{"id":"7baf7de5-6b4b-4609-bd54-36dc73f13efd","shortId":"qkFbKa","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 98) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled in USDC on the Base network using the x402 \"exact\" scheme, with a maximum cost of $0.02 per request (20,000 base units of USDC with 6 decimals).\n\nThe provider lowpaymentfee.com hosts a broader suite of pay-per-call APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/crypto data feeds, and utility services — all priced at $0.02 per request with no API keys, no rate limits, and no commitments. However, this specific listing covers only the `/api/v1/emails/98/attachments` endpoint, whose exact response schema and attachment content are not documented in the available crawl material.\n\nBecause the endpoint path is hardcoded to a specific email ID (98), it is unclear whether this is a general-purpose email attachment retrieval service or a single static resource. No OpenAPI spec, request/response examples, or detailed documentation were found. The docs, API, pricing, and README pages all returned only a \"Connect wallet\" prompt with no substantive content.","tags":[],"capabilities":["x402-payment","usdc-base","email-attachments","pay-per-request","json-response"],"categories":["data","email"],"synonyms":["email attachment API","x402 email endpoint","pay-per-call email","micropayment attachment retrieval","Base USDC API","lowpaymentfee email"],"warnings":["No OpenAPI or schema documentation available — request body and response format are unknown.","Endpoint path is hardcoded to email ID 98; unclear if this generalizes to other email IDs.","All documentation pages (docs, API, pricing, README) returned only 'Connect wallet' with no content.","The email attachments endpoint is not listed on the provider's own homepage among their advertised APIs.","Response content and attachment format are completely undocumented."],"endpointUrl":"https://lowpaymentfee.com/api/v1/emails/98/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/98/attachments","description":"Premium API Access","outputSchema":{"input":{"type":"http","method":"GET","discoverable":true}},"maxAmountRequired":"20000","maxTimeoutSeconds":300}]},"qualityScore":"0.250","qualityRationale":"The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the endpoint path is hardcoded to a single email ID with no explanation of what it returns. 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":"2026-04-21T19:23:24.259Z","embedding":[-0.035736084,-0.0070762634,0.058898926,0.022964478,0.00055646896,-0.05480957,-0.032104492,0.047027588,0.06378174,-0.0680542,0.014709473,-0.042755127,-0.007911682,-0.033477783,-0.032226562,-0.0070610046,0.033721924,-0.04611206,-0.037078857,0.022384644,0.04598999,-0.02079773,-0.039154053,0.0031909943,-0.0034809113,-0.007858276,-0.016189575,0.009140015,-0.00017559528,-0.051086426,0.020477295,-0.02659607,-0.017181396,0.01084137,-0.027740479,0.04425049,-0.021697998,0.027175903,0.021240234,0.010383606,0.009773254,-0.019851685,0.022888184,0.013885498,-0.04006958,-0.011199951,0.024246216,-0.03302002,0.01914978,0.0014438629,-0.010650635,0.009407043,0.0022792816,0.008598328,0.008293152,0.026