekit.com/overview/concepts and github.com/agentcommercekit/ack

Instances

No instances recorded yet.

References

The ACK concepts page describes Agent Commerce Kit as open protocols: ACK-ID for agent identity and ownership chains built on DIDs and verifiable credentials, and ACK-Pay for payment initiation, verifiable receipts and settlement-agnostic flows that support x402; it says Catena Labs initially developed it and contributed it as MIT-licensed open source, and gives no version, status or date. — https://www.agentcommercekit.com/overview/concepts VERIFIED
The agentcommercekit/ack repository is MIT licensed, created 2025-05-19 and last pushed 2026-10-16, with package tags up to agentcommercekit@0.11.0. — https://github.com/agentcommercekit/ack (2026-10-16) VERIFIED
Business Wire carries Catena Labs' launch announcement of Agent Commerce Kit. — https://www.businesswire.com/news/home/20250520361792/en/ (2025-05-20) REPORTED

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