{"id":"3ad5d589-8ad1-4a69-bc88-5c63392b0db9","shortId":"T3jQJT","kind":"x402","title":"Retrieve email attachments via x402 micropayment on Base for $0.02 per request.","tagline":"Retrieve email attachments via x402 micropayment on Base for $0.02 per request.","description":"This endpoint at lowpaymentfee.com provides access to email attachments (specifically email ID 63) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled in USDC on the Base network at $0.02 per call (maxAmountRequired of 20,000 base units with 6 decimals = $0.02), with no API keys, rate limits, or subscriptions required.\n\nThe provider lowpaymentfee.com hosts a broader suite of x402-gated APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance and crypto market data, and infrastructure utilities — all priced at $0.02 per request. However, this specific listing covers only the `/api/v1/emails/63/attachments` endpoint. The exact nature of the email data served (whether it is sample/demo data or a real mailbox) is not documented, and the provider's docs, pricing, and API pages are essentially empty beyond a wallet-connect prompt. The endpoint is confirmed live via a valid x402 402 challenge.","tags":[],"capabilities":["x402-payment","email-attachments","usdc-base","micropayment","post-json"],"categories":["data","email"],"synonyms":["email attachment API","x402 email endpoint","pay-per-request email","Base USDC API","lowpaymentfee email","micropayment email access"],"warnings":["No API documentation available — docs, pricing, and API pages only show a wallet-connect prompt","Endpoint is scoped to a single hardcoded email ID (63); unclear what data is returned","No request body schema or response schema documented","Provider appears to be a demo/showcase site for x402 protocol; data authenticity is unknown"],"endpointUrl":"https://lowpaymentfee.com/api/v1/emails/63/attachments","protocol":"x402","transport":"http","auth":{"type":"x402","details":[{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","extra":{"name":"USD Coin","version":"2"},"payTo":"0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3","scheme":"exact","network":"base","mimeType":"application/json","resource":"https://lowpaymentfee.com/api/v1/emails/63/attachments","description":"Premium API Access","outputSchema":{"input":{"type":"http","method":"GET","discoverable":true}},"maxAmountRequired":"20000","maxTimeoutSeconds":300}]},"qualityScore":"0.300","qualityRationale":"The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI schema, no request/response documentation, no examples, and the docs pages are empty. The purpose of the email attachments endpoint is unclear — it references a hardcoded email ID 63 with no explanation. This is effectively a stub listing.","verified":false,"liveness":"unknown","lastLivenessCheck":null,"agentReviews":{"count":0,"score_avg":null,"cost_usd_avg":null,"success_rate":null,"latency_p50_ms":null,"narrative_summary":null,"summary_updated_at":null},"enrichmentModel":"anthropic/claude-opus-4.6","enrichmentVersion":2,"enrichedAt":"2026-04-21T19:17:54.005Z","embedding":[-0.03366089,-0.013000488,0.061676025,0.020309448,0.004699707,-0.05596924,-0.03161621,0.046081543,0.06021118,-0.07952881,0.03564453,-0.037017822,-0.027908325,-0.02670288,-0.03744507,0.008323669,0.02848816,-0.039215088,-0.043518066,0.028640747,0.04269409,-0.007