{"id":"27cd08e9-1822-461b-8396-3a2cb82c6786","shortId":"RsE4Pm","kind":"x402","title":"Retrieve email attachments via x402 micropayment on Base (USDC, $0.02/request).","tagline":"Retrieve email attachments via x402 micropayment on Base (USDC, $0.02/request).","description":"This endpoint at lowpaymentfee.com provides access to email attachments (specifically email ID 55) behind an x402 paywall. It accepts POST requests and returns application/json responses. Payment is settled on the Base network using USDC (contract 0x8335…2913) with a maximum cost of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals).\n\nThe endpoint is part of a broader platform at lowpaymentfee.com that offers a variety of x402-gated APIs spanning data & analytics, AI/ML inference, finance & Web3, and infrastructure utilities — all priced at $0.02 per request. The platform advertises no API keys, no rate limits, and instant access. However, the specific endpoint listed here (`/api/v1/emails/55/attachments`) is not documented on the provider's landing page among the advertised API categories, so its exact functionality and response schema are unclear.\n\nNo OpenAPI spec, detailed documentation, or example responses were found during the crawl. The docs, pricing, API, and README pages all rendered only a \"Connect wallet\" prompt with no additional content. Because of this, the precise input parameters and output format for this email-attachments endpoint remain unknown.","tags":[],"capabilities":["x402-payment","usdc-base","email-attachments","micropayment","post-endpoint"],"categories":["storage","email"],"synonyms":["email attachment API","x402 email endpoint","paid email access","Base USDC API","micropayment email","lowpaymentfee email"],"warnings":["This specific endpoint (/api/v1/emails/55/attachments) is not listed among the provider's advertised APIs on the landing page — its purpose and data source are unclear.","No OpenAPI spec or schema documentation was found; input parameters and response format are unknown.","All documentation pages (docs, pricing, API, README) returned only a 'Connect wallet' prompt with no usable content.","The endpoint path references a hardcoded email ID (55), suggesting it may be a demo or test resource rather than a general-purpose API."],"endpointUrl":"https://lowpaymentfee.com/api/v1/emails/55/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/55/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 (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no documentation, no example requests or responses, and this specific endpoint is not listed among the provider's advertised APIs. Functionality is essentially a stub.","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":"2026-04-21T19:16:19.706Z","embedding":[-0.03668213,-0.005844116,0.05340576,0.026245117,-0.0069847107,-0.05633545,-0.043395996,0.040374756,0.061676025,-0.062194824,0.018218994,-0.042785645,-0.024932861,-0.03387451,-0.043884277,-0.00017607212,0.02734375,-0.034576416,-0.036071777,0.03253174,0.052459717,-0.015640259,-0.028457642,0.0052948,-0.012023926,-0.005466461,-0.012451172,0.0007009506,-0.0008234978,-0.041168213,0.018081665,-0.028427124,-0.019454956,0.017028809,-0.03387451,0.047576904,-0.017196655,