ACP Acronym Collision: Disambiguating Three Protocols

Key takeaways

1. Date / source. August 2, 2026, tech-watch note by Didier Girard.
2. Key framing. three protocols compete for the ACP acronym, with no technical overlap whatsoever, and the surface resemblance is maximal ("protocol", "agents", "open source", "2025-2026"). ### The disentangling | Acronym | Full name | Connects | Origin | |---|---|---|---| | ACP #1 | Agent Client Protocol | a client to an agent | Zed, August 2025 | | ACP #2 | Agentic Commerce Protocol | an agent to a merchant | OpenAI + Stripe, Sept. 29, 2025 | | ACP #3 | Agent Communication Protocol | an agent to an agent | IBM Research / BeeAI | An analogy that holds: ACP #1 is to the agent what LSP is to the language — before, N editors × M agents = N×M custom integrations; afterward, N+M suffices. And the distinction with MCP fits in two lines: MCP connects an agent to its tools and data, ACP connects a client to an agent; the two stack. ### The curation rule, the note's real deliverable "A bare acronym is never indexed." The canonical entity is the full name; the acronym is only an alias, and an alias can be carried by several entities. Directly applicable to this repository — see [docs/reference/ontologie-kg.md](docs/reference/ontologie-kg.md) and scripts/entity_aliases.tsv. ### Verification carried out on this corpus on August 2, 2026 | Note's claim | Result | |---|---| | "Zero about Zed's protocol" | confirmed — the string "Agent Client Protocol" was absent from fiches/ and kb/; the gap was closed the same day by [[agentclientprotocol-introduction-2026-08-02]] | | "Twelve results" | not reproducible by grep — 3 fiches contain the token ACP, for 32 occurrences. The "twelve" likely comes from a semantic engine. The figure cannot be verified; the qualitative conclusion can | | Was the trap even possible? | already armed — the bare acronym ACP was typed as an entity in the graph, the subject of triples in two fiches, alongside a variant Agentic Commerce Protocol (ACP), i.e. three entities for the same protocol | | Materialized defect | the page kb/Agentic-Commerce-Protocol.md read "category: Google agentic commerce protocol" and the relation Google created → Agentic Commerce Protocol (confidence 0.99), whereas ACP belongs to OpenAI + Stripe and Google's protocol is UCP (+ AP2) | The collision described had therefore already produced an attribution error in the graph. Fixed on August 2: variants normalized to Agentic Commerce Protocol, and symmetrically UCP → Universal Commerce Protocol, ACS → Agentic Commerce Suite. The rule wasn't preventive here, it was corrective. ### ACP #1 governance, a nuance to add The note states "Zed launched the thing, then let it go". The opening move is real and verifiable (its own organization, versioned specification, public registry, JetBrains implementation), but public sources describe shared Zed × JetBrains governance — a registry co-launched in January 2026 —, with ACP still presented on Zed's side as its open standard and Zed 1.0's flagship feature. Openness, yes; relinquishment, no. Detail since disproved by the primary source: the number ACP 1.2 is not corroborated, the specification's navigation showing v1 (Latest) and v2 (Draft). The URL cdn.agentclientprotocol.com/registry remains unconfirmed. ### Buzz, the concrete case — verified and accurate Published by Block on July 21, 2026, Apache-2.0. A self-hostable workspace on Nostr; every human or agent participant is a key pair (Schnorr); every message, workflow step, and git push is a signed event in an append-only log. Three building blocks: buzz-acp (a harness translating Buzz events to an agent, in ACP over stdio), buzz-agent (an ACP agent calling an LLM and using MCP tools), buzz-dev-mcp (an MCP shell + editing server). Three harnesses shipped out of the box: Goose (Block), Claude Code (Anthropic), Codex (OpenAI). This is not "a product that uses ACP" but a demonstration that the decoupling holds: three agents from three competing vendors plugged in through the same harness, and a fourth — Hermes (Nous Research) — connected without Block writing a line. The N+M promise becomes an observable fact. Nuance: on Hermes's side, the public source frames the addition as an ACP server mode opening up Zed, JetBrains, and Neovim, the benefit for Buzz being a consequence of ACP rather than a targeted integration — which reinforces the argument. Enterprise-architecture reading: Buzz provides a sovereign, auditable multi-agent substrate, with no third-party SaaS dependency — signed log, self-hosted relay, cryptographic identities. It is the self-hosted option for the portability need analyzed in [[janakiram-agent-platform-portability-contract-2026-07-20]]. ### Claude subscription and third-party agents 2026 timeline as reported by the note, not re-verified: January 9, silent technical blocking of subscription OAuth tokens outside official tools → February 17-20, formalization in the docs and the Consumer Terms (the OpenClaw episode) → April 4, full enforcement → May 13-14, announcement of separate Agent SDK credits ($20 Pro / $100 Max 5x / $200 Max 20x) effective June 15 → June 15, the change suspended the very day it took effect. Status as reported on August 2, 2026: the Agent SDK, claude -p, and third-party applications draw from the subscription's limits, separate credit not existing. Dated by construction: to be re-verified before any decision. ### The rule that will outlast the terms of service The line drawn separates "ordinary, individual" usage from routing other people's requests via Free/Pro/Max credentials. An owner-only agent consumes your subscription for you; an anyone agent in a shared channel routes your colleagues' requests through your account, and that's the moment to switch to a usage-billed API key. The distinction is not legal but architectural: who is consuming, and on whose behalf — to be settled at design time. This is the ambient authority from [[valente-zalewski-beyond-zero-enterprise-security-ai-era-2026-07-20]] transposed from authorization to billing: an agent that inherits its human's permissions and acts on a third party's behalf poses the same boundary problem, whether accessing a document or consuming a quota.