824951,0.017456055,0.008125305,-0.023925781,0.038604736,-0.016586304,-0.06774902,-0.023635864,-0.01713562,0.0005378723,0.045959473,-0.02861023,0.03250122,0.021362305,0.08392334,0.027175903,0.058685303,0.052978516,0.010627747,0.016479492,-0.024475098,0.002231598,0.018310547,-0.03741455,-0.031799316,0.0028495789,-0.009338379,-0.04486084,0.009536743,-0.04525757,-0.03164673,-0.0009813309,0.033691406,-0.025939941,0.036987305,-0.0993042,0.0064926147,-0.0149383545,-0.016540527,0.0044136047,-0.006942749,-0.023208618,-0.0015621185,0.003353119,0.0061073303,0.0024147034,-0.03665161,0.002872467,-0.018035889,0.041992188,0.022079468,0.008728027,0.009338379,0.014503479,0.0014858246,-0.0045394897,0.0027675629,-0.015686035,0.00053071976,0.038604736,0.00043034554,-0.03881836,0.035369873,-0.03463745,0.023895264,-0.030517578,0.04840088,0.009002686,-0.004600525,0.011795044,-0.03302002,-0.015655518,0.022659302,-0.03866577,-0.004295349,0.07299805,0.019973755,0.04788208,-0.03717041,-0.013809204,-0.00036144257,0.010307312,-0.017059326,-0.052215576,-0.022628784,0.051483154,-0.02809143,0.0070381165,0.0078048706,-0.082214355,0.010307312,-0.03942871,-0.008468628,-0.01134491,-0.00573349,-0.0010881424,-0.014846802,0.009056091,0.0010242462,-0.019546509,-0.02885437,-0.0014839172,0.016159058,-0.012886047,0.024002075,-0.02192688,0.00749588,0.021957397,-0.010345459,0.021057129,0.039978027,0.0070762634,-0.06451416,-0.06463623,-0.019226074,0.0014648438,-0.015052795,-0.026473999,0.011528015,-0.01084137,-0.05432129,0.009918213,-0.005794525,0.0009613037,-0.037261963,0.0046157837,-0.042755127,0.0032672882,-0.0053482056,-0.05432129,-0.01499176,-0.0065345764,0.07208252,0.008712769,0.02330017,0.039123535,-0.015823364,0.03451538,0.015525818,-0.024276733,-0.016952515,0.016983032,-0.016937256,0.021987915,-0.0021953583,-0.0178833,-0.011909485,0.039916992,0.0524292,-0.017623901,0.004623413,-0.001572609,-0.009361267,-0.011993408,-0.025909424,0.032073975,0.0069732666,0.0019006729,0.028930664,-0.02809143,-0.041137695,0.008323669,0.018478394,0.00920105,0.047576904,-0.008682251,0.007904053,0.02960205,0.032287598,-0.03604126,0.029083252,0.014122009,0.01210022,-0.009513855,-0.0284729,0.02078247,0.03869629,-0.01335907,0.016494751,-0.023254395,0.040374756,-0.021484375,-0.0038928986,0.015296936,-0.012237549,-0.0317688,-0.027236938,0.0075263977,0.02418518,-0.009399414,-0.039764404,-0.044891357,-0.047058105,0.0635376,0.026947021,0.028320312,0.0023956299,-0.012924194,-0.02911377,-0.0074691772,-0.04928589,0.026855469,0.07635498,0.008148193,-0.0074806213,0.048675537,-0.010536194,-0.03994751,0.009849548,0.0127334595,-0.020584106,-0.017593384,0.010765076,-0.064819336,0.029571533,-0.0038928986,0.053131104,0.06323242,-0.0039787292,-0.051116943,0.0044441223,-0.027542114,-0.03652954,-0.022232056,0.004295349,-0.018051147,-0.0062217712,0.012329102,-0.026641846,0.023223877,0.009063721,0.0149383545,0.012161255,0.016067505,-0.044006348,-0.02519226,-0.014076233,0.01939392,-0.057678223,-0.0015449524,-0.0061836243,0.060150146,-0.04473877,0.043548584,-0.030761719,-0.0065994263,0.05340576,0.018844604,-0.049438477,0.0029945374,0.008018494,0.014801025,0.059814453,-0.0035533905,0.001748085,-0.020431519,0.04168701,-0.05279541