0.0340271,0.01399231,0.007030487,0.011444092,-0.021118164,0.0049934387,0.0023975372,-0.041229248,-0.00932312,0.017456055,-0.036132812,0.016494751,-0.007259369,-0.00819397,0.007003784,0.005683899,0.026107788,0.027252197,0.033325195,0.019607544,0.00088977814,-0.012863159,0.03967285,-0.017333984,-0.06188965,-0.020019531,-0.007709503,0.0026397705,0.042907715,-0.025497437,0.0423584,0.025344849,0.08227539,0.029754639,0.05404663,0.05117798,0.014419556,0.0087509155,-0.027633667,-0.0024414062,0.010612488,-0.044647217,-0.028884888,-0.0052871704,-0.020767212,-0.05279541,-0.011550903,-0.043182373,-0.04309082,-0.0036888123,0.02558899,-0.033416748,0.034057617,-0.103637695,0.0060310364,-0.002313614,-0.007911682,-0.0028495789,-0.013160706,-0.029220581,-0.0008883476,0.0038642883,0.0184021,0.009239197,-0.036315918,0.00674057,-0.018798828,0.04647827,0.011650085,0.010803223,0.017242432,0.017211914,0.0124053955,-0.01335144,-0.0026741028,-0.0154418945,0.0017366409,0.035186768,-0.0034122467,-0.025054932,0.033935547,-0.032928467,0.02935791,-0.030654907,0.05065918,0.010734558,-0.009651184,0.005378723,-0.03149414,-0.005428314,0.020324707,-0.042541504,0.004459381,0.07312012,0.024459839,0.050628662,-0.040283203,-0.019378662,0.0143585205,0.011398315,-0.017425537,-0.046875,-0.027374268,0.05255127,-0.025619507,0.015899658,0.0032997131,-0.095336914,0.008125305,-0.037597656,0.0020256042,-0.0010490417,-0.008338928,0.011482239,-0.0060043335,0.0042304993,-0.0045814514,-0.021835327,-0.03050232,-0.00065612793,0.023849487,-0.005054474,0.015930176,-0.009170532,0.0034446716,0.010055542,-0.010467529,0.013832092,0.040405273,0.01133728,-0.0637207,-0.06542969,-0.023147583,-0.00014984608,-0.010353088,-0.028381348,0.014595032,-0.010772705,-0.064941406,0.006626129,-0.013870239,-0.0018730164,-0.032409668,0.004524231,-0.034484863,0.010635376,-0.014701843,-0.06213379,-0.015327454,-0.009803772,0.07824707,0.007369995,0.020812988,0.039398193,-0.013427734,0.029067993,0.019363403,-0.017974854,-0.021514893,0.011138916,-0.0206604,0.034729004,0.002872467,-0.013687134,-0.018539429,0.038757324,0.055358887,-0.008415222,0.005252838,0.0023841858,-0.009147644,-0.012138367,-0.028396606,0.02381897,0.009735107,-0.006549835,0.03604126,-0.03729248,-0.030273438,0.016479492,0.018814087,0.017990112,0.055114746,-0.006511688,0.014122009,0.026885986,0.032165527,-0.028869629,0.033843994,0.015060425,0.012481689,-0.0047836304,-0.030685425,0.020874023,0.037628174,-0.01928711,0.019088745,-0.017501831,0.035858154,-0.008148193,-0.012626648,0.01864624,-0.012542725,-0.018310547,-0.032806396,0.0071144104,0.023880005,-0.004261017,-0.04196167,-0.04260254,-0.04260254,0.0592041,0.032684326,0.02999878,0.0049934387,-0.0052261353,-0.021224976,-0.0052948,-0.05633545,0.028045654,0.06719971,0.005809784,-0.01928711,0.043548584,-0.017593384,-0.04534912,0.010307312,0.009765625,-0.01576233,-0.015396118,0.012664795,-0.052337646,0.031402588,-0.00843811,0.05142212,0.062042236,-0.0072364807,-0.050354004,-0.000042557716,-0.023880005,-0.020706177,-0.024017334,-0.0052986145,-0.01348114,-0.013839722,0.009880066,-0.022201538,0.024765015,0.0061531067,0.01626587,-0.00018548965,0.020309448,-0.032226562,-0.023498535,-0.011260986,0.02229309,-0.055877686,-0.00541687,-0.0010595322,0.057891846,-0.05