419586,-0.02658081,0.008842468,-0.0030937195,-0.008506775,-0.01537323,-0.0005531311,0.002746582,-0.05102539,0.0184021,-0.02053833,-0.017288208,0.019378662,-0.030441284,0.0473938,-0.035186768,0.035308838,0.010726929,-0.0002708435,0.0132751465,-0.028793335,0.016311646,0.013748169,-0.030456543,-0.017349243,0.02178955,-0.03253174,0.01361084,-0.0066566467,-0.018447876,0.010757446,0.012840271,0.0023231506,0.021194458,0.03024292,0.014976501,0.009162903,-0.008232117,0.02696228,-0.007785797,-0.06689453,-0.023345947,0.00017523766,-0.0010871887,0.046813965,-0.022979736,0.044006348,0.017456055,0.1015625,0.02658081,0.052368164,0.059570312,0.0013990402,0.0075912476,-0.03353882,-0.00044083595,0.017593384,-0.03945923,-0.030899048,0.0058631897,-0.013465881,-0.04449463,0.01852417,-0.03567505,-0.043945312,-0.00004965067,0.033935547,-0.028335571,0.038085938,-0.093322754,-0.0045051575,-0.014419556,-0.010055542,0.007858276,-0.004081726,-0.02645874,-0.0047721863,0.0051193237,0.0007443428,0.003162384,-0.03439331,-0.00019919872,-0.018707275,0.039886475,0.022399902,0.02015686,0.016036987,0.009803772,0.01348114,-0.017364502,-0.0032463074,-0.009689331,-0.008773804,0.034210205,0.0011377335,-0.013458252,0.03277588,-0.033203125,0.017089844,-0.030303955,0.04949951,0.018737793,-0.0090789795,0.015686035,-0.037994385,-0.018127441,0.009048462,-0.027877808,0.003665924,0.06695557,0.023773193,0.0725708,-0.042938232,-0.029556274,0.006095886,0.02458191,-0.022537231,-0.0496521,-0.024353027,0.04876709,-0.031066895,0.0058174133,0.006511688,-0.075683594,0.012527466,-0.05255127,-0.00018596649,0.004547119,0.0017347336,0.014030457,-0.012413025,-0.000957489,0.0002734661,-0.024246216,-0.018127441,0.0006837845,0.028335571,-0.016967773,0.0140686035,-0.015792847,0.0058021545,0.02784729,-0.022033691,0.012260437,0.041748047,0.0017662048,-0.061035156,-0.06640625,-0.029296875,0.0011749268,-0.01386261,-0.016296387,0.012893677,-0.005115509,-0.07196045,0.004825592,-0.0010633469,0.008216858,-0.032592773,0.0005221367,-0.045196533,0.011810303,-0.001991272,-0.050628662,-0.009468079,-0.005821228,0.078430176,0.0043754578,0.015457153,0.04522705,-0.01222229,0.028869629,0.039886475,-0.01966858,-0.015930176,0.022583008,-0.015525818,0.022705078,0.017608643,-0.010421753,-0.016479492,0.03314209,0.051696777,-0.01739502,-0.0039100647,0.0056152344,-0.016784668,-0.013328552,-0.017654419,0.028335571,0.001168251,-0.00096940994,0.029937744,-0.037506104,-0.026351929,0.0054855347,0.0062675476,0.01826477,0.06060791,-0.01121521,0.0028038025,0.03439331,0.027999878,-0.028945923,0.023391724,0.018951416,0.0073623657,-0.00856781,-0.029830933,0.024749756,0.027496338,-0.01663208,0.027008057,-0.013801575,0.036895752,-0.018981934,-0.008880615,0.01889038,-0.0008792877,-0.02507019,-0.03326416,0.008270264,0.022003174,-0.0064048767,-0.037994385,-0.045440674,-0.04135132,0.06298828,0.031829834,0.013404846,-0.0030097961,-0.014633179,-0.03237915,-0.0040283203,-0.060760498,0.027389526,0.06994629,0.0023956299,-0.017242432,0.046905518,-0.006427765,-0.05041504,0.011894226,0.020767212,-0.021118164,-0.013458252,0.018081665,-0.05041504,0.024047852,0.008483887,0.040771484,0.05444336,-0.00157547,-0.038757324,0.005882263,-0.015151978,-0.03213501,-0.020217896,0.011245728,-0.009529114,-0.00299263,0.023422241,-0.032806396,0.022460938,0.0016107559,0.024932861,-0.0045814514,0.02168274,-0.041992188,-0.0104904