,0.007774353,0.009216309,0.0149383545,0.015960693,0.027175903,-0.027282715,-0.03112793,0.0064697266,-0.01751709,0.025222778,-0.03451538,0.048095703,-0.002878189,-0.0032920837,-0.036224365,-0.019378662,-0.010574341,0.012924194,-0.013031006,0.012138367,-0.03781128,-0.013771057,0.023666382,0.012779236,0.00035071373,-0.0038013458,0.03866577,0.0033016205,-0.004638672,-0.018417358,-0.039886475,-0.038024902,-0.046875,0.0074882507,0.009300232,0.0075149536,0.021087646,-0.030670166,0.009094238,0.034484863,0.006954193,0.0158844,0.006526947,0.01398468,-0.09820557,-0.01890564,-0.029006958,-0.023147583,0.011619568,0.038909912,0.008171082,0.07128906,-0.0006752014,-0.03805542,-0.064575195,0.030151367,-0.05142212,0.018371582,0.03970337,-0.0069351196,-0.015075684,-0.009712219,-0.00440979,-0.00052785873,0.06542969,0.012748718,0.03567505,0.06732178,0.050323486,-0.011878967,-0.0043640137,0.030151367,-0.0023021698,-0.01474762,-0.009254456,-0.027694702,-0.015335083,0.0234375,-0.0020942688,-0.020217896,-0.059753418,0.036346436,0.06964111,0.0725708,0.019927979,0.013031006,0.0007305145,-0.028274536,-0.001953125,-0.02204895,-0.01474762,-0.01461792,-0.0440979,0.012252808,-0.015548706,0.029373169,-0.032165527,0.0048065186,-0.0014305115,0.0073928833,-0.007949829,0.059661865,0.012825012,0.0061950684,0.02999878,0.031463623,0.037322998,0.020080566,-0.028198242,0.04446411,0.046020508,-0.03543091,-0.008384705,0.03894043,-0.011383057,0.000051379204,-0.048431396,-0.039611816,-0.010498047,-0.050231934,-0.066589355,-0.009208679,-0.022598267,0.039245605,0.05203247,-0.023010254,-0.048583984,0.0030670166,-0.0068588257,-0.06323242,0.012672424,-0.037902832,0.012504578,0.010627747,-0.008506775,0.018798828,0.015129089,-0.01612854,-0.014289856,0.02355957,-0.009506226,0.020614624,-0.020202637,0.00093126297,-0.026412964,0.011352539,0.004371643,0.043823242,0.015319824,0.036499023,0.016906738,0.0013380051,-0.030258179,-0.0592041,0.017486572,-0.05105591,0.019424438,0.041381836,-0.0129470825,0.0011091232,-0.000854969,-0.015510559,-0.031921387,0.024810791,-0.056915283,-0.015258789,-0.0034809113,-0.021133423,-0.025787354,-0.056152344,-0.048065186,-0.042755127,0.06890869,0.029220581,0.011871338,-0.018966675,-0.009292603,0.010978699,0.0046310425,0.03161621,-0.013465881,-0.020706177,-0.008728027,-0.005996704,-0.03213501,-0.015930176,0.032440186,-0.03125,-0.012573242,0.023666382,0.0022125244,0.02482605,0.009094238,0.0008406639,0.013717651,-0.012825012,0.0058898926,0.024093628,0.034698486,0.02168274,-0.012145996,-0.026947021,0.020614624,-0.0020332336,0.04458618,-0.02293396,-0.031585693,-0.011703491,0.01864624,0.020004272,-0.014953613,-0.00945282,0.0020198822,-0.046844482,-0.07147217,0.020324707,-0.015899658,0.04107666,0.02104187,0.018096924,0.021759033,-0.025039673,0.010528564,0.013069153,-0.032684326,-0.030899048,-0.011116028,-0.026550293,-0.011604309,0.00063705444,-0.00894928,0.027664185,-0.016235352,0.0065841675,0.0104599,-0.008666992,0.02557373,-0.014198303,0.014770508,0.019317627,0.005420685,0.00289917,0.030593872,0.025878906,-0.042144775,0.03125,-0.009361267,0.019851685,-0.010154724,0.033081055,0.052947998,-0.019226074,-0.0022850037,-0.00093460083,-0.024963379,-0.017578125,0.0019025803,0.026