505371,0.047668457,-0.02558899,-0.005542755,0.06402588,0.012229919,-0.055267334,0.0028572083,0.011428833,0.019638062,0.053466797,0.005455017,0.0041618347,-0.017425537,0.030319214,-0.041900635,0.0049552917,0.0059280396,0.030715942,0.016189575,0.032073975,-0.039520264,-0.029510498,0.0010910034,-0.002866745,0.027740479,-0.036224365,0.05368042,0.0014104843,0.0008177757,-0.0368042,-0.031341553,-0.012626648,0.01146698,-0.02670288,0.00019478798,-0.042053223,-0.0137786865,0.027664185,0.00034618378,-0.0038814545,-0.0039787292,0.045013428,-0.0016937256,-0.0064430237,-0.009468079,-0.0151901245,-0.046447754,-0.04486084,-0.0015611649,0.0036468506,0.008956909,0.016571045,-0.026809692,0.0063934326,0.030914307,0.009124756,0.017684937,0.0066947937,0.018432617,-0.08996582,-0.01751709,-0.021896362,-0.025772095,0.016555786,0.01889038,0.010391235,0.076049805,0.0018196106,-0.033325195,-0.060821533,0.033721924,-0.05368042,0.015060425,0.04434204,-0.010894775,-0.014533997,-0.0058517456,-0.007575989,0.004096985,0.05593872,0.017440796,0.03250122,0.06585693,0.05670166,-0.01651001,-0.00046491623,0.028045654,0.0017948151,-0.020202637,-0.0098724365,-0.03717041,-0.01864624,0.021652222,-0.0009727478,-0.022399902,-0.054229736,0.03503418,0.06585693,0.07952881,0.027023315,0.017593384,-0.0032997131,-0.036590576,0.001572609,-0.023284912,-0.013069153,-0.013801575,-0.040252686,0.008056641,-0.012413025,0.026535034,-0.039886475,0.001748085,-0.0035057068,0.0061912537,-0.013519287,0.06732178,0.005630493,-0.0054740906,0.02911377,0.03186035,0.035827637,0.016204834,-0.023269653,0.032928467,0.045776367,-0.020095825,-0.016464233,0.03326416,-0.010131836,0.0067481995,-0.050476074,-0.049682617,-0.011810303,-0.048339844,-0.06573486,-0.0036468506,-0.015991211,0.050201416,0.05078125,-0.02809143,-0.046813965,0.0050239563,-0.017974854,-0.052490234,0.006881714,-0.046691895,0.019882202,0.017700195,-0.007701874,0.013191223,0.014923096,-0.012390137,-0.019317627,0.03286743,-0.014434814,0.010185242,-0.025894165,-0.0003068447,-0.03567505,0.024002075,0.008430481,0.03262329,0.014816284,0.039764404,0.0143585205,-0.0060920715,-0.02734375,-0.062408447,0.019134521,-0.04776001,0.02154541,0.044647217,-0.008811951,0.0010929108,0.0006008148,-0.013755798,-0.03765869,0.033050537,-0.062347412,-0.015586853,-0.0018405914,-0.032073975,-0.02709961,-0.06112671,-0.04574585,-0.035491943,0.07385254,0.028427124,0.01058197,-0.014480591,-0.018356323,0.01499939,0.0025596619,0.024673462,-0.01411438,-0.025985718,-0.02217102,-0.012031555,-0.041107178,-0.010940552,0.030151367,-0.023971558,-0.016799927,0.019439697,-0.000054478645,0.031555176,0.007926941,-0.009460449,0.013381958,-0.009651184,-0.00009590387,0.020431519,0.036499023,0.0124435425,-0.010955811,-0.03677368,0.027145386,-0.005847931,0.042297363,-0.021530151,-0.029403687,-0.024093628,0.022338867,0.01449585,-0.02041626,-0.010917664,0.0005865097,-0.043121338,-0.066223145,0.012184143,-0.008308411,0.039215088,0.017486572,0.014816284,0.020568848,-0.016738892,0.003921509,0.0105896,-0.039245605,-0.024398804,-0.011924744,-0.014511108,-0.013687134,0.0040626526,-0.010856628,0.020812988,-0.0118637085,0.01234436,0.014831543,0.00012516975,0.030532837,-0.013175964,0.019332886,0.029815674,0.0051078796,0.0031814575,0.029968262,0.015