175,-0.0074310303,0.022277832,-0.057373047,0.0064849854,-0.017303467,0.046661377,-0.0574646,0.033935547,-0.02331543,0.0028686523,0.06137085,0.022018433,-0.05444336,-0.007160187,0.016082764,0.013954163,0.057739258,0.0014657974,-0.0023097992,-0.010040283,0.039001465,-0.041809082,0.003829956,0.0074691772,0.024002075,0.008872986,0.03753662,-0.029571533,-0.030090332,0.010681152,-0.005241394,0.023620605,-0.040100098,0.044281006,-0.0026798248,0.010620117,-0.03717041,-0.010009766,-0.01876831,-0.0053253174,-0.010566711,0.0061187744,-0.037963867,-0.0127334595,0.02986145,0.014701843,-0.0010967255,-0.008888245,0.044952393,-0.009498596,-0.010253906,-0.023849487,-0.030593872,-0.03564453,-0.053009033,0.007575989,0.012229919,0.017318726,0.014167786,-0.041992188,0.002319336,0.03845215,0.0047798157,0.022109985,0.007171631,0.021270752,-0.08630371,-0.0051345825,-0.023376465,-0.018066406,0.025863647,0.042877197,0.011779785,0.07824707,0.005836487,-0.043640137,-0.054779053,0.03024292,-0.048614502,0.024291992,0.03753662,-0.007209778,-0.0064048767,-0.008842468,-0.01134491,0.018722534,0.055145264,0.02053833,0.021575928,0.05596924,0.0501709,-0.013267517,-0.0069389343,0.018432617,0.0027751923,-0.017868042,-0.004196167,-0.030410767,-0.015686035,0.026229858,-0.00096940994,-0.01713562,-0.048858643,0.043395996,0.07104492,0.07373047,0.030563354,0.011390686,-0.0090789795,-0.04562378,0.004562378,-0.023895264,-0.02909851,-0.015960693,-0.04849243,0.012939453,-0.012435913,0.030303955,-0.04827881,-0.0048179626,-0.0037975311,0.006816864,-0.005924225,0.047912598,0.011154175,-0.0025138855,0.029785156,0.025970459,0.02784729,0.008888245,-0.036224365,0.029403687,0.036834717,-0.020690918,-0.011909485,0.03555298,-0.009422302,-0.0047454834,-0.046875,-0.052612305,-0.01058197,-0.059814453,-0.068481445,-0.0066566467,-0.030303955,0.03869629,0.041870117,-0.029144287,-0.050079346,-0.00013649464,-0.007865906,-0.061645508,0.009933472,-0.03955078,0.011962891,0.011909485,-0.018447876,0.017822266,0.015533447,-0.011772156,-0.014205933,0.028945923,-0.014671326,0.00970459,-0.031341553,0.00831604,-0.02960205,0.015472412,0.0049552917,0.03074646,0.024673462,0.03488159,0.012329102,-0.0015192032,-0.023254395,-0.058532715,0.01272583,-0.047058105,0.021896362,0.04107666,-0.0012569427,-0.0018482208,0.013420105,-0.019195557,-0.03237915,0.031677246,-0.06781006,-0.017944336,0.006134033,-0.027236938,-0.017745972,-0.06768799,-0.042907715,-0.0496521,0.059814453,0.029342651,0.0067100525,-0.012878418,-0.011390686,0.015670776,0.0014228821,0.024841309,-0.013671875,-0.014305115,-0.0110321045,-0.011207581,-0.036224365,-0.0043258667,0.024734497,-0.02607727,-0.021575928,0.014480591,-0.006011963,0.031143188,0.006893158,-0.012489319,0.011833191,0.0029296875,0.015960693,0.021896362,0.03778076,0.027389526,-0.012924194,-0.035705566,0.030593872,0.0050086975,0.0513916,-0.027648926,-0.02822876,-0.011474609,0.024154663,0.013290405,-0.02130127,-0.008460999,-0.006969452,-0.035308838,-0.07946777,0.011024475,-0.020858765,0.03717041,0.014030457,0.016952515,0.017715454,-0.019180298,0.011962891,0.010429382,-0.044952393,-0.023834229,-0.0121154785,-0.01852417,0.0016613007,0.00056791306,-0.009468079,0.023223877,-0.01133728,0.0010309219,0.008476257,-0.011657715,0.028884888,-0.0098724365,0.011077881,0.02520752,0.0047302246,0.0012140274,0.029251099,0.018417358,-0.031921387,0.0259552,-0.0044822693,