367188,0.02168274,-0.015563965,-0.04119873,0.02230835,0.024612427,-0.045806885,-0.02557373,0.007385254,-0.0021343231,-0.034362793,0.02305603,0.00554657,0.032836914,-0.008651733,-0.0018224716,0.009849548,0.03164673,0.037109375,-0.011360168,0.007133484,0.014762878,0.004901886,-0.008628845,0.014465332,0.0050849915,0.019042969,0.010498047,0.02168274,0.0023269653,-0.0031414032,-0.0062446594,-0.030761719,-0.0041542053,0.026107788,-0.017715454,0.032073975,0.0030021667,0.044830322,-0.012878418,0.025802612,0.022018433,-0.04397583,-0.00020182133,-0.0014715195,0.05996704,-0.0039749146,-0.023422241,0.014709473,0.015144348,0.023208618,-0.0670166,-0.007659912,0.0017127991,0.026550293,-0.04434204,-0.03390503,-0.04864502,-0.012504578,0.02281189,0.01260376,0.016067505,0.02809143,-0.021362305,0.008003235,0.0013465881,0.009246826,-0.0014600754,-0.0019512177,-0.028167725,-0.017364502,0.0008468628,0.029449463,-0.023406982,0.011184692,0.009490967,-0.0262146,0.00063467026,-0.0289917,0.0008778572,-0.006828308,-0.002401352,0.03253174,0.00010973215,0.012184143,-0.033691406,-0.026565552,0.015640259,0.0055122375,0.025802612,-0.045959473,0.011070251,-0.0058517456,0.010375977,-0.00078725815,0.004371643,0.01373291,0.011474609,0.0079193115,0.032440186,-0.055419922,0.034484863,-0.020477295,-0.0033626556,0.0075263977,-0.027694702,0.005428314,-0.011260986,0.014007568,0.042297363,-0.009307861,-0.03302002,-0.023025513,-0.06842041,-0.009124756,-0.046020508,0.010154724,0.026977539,0.02519226,-0.022277832,0.012023926,0.0034427643,-0.0004901886,-0.00605011,0.0013904572,0.0104599,0.03982544,0.028808594,0.022750854,-0.020370483,-0.026519775,-0.009246826,-0.008781433,-0.0076026917,-0.016204834,-0.018539429,-0.0038146973,0.023452759,-0.0002527237,-0.033325195,-0.008811951,0.0023956299,-0.02243042,0.03366089,-0.0030117035,0.008018494,-0.012840271,-0.03213501,0.010528564,0.0032100677,-0.009399414,0.02243042,0.0082473755,-0.013549805,-0.044433594,0.0027923584,0.0149002075,0.005168915,0.008079529,-0.04107666,-0.010498047,-0.03314209,-0.045410156,-0.009513855,-0.0129776,0.008666992,-0.020629883,0.00050115585,-0.064575195,0.017181396,0.0015268326,0.0059165955,0.037872314,0.023132324,0.02267456,-0.0110321045,0.010925293,-0.021759033,-0.016143799,-0.03829956,0.020492554,0.01007843,0.0020561218,0.036590576,0.03515625,0.0020446777,-0.024047852,0.0042266846,-0.017303467,0.011444092,-0.010398865,0.018127441,-0.018753052,0.005554199,0.0049362183,-0.011299133,-0.033813477,-0.0048561096,0.08081055,0.0014562607,0.0040130615,0.01928711,-0.015945435,0.018234253,0.015510559,-0.020812988,0.009689331,-0.022521973,-0.0047798157,-0.012794495,0.02394104,-0.017822266,0.01878357,-0.02885437,-0.046875,-0.0031414032,-0.024963379,-0.018234253,-0.062438965,-0.01878357,-0.046081543,0.003080368,-0.013809204,-0.03491211,0.015319824,0.005962372,-0.0012388229,-0.07092285,0.006828308,0.034362793,-0.015838623,0.027511597,0.00459671,0.014343262,0.02923584,-0.016159058,-0.0034236908,0.0044288635,-0.039367676,-0.014877319,-0.03665161,0.03378296,0.007106781,-0.016311646,0.03173828,-0.0071372986,0.008491516,-0.031829834,0.018035889,-0.0044822693,-0.00063467026,-0.019302368,0.0008788109,-0.016784668,0.0129776,0.05569458,-0.028