991211,-0.039855957,0.025054932,-0.0022201538,0.018005371,-0.012306213,0.037200928,0.04373169,-0.015792847,0.009277344,-0.00415802,-0.019836426,-0.02204895,-0.0003259182,0.018081665,0.016540527,-0.007980347,-0.041046143,0.02508545,0.03250122,-0.045196533,-0.02243042,0.009887695,0.0023899078,-0.036590576,0.022827148,0.009925842,0.038909912,-0.0070228577,-0.007911682,0.008018494,0.031982422,0.036468506,0.0011539459,0.014549255,0.01322937,0.0066566467,-0.0014867783,0.013954163,-0.006690979,0.01914978,0.0025424957,0.016906738,0.0037269592,0.005001068,-0.008491516,-0.025314331,-0.017730713,0.026992798,-0.02267456,0.03338623,0.0021514893,0.03781128,-0.013031006,0.031066895,0.035949707,-0.03982544,0.0049438477,-0.0013189316,0.05227661,0.0002579689,-0.016204834,0.01638794,0.0031108856,0.026779175,-0.062286377,-0.0042381287,0.00497818,0.03451538,-0.04019165,-0.047027588,-0.0501709,-0.018661499,0.026550293,0.005847931,0.019989014,0.026535034,-0.023223877,0.0031929016,-0.0021972656,0.015060425,-0.00032901764,-0.006816864,-0.027557373,-0.019454956,-0.00073480606,0.025650024,-0.02178955,0.006587982,0.009567261,-0.031463623,-0.0005135536,-0.04196167,0.012191772,-0.010650635,-0.0047836304,0.036315918,-0.009384155,0.0129470825,-0.025161743,-0.028503418,0.01574707,0.012390137,0.022827148,-0.03390503,0.013252258,-0.008094788,0.003030777,-0.009544373,0.0060310364,0.014160156,0.015586853,0.0060806274,0.03164673,-0.052093506,0.031585693,-0.009788513,-0.00088214874,0.006580353,-0.034301758,-0.00116539,-0.015327454,0.017837524,0.04055786,-0.008033752,-0.024902344,-0.033966064,-0.06842041,-0.011276245,-0.04727173,0.010757446,0.014717102,0.024734497,-0.026382446,0.013793945,0.00774765,-0.002161026,-0.0018196106,0.0011119843,0.018249512,0.045654297,0.032562256,0.028503418,-0.020645142,-0.029937744,-0.0017061234,-0.010894775,-0.0039024353,-0.022262573,-0.023605347,-0.0034694672,0.022750854,0.0031661987,-0.029556274,-0.010269165,-0.0020961761,-0.03277588,0.03173828,-0.0044136047,0.014556885,-0.00566864,-0.03338623,0.0062942505,0.003944397,-0.011497498,0.013931274,0.005432129,-0.009353638,-0.048065186,-0.0005059242,0.024841309,0.0028533936,0.010635376,-0.04525757,-0.0069007874,-0.02684021,-0.045288086,-0.004337311,-0.017562866,0.01361084,-0.02154541,-0.0049438477,-0.0637207,0.017730713,0.005203247,0.0033512115,0.03878784,0.02420044,0.020339966,-0.011123657,0.007698059,-0.008544922,-0.021270752,-0.041137695,0.007774353,0.010131836,-0.0044403076,0.034820557,0.0435791,0.006088257,-0.024597168,0.003479004,-0.024642944,0.0002720356,-0.00982666,0.029403687,-0.008117676,-0.00090026855,0.008621216,-0.02243042,-0.030532837,-0.0054969788,0.08081055,-0.001572609,0.020706177,0.0046081543,-0.008361816,0.02178955,0.019180298,-0.028076172,0.007537842,-0.025726318,-0.0060424805,-0.017211914,0.032836914,-0.011695862,0.010665894,-0.029785156,-0.05053711,-0.0023231506,-0.020492554,-0.012268066,-0.06298828,-0.018707275,-0.04748535,0.008834839,-0.0129852295,-0.030410767,0.013710022,0.008781433,-0.006793976,-0.06665039,0.009521484,0.0423584,-0.014663696,0.023483276,-0.00013327599,0.015960693,0.027679443,-0.010719299,-0.0040664673,0.013145447,-0.05001831,-0.016967773,-0.03765869,0.03829956,0.0005373955,-0.012550354,0.03213501,0.0013790