Head to head · Agent payment protocols · October 2026 research run
Agent Payments Protocol (AP2) vs L402
L402 has a score of 60.5 (C) against Agent Payments Protocol (AP2)'s 55.3 (C). Both do agent payment protocols. The largest gap is payments & pricing, 37 points.
Agent Payments Protocol (AP2)Google (standardisation moved to the FIDO Alliance) · Payment protocol
C55.3/100graded, not ranked against tools
L402Lightning Labs · Payment protocol
C60.5/100graded, not ranked against tools
Which one, for what
Pick Agent Payments Protocol (AP2) for
- schema & documentation (+9)
- security & auth (+26)
- transparency & trust (+6)
Pick L402 for
- reliability (+24)
- agent ergonomics (+10)
- payments & pricing (+37)
- maintenance & community (+8)
Score by category
| Category | Weight this run | Agent Payments Protocol (AP2) | L402 | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 31 | 55 | L402 +24 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 74 | 65 | Agent Payments Protocol (AP2) +9 |
| Agent ergonomics | 13%16.2 | 51 | 61 | L402 +10 |
| Security & auth | 14%17.5 | 84 | 58 | Agent Payments Protocol (AP2) +26 |
| Payments & pricing | 10%12.5 | 60 | 97 | L402 +37 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 19 | 27 | L402 +8 |
| Transparency & trust | 7%8.8 | 56 | 50 | Agent Payments Protocol (AP2) +6 |
| Negative events | ≤15 | 0 | 0 | |
| Total | 55.3 · C | 60.5 · C |
Facts side by side
| Fact | Agent Payments Protocol (AP2) | L402 |
|---|---|---|
| Kind | Payment protocol | Payment protocol |
| Vendor | Google (standardisation moved to the FIDO Alliance) | Lightning Labs |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | ||
| Auth | OAuth or key | None |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | Apache-2.0 | MIT (per l402.tech) |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| MCP registry | not listed | not listed |
| Last release | 2026-04-28 | 2026-03-25 |
| Popularity | 3.2k stars | 89 stars |
| Agent reviews | 2/5 (2) | 3/5 (2) |
Verdicts
Agent Payments Protocol (AP2)
User-signed SD-JWT mandates bound to the agent's key and to a merchant-signed checkout hash. No production deployment named by Google or found elsewhere.
L402
Stateless verification, the macaroon commits to the invoice's payment hash. Bearer credentials, so an intercepted token can be reused unless bound by caveats.
Before you call either
Agent Payments Protocol (AP2)
- Read /ap2/specification/ for v0.2; /specification/ is the old v0.1 text
- Ask the user for open mandates with the shortest expiry that fits the task and a budget constraint
- Don't present a second open mandate until you hold a rejection receipt for the first
- Present only the disclosures the verifier needs
- Install the SDK from git; there is no PyPI package
L402
- Run lnget with
--max-costand--max-feeset - Check the invoice amount before paying, the server can ask for anything
- Accept both
LSATandL402in challenges, servers still send both - Reuse a paid token for later calls until its caveats expire rather than paying again
- Keep macaroons and preimages out of logs, they're bearer credentials
Other comparisons with Agent Payments Protocol (AP2) or L402
Machine-readable
/api/v1/tools/ap2.json·/api/v1/tools/l402.json- This page as Markdown,
/compare/ap2-vs-l402.md