839111,0.02748108,-0.0077552795,-0.005340576,0.012794495,0.025878906,0.05142212,-0.032562256,0.016830444,0.008346558,0.0054969788,0.035614014,-0.03137207,0.029754639,0.030136108,-0.021453857,0.025222778,0.0107803345,-0.029464722,-0.028198242,-0.01436615,0.029830933,-0.00957489,0.011962891,-0.010566711,0.0051994324,-0.03805542,0.016830444,0.010681152,0.0068092346,-0.015533447,-0.036499023,-0.024047852,0.01789856,0.0026626587,-0.0087509155,0.016815186,0.0110321045,0.041259766,-0.011566162,-0.017791748,-0.0004131794,0.01763916,0.008522034,-0.0026187897,0.03741455,-0.0027160645,0.0065994263,0.021331787,0.006580353,-0.030136108,-0.010421753,-0.0284729,-0.0047416687,-0.004295349,-0.031463623,0.005367279,0.006526947,0.0046424866,-0.0029296875,-0.0012264252,0.005012512,-0.030258179,-0.002904892,-0.021942139,-0.009994507,0.036132812,-0.0019874573,-0.0006761551,0.041107178,0.005592346,0.045532227,0.014770508,-0.01878357,0.029006958,0.035491943,0.0056991577,-0.028305054,-0.009590149,0.006504059,0.00025057793,0.0044555664,-0.0236969,0.0050201416,0.041931152,-0.012023926,0.000033318996,0.009361267,0.02558899,-0.024307251,0.010116577,-0.007835388,0.03692627,0.012283325,0.00944519,-0.05419922,0.023498535,-0.0008845329,0.0018835068,0.012390137,-0.022201538,-0.016845703,0.042266846,0.02178955,-0.0066566467,0.036834717,-0.0121536255,0.046966553,-0.014350891,-0.03845215,0.0287323,-0.015449524,-0.02633667,0.034362793,0.0087509155,-0.000910759,0.015716553,-0.037597656,0.052581787,-0.0119018555,-0.0099487305,-0.014884949,-0.014595032,-0.022247314,-0.0289917,0.0020389557,-0.016662598,-0.024902344,-0.012672424,0.0011959076,0.043182373,0.02571106,0.025131226,0.034454346,0.017974854,-0.00011265278,-0.034210205,-0.05480957,0.0030612946,0.006450653,0.028076172,-0.0017414093,0.05026245,0.06347656,0.0075187683,0.0234375,0.017196655,0.03475952,0.0055160522,0.018096924,-0.03994751,0.014877319,-0.012710571,-0.0033302307,0.006629944,0.045684814,-0.0132751465,0.0016202927,-0.00006490946,0.027862549,-0.02861023,0.035827637,0.06842041,-0.002653122,0.0034732819,0.015129089,-0.0036830902,-0.059387207,0.0029850006,-0.029754639,0.051208496,0.017807007,0.05267334,0.06347656,0.017288208,-0.008728027,0.014656067,-0.022613525,-0.019058228,0.03604126,0.031204224,-0.019012451,-0.013092041,-0.03314209,0.0006542206,-0.04486084,-0.028244019,0.010299683,0.010368347,-0.0032539368,0.006134033,0.00090169907,0.007411957,0.030410767,0.022659302,-0.007118225,0.008399963,0.035705566,0.024398804,0.008506775,0.032073975,-0.02482605,0.021118164,-0.022598267,-0.032073975,0.00067281723,-0.0012197495,-0.01133728,-0.039154053,0.021591187,0.0014753342,0.042633057,0.03451538,-0.0030441284,0.02659607,0.013809204,-0.0033855438,0.019744873,0.056854248,0.010482788,-0.004714966,0.03479004,0.011306763,0.026931763,0.0065078735,0.013832092,0.013336182,-0.0124435425,-0.00036478043,0.0044898987,0.019241333,-0.005970001,0.01689148,-0.0068092346,-0.011070251,0.010284424,0.03479004,-0.0010671616,0.003282547,-0.010978699,0.011459351,-0.016464233,0.009292603,0.0005364418,-0.015602112,0.04046631,0.017593384,0.045806885,-0.00242424,0.014198303,-0.005428314,-0.022369385,-0.01953125,0.0028705597,-0.035217285,0.014732361,0.0