0.023620605,-0.008392334,0.043945312,0.049224854,-0.004272461,-0.0005760193,0.0060272217,-0.02078247,-0.021530151,0.0036811829,0.024246216,0.02357483,-0.015472412,-0.045806885,0.010726929,0.035064697,-0.03491211,-0.020324707,-0.004585266,0.004760742,-0.042297363,0.020095825,-0.0008072853,0.028945923,-0.0051078796,-0.0018529892,-0.00032162666,0.031677246,0.037475586,-0.0048599243,0.008132935,0.014533997,0.005622864,-0.013389587,0.022109985,-0.0066947937,0.025115967,0.006729126,0.014915466,-0.0036334991,0.0018901825,-0.0008172989,-0.024414062,0.00409317,0.023590088,-0.00315094,0.031951904,0.0034332275,0.039489746,-0.012290955,0.019210815,0.024749756,-0.03918457,0.00447464,-0.006942749,0.045684814,0.013504028,-0.014152527,0.019226074,0.011009216,0.019714355,-0.060272217,-0.013557434,-0.002527237,0.024658203,-0.042419434,-0.038848877,-0.051757812,-0.017608643,0.021484375,-0.0021038055,0.020812988,0.03186035,-0.019332886,0.003522873,-0.0062942505,0.017837524,-0.003484726,-0.00242424,-0.04446411,-0.013710022,-0.0041656494,0.020477295,-0.02998352,0.013130188,0.0019292831,-0.026611328,-0.0030117035,-0.030014038,0.00084114075,-0.009490967,-0.0072669983,0.032928467,-0.0065956116,0.014633179,-0.03010559,-0.03048706,0.00630188,0.009513855,0.021514893,-0.03982544,0.008224487,-0.010925293,0.007221222,-0.008323669,-0.0054473877,0.01083374,0.008705139,-0.009788513,0.02835083,-0.050994873,0.030914307,-0.013977051,0.001739502,-0.0010023117,-0.03366089,-0.0011692047,-0.024612427,0.021881104,0.036468506,-0.006565094,-0.034301758,-0.034362793,-0.0635376,-0.00894928,-0.04876709,-0.0026855469,0.017868042,0.017532349,-0.03201294,0.013572693,0.012321472,0.004459381,-0.0055122375,-0.00415802,0.015258789,0.0357666,0.0317688,0.019104004,-0.027450562,-0.025650024,-0.0044059753,-0.013153076,-0.008308411,-0.019683838,-0.021896362,-0.0033359528,0.023849487,0.002090454,-0.031555176,-0.011367798,-0.008743286,-0.017089844,0.041900635,-0.011024475,0.006111145,-0.0055122375,-0.03237915,0.004722595,0.0010070801,-0.010223389,0.01626587,0.0158844,-0.013076782,-0.041870117,0.008872986,0.019485474,0.0031871796,0.009017944,-0.055541992,-0.008880615,-0.027420044,-0.045135498,-0.01108551,-0.006664276,0.017471313,-0.020553589,0.00705719,-0.059051514,0.01020813,-0.00065374374,0.003824234,0.035369873,0.026535034,0.016860962,-0.0043640137,0.015357971,-0.020584106,-0.012527466,-0.040039062,0.0065307617,0.00983429,0.003364563,0.03503418,0.03793335,0.0004248619,-0.03555298,-0.0004608631,-0.012031555,0.00274086,-0.0072402954,0.026809692,-0.016479492,0.0076789856,0.0041770935,-0.017242432,-0.034729004,-0.01171875,0.08148193,-0.00042796135,0.0024738312,0.016281128,-0.0024280548,0.016647339,0.020736694,-0.015304565,0.011550903,-0.0116119385,-0.0063934326,-0.012191772,0.022369385,-0.006538391,0.010147095,-0.027572632,-0.051940918,-0.0031757355,-0.02281189,-0.024749756,-0.06640625,-0.017166138,-0.047576904,0.0041236877,-0.024597168,-0.03036499,0.01007843,0.0032730103,-0.0021953583,-0.064941406,0.013343811,0.04623413,-0.015838623,0.036621094,0.005645752,0.01285553,0.026306152,-0.0056495667,-0.00422287,0.015548706,-0.053710938,-0.013153076,-0.029785156,0.036254883,0.0028953552,-0.012916565,0.022705078,-0.0034122467,0.014434814,-0.019256592,0.016296387,-0.0062942505,0.004360199,-0.010826111,0.0055122375,-0.017318726,0.021224976,0.043273926,-0.02684021,0.