131,0.005104065,-0.02748108,0.013427734,-0.0026302338,-0.005290985,-0.028121948,-0.0053977966,-0.014511108,0.012252808,0.062347412,-0.032165527,0.026550293,-0.008522034,-0.009231567,0.005706787,0.026321411,0.040985107,-0.03277588,0.019683838,0.006126404,0.004085541,0.040039062,-0.03781128,0.030685425,0.023864746,-0.014816284,0.0184021,0.011711121,-0.03262329,-0.028961182,-0.016525269,0.034576416,-0.00806427,0.017059326,-0.0070991516,0.008522034,-0.029968262,0.01890564,0.015533447,0.011451721,-0.01398468,-0.029403687,-0.020751953,0.015151978,0.005558014,-0.0058631897,0.021362305,0.017242432,0.036254883,-0.021133423,-0.021438599,0.006088257,0.024841309,0.017074585,-0.0065994263,0.032470703,-0.0044670105,0.004901886,0.018035889,0.012420654,-0.028762817,-0.008125305,-0.019882202,-0.006565094,0.0045547485,-0.023910522,0.013801575,0.0034770966,0.0023117065,-0.0060691833,-0.010009766,0.0071792603,-0.020736694,-0.014854431,-0.012756348,-0.014480591,0.032318115,0.0024795532,0.004463196,0.03225708,0.004573822,0.044403076,0.01361084,-0.01625061,0.032348633,0.036376953,-0.0030937195,-0.025299072,-0.0069007874,0.0041503906,0.0032691956,0.0056266785,-0.019042969,0.0059509277,0.035858154,-0.014663696,0.012756348,0.0018701553,0.014442444,-0.01739502,-0.00021386147,-0.008598328,0.035827637,0.013870239,0.01574707,-0.047576904,0.029144287,0.0008597374,-0.009002686,0.00844574,-0.017837524,-0.012145996,0.03277588,0.014945984,-0.014312744,0.035461426,-0.01234436,0.052368164,-0.016082764,-0.026062012,0.029144287,-0.011299133,-0.024002075,0.024917603,0.0034599304,0.0003042221,0.014625549,-0.03213501,0.04196167,-0.016921997,-0.006954193,-0.014266968,-0.0064735413,-0.026550293,-0.022232056,0.0070495605,-0.014442444,-0.028717041,-0.0072288513,-0.002002716,0.048339844,0.029067993,0.027786255,0.01928711,0.028198242,0.0001385212,-0.034423828,-0.053253174,0.0060653687,0.0029754639,0.026321411,-0.0037193298,0.039794922,0.06317139,0.010536194,0.016693115,0.024520874,0.040222168,0.005027771,0.026123047,-0.030654907,0.01991272,-0.010398865,-0.0074920654,0.00705719,0.046081543,-0.008178711,0.0010700226,-0.012634277,0.03363037,-0.03152466,0.036132812,0.077819824,0.0023860931,0.0070495605,0.018875122,-0.006465912,-0.058135986,0.013175964,-0.025802612,0.04953003,0.019927979,0.05050659,0.056793213,0.013305664,-0.003780365,0.0116119385,-0.018981934,-0.016448975,0.03161621,0.027511597,-0.006965637,-0.002746582,-0.029632568,-0.00052547455,-0.034088135,-0.022613525,0.0035858154,0.008277893,-0.002105713,0.0024051666,0.0049476624,0.0045776367,0.033843994,0.014480591,-0.007736206,0.018218994,0.03274536,0.022994995,0.012016296,0.036315918,-0.014533997,0.022964478,-0.030426025,-0.026428223,-0.006793976,0.0012407303,-0.008842468,-0.028656006,0.027832031,0.004207611,0.039855957,0.035308838,-0.0053100586,0.018005371,0.013755798,-0.008399963,0.01600647,0.039489746,0.014793396,-0.0048980713,0.030349731,0.024307251,0.022384644,0.015289307,0.01927185,0.0027542114,-0.011634827,-0.004348755,0.00283432,0.022384644,-0.00037407875,0.02180481,-0.000351429,-0.008636475,0.010192871,0.03616333,0.00034499168,0.009277344,-0.0050086975,0.017837524,-0.0077171326,0.012306213,-0.0036525726,-0.018981934,0.03842163,0.02458191,0.047180176,-0.0064926147,0.