043678284,-0.019836426,-0.04244995,0.026367188,0.006603241,-0.0138168335,0.04550171,0.026901245,-0.021606445,0.0047035217,0.032470703,0.002922058,-0.0074882507,0.0050964355,-0.017913818,0.015014648,0.044006348,0.023376465,0.0019454956,-0.031066895,-0.005622864,0.0070762634,0.0042533875,-0.021377563,0.00065231323,-0.002281189,-0.012710571,0.021377563,0.00023257732,0.017028809,0.022003174,-0.019470215,-0.00080394745,0.012718201,0.019958496,0.0054016113,-0.011054993,-0.015090942,0.018341064,-0.0011692047,0.022018433,0.03756714,0.0012273788,0.021530151,-0.004562378,-0.0131073,-0.0071640015,-0.005290985,0.027175903,-0.025115967,0.0021762848,-0.01436615,0.03656006,-0.014457703,-0.016326904,-0.0068130493,-0.005760193,-0.017105103,-0.004333496,0.02758789,0.012489319,0.021835327,0.028762817,0.015434265,-0.03189087,0.05404663,-0.025848389,0.050598145,-0.02885437,0.012901306,0.064331055,0.04458618,0.040222168,-0.00737381,0.023468018,-0.039031982,0.0018196106,0.051513672,0.02268982,0.026824951,-0.010040283,-0.02670288,0.0390625,-0.0087890625,0.040130615,-0.045806885,0.0027427673,0.010925293,-0.023025513,-0.008544922,-0.00013840199,0.0018310547,0.010063171,0.025268555,-0.025497437,-0.008094788,-0.006877899,-0.02394104,0.0064735413,-0.022598267,-0.01890564,0.0026950836,-0.025039673,0.0037631989,-0.0011959076,-0.00097084045,0.023895264,0.02017212,-0.025115967,-0.011734009,0.00062322617,0.019454956,-0.013702393,0.033203125,0.043518066,0.007041931,0.028076172,0.03164673,-0.016082764,0.024215698,-0.007457733,0.01210022,0.04675293,0.0090789795,-0.0032463074,0.022369385,0.009979248,-0.024124146,0.012168884,0.045288086,-0.0047721863,0.005897522,-0.0015068054,0.021148682,-0.009307861,0.010139465,-0.021072388,0.0019321442,-0.006580353,-0.027664185,0.00081682205,0.025482178,-0.012031555,0.007987976,-0.0067710876,-0.0036067963,0.011543274,0.037109375,0.03930664,-0.03363037,-0.009780884,-0.0024051666,-0.01852417,-0.0075912476,-0.009506226,-0.0110321045,-0.04055786,0.01939392,0.030899048,0.008399963,0.029678345,-0.011390686,-0.022216797,0.015396118,0.013145447,0.0028190613,-0.009124756,-0.0063552856,0.010543823,-0.020004272,0.006427765,-0.011489868,-0.008178711,0.005592346,0.030563354,-0.0068511963,-0.03945923,0.013336182,-0.026901245,0.0024642944,-0.012130737,-0.0017175674,0.025497437,0.0051345825,-0.0043411255,0.0046043396,0.00016796589,-0.011520386,-0.008766174,-0.010856628,-0.0010700226,0.0440979,-0.0009741783,0.0010156631,0.020935059,0.05532837,0.01725769,0.037506104,0.0031661987,0.055480957,0.013084412,-0.016616821,-0.031021118,0.0071640015,-0.031799316,-0.017547607,0.015151978,-0.03918457,-0.019882202,0.013870239,0.004421234,-0.018157959,-0.021224976,0.004524231,-0.012825012,-0.0045280457,0.038391113,-0.009559631,0.00049877167,0.0004811287,0.022232056,0.016296387,-0.030944824,-0.060150146,0.0005412102,-0.009529114,-0.024887085,-0.056030273,0.012565613,-0.022994995,0.00017368793,-0.01687622,-0.0036239624,0.00084638596,0.022720337,-0.019515991,-0.008842468,-0.013465881,0.02180481,0.0109939575,0.0028972626,0.020309448,-0.033081055,-0.05038452,-0.030059814,-0.016067505,-0.016342163,0.034698486,-0.00027012825,0.021133423,0.026977539,-0.021224976,0.0018749237,-0.009