{"uid":"cap_y7Nxeq8tNhx4X13lwAyx8","slug":"delx-seeded-a-b-assignment-0788e009","name":"Delx Seeded A/B Assignment","description":"Seeded Ab Assignment: Seeded Ab Assignment assigns a stable subject to A or B using caller weights from bounded caller-supplied values without an external provider. Call Seeded Ab Assignment when an agent needs a reproducible decision that another run can independently replay. Returns the deterministic selection plus seed provenance, population bounds, and the operation-specific outcome for Seeded Ab Assignment as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-party, s…","url":"https://api.delx.ai/api/v1/x402/seeded-ab-assignment","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_WqsjED7XK5PUQILP44HBI","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 variant (A or B) using a seed and configurable weight, returning a stable bucket value and variant label.","exampleAgentPrompt":"Assign user ID 'user_8821' to an A/B variant using experiment seed 'checkout-flow-v3' with a 70% weight for variant A.","exampleUseCases":[{"title":"Feature rollout percentage split","prompt":"I want to gradually roll out a new checkout UI — assign user 'uid_4499' to either the old or new experience using seed 'checkout-rollout-q3' with a 20% chance of landing in variant A."},{"title":"Reproducible experiment bucketing","prompt":"For my pricing experiment, deterministically assign customer 'cust_92817' to a test variant using seed 'pricing-exp-2024' and an even 50/50 weight between A and B."},{"title":"Personalization cohort assignment","prompt":"I need to consistently put user 'member_7731' into the same recommendation cohort every time — use seed 'reco-algo-beta' and weight A at 30% to assign them to a variant."}],"resultDescription":"Returns a JSON object with a floating-point bucket value (0–1), a variant label ('A' or 'B'), operation name, status ('pass'), and evidence block confirming no data retention and zero external calls made during computation.","failureModes":["Missing required 'seed' or 'subject' fields returns a validation error","weight_a outside 0–1 range may produce unexpected bucketing behavior","Very long seed or subject strings (approaching 8192 char limit) may cause payload rejection","Network timeouts on the $0.001 USDC x402 payment flow before computation begins"],"whenToPreferThis":"Use this endpoint when you need deterministic, reproducible A/B variant assignment — i.e., the same seed+subject pair must always return the same variant. Prefer it over random assignment when you need consistency across sessions or services without storing assignment state, and when you want configurable weighting between variants.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:18:45.757Z","isFirstParty":false}