Bug: fail to create an invoice with blinded path

[Retropex]

Hi,

I have recently heard of this project and I'm trying to test it

I have successfully connected lndk to my lnd node and I'm trying to pay an offer from another cln node but it fail to fetch the invoice.

To create the bolt12 offer I used that command lndk-cli -n mainnet create-offer 1 1satoffer and then on cln I'm trying to fetch the invoice with this command lightning-cli fetchinvoice <the invoice>

after few second cln time out:

{
   "code": 1005,
   "message": "Timeout waiting for response"
}

relevant logs of lndk:

Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.007855163+02:00 DEBUG lndk::onion_messenger - Incoming messages sent: IncomingMessage(PublicKey(9c837cbb7ae217737e67269b98f65c6994995e82f45189ddb2a91584a310ac0d949336cee244cfd6beac0df30dc1ca2056599a5514b4af2767ee19e20f6c1858), OnionMessage { blinding_point: PublicKey(0ee2094a78dc302c5b6d12d13884db0f9a82d04bd78d7f139a37e57810f2723404d9d22b8f4e5078d134d66683b0b1388ddb94c3243dcc97c3a5931b5e686ad8), onion_routing_packet: Onion message packet version 0 with hmac [92, 130, 66, 43, 220, 141, 17, 213, 84, 85, 233, 114, 129, 255, 87, 237, 15, 128, 159, 38, 61, 235, 138, 95, 169, 57, 161, 126, 211, 89, 141, 200] }).
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.007877536+02:00 INFO lndk::onion_messenger - Consume messenger events received: messenger event: 020dac10a38415a9b2dd8951f4825e9994695cf6989b26677e7317e27abb7c839c incoming onion message.
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.009413131+02:00 TRACE ldk - Forwarding an onion message to peer 028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.100377750+02:00 INFO lndk::onion_messenger - Sending outgoing onion message to 028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605.
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.101099592+02:00 DEBUG lndk::onion_messenger - Sent outgoing onion message OnionMessage { blinding_point: PublicKey(480a1d3780b3eb06541a7dfc1e2062534678965c7059d9b40c69997545f147b92e696155297db770c7caa9957096706817f54fd0d4ca9e6eba99b1cb2c9981bd), onion_routing_packet: Onion message packet version 0 with hmac [192, 123, 122, 55, 203, 5, 63, 161, 127, 160, 253, 125, 56, 112, 88, 51, 219, 45, 103, 1, 76, 255, 43, 17, 193, 254, 162, 76, 59, 15, 140, 58] } to 028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605.
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.470984323+02:00 DEBUG lndk::onion_messenger - Incoming messages sent: IncomingMessage(PublicKey(05760ddbbd226c1e451be108ae47023372d7e50b343b62ff0c5c5ac20c72a28dd659504e980324f607222479172c0f37ad095a9b278a94fe48b9228e24234302), OnionMessage { blinding_point: PublicKey(721747e5630b59ac9aec7561139cb22b05a2fce6158d1b1bd3c5a37acb1ee44e21f2c309ae383bbf6d4e9f27259bac0e2eaec35399f449d5460e68bb91c681d8), onion_routing_packet: Onion message packet version 0 with hmac [85, 170, 163, 216, 238, 69, 209, 23, 47, 157, 79, 253, 130, 32, 152, 49, 146, 68, 30, 142, 113, 38, 43, 38, 122, 150, 31, 126, 131, 36, 25, 224] }).
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.471011981+02:00 INFO lndk::onion_messenger - Consume messenger events received: messenger event: 028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605 incoming onion message.
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.472196737+02:00 TRACE ldk - Received an onion message with a reply_path: Offers((PayerTlvStreamRef { metadata: Some([188, 57, 33, 192, 1, 72, 26, 221, 100, 129, 168, 117, 17, 116, 222, 153]) }, OfferTlvStreamRef { chains: None, metadata: None, currency: None, amount: Some(1), description: Some("1satoffer"), features: None, absolute_expiry: None, paths: Some([BlindedMessagePath(BlindedPath { introduction_node: NodeId(PublicKey(05760ddbbd226c1e451be108ae47023372d7e50b343b62ff0c5c5ac20c72a28dd659504e980324f607222479172c0f37ad095a9b278a94fe48b9228e24234302)), blinding_point: PublicKey(480a1d3780b3eb06541a7dfc1e2062534678965c7059d9b40c69997545f147b92e696155297db770c7caa9957096706817f54fd0d4ca9e6eba99b1cb2c9981bd), blinded_hops: [BlindedHop { blinded_node_id: PublicKey(71cae302661cf3e3b2e2e2909f17a495e2859fc827a474487cc84b3edce47545339e38985a70832edfbe07cc31a6bc6ffef1a8ae57699e3fcac1f8e77eec3d8e), encrypted_payload: [147, 25, 46, 42, 160, 89, 195, 100, 156, 3, 101, 27, 22, 91, 4, 114, 239, 12, 124, 103, 245, 181, 250, 64, 61, 239, 107, 85, 105, 90, 229, 206, 199, 64, 119, 12, 178, 195, 199, 207, 145, 134, 194, 212, 36, 212, 135, 254, 82, 203, 249] }, BlindedHop { blinded_node_id: PublicKey(27ba97b86b8728ff8ec0e60037b5f4b316718022e264bac22af2821f9b396705240b3db324033ff105b448ecaab22d346251e297fd72fd2bef6ebbafc2e1aea3), encrypted_payload: [134, 201, 16, 66, 93, 74, 82, 146, 121, 99, 30, 89, 180, 80, 41, 95, 18, 220, 53, 83, 218, 64, 56, 114, 220, 142, 168, 169, 11, 39, 122, 191, 73, 19, 180, 47, 217, 253, 0, 93, 63, 90, 102, 218] }] }), BlindedMessagePath(BlindedPath { introduction_node: NodeId(PublicKey(9041b52c9c2000cb4e5dfc9e5960b0fcee99d4982d320ff806f6793b2c440071204d3db3605bada4c4cdc01c67c91a3f06b31a9932339e3f047528ca91a5f2a4)), blinding_point: PublicKey(834ff3b79925dda522b9728420d411682c8236eca5e347827d28a1c4316bdce2cb3b2483208f1ed2857407bff5a4f0d29fe4f4646a74b0266b9228ba73c7abdb), blinded_hops: [BlindedHop { blinded_node_id: PublicKey(0ef1bf959684def25f7ff1fc98ffb745e4eac7b2052f7b84e745e3cd789ffe6b637043cedecf8c877b57bdf214d6feb4d2136914f3d99e4c61bb7c644573cf4a), encrypted_payload: [250, 246, 27, 160, 19, 66, 126, 49, 123, 58, 253, 183, 65, 30, 121, 212, 136, 37, 238, 25, 121, 152, 1, 162, 154, 180, 211, 232, 48, 192, 245, 192, 89, 121, 125, 100, 250, 185, 86, 80, 217, 63, 210, 129, 107, 82, 40, 111, 182, 19, 105] }, BlindedHop { blinded_node_id: PublicKey(8f1031be8f022dac083551a883ff996c769c444879e6e00ad7a13590f9de3f39f084677e9f99168dc8f323b531e29232d5a371c888cffbe744a49eb29be9853a), encrypted_payload: [89, 79, 253, 130, 95, 97, 55, 76, 122, 244, 153, 28, 226, 196, 248, 43, 182, 229, 127, 172, 4, 236, 240, 94, 46, 197, 184, 130, 120, 137, 155, 127, 13, 28, 111, 64, 82, 40, 0, 65, 249, 1, 2, 123] }] }), BlindedMessagePath(BlindedPath { introduction_node: NodeId(PublicKey(8f3f7a5966c3e270c3bf26a944ee9568184a6ace8691987d58fbe8fd25f04e861de21fc3e5abe4d15ca16421edc74405c694b4147aacc10f65d509ed44f06d26)), blinding_point: PublicKey(9ac67d653d2a766745e44bc9566a36fb4398a9bfc708f3f0f3f209a8c801241b20d3a2649acbb4bb27fd342668dda103da688d38b88e9f72a98232d97157bb3f), blinded_hops: [BlindedHop { blinded_node_id: PublicKey(f7717006535074f21e60e5d26c09c7179abd2d447579137523234305d5ddfed54571380b4f871b6e9fd90398f07f8fdf79001a24214772a44c9e4532d50dbb69), encrypted_payload: [63, 1, 6, 101, 124, 224, 248, 76, 168, 245, 185, 137, 56, 247, 7, 197, 121, 110, 157, 240, 111, 226, 152, 24, 1, 56, 31, 8, 165, 154, 220, 73, 73, 189, 59, 69, 219, 67, 148, 137, 169, 115, 39, 209, 11, 175, 98, 232, 137, 197, 60] }, BlindedHop { blinded_node_id: PublicKey(ff41502e3d64dc799967d1b0d0c9e7913083672c7693ce672d9921d05f6c06fad20887cf791103c4318310792dd46e42d7d673f75a8610c74c2ecb8b7e2d845e), encrypted_payload: [199, 4, 33, 221, 29, 102, 160, 236, 198, 236, 243, 232, 207, 237, 91, 99, 97, 249, 34, 197, 135, 72, 158, 88, 231, 79, 137, 5, 135, 249, 107, 173, 168, 109, 241, 35, 123, 194, 206, 119, 216, 79, 119, 160] }] })]), issuer: None, quantity_max: None, issuer_id: Some(PublicKey(650cc9e7980fbfcf75c5d1e67c20d2f297b1e5a79b8870697475120f68b1611f16cb4f2675e10feb46ab1014e5e66cf58642ee6ba1405a271ed5e5ad735eb352)) }, InvoiceRequestTlvStreamRef { chain: None, amount: None, features: None, quantity: None, payer_id: Some(PublicKey(97eb89d1514307cc9c2c632828deca40a75120ee422748ab38304d24e8db03cb59e3799de419a1589f2bc654e8d77740337400c49d9f582aab2912d1180d6195)), payer_note: None, paths: None, offer_from_hrn: None }, SignatureTlvStreamRef { signature: Some(Signature(93177960701f4da3fa246832b7dfd6d208b182ac8b9f1e41b5b80695ddf8fd77495b6f69664a00dfb0d40ff0984fd1c7e940adcec84b863f005d60c7ba1edbc2)) }, ExperimentalOfferTlvStreamRef, ExperimentalInvoiceRequestTlvStreamRef))
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.472276235+02:00 TRACE lndk::offers::handler - Creating invoice
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.472283695+02:00 TRACE lndk::offers::lnd_requests - Creating invoice
Oct 20 18:33:25 server lndk[3238389]: 2025-10-20T18:33:25.522886765+02:00 ERROR lndk::offers::handler - Error creating invoice: Failed to add invoice to lnd node: could not build any blinded paths