020019531,-0.0043258667,-0.028533936,-0.021026611,0.0074539185,-0.038635254,0.013031006,0.0043792725,-0.025100708,-0.039642334,0.026763916,0.0020980835,-0.01184845,0.041656494,0.0317688,-0.015914917,0.0031967163,0.030456543,0.003118515,-0.005504608,0.010177612,-0.018722534,0.013389587,0.04486084,0.018356323,-0.0004298687,-0.029754639,-0.009239197,0.012611389,0.0049858093,-0.019622803,0.0047721863,-0.005191803,-0.02482605,0.024841309,0.009117126,0.014556885,0.020385742,-0.021026611,-0.0036468506,0.013725281,0.024795532,0.0042495728,-0.015060425,-0.01953125,0.024765015,-0.0064430237,0.032104492,0.041625977,-0.0015563965,0.021255493,-0.0037231445,-0.006000519,-0.008903503,-0.007118225,0.02154541,-0.022125244,0.0034885406,-0.019744873,0.025543213,-0.018493652,-0.011734009,-0.007965088,-0.0064582825,-0.020812988,-0.0011730194,0.025894165,0.012184143,0.025878906,0.030914307,0.012214661,-0.026046753,0.05859375,-0.029937744,0.04119873,-0.02331543,0.020050049,0.05834961,0.05014038,0.037200928,-0.01033783,0.023483276,-0.032043457,0.0009946823,0.043914795,0.02319336,0.02557373,-0.009994507,-0.020385742,0.03451538,-0.0037269592,0.03793335,-0.04156494,0.00010114908,0.013404846,-0.023117065,-0.016983032,-0.00022435188,-0.0044898987,0.011764526,0.02760315,-0.036499023,-0.005428314,-0.010856628,-0.015571594,0.01512146,-0.022094727,-0.015098572,-0.002254486,-0.02142334,0.0069351196,0.0010032654,0.0014247894,0.016799927,0.0236969,-0.028198242,-0.023132324,0.0063438416,0.022109985,-0.013832092,0.0309906,0.039855957,0.007030487,0.031463623,0.030090332,-0.010116577,0.025268555,-0.009346008,0.020385742,0.044891357,0.0072021484,-0.009750366,0.028945923,0.0030555725,-0.029678345,0.019866943,0.052764893,-0.0022888184,0.0152282715,0.0036334991,0.013702393,-0.003768921,0.005104065,-0.02470398,-0.004425049,-0.011817932,-0.03591919,0.008575439,0.028579712,-0.011657715,0.0006017685,0.0039596558,-0.014343262,0.008399963,0.03933716,0.040924072,-0.046783447,-0.008918762,0.005050659,-0.015045166,-0.012161255,-0.0058898926,-0.009399414,-0.04296875,0.01979065,0.033599854,0.0035495758,0.028427124,-0.014518738,-0.019927979,0.02330017,0.014831543,0.010299683,-0.010070801,-0.009300232,0.008407593,-0.027145386,0.011138916,-0.013343811,-0.008880615,0.010055542,0.030761719,-0.007221222,-0.0385437,0.023284912,-0.017868042,0.0010843277,-0.009925842,0.0042304993,0.021942139,0.001458168,-0.005001068,-0.0003798008,0.002986908,-0.012260437,-0.0146484375,-0.016036987,-0.008369446,0.047302246,-0.00007742643,-0.0048217773,0.022766113,0.049682617,0.0151901245,0.032287598,0.004257202,0.053710938,0.010055542,-0.015060425,-0.039978027,0.00019133091,-0.033599854,-0.015731812,0.0143966675,-0.049041748,-0.024124146,0.012908936,-0.0023937225,-0.019454956,-0.023910522,0.0016288757,-0.008155823,-0.013023376,0.0345459,-0.010009766,0.005847931,-0.007144928,0.015686035,0.022644043,-0.020263672,-0.052947998,-0.003604889,-0.0075416565,-0.028656006,-0.06210327,0.024902344,-0.023391724,-0.0036811829,-0.014907837,0.0032577515,0.007297516,0.020339966,-0.013557434,-0.0043678284,-0.018539429,0.033203125,0.0046081543,0.0043754578,0.015548706,-0.03050232,-0.055114746,-0.025253296,-0.018753052,-0.023117065,0.031677246,0.002702713,0.018981934,0.0262146,-0.017