01953125,-0.029220581,-0.006790161,0.01159668,0.018951416,0.05267334,-0.030136108,0.024383545,0.0032367706,-0.0019083023,0.035125732,-0.030944824,0.03503418,0.021102905,-0.017349243,0.017059326,0.005252838,-0.038604736,-0.0158844,-0.02217102,0.030914307,-0.005378723,0.010032654,-0.0027122498,0.012130737,-0.027755737,0.026992798,0.009162903,0.012763977,-0.013801575,-0.028717041,-0.012863159,0.0070533752,0.006088257,-0.0059394836,0.0151901245,0.019180298,0.0385437,-0.011810303,-0.017242432,-0.00091552734,0.018585205,0.011436462,-0.010536194,0.03326416,-0.006664276,0.008514404,0.028152466,0.0036392212,-0.03604126,-0.024108887,-0.023727417,-0.009849548,-0.0016107559,-0.022598267,0.010421753,0.013343811,-0.0043029785,-0.0056648254,-0.0071640015,0.0051612854,-0.028717041,-0.013923645,-0.009994507,-0.0028038025,0.04034424,0.0046806335,0.0042304993,0.03086853,0.009857178,0.048706055,0.008621216,-0.014434814,0.031951904,0.041137695,-0.0046691895,-0.03161621,-0.008583069,0.0048561096,-0.007411957,0.012031555,-0.026123047,0.005214691,0.037475586,-0.010070801,0.011024475,0.011558533,0.021942139,-0.020736694,0.0021305084,-0.0119018555,0.03302002,0.011795044,0.009147644,-0.05154419,0.024414062,-0.006958008,-0.011108398,-0.002981186,-0.024230957,-0.016098022,0.035095215,0.015090942,0.0004851818,0.033966064,-0.0060157776,0.043304443,-0.012245178,-0.016845703,0.028533936,-0.011550903,-0.025024414,0.02861023,0.013595581,-0.008483887,0.010971069,-0.017929077,0.049926758,-0.01096344,-0.0056495667,-0.0037765503,-0.01663208,-0.027038574,-0.025756836,0.0047302246,-0.018066406,-0.020553589,-0.002073288,-0.0033836365,0.043182373,0.034301758,0.032226562,0.033294678,0.018112183,-0.012519836,-0.040527344,-0.061279297,0.008811951,-0.0013237,0.027542114,-0.0023002625,0.048980713,0.070739746,0.0065078735,0.013381958,0.016082764,0.035369873,0.013389587,0.01260376,-0.043884277,0.017089844,-0.016738892,-0.013420105,0.00049877167,0.04916382,-0.015068054,-0.0044517517,-0.007911682,0.02128601,-0.019638062,0.02607727,0.06500244,0.004722595,0.0048294067,0.016189575,-0.009307861,-0.056518555,0.007858276,-0.02835083,0.047546387,0.0236969,0.04034424,0.05895996,0.017288208,-0.0048599243,0.018920898,-0.02243042,-0.023773193,0.036590576,0.034240723,-0.017028809,-0.009208679,-0.035491943,0.006084442,-0.04248047,-0.021072388,0.01436615,0.011604309,0.008926392,0.007972717,-0.008888245,0.011604309,0.038085938,0.028182983,-0.005760193,0.007827759,0.023956299,0.0206604,0.013595581,0.039764404,-0.008773804,0.02420044,-0.033935547,-0.021026611,-0.008140564,-0.008392334,-0.007671356,-0.027145386,0.025772095,0.0054473877,0.034484863,0.04095459,-0.012634277,0.02078247,0.016433716,-0.0028476715,0.028182983,0.046966553,0.0082473755,0.0023479462,0.028457642,0.027008057,0.012298584,0.008605957,0.0035037994,0.0053634644,-0.018234253,0.0042381287,-0.0030708313,0.015914917,0.0007314682,0.024642944,-0.007610321,-0.003900528,0.010635376,0.026306152,0.000029027462,0.014633179,0.002855301,0.016082764,-0.005569458,0.015090942,0.008544922,-0.024154663,0.034454346,0.018508911,0.04937744,-0.0029239655,0.0071144104,-0.0044174194,-0.028915405,-0.023895264,0.008491516,-0.03869629,0.018554688,0.006538391,-0.030258179,-0.041534424,0.020431519,0.012626648,-0.015792847,0.04144287,0.025024414,-0.024169922,-0.0003004074,0.031066895,0.00415802,-0.0075531006,0.0079422,-0.01737