{"uid":"cap_Pv3_lNmfJzO-edYdajqiu","slug":"json-pattern-fields-check-c09325b4","name":"JSON Pattern Fields Check","description":"JSON Pattern Fields Check: JSON Pattern Fields Check checks selected string fields against a bounded regular expression from bounded caller-supplied values without an external provider. Call JSON Pattern Fields Check before an agent hands structured data or a batch plan to a downstream tool with a stricter contract. Returns the bounded transformation or validation finding with counts, normalized values, and a versioned result contract for JSON Pattern Fields Check as versioned deterministic JSO…","url":"https://api.delx.ai/api/v1/x402/json-pattern-fields-check","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"fields":{"type":"array","items":{"type":"string","maxLength":8192},"maxItems":256,"description":"Fields supplied to JSON Pattern Fields Check; used only for this bounded calculation and processed in memory without retention."},"object":{"type":"object","description":"Object supplied to JSON Pattern Fields Check; used only for this bounded calculation and processed in memory without retention.","maxProperties":128,"additionalProperties":true},"pattern":{"type":"string","maxLength":8192,"description":"Pattern supplied to JSON Pattern Fields Check; used only for this bounded calculation and processed in memory without retention."}}},"responseSchema":{"type":"json","example":{"result":{"passed":true,"invalid_fields":[]},"schema":"delx/util-json-pattern-fields-check/v1","status":"pass","evidence":{"retained":false,"input_sha256":"76c212959ee62ae10d1069f1f04a0f1ac36073c0c300552b25ad1c9929a1bd35","external_calls":0},"operation":"data_batch:json_pattern_fields_check"}},"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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_N8mjUgTz4cf4phc7TlzhY","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates selected string fields of a JSON object against a caller-supplied regular expression, returning match counts and normalized values in a versioned deterministic result.","exampleAgentPrompt":"Before I send this order JSON to the fulfillment API, check that the fields 'sku' and 'trackingCode' both match the pattern '^[A-Z]{2}\\d{6}$' — give me the match counts and any values that fail.","exampleUseCases":[{"title":"Pre-flight check before strict downstream API","prompt":"I'm about to send this batch plan JSON to our logistics partner. Can you check that the 'shipmentId' and 'warehouseCode' fields all match the pattern '^WH-\\d{4}-[A-Z]{3}$' and tell me which ones fail?"},{"title":"Validate user-submitted form data","prompt":"A user just submitted a registration form and I've got it as a JSON object. Check that the 'phone' and 'postalCode' fields match '^\\d{10}$' and '^\\d{5}(-\\d{4})?$' respectively and return the counts of matches and mismatches."},{"title":"Audit agent-generated structured output","prompt":"My agent produced a JSON result with 'invoiceNumber', 'poReference', and 'vendorCode' fields. Run a pattern check against '^[A-Z]{3}-\\d{8}$' on all three fields so I know if any values are malformed before I store them."}],"resultDescription":"Returns a versioned deterministic JSON object containing match counts per field, normalized field values, and a validation finding summary indicating which fields passed or failed the supplied regular expression pattern.","failureModes":["Pattern exceeds maxLength of 8192 characters — request rejected","Object has more than 128 properties — request rejected","Fields array exceeds 256 items — request rejected","Invalid regular expression syntax causes pattern compilation failure","Named fields not found in the object result in zero-match findings","Payment not included or insufficient USDC — 402 response"],"whenToPreferThis":"Use this endpoint when an agent needs to validate one or more string fields within a JSON object against a known regular expression before passing structured data to a downstream tool with a strict schema contract. It is especially useful for pre-flight checks in agentic pipelines where field format compliance must be confirmed deterministically without calling an external provider or storing data.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:09:14.375Z","isFirstParty":false}