{"uid":"cap_MqCGbylmUl0-tIM6cdqNv","slug":"delx-commerce-seeded-a-b-assignment-c4fa38ac","name":"Delx Commerce — Seeded A/B Assignment","description":"Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.","url":"https://commerce.delx.ai/api/v1/x402/seeded-ab-assignment?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"seed":{"type":"string","maxLength":8192,"description":"Seed supplied to Seeded Ab Assignment; used only for this bounded calculation and processed in memory without retention."},"subject":{"type":"string","maxLength":8192,"description":"Subject supplied to Seeded Ab Assignment; used only for this bounded calculation and processed in memory without retention."},"weight_a":{"type":"number","description":"Weight A supplied to Seeded Ab Assignment; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"bucket":0.207537504388443,"variant":"A"},"schema":"delx/util-seeded-ab-assignment/v1","status":"pass","evidence":{"retained":false,"input_sha256":"96739ac478c933dfd4385515e11012fab06dfd8342764dd368da174bbe750bfa","external_calls":0},"operation":"seeded_decision:seeded_ab_assignment"}},"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_8MWczYcmlMf48i3LvtIKv","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":"Deterministically assigns a subject to an A/B test variant (A or B) based on a seed and optional weight, returning a verifiable bucket value and variant label.","exampleAgentPrompt":"Assign user 'user_8842' to an A/B test variant using seed 'experiment-v3' with a 70% weight for variant A — give me the bucket value and which variant they land in.","exampleUseCases":[{"title":"Feature flag rollout by user ID","prompt":"I need to deterministically assign user 'acct_20291' to either the new checkout flow or the old one using seed 'checkout-redesign-q2' — weight A at 80% and tell me which variant they get."},{"title":"Reproducible experiment bucketing for replay","prompt":"Re-run the A/B assignment for subject 'session_4477' with seed 'promo-banner-test' and equal weights so I can verify they were in variant B during last week's experiment."},{"title":"Agent routing by variant split","prompt":"Split incoming agent requests between two prompt strategies — assign subject 'req_id_9912' using seed 'prompt-strategy-sept' with 60% weight for variant A and tell me the bucket score."}],"resultDescription":"Returns a JSON object with the assigned variant ('A' or 'B'), a numeric bucket value between 0 and 1, the operation schema identifier, a pass/fail status, and an evidence block confirming no data was retained, the SHA-256 hash of the input, and that zero external calls were made.","failureModes":["Missing required fields (seed or subject) may return a validation error","Malformed JSON body returns a 400-level error","Payment not included or insufficient USDC results in a 402 Payment Required response","seed or subject strings exceeding 8192 characters may be rejected","Network timeout on the Base/Solana payment settlement layer"],"whenToPreferThis":"Choose this endpoint when you need a stateless, reproducible, and verifiable A/B assignment with no data retention — especially in agent pipelines where auditability matters, you want a cryptographic hash of inputs as evidence, and you need to pay per-result with no upfront signup or subscription.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T00:54:02.968Z","isFirstParty":false,"canonicalSlug":"delx-commerce-seeded-a-b-assignment-c4fa38ac"}