{"uid":"cap_ZDrN4qrfrYBQhwpoTw4Un","slug":"pennyrail-number-sum-30b8b8af","name":"PennyRail Number Sum","description":"Machine-readable settlement service","url":"https://pennyrail.vercel.app/api/f/number.sum","method":"POST","headers":{},"bodySchema":{"type":"object","required":["input"],"properties":{"input":{"type":"array","description":"number[]"}}},"responseSchema":{"type":"object","required":["operation","result"],"properties":{"result":{},"operation":{"type":"string"}},"additionalProperties":true},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ybuv7TC8MO8LTMQowJ1ap","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the sum of an array of numbers via a paid REST API endpoint","exampleAgentPrompt":"Can you add up these numbers for me using PennyRail: 14, 27, 3, 99, and 5?","exampleUseCases":[{"title":"Summing invoice line items","prompt":"I have a list of invoice amounts — 120.50, 340, 75.25, and 89.99 — can you add them all up and tell me the total?"},{"title":"Aggregating sensor readings","prompt":"I've got a batch of sensor readings: 4.2, 7.8, 3.1, 9.0, and 2.5 — what's the combined total across all of them?"},{"title":"Running score tally for a game","prompt":"Can you total up these player scores for me: 450, 320, 875, 210, and 640?"}],"resultDescription":"Returns a JSON object with an 'operation' string (e.g. 'sum') and a 'result' field containing the computed sum of the input numbers.","failureModes":["Missing 'input' field returns validation error","Empty array may return 0 or an error depending on implementation","Non-numeric values in the array may cause computation failure or be ignored","Payment not processed (402 response) if USDC balance is insufficient","Network timeout on the Vercel deployment under cold-start conditions"],"whenToPreferThis":"Choose this endpoint when you need a simple, machine-readable summation of a list of numbers over a paid x402-compatible API, especially in agentic workflows that already handle micropayment authorization via the x402 protocol. Best suited for lightweight numeric aggregation tasks where spinning up a compute environment is overkill.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T18:52:02.826Z","isFirstParty":false}