UCP Protocol Tracker
Every published version of the Universal Commerce Protocol — what it requires, how widely it's adopted across the stores we monitor, and whether real profiles are still in sync with the current upstream spec.
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2026-08-25 Latest In sync
August 25, 2026Required profile fields:
versionservicespayment_handlers57.3% adoption · 11,086 storesView version detail & adopters → -
2026-04-08 In sync
April 8, 2026Required profile fields:
versionservicespayment_handlers42.5% adoption · 8,222 storesView version detail & adopters → -
2026-01-23 In sync
January 23, 2026Required profile fields:
versionservicespayment_handlers<0.1% adoption · 12 storesView version detail & adopters → -
2026-01-11 In sync
January 11, 2026Required profile fields:
versionservicespayment_handlers<0.1% adoption · 16 storesView version detail & adopters →
Developer activity
Refreshed 2 hours agoA protocol is only as real as the work going into it. These are the public repositories behind the standards an agentic-commerce merchant may be asked to support, read live from the GitHub API. We publish the counts and leave the conclusions to you.
| Protocol | Stars | Forks | Contributors | Commits 30d | Commits 90d | Open PRs | Last commit | Last release |
|---|---|---|---|---|---|---|---|---|
| Substrate | ||||||||
| MCP The specification for how agents call tools. modelcontextprotocol/modelcontextprotocol Governed by the Linux Foundation's Agentic AI Foundation since December 2025. | 9,433 +169 / 21d | 1,863 | 372 | 68 | 397 | 58 median 138d −21 / 21d | 1d ago | 75d ago 2026-07-28 |
| MCP — reference servers Reference server implementations and the ecosystem index. modelcontextprotocol/servers Governed by the Linux Foundation's Agentic AI Foundation since December 2025. | 91,158 +649 / 21d | 11,777 | 428 | 417 | 466 | 282 median 33d* −35 / 21d | 1d ago | 1d ago v1.0.0 |
| MCP Registry The official index agents resolve MCP servers from. modelcontextprotocol/registry Governed by the Linux Foundation's Agentic AI Foundation since December 2025. | 7,339 +72 / 21d | 1,027 | 78 | 18 | 64 | 47 median 89d −2 / 21d | 0d ago | 66d ago v1.8.1 |
| Commerce | ||||||||
| UCP Merchant commerce capabilities declared for agents. Universal-Commerce-Protocol/ucp | 3,416 +33 / 21d | 477 | 63 | 28 | 92 | 124 median 37d* +16 / 21d | 2d ago | 47d ago v2026-08-25 |
| WebMCP Page-side tool calls inside the shopper's own browser tab. webmachinelearning/webmcp A W3C Web Machine Learning Community Group draft as of 2026, not on the Recommendation track. The Chromium origin trial runs from Chrome 149 to 156, so implementation work sits largely outside this repository. | 4,586 +461 / 21d | 323 | 26 | 21 | 48 | 8 median 28d −2 / 21d | 2d ago | — |
| ACP Product feed and checkout hand-off for agent purchases. agentic-commerce-protocol/agentic-commerce-protocol Maintained by OpenAI and Stripe as of September 2026, per the project's own description. | 1,570 +24 / 21d | 253 | 26 | 0 | 1 | 55 median 183d +2 / 21d | 86d ago | — |
| UCP CLI (Shopify) First-party tooling for building and testing UCP endpoints. Shopify/ucp-cli | 79 +4 / 21d | 12 | 7 | 11 | 51 | 6 median 17d +3 / 21d | 27d ago branches 14d newer | 27d ago v0.9.0 |
| Payments | ||||||||
| AP2 Signed mandates evidencing what a shopper authorised. google-agentic-commerce/AP2 Donated by Google to the FIDO Alliance in April 2026. Specification work continues in the FIDO Agentic Authentication and Payments working groups rather than in this repository. | 3,219 +35 / 21d | 510 | 19 | 0 | 0 | 91 median 167d +7 / 21d | 165d ago branches 48d newer | 166d ago v0.2.0 |
| x402 HTTP 402 stablecoin settlement, mostly for APIs and content. x402-foundation/x402 Contributed by Coinbase to the Linux Foundation's x402 Foundation in April 2026. The repository at coinbase/x402 is a fork of this one. | 6,709 +81 / 21d | 2,164 | 333 | 75 | 281 | 335 median 8d* +87 / 21d | 2d ago | — |
| Agent-to-agent | ||||||||