028809,-0.0016784668,-0.008018494,-0.0033569336,-0.009292603,-0.0069465637,-0.043060303,0.009475708,0.04260254,-0.005001068,0.0034923553,0.039642334,-0.012702942,-0.017715454,0.018920898,0.03805542,0.007446289,0.0181427,0.010253906,-0.0039749146,-0.013069153,-0.006011963,-0.017440796,0.012748718,0.005870819,0.0025901794,-0.006580353,0.027038574,0.021102905,-0.008758545,0.011497498,0.016815186,-0.006500244,-0.012382507,0.015838623,0.017959595,0.0031814575,0.0009717941,-0.014533997,0.0041999817,0.061279297,0.026992798,0.008148193,-0.0030059814,0.0035762787,-0.026779175,-0.00274086,0.012191772,-0.023529053,-0.03161621,-0.016204834,-0.021560669,-0.0011205673,-0.010932922,0.009849548,0.0006928444,0.030303955,-0.0023956299,-0.048309326,-0.005809784,0.050476074,0.0067481995,-0.018005371,-0.010467529,0.0025634766,0.008529663,-0.034240723,-0.003835678,-0.045288086,-0.03527832,0.0010662079,-0.012107849,0.010574341,0.00024604797,-0.013969421,0.0022792816,0.007484436,-0.025344849,0.01058197,0.018508911,-0.02268982,0.00466156,0.005203247,0.025650024,-0.011779785,0.0057678223,-0.010215759,0.0037612915,-0.0079574585,-0.01739502,0.02973938,-0.021240234,0.011383057,0.013534546,-0.0012712479,0.01852417,0.0067367554,0.0046157837,-0.035583496,-0.0004222393,0.008666992,-0.013648987,0.026351929,-0.011833191,-0.02470398,-0.015731812,-0.021530151,-0.04486084,0.018417358,0.02911377,0.016311646,-0.005142212,0.038024902,-0.043395996,0.00081920624,-0.009155273,0.01499939,-0.033203125,-0.017349243,0.024261475,-0.019622803,0.001080513,-0.015625,0.0036754608,-0.020111084,-0.020690918,0.008071899,0.004257202,0.0032577515,0.024276733,0.024047852,0.03955078,0.010055542,0.021896362,0.003528595,-0.0024909973,0.020309448,-0.001502037,0.04611206,-0.032928467,-0.027526855,-0.0067100525,0.009674072,-0.003643036,-0.0062446594,0.0019435883,-0.01965332,-0.031921387,0.0073242188,-0.008781433,0.029678345,-0.00094127655,0.020751953,-0.015792847,-0.004234314,-0.021469116,-0.01121521,-0.032928467,0.014160156,0.03125,0.02507019,-0.0066947937,-0.026550293,-0.032440186,0.026473999,0.008621216,0.014198303,-0.041168213,-0.029846191,0.00447464,0.0003066063,0.0011415482,0.013442993,-0.03842163,-0.0072021484,0.0009403229,0.0020313263,0.0024261475,0.008880615,0.017120361,-0.006313324,-0.008880615,0.0026130676,0.029937744,-0.014762878,-0.0010509491,-0.018661499,-0.0154953,0.041809082,0.006160736,-0.023605347,0.019042969,0.03253174,-0.032409668,0.050323486,-0.011222839,-0.0018844604,-0.008956909,0.0020942688,-0.041656494,-0.0055732727,0.009643555,-0.0018119812],"createdAt":"2026-04-21T18:32:12.269Z","updatedAt":"2026-04-22T02:31:50.457Z","lastSeenAt":"2026-04-22T02:31:50.457Z","tsv":"'/api/v1/emails/55/attachments':131 '/request':11,22 '0.02':10,21,71,110 '000':66 '0x8335':58 '20':65 '2913':59 '55':35 '6':76 'Base USDC API' 'accept':41 'access':28,124 'addit':184 'advertis':115,143 'ai/ml':100 'among':141 'analyt':99 'api':96,117,144,171 'application/json':46 'attach':3,14,31,200 'base':8,19,53,67 'behind':36 'broader':84 'categori':145 'connect':179 'content':185 'contract':57 'cost':63 'crawl':167 'data':98 'decim':77 'detail':158 'doc':169 'document':134,159 'email':2,13,30,33,199 'email attachment API' 'email-attach':198 'email-attachments' 