Let me know if you have any idea to fix that,
Thanks!

[a-mpch]

hello! thanks for reaching out. Seems like a LND issue. Would you be able to review the logs on LND?

[Retropex]

Sure but LND logs are not really helpful here, when I try to fetch the invoice there is just this line added in the logs:

Oct 21 10:10:03 server lnd[3236599]: 2025-10-21 10:10:03.232 [ERR] RPCS: [/lnrpc.Lightning/AddInvoice]: could not build any blinded paths

[Retropex]

I have increased the log level and here are the logs of LND:

Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.304 [DBG] RPCS: [/signrpc.Signer/DeriveSharedKey] requested
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.305 [DBG] RPCS: [/signrpc.Signer/DeriveSharedKey] requested
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.347 [DBG] DISC: Processed ChannelUpdate: peer=03e81689bfd18d0accb28d720ed222209b1a5f2c6825308772beac75b1fe35d491@46.105.76.211:9735, short_chan_id=968193655657332738, timestamp=2025-10-21 10:15:02 +0200 CEST
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.364 [DBG] RPCS: [/lnrpc.Lightning/SendCustomMessage] requested
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.364 [DBG] PEER: Peer(028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605): Sending <unknown>(type=513) to 028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605@24.125.100.114:57292
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.733 [DBG] PEER: Peer(028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605): Received <unknown>(type=513) from 028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605@24.125.100.114:57292
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.733 [DBG] SRVR: Custom message received: peer=028da2720cc25a5c0cff623b340be5d772330247ae08e11b451e6c22bddb0d7605, type=513
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.734 [DBG] RPCS: [/signrpc.Signer/DeriveSharedKey] requested
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.734 [DBG] RPCS: [/signrpc.Signer/DeriveSharedKey] requested
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.737 [DBG] RPCS: [/lnrpc.Lightning/AddInvoice] requested
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.802 [DBG] BLPT: Not using route (979900156066332672 (0 mSAT), cltv 0) as a blinded path since it resulted in an invalid blinded path
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.802 [DBG] BLPT: Not using route (979894658377383936 (0 mSAT), cltv 0) as a blinded path since it resulted in an invalid blinded path
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.802 [DBG] BLPT: Not using route (979892459371036672 (0 mSAT), cltv 0) as a blinded path since it resulted in an invalid blinded path
Oct 21 10:16:41 server lnd[735168]: 2025-10-21 10:16:41.802 [ERR] RPCS: [/lnrpc.Lightning/AddInvoice]: could not build any blinded paths

Perhaps I should patch my node with this PR lightningnetwork/lnd#10029 ?

[a-mpch]

hmm strange that LND is trying to use 0 mSAT as blinded path. Patching your node with that PR might help, but the idea was to enable amt 0 offers and pulling 0 amount invoices.

I'll test it out and will come with responses.

[Retropex]

Just retried with the patch and I get the exact same error.

[f3r10]

I did some tests using polar with the following versions: LND v0.18.4-beta LND v0.19.1-beta v25.02.2, and the results were successful.

I also did some tests using a local setup with LDN 0.19.99-beta and CLN v25.02-3, and the results were also successful.

Which versions are you using @Retropex ?

[Retropex]

Hey, I'm using LND v0.19.3-beta and core lightning v25.02

[a-mpch]

does lncli addinvoice --amt 1 --blind works on your lnd node?

[Retropex]

Yes without problem:

$ lncli addinvoice --amt 1  --blind
{
    "r_hash": "2ade7...",
    "payment_request": "lnbc10n1p5...",
    "add_index": "136",
    "payment_addr": "c54d5..."
}

[ziggie1984]

Try using that shouldn't work as well:

lncli addinvoice --amt 0  --blind

try higher amounts, maybe there is a rounding issue in LNDK

[Retropex]

tried 0, 999 and 3000 and all works

[Retropex]

Hey, is there any other way to proceed? I still cannot be paid to my bolt12 offer with lnd v0.20

[a-mpch]

Hey! @Retropex, sorry I've been MIA. On the following week I'll have time to review this. Thanks for the patience!