| A2A Agent-to-agent task delegation between organisations. a2aproject/A2A Created by Google; a hosted project of the Linux Foundation's Agentic AI Foundation since August 2026. | 26,112 +240 / 21d | 2,660 | 171 | 19 | 60 | 64 median 73d +3 / 21d | 4d ago | 136d ago v1.0.1 |
| Conventions | ||||||||
| ARD A catalog of the agentic resources a domain offers — MCP servers, agents, APIs and skills. ards-project/ard-spec A proposal-stage specification (v0.91, August 2026) authored across Google, Microsoft and Hugging Face. No formal governing body is named. | 481 +15 / 21d | 67 | 16 | 17 | 37 | 2 median 42d −7 / 21d | 0d ago | — |
| llms.txt A plain-text site summary convention for language models. AnswerDotAI/llms-txt | 2,656 +31 / 21d | 171 | 15 | 5 | 15 | 30 median 174d +1 / 21d | 17d ago | 17d ago 0.0.7 |
| Agent Skills Packaged instructions an agent loads for a given task. anthropics/skills | 180,582 +3,208 / 21d | 21,405 | 15 | 5 | 17 | 1,001 median 14d* +98 / 21d | 2d ago | — |
Collected once a day from the GitHub REST API. Grouped by layer and listed in a fixed order — this is not a ranking, and a busy repository is not the same thing as a widely adopted protocol. Stars measure who bookmarked a repository, not who deployed the protocol. Some rows carry a note: several of these protocols changed hands during 2026, and a repository often falls quiet on the day its specification work moves elsewhere, so the count alone would read as something false. Notes state dated, checkable facts — never an assessment. Spot something wrong? Tell us.
What each column counts, and how it maps to CHAOSS
- Stars
- GitHub stargazers. A popularity signal only: it measures who bookmarked a repository, not who deployed the protocol.
- Forks
- Independent copies of the repository on GitHub. CHAOSS: Technical Fork. CHAOSS additionally separates forks that have opened a change request from those that never have. We report the total only.
- Contributors
- Distinct non-anonymous contributors over the repository's whole history, as GitHub reports them. GitHub links only the first 500 author addresses to accounts, so this understates the largest projects. CHAOSS: Contributors. Not the same measurement: CHAOSS counts contributors active in the last 90 days, ours counts everyone who ever contributed. Read it as reach, not as current staffing.
- Commits 30d / 90d
- Commits landed on the repository's default branch inside the window. CHAOSS: Code Changes: Commits. Default branch only. Work on other branches is not counted, which is why a row can show zero while its branches move.
- Open PRs
- Pull requests currently open. The median age is measured across the 100 most recent and marked * where more exist. CHAOSS: Change Requests. CHAOSS counts change requests opened in a period; we report the standing open queue instead, because the backlog is what a would-be contributor meets.
- Last commit
- Days since the most recent commit on the default branch. CHAOSS: Activity Dates and Times.
- Last release
- Days since the most recent tagged release, with the tag. CHAOSS: Release Frequency. CHAOSS measures release cadence over time; we report recency of the last one.
How we track this
We pull the canonical schema from the official Universal Commerce Protocol repository and compare it against what real profiles declare across the stores we monitor. Adoption figures are live from the UCP Checker index; the sync status reflects our last automated comparison against the upstream schema.
The developer-activity table is a separate reading, collected once a day from the GitHub API. It measures how much work is going into each specification, which is not the same question as how many stores have implemented it — a protocol can be busy and barely deployed, or quiet and everywhere. We publish both and rank neither.
Validate your own profile against any version with the UCP Validator, or set up alerts to be emailed when a new spec version ships.
Frequently Asked Questions
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