976,0.008094788,0.051757812,0.031433105,0.009674072,-0.035858154,-0.010604858,0.004425049,0.007827759,-0.020584106,0.0062561035,-0.0016832352,-0.00015354156,0.023269653,0.0040245056,0.010650635,0.023010254,-0.021102905,-0.0008354187,0.012542725,0.018234253,0.008720398,-0.010238647,-0.013961792,0.027038574,-0.002878189,0.02407837,0.04119873,0.0013875961,0.022872925,0.006587982,-0.0008416176,-0.0067863464,-0.010177612,0.017623901,-0.022140503,0.0068855286,-0.01802063,0.030792236,-0.016418457,0.0019245148,-0.016036987,-0.0001269579,-0.019348145,-0.004501343,0.024383545,0.008476257,0.02619934,0.028961182,0.008781433,-0.03640747,0.061798096,-0.035827637,0.035339355,-0.023025513,0.013763428,0.066101074,0.03955078,0.038391113,-0.0103302,0.027038574,-0.03704834,-0.0011034012,0.04437256,0.018737793,0.02633667,-0.0007967949,-0.02053833,0.037750244,-0.009712219,0.043273926,-0.040863037,0.00034475327,0.0059890747,-0.021469116,-0.018951416,0.00035572052,0.004386902,0.006664276,0.018417358,-0.03250122,-0.0082473755,-0.016281128,-0.013954163,0.009468079,-0.022216797,-0.01626587,-0.010910034,-0.02330017,0.001742363,-0.0011548996,-0.0031986237,0.027618408,0.02319336,-0.033935547,-0.015068054,0.004638672,0.030532837,-0.018310547,0.022140503,0.03845215,0.007659912,0.025634766,0.03173828,-0.01121521,0.023849487,-0.00774765,0.022598267,0.048919678,-0.012229919,-0.0044021606,0.017684937,0.0021076202,-0.017807007,0.010871887,0.045562744,0.0009212494,0.006225586,-0.00053310394,0.017349243,0.0024719238,0.018478394,-0.02848816,0.0026550293,-0.010383606,-0.031204224,-0.0024280548,0.027389526,-0.007133484,0.002872467,-0.005596161,-0.0010919571,0.013092041,0.036621094,0.047332764,-0.04550171,-0.0025196075,-0.0011234283,-0.018371582,-0.0042419434,-0.012390137,-0.009597778,-0.041534424,0.018569946,0.03010559,0.0065689087,0.028915405,-0.021972656,-0.009094238,0.021972656,0.012916565,0.00308609,-0.010795593,-0.014778137,0.014533997,-0.020690918,0.0037136078,-0.016983032,-0.009712219,0.012283325,0.029022217,-0.012451172,-0.039520264,0.019760132,-0.02381897,0.0075912476,-0.0209198,0.0041770935,0.025543213,0.0070343018,-0.00088214874,0.0036392212,0.009109497,-0.0064315796,-0.008544922,-0.008666992,0.0027046204,0.056427002,0.0000011920929,0.0010261536,0.0158844,0.040283203,0.018173218,0.038360596,0.004047394,0.050842285,0.011741638,-0.022720337,-0.03729248,0.0121154785,-0.027267456,-0.011817932,0.017364502,-0.039886475,-0.018035889,0.01235199,-0.0032787323,-0.021270752,-0.017211914,0.008880615,-0.022613525,-0.012786865,0.0317688,-0.015090942,0.0021762848,-0.0023937225,0.019119263,0.021438599,-0.030593872,-0.05508423,-0.0029258728,-0.0050315857,-0.027618408,-0.06530762,0.023468018,-0.026779175,-0.0068855286,-0.013671875,-0.00007349253,0.010574341,0.027908325,-0.019638062,-0.00025749207,-0.011566162,0.01977539,0.015731812,0.0016708374,0.022644043,-0.03552246,-0.052856445,-0.027999878,-0.022354126,-0.0149383545,0.04574585,0.008430481,0.024093628,0.020584106,-0.016159058,-0.0015926361,-0.010528564,-0.00016152859,-0.010688782,-0.016296387,-0.04537964,0.0053138733,0.046813965,-0.011932373,0.01020813,0.046203613,-0.007522583,-0.022094727,0.013328552,0.0335083,0.0051002502,0.02017212,0.0055007935,-0.013328552,-0.0031013489,-0.0053901672,-0.00894165,0.010627747,0.014762878,-0.0010166168,-0.010574341,0.01878357,0.023590088,-0.0044784546,0