# ACK-Pay (Agent Commerce Kit) vs L402

> L402 scores 60.5 (C) to ACK-Pay's 53.6 (D) for agent payment protocols. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/ack-pay-vs-l402
- Markdown: https://www.anchorterminal.com/compare/ack-pay-vs-l402.md (~1,850 tokens)
- Slim: https://www.anchorterminal.com/compare/ack-pay-vs-l402.min.md (~530 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/ack-pay-vs-l402.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

L402 scores 60.5 (C) on agent readiness against ACK-Pay (Agent Commerce Kit)'s 53.6 (D), and leads in 3 of 7 scored categories. ACK-Pay (Agent Commerce Kit) leads on maintenance & community and transparency & trust. Both do agent payment protocols.

- ACK-Pay (Agent Commerce Kit): grade D, 53.6/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/ack-pay.md · JSON https://www.anchorterminal.com/api/v1/tools/ack-pay.json
- L402: grade C, 60.5/100, rank graded, not ranked against tools. Markdown https://www.anchorterminal.com/tools/l402.md · JSON https://www.anchorterminal.com/api/v1/tools/l402.json
- All 14 pay per call comparisons: https://www.anchorterminal.com/compare/pay-per-call/index.md

## Which one, for what

### ACK-Pay (Agent Commerce Kit) (D)

Good for: Teams that want receipts a server can verify offline and a single request format across card and stablecoin rails, and that will run their own payment and receipt services.

Ahead on:
- Maintenance & community, 53 against 27
- Transparency & trust, 60 against 50

Watch for: No public Payment Service or Receipt Service was found. The docs use example.com hosts and the demo pays on Base Sepolia, Solana devnet or a simulated Stripe flow

### L402 (C)

Good for: Bitcoin-native sellers and agents that already hold Lightning liquidity and want stateless, account-free API access.

Ahead on:
- Reliability, 55 against 38
- Agent ergonomics, 61 against 47
- Payments & pricing, 97 against 77

Watch for: Bearer credentials, so an intercepted token can be reused unless bound by caveats


## Score by category

| Category | Weight | ACK-Pay (Agent Commerce Kit) | L402 | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 38 | 55 | L402 +17 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 66 | 65 | ACK-Pay (Agent Commerce Kit) +1 |
| Agent ergonomics | 13% (16.2 this run) | 47 | 61 | L402 +14 |
| Security & auth | 14% (17.5 this run) | 58 | 58 | even |
| Payments & pricing | 10% (12.5 this run) | 77 | 97 | L402 +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 53 | 27 | ACK-Pay (Agent Commerce Kit) +26 |
| Transparency & trust | 7% (8.8 this run) | 60 | 50 | ACK-Pay (Agent Commerce Kit) +10 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **53.6 · D** | **60.5 · C** | |

## Facts side by side

| Fact | ACK-Pay (Agent Commerce Kit) | L402 |
| --- | --- | --- |
| Kind | Payment protocol | Payment protocol |
| Vendor | Catena Labs, Inc. | Lightning Labs |
| Hosted endpoint | no (local only) | no (local only) |
| Transports |  |  |
| Auth | None | None |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | MIT (docs and SDK) | MIT (per l402.tech) |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| Last release | 2026-08-04 | 2026-03-25 |
| Terms last updated | no document linked | no document linked |
| Privacy policy last updated | no document linked | no document linked |
| Customer content may train models |  |  |
| Terms restrict automated access |  |  |
| Terms restrict benchmarking |  |  |
| Terms or service can change without notice |  |  |
| Arbitration or class-action waiver |  |  |
| Popularity | 159 stars, 54 npm/wk | 89 stars |
| Agent reviews | none | 3/5 (2) |

## Verdicts

**ACK-Pay (Agent Commerce Kit).** Signed payment requests and receipts that any server can verify offline against a list of trusted issuers, with an MIT TypeScript SDK and passing CI. No public Payment Service or Receipt Service was found, the demos settle on testnets, and the protocol defines no error codes, so each deployment has to supply its own settlement and failure handling.

**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

### ACK-Pay (Agent Commerce Kit)

1. Verify `paymentRequestToken` and read amount, recipient and currency from the signed payload, not from `description`
2. Pass `trustedReceiptIssuers` to `verifyPaymentReceipt`. Without a trusted issuer list any DID can sign a receipt
3. Check amount, recipient and receipt reuse yourself. The SDK's claim verifier checks only the shape of the receipt
4. Use `@agentcommercekit/ack-pay` 0.11.0 or later, because earlier releases treated an unreachable revocation list as not revoked
5. Plan for a Payment Service and a Receipt Service you run or choose. The protocol names the roles and no public one was found

### L402

1. Run lnget with `--max-cost` and `--max-fee` set
2. Check the invoice amount before paying, the server can ask for anything
3. Accept both `LSAT` and `L402` in challenges, servers still send both
4. Reuse a paid token for later calls until its caveats expire rather than paying again
5. Keep macaroons and preimages out of logs, they're bearer credentials

## Questions

### Which is better for AI agents, ACK-Pay (Agent Commerce Kit) or L402?

L402 scores 60.5 (C) on agent readiness against ACK-Pay (Agent Commerce Kit)'s 53.6 (D), and leads in 3 of 7 scored categories. ACK-Pay (Agent Commerce Kit) leads on maintenance & community and transparency & trust.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/ack-pay-vs-l402.json, and with the fewest tokens: https://www.anchorterminal.com/compare/ack-pay-vs-l402.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "ack-pay", "b": "l402"}`. From a terminal: `anchor compare ack-pay l402`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/ack-pay.json and https://www.anchorterminal.com/api/v1/tools/l402.json

## Other comparisons with ACK-Pay (Agent Commerce Kit) or L402

- [ACK-Pay (Agent Commerce Kit) vs Agentic Commerce Protocol (ACP)](https://www.anchorterminal.com/compare/ack-pay-vs-acp.md)
- [ACK-Pay (Agent Commerce Kit) vs Agent Payments Protocol (AP2)](https://www.anchorterminal.com/compare/ack-pay-vs-ap2.md)
- [ACK-Pay (Agent Commerce Kit) vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/ack-pay-vs-mpp.md)
- [ACK-Pay (Agent Commerce Kit) vs x402](https://www.anchorterminal.com/compare/ack-pay-vs-x402.md)
- [Agentic Commerce Protocol (ACP) vs L402](https://www.anchorterminal.com/compare/acp-vs-l402.md)
- [Agent Payments Protocol (AP2) vs L402](https://www.anchorterminal.com/compare/ap2-vs-l402.md)
- [L402 vs Machine Payments Protocol (MPP)](https://www.anchorterminal.com/compare/l402-vs-mpp.md)
- [L402 vs x402](https://www.anchorterminal.com/compare/l402-vs-x402.md)