'endpoint':24,79,128,201 'equal':70 'exact':148 'exampl':161 'financ':102 'format':195 'found':164 'function':149 'gate':95 'howev':125 'id':34 'infer':101 'infrastructur':105 'input':191 'instant':123 'key':118 'land':139 'limit':121 'list':129 'lowpaymentfee email' 'lowpaymentfee.com':26,87 'maximum':62 'micropay':6,17 'micropayment' 'micropayment email' 'network':54 'offer':89 'openapi':156 'output':194 'page':140,174 'paid email access' 'paramet':192 'part':81 'payment':48 'paywal':39 'per':72,111 'platform':85,114 'post':42 'post-endpoint' 'precis':190 'price':108,170 'prompt':181 'provid':27,137 'rate':120 'readm':173 'remain':202 'render':176 'request':43,73,112 'respons':47,151,162 'retriev':1,12 'return':45 'schema':152 'settl':50 'span':97 'spec':157 'specif':32,127 'unclear':154 'unit':68 'unknown':203 'usdc':9,20,56,74 'usdc-base' 'use':55,75 'util':106 'varieti':91 'via':4,15 'wallet':180 'web3':103 'x402':5,16,38,94 'x402 email endpoint' 'x402-gated':93 'x402-payment'","prices":[{"id":"d0a7c9e3-917b-4eab-968f-e3b46b456536","listingId":"27cd08e9-1822-461b-8396-3a2cb82c6786","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/55/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":"2026-04-21T18:32:12.269Z"}],"sources":[{"listingId":"27cd08e9-1822-461b-8396-3a2cb82c6786","source":"x402_bazaar","sourceId":"https://lowpaymentfee.com/api/v1/emails/55/attachments","sourceUrl":"https://api.cdp.coinbase.com/platform/v2/x402/discovery/resources","isPrimary":true,"firstSeenAt":"2026-04-21T18:32:12.269Z","lastSeenAt":"2026-04-22T02:31:50.457Z"}],"details":{"listingId":"27cd08e9-1822-461b-8396-3a2cb82c6786","quickStartSnippet":"curl -X POST https://lowpaymentfee.com/api/v1/emails/55/attachments \\\n  -H \"X-PAYMENT: <x402-payment-header>\" \\\n  -H \"Content-Type: application/json\"","exampleRequest":null,"exampleResponse":null,"schema":{"input":{"type":"http","method":"GET","discoverable":true}},"openapiUrl":null,"agentsTxtUrl":null,"citations":[{"claim":"The x402 challenge returns maxAmountRequired of 20,000 base units in USDC on Base network","source_url":"https://lowpaymentfee.com/api/v1/emails/55/attachments"},{"claim":"The platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant access","source_url":"https://lowpaymentfee.com"},{"claim":"USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base","source_url":"https://lowpaymentfee.com/api/v1/emails/55/attachments"}],"useCases":["Programmatically retrieving email attachments behind a paywall","Agent-driven access to stored email data with per-request USDC payment","Integrating email attachment retrieval into automated workflows without API keys"],"bestFor":["Agents needing on-demand email attachment access with no subscription","Developers experimenting with x402 micropayment protocols on Base","Low-volume, pay-per-use email data retrieval"],"notFor":["Bulk email processing requiring high throughput and predictable pricing","Users who need detailed API documentation and response schemas before integrating","Non-crypto users who cannot settle payments in USDC on Base"],"kindDetails":{"x402_version":1,"resource_type":"http","bazaar_last_updated":"2026-02-17T23:13:21.003Z"},"updatedAt":"2026-04-22T02:31:50.457Z"}}