Agentic-Payment/agent-payment-protocols-tracker-2026-10

Agent Payment Protocols Adoption Tracker (October 2026): x402 vs AP2 vs ACP vs L402

Disclosure: Published by PinkWallet, which builds Pink Agentic AI Payments (an agent spending-control layer). Pink is not one of the protocols measured and does not integrate with any of them today.

A monthly snapshot of public adoption signals for x402, AP2 (Agent Payments Protocol) and ACP (Agentic Commerce Protocol), plus L402 as a longer-running comparison point. Measured 2026-10-08/09.

Full report, methodology, findings, and reproduction script: https://github.com/Pink-Agentic-Payments/agent-payment-protocols-tracker

Summary

[^npm]: Sum of official npm packages. x402: x402, x402-fetch, x402-axios, x402-express, x402-next (all maintained in the x402 monorepo). AP2 and ACP have no official npm package we could confirm; L402's possible SDK package could not be identified with confidence. "n/a" means not measurable, not zero. [^pypi]: x402's official PyPI package is x402. AP2's and ACP's spec repos reference no official PyPI package. A PyPI package named ap2 exists but belongs to an unrelated third-party repo, not Google's, and is excluded. [^mcp]: Distinct server names in the official MCP Registry naming each protocol. ACP's figure is the manually verified count (2 of 8 raw matches; the other 6 are unrelated tools that also abbreviate to "ACP"). [^fac]: x402's figure is its official facilitators directory (docs.x402.org). L402's figure is its README's hand-maintained "Implementations" list. AP2 and ACP publish no equivalent ecosystem/partners page as of 2026-10-08.

Findings (condensed)

1. 1.x402 has by far the largest GitHub footprint: 6,689 stars / 333 contributors vs. 3,211 / 19 for AP2 and 1,568 / 26 for ACP.
2. 2.x402's spec repo is far more active: 281 commits in the last 90 days vs. 1 for ACP and 0 for AP2.
3. 3.x402 has a measured package-download footprint (458,455 npm downloads/week, 204,765 PyPI downloads/month on the official packages); AP2 and ACP have none we could confirm.
4. 4.x402 dominates the MCP ecosystem: 214 distinct registered MCP servers vs. 3 for AP2 and 2 verified for ACP.
5. 5.x402's GitHub code-footprint search also leads (28,297 repos), vs. 2,587 for AP2 and 977 for ACP (approximate GitHub search counts).
6. 6.AP2 has one versioned release (v0.2.0); ACP ships on a rolling date-stamped API version instead of releases.
7. 7.x402 is the only one of the three with a maintained facilitator directory (15 listed).
8. 8.L402 is now the smallest by every GitHub metric measured, despite being the oldest (2020).
9. 9.Visa's "Trusted Agent Protocol" and Mastercard's "Agent Pay" have no public spec repo and are excluded.
10. 10.L402 has two competing "canonical" homes on GitHub; this tracker measured only lightninglabs/L402.

Full findings with exact source rows: see FINDINGS.md in the GitHub repo.

What none of these protocols decide

x402's own spec is explicit: "Out of Scope: This specification does not include: ... Client-side budget management" (specs/x402-specification-v2.md). AP2, ACP and L402 likewise have no standing per-agent budget, payee-rule, or human-approval primitive in their specs. See WHATNONEDECIDE.md in the GitHub repo for full detail with quotes and sources.

Where Pink fits

The per-agent budget, payee-rule and human-approval layer that these specs leave out is what Pink Agentic AI Payments does for payments an agent makes through Pink's own MCP server. It does not plug into x402, AP2, ACP or L402 today. Try it in the public sandbox with test money: https://agentic-sandbox.pinkwallet.com

Files

• —tracker.csv: the full dataset, one row per (protocol, metric), with source_url and method columns for every value.

License

CC BY 4.0. Attribution: PinkWallet, Agent Payment Protocols Adoption Tracker (October 2026).

How to cite

PinkWallet (2026). Agent Payment Protocols Adoption Tracker (October 2026). Version 2026.10. CC BY 4.0. https://github.com/Pink-Agentic-Payments/agent-payment-protocols-tracker