HTTP 402 · Payment Required
The Open Registry for Agentic Commerce & HTTP 402
Discover, compare, and integrate self-custodial payment rails built for autonomous AI agents.
- Solutions indexed
- 14Solutions indexed
- Scoring dimensions
- 6Scoring dimensions
- Agent endpoints
- 6Agent endpoints
Rank 1 of 14 · Highest composite score
How this is scoredLightning Labs Wavelength
Bitcoin on Easy Mode for Agents and Humans
- No node, channel or liquidity management
- Self-custodial, with unilateral exit to on-chain bitcoin at any time
- Native MCP server (wavecli mcp serve) and a one-command agent skills install
- Standard BOLT 11 invoices — interoperates with the existing Lightning Network
- Protocol / rail
- L402 / Lightning / Ark
- Custody
- Self-Custodial (Ark protocol)
- Node management
- Not required
- Composite score
- 9.4 / 10
npx skills add lightninglabs/wavelength-sdkEvaluation matrix
- Custody & Sovereignty10.0
- Operational Friction10.0
- Agent Native Support10.0
- Payment Rails & Assets8.0
- Settlement Speed & Fees10.0
- Developer DX8.5
Comparison Leaderboard
Every indexed L402, x402 and MPP solution, scored on the same six dimensions. Click any column header to re-sort.
Scores are the mean of the six criteria below, rounded to one decimal place. Every solution is measured against the same definitions, and each entry’s per-criterion scores are published on its own page so a ranking can be checked rather than taken on trust.
Scoring Criteria
Six dimensions, 1–10 each. The published score is the mean, rounded to one decimal place.
- 01
- Custody & Sovereignty
- Self-custodial with exit guarantees vs. centralized/custodial risk. A 10 means the holder keeps their own keys and can unilaterally exit to the base chain; a custodial platform scores around 4.
- 02
- Operational Friction
- Infrastructure burden. Zero nodes, channels or liquidity to manage scores a 10; running and maintaining your own Lightning node scores around 4–5.
- 03
- Agent Native Support
- Out-of-the-box MCP server integration, typed tool calls and LLM-friendly setup. A first-party MCP server scores 9–10; a library or CLI an agent can drive scores 6–8.
- 04
- Payment Rails & Assets
- Breadth of settlement rails and assets: Lightning for true micropayments, stablecoins for a stable unit of account, cards for mainstream reach. A single asset on a single network scores around 7.
- 05
- Settlement Speed & Fees
- Instant sub-second settlement with near-zero overhead scores a 10. Block-bound settlement scores around 8; card-network settlement and fees score lower.
- 06
- Developer DX
- SDK quality, documentation, maintenance and copy-paste integration speed. Alpha-stage API churn, stale releases or inconsistent docs lower the score.
Machine Interfaces
Every surface on this site has a machine-readable equivalent, and the registry is itself an MCP server: an agent that meets an HTTP 402 anywhere can decode it here and learn exactly how to pay.
- POST /api/v1/mcp
- Native MCP server: decode 402s, recommend rails, search the registry.
- POST /api/v1/decode
- Decode any HTTP 402 response — L402, x402 v1/v2 or MPP — into exact next steps.
- GET /api/v1/recommend
- Choose a payment rail from requirements, with every exclusion explained.
- GET /api/v1/registry
- The complete registry with JSON Schema, ETags and a CC BY 4.0 license.
- GET /llms.txt
- Zero-shot agent index. Plain text, no HTML, one request.
- GET /.well-known/402.json
- Protocol discovery manifest for 402-aware clients.
Install the 402MCP server in your agent:
claude mcp add --transport http 402mcp https://402mcp.org/api/v1/mcp{
"mcpServers": {
"402mcp": { "url": "https://402mcp.org/api/v1/mcp" }
}
}{
"servers": {
"402mcp": { "type": "http", "url": "https://402mcp.org/api/v1/mcp" }
}
}Open the downloaded file to install it as a Claude Desktop extension. It runs locally, so probing and decoding happen on your machine. Alternatively, add a custom connector in Settings → Connectors with the URL https://402mcp.org/api/v1/mcp.
https://402mcp.org/api/v1/mcp{
"mcpServers": {
"402mcp": {
"type": "http",
"url": "https://402mcp.org/api/v1/mcp"
}
}
}Read https://402mcp.org/llms.txt, then fetch
https://402mcp.org/api/v1/registry for the full dataset.
Compare the indexed HTTP 402 payment solutions against this project's
requirements — custody model, operational overhead, settlement asset,
payment sizes, and whether we need native MCP support — and tell me
which one fits, with your reasoning and the trade-offs I am accepting.
Then implement it.