162903,-0.0032081604,-0.010383606,-0.011421204,-0.047027588,0.010971069,0.042785645,-0.0069236755,-0.0013837814,0.04928589,-0.012001038,-0.020065308,0.01789856,0.039855957,0.009674072,0.008865356,0.008422852,-0.013618469,-0.0010881424,-0.0012311935,-0.011917114,0.009063721,0.012901306,0.0025100708,-0.010375977,0.02305603,0.015533447,-0.0037670135,0.009971619,0.012184143,-0.0048713684,-0.004940033,0.017074585,0.017654419,0.00617218,-0.0004799366,-0.0096206665,-0.010597229,0.0625,0.032684326,0.016311646,-0.005252838,-0.00072050095,-0.012863159,0.0009059906,0.011520386,-0.01826477,-0.039398193,-0.019210815,-0.022857666,-0.0015144348,-0.0076293945,0.011810303,0.0067443848,0.031921387,-0.0008583069,-0.053588867,-0.014671326,0.049346924,0.00592041,-0.024856567,-0.014442444,0.0053100586,0.0044517517,-0.037902832,-0.006450653,-0.043548584,-0.041381836,0.0069999695,-0.0011110306,0.004322052,0.008323669,-0.01499176,0.0056419373,0.01687622,-0.021118164,0.0071525574,0.018341064,-0.026321411,0.0018310547,0.0037250519,0.025024414,-0.014694214,0.0029754639,-0.005153656,0.008323669,-0.009635925,-0.02067566,0.023773193,-0.022521973,0.018157959,0.010688782,0.008522034,0.017486572,0.0087509155,-0.0023860931,-0.037353516,-0.0024261475,0.008918762,-0.013717651,0.03338623,-0.021072388,-0.031585693,-0.009567261,-0.030914307,-0.042022705,0.011657715,0.019500732,0.008605957,-0.006465912,0.032226562,-0.041992188,0.002166748,-0.013969421,0.005458832,-0.035949707,-0.020614624,0.018569946,-0.019332886,0.0019760132,-0.022064209,-0.006210327,-0.026321411,-0.01687622,0.0104522705,0.008071899,-0.0028152466,0.022338867,0.025039673,0.047180176,0.00945282,0.017166138,0.0019245148,-0.0034866333,0.020996094,-0.0016651154,0.037506104,-0.034210205,-0.032836914,-0.013694763,-0.002445221,-0.004272461,-0.0045547485,0.004257202,-0.019241333,-0.02407837,-0.001241684,-0.007335663,0.029678345,-0.00051641464,0.019104004,-0.02003479,-0.006679535,-0.02746582,-0.012565613,-0.03277588,0.01423645,0.023895264,0.021377563,-0.001660347,-0.02130127,-0.029830933,0.022537231,0.003206253,0.016571045,-0.044769287,-0.029373169,-0.0030555725,0.0065841675,-0.00025892258,0.025909424,-0.024169922,-0.008399963,0.014961243,0.0014982224,0.004459381,0.0046463013,0.018081665,-0.0048103333,-0.008987427,-0.0032253265,0.036499023,-0.022705078,0.004245758,-0.016342163,-0.010307312,0.041046143,0.008323669,-0.02633667,0.01838684,0.032684326,-0.03793335,0.047729492,-0.0184021,-0.0048713684,-0.0073661804,0.0026721954,-0.042266846,-0.013244629,0.014801025,0.0009994507],"createdAt":"2026-04-21T18:32:13.039Z","updatedAt":"2026-04-22T02:31:51.382Z","lastSeenAt":"2026-04-22T02:31:51.382Z","tsv":"'/api/v1/emails/98/attachments':133 '0.02':10,22,69,113 '000':73 '20':72 '6':79 '98':37,161 'Base USDC API' 'accept':44 'access':30 'ai/ml':97 'analysi':100 'analyt':96 'api':93,118,193 'attach':3,15,33,140,173 'avail':147 'base':8,20,57,74 'behind':38 'broader':86 'call':92 'classif':102 'commit':125 'connect':202 'content':141,208 'cost':67 'cover':130 'crawl':148 'data':95,105 'decim':80 'detail':187 'doc':192 'document':144,188 'email':2,14,32,35,159,172 'email attachment API' 'email-attachments' 'embed':103 'endpoint':26,43,134,152 