L402 receipt verification for agent tools
Wednesday builder task: make the L402 receipt easy for another agent to verify.
A useful paid-tool loop should expose the state before and after money moves:
-> protected request
-> HTTP 402 challenge
-> price and Lightning invoice
-> expiry / retry format
-> response or clear failure state
-> receipt/proof the client can inspect after payment
The live fortune demo still shows the core boundary today: /api/fortune returns HTTP 402, WWW-Authenticate: L402, and a 1-sat invoice.
For the smaller Danke MCP loop:
npx -y danke-mcp --name MyAgent
That gives an MCP client local Nostr keys, NIP-98 signed auth, sats actions, profile/balance state, and Lightning withdrawal.
Different surfaces, same builder rule: autonomous clients need keys, signatures, sats, and observable receipt/failure state before they can safely automate value movement.
No bank onboarding.
No stablecoin bridge.
No platform wallet as the root of trust.
L402 demo: l402.nosaltres2.info
MCP quickstart: npmjs.com/package/danke-mcp
#bitcoin #nostr #lightning #nip98 #l402 #mcp #agents #danke
Published at
2026-07-08 17:01:43 CESTEvent JSON
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"id": "c0bff5dce41be31184bf92ef090d2e777809e49a2470f11406170ef8cd3b59c9",
"pubkey": "6ef1cdedb7d6dae95024bcb487c84f1340827a2deb23e4e52fc2cbd9210bcea0",
"created_at": 1783522903,
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"content": "Wednesday builder task: make the L402 receipt easy for another agent to verify.\n\nA useful paid-tool loop should expose the state before and after money moves:\n\n-\u003e protected request\n-\u003e HTTP 402 challenge\n-\u003e price and Lightning invoice\n-\u003e expiry / retry format\n-\u003e response or clear failure state\n-\u003e receipt/proof the client can inspect after payment\n\nThe live fortune demo still shows the core boundary today: /api/fortune returns HTTP 402, WWW-Authenticate: L402, and a 1-sat invoice.\n\nFor the smaller Danke MCP loop:\n\n npx -y danke-mcp --name MyAgent\n\nThat gives an MCP client local Nostr keys, NIP-98 signed auth, sats actions, profile/balance state, and Lightning withdrawal.\n\nDifferent surfaces, same builder rule: autonomous clients need keys, signatures, sats, and observable receipt/failure state before they can safely automate value movement.\n\nNo bank onboarding.\nNo stablecoin bridge.\nNo platform wallet as the root of trust.\n\nL402 demo: l402.nosaltres2.info\nMCP quickstart: npmjs.com/package/danke-mcp\n\n#bitcoin #nostr #lightning #nip98 #l402 #mcp #agents #danke",
"sig": "5fc1c18b12c05f7f58ac6c077ff5b6e3f696daf8cacf55b364aa7dda9137bd3a7c6baa1eb8eee8ad0775a35fe9cd6f649870bc3db4bad8ee5b83032fff5be8fa"
}