.017074585,0.016799927,-0.0017137527,-0.023117065,0.02281189,0.01927185,0.0068626404,0.00020885468,-0.009513855,-0.0049476624,0.06384277,0.040771484,0.012901306,-0.00970459,0.008087158,-0.022262573,0.007904053,0.011497498,-0.02178955,-0.022949219,-0.011878967,-0.027160645,0.00089645386,-0.013809204,0.013572693,0.0031776428,0.041900635,0.00085783005,-0.051574707,-0.009094238,0.04574585,0.012809753,-0.019195557,-0.008491516,0.014556885,0.0065574646,-0.032562256,-0.005558014,-0.045715332,-0.034606934,-0.0067329407,0.0041007996,0.017486572,0.0027942657,-0.013389587,0.0103302,0.014511108,-0.02166748,0.009246826,0.018737793,-0.023101807,-0.0005106926,-0.0016469955,0.02230835,-0.013633728,0.004196167,-0.00283432,-0.00041532516,-0.016723633,-0.01928711,0.020141602,-0.017684937,0.017715454,0.007736206,0.0014925003,0.014015198,0.006931305,0.0010976791,-0.04095459,0.006061554,0.016693115,-0.013809204,0.027679443,-0.013175964,-0.025146484,-0.013771057,-0.022750854,-0.03845215,0.013824463,0.021530151,0.018096924,-0.0012331009,0.035949707,-0.047698975,0.0090789795,-0.008308411,0.012275696,-0.021484375,-0.0132369995,0.022140503,-0.020568848,-0.0028591156,-0.018737793,-0.005744934,-0.028762817,-0.016937256,0.005393982,0.004825592,0.0014467239,0.0340271,0.025527954,0.03793335,0.007820129,0.020080566,-0.001493454,0.0045433044,0.019699097,-0.004699707,0.033081055,-0.031402588,-0.028640747,-0.01914978,0.0022087097,-0.00548172,-0.008857727,0.0009074211,-0.01838684,-0.028152466,-0.0010309219,-0.010520935,0.03125,-0.0082473755,0.019958496,-0.024215698,-0.006477356,-0.025100708,-0.0119018555,-0.03955078,0.010513306,0.018875122,0.027618408,-0.005317688,-0.022720337,-0.029251099,0.024734497,0.0031661987,0.01663208,-0.04876709,-0.037963867,0.0035820007,0.011199951,0.000007987022,0.020553589,-0.030639648,-0.007888794,0.0082092285,0.005443573,0.008872986,0.009254456,0.008132935,0.00074243546,-0.01222229,-0.0021247864,0.033081055,-0.025878906,-0.0061302185,-0.023544312,-0.007648468,0.038726807,0.010299683,-0.019607544,0.025405884,0.02960205,-0.041809082,0.052612305,-0.019012451,-0.002653122,-0.0014543533,0.0051956177,-0.038208008,-0.011398315,0.016906738,0.006587982],"createdAt":"2026-04-21T18:32:12.541Z","updatedAt":"2026-04-22T05:31:59.700Z","lastSeenAt":"2026-04-22T05:31:59.700Z","tsv":"'/api/v1/emails/63/attachments':125 '0.02':10,22,60,72,115 '000':66 '20':65 '402':174 '6':70 '63':37 'Base USDC API' 'accept':44 'access':30 'ai/ml':97 'analysi':100 'analyt':96 'api':75,93,154 'attach':3,15,33 'base':8,20,57,67 'behind':38 'beyond':159 'broader':87 'call':62 'challeng':175 'classif':102 'confirm':168 'connect':163 'cover':122 'crypto':106 'data':95,108,133,139 'decim':71 'doc':151 'document':146 'email':2,14,32,35,132 'email attachment API' 'email-attachments' 'embed':103 'empti':158 'endpoint':26,43,126,166 'essenti':157 'exact':128 'financ':104 'gate':92 'host':85 'howev':118 'id':36 'infer':98 'infrastructur':110 'json':49 'key':76 'limit':78 'list':121 'live':169 'lowpaymentfee email' 'lowpaymentfee.com':28,84 'mailbox':143 'market':107 'maxamountrequir':63 'micropay':6,18 'micropayment' 'micropayment email access' 'natur':129 'network':58 'page':155 'pay-per-request email' 'payment':50 'paywal':41 'per':11,23,61,116 'post':45 'post-json' 'price':113,152 'prompt':164 'provid':29,83,149 'rate':77 'real':142 