'exact':62,136 'exampl':185 'feed':106 'finance/crypto':104 'found':190 'general':170 'general-purpos':169 'hardcod':155 'host':84 'howev':126 'id':36,160 'infer':98 'json':49 'json-response' 'key':119 'limit':122 'list':129 'lowpaymentfee email' 'lowpaymentfee.com':28,83 'materi':149 'maximum':66 'micropay':6,18 'micropayment attachment retrieval' 'network':58 'openapi':182 'page':197 'path':153 'pay':90 'pay-per-cal':89 'pay-per-call email' 'pay-per-request' 'payment':50 'paywal':41 'per':11,23,70,91,114 'post':45 'price':111,194 'prompt':204 'provid':29,82 'purpos':171 'rate':121 'readm':196 'request':12,24,46,71,115 'request/response':184 'resourc':180 'respons':137 'retriev':1,13,174 'return':48,199 'schema':138 'scheme':63 'sentiment':99 'servic':109,175 'settl':52 'singl':178 'span':94 'spec':183 'specif':34,128,158 'static':179 'substant':207 'suit':87 'summar':101 'unclear':164 'unit':75 'usdc':54,77 'usdc-base' 'use':59 'util':108 'via':4,16 'wallet':203 'whether':165 'whose':135 'x402':5,17,40,61 'x402 email endpoint' 'x402-payment'","prices":[{"id":"adb70212-187e-4a1c-95df-540e3282d910","listingId":"7baf7de5-6b4b-4609-bd54-36dc73f13efd","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/98/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":"2026-04-21T18:32:13.039Z"}],"sources":[{"listingId":"7baf7de5-6b4b-4609-bd54-36dc73f13efd","source":"x402_bazaar","sourceId":"https://lowpaymentfee.com/api/v1/emails/98/attachments","sourceUrl":"https://api.cdp.coinbase.com/platform/v2/x402/discovery/resources","isPrimary":true,"firstSeenAt":"2026-04-21T18:32:13.039Z","lastSeenAt":"2026-04-22T02:31:51.382Z"}],"details":{"listingId":"7baf7de5-6b4b-4609-bd54-36dc73f13efd","quickStartSnippet":"curl -X POST https://lowpaymentfee.com/api/v1/emails/98/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 challenge with x402Version 1, exact scheme, USDC on Base network, maxAmountRequired 20000","source_url":"https://lowpaymentfee.com/api/v1/emails/98/attachments"},{"claim":"USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base","source_url":"https://lowpaymentfee.com/api/v1/emails/98/attachments"},{"claim":"Provider advertises $0.02 per request, no API keys, no rate limits, instant access on Base network","source_url":"https://lowpaymentfee.com"},{"claim":"Provider lists APIs across data/analytics, AI/ML, finance/web3, and infrastructure categories","source_url":"https://lowpaymentfee.com"}],"useCases":["Retrieving attachments from a specific email record via programmatic API call","Agent-driven document retrieval behind a crypto micropayment wall","Demonstrating x402 payment protocol integration for email data access"],"bestFor":["Agents needing to fetch email attachments without API key registration","Developers experimenting with x402 micropayment protocol on Base","One-off attachment retrieval at very low cost ($0.02)"],"notFor":["Bulk email processing or mailbox management","General-purpose email sending or SMTP relay","Users who need detailed API documentation before integrating"],"kindDetails":{"x402_version":1,"resource_type":"http","bazaar_last_updated":"2026-02-17T23:13:19.876Z"},"updatedAt":"2026-04-22T02:31:51.382Z"}}