'request':12,24,46,117 'requir':81 'retriev':1,13 'return':48 'sample/demo':138 'sentiment':99 'serv':134 'settl':52 'span':94 'specif':34,120 'subscript':80 'suit':88 'summar':101 'unit':68 'usdc':54 'usdc-base' 'util':111 'valid':172 'via':4,16,170 'wallet':162 'wallet-connect':161 'whether':135 'x402':5,17,40,91,173 'x402 email endpoint' 'x402-gated':90 'x402-payment'","prices":[{"id":"33665d59-0e58-41d4-9ce5-6813f81e4d9e","listingId":"3ad5d589-8ad1-4a69-bc88-5c63392b0db9","amountUsd":null,"unit":"per_call","nativeCurrency":"USD COIN","nativeAmount":"20000","chain":"base","payTo":"0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3","paymentMethod":"x402-usd coin","isPrimary":true,"details":{"scheme":"exact","mime_type":"application/json","accepts_all":[{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","extra":{"name":"USD Coin","version":"2"},"payTo":"0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3","scheme":"exact","network":"base","mimeType":"application/json","resource":"https://lowpaymentfee.com/api/v1/emails/63/attachments","description":"Premium API Access","outputSchema":{"input":{"type":"http","method":"GET","discoverable":true}},"maxAmountRequired":"20000","maxTimeoutSeconds":300}],"asset_contract":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","max_timeout_seconds":300},"createdAt":"2026-04-21T18:32:12.541Z"}],"sources":[{"listingId":"3ad5d589-8ad1-4a69-bc88-5c63392b0db9","source":"x402_bazaar","sourceId":"https://lowpaymentfee.com/api/v1/emails/63/attachments","sourceUrl":"https://api.cdp.coinbase.com/platform/v2/x402/discovery/resources","isPrimary":true,"firstSeenAt":"2026-04-21T18:32:12.541Z","lastSeenAt":"2026-04-22T05:31:59.700Z"}],"details":{"listingId":"3ad5d589-8ad1-4a69-bc88-5c63392b0db9","quickStartSnippet":"curl -X POST https://lowpaymentfee.com/api/v1/emails/63/attachments \\\n  -H \"Content-Type: application/json\" \\\n  -H \"X-PAYMENT: <x402-payment-token>\"","exampleRequest":null,"exampleResponse":null,"schema":{"input":{"type":"http","method":"GET","discoverable":true}},"openapiUrl":null,"agentsTxtUrl":null,"citations":[{"claim":"The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 in USDC on Base","source_url":"https://lowpaymentfee.com/api/v1/emails/63/attachments"},{"claim":"All APIs on lowpaymentfee.com are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base network","source_url":"https://lowpaymentfee.com"},{"claim":"USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","source_url":"https://lowpaymentfee.com/api/v1/emails/63/attachments"}],"useCases":["Retrieving email attachments programmatically with per-call micropayments","Integrating email data retrieval into agent workflows without API key management","Demonstrating x402 payment protocol usage on Base network"],"bestFor":["Agents needing one-off email attachment retrieval without subscription overhead","Developers experimenting with x402 protocol integrations","Workflows requiring keyless, pay-per-use API access"],"notFor":["Bulk email processing or high-volume mailbox access","Users who need documented request/response schemas before integrating","Anyone needing access to arbitrary email IDs (this endpoint is scoped to email 63)"],"kindDetails":{"x402_version":1,"resource_type":"http","bazaar_last_updated":"2026-02-17T23:13:20.628Z"},"updatedAt":"2026-04-22T05:31:59.700Z"}}