{"uid":"cap_ovKMgBddphA1y95RvmMxk","slug":"preplayer-ai-json-schema-validator-1874e6e1","name":"PrepLayer.ai JSON Schema Validator","description":"Deterministic JSON-Schema subset validator. Catches malformed JSON before it breaks a pipeline. Supports: type, required, properties, items, minLength, maxLength, pattern, enum, minimum, maximum, additionalProperties. No external dependencies.","url":"https://api.maximusmediahouse.com/v1/validate_json?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"json":{"type":"string","description":"The JSON string to parse and validate."},"schema":{"type":"object","properties":{"enum":{"type":"array"},"type":{"enum":["string","number","integer","boolean","null","array","object"],"type":"string"},"items":{"type":"object"},"maximum":{"type":"number"},"minimum":{"type":"number"},"pattern":{"type":"string"},"required":{"type":"array","items":{"type":"string"}},"maxLength":{"type":"integer","minimum":0},"minLength":{"type":"integer","minimum":0},"properties":{"type":"object"},"additionalProperties":{"type":"boolean"}},"description":"JSON-Schema subset. Omit for parse-only validation."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","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":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_jyaClzdaDmIW14h4ehEww","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates a JSON string against a JSON-Schema subset (type, required, properties, items, minLength, maxLength, pattern, enum, minimum, maximum, additionalProperties) and catches parse errors before they break a pipeline.","exampleAgentPrompt":"Can you validate this JSON string against my schema before I push it to the pipeline? The JSON is '{\"name\":\"Alice\",\"age\":30}' and the schema requires 'name' as a string and 'age' as a number between 0 and 120, with no additional properties allowed.","exampleUseCases":[{"title":"Pre-pipeline payload guard","prompt":"Before I send this webhook payload to the database, check that it's valid JSON and matches my schema — it must have a required 'user_id' string and 'amount' number between 0 and 10000, with no extra fields allowed. Here's the payload: '{\"user_id\":\"u_123\",\"amount\":49.99}'"},{"title":"API input validation in agent workflow","prompt":"I'm building an agent that receives user-submitted JSON configs. Can you validate this config against my schema where 'mode' must be one of ['fast','slow','balanced'] and 'retries' must be an integer between 1 and 5? Config is: '{\"mode\":\"fast\",\"retries\":3}'"},{"title":"Catch malformed JSON before processing","prompt":"This JSON came in from an external partner and I'm not sure it's well-formed — can you just parse it and tell me if it's valid JSON? If it is, also check that the 'email' field matches the pattern '^[^@]+@[^@]+$' and 'status' is one of ['active','inactive']. Here's the string: '{\"email\":\"bob@example.com\",\"status\":\"active\"}'"}],"resultDescription":"Returns a validation result indicating whether the JSON string is valid (parses correctly and satisfies all schema constraints). On failure, returns structured error details identifying which constraints were violated (e.g. missing required field, wrong type, value out of range, pattern mismatch, disallowed additional property). On success, confirms the JSON is well-formed and schema-compliant.","failureModes":["Unparseable JSON string returns a parse error before schema checks begin","Schema constraints not in the supported subset (e.g. oneOf, allOf, $ref) are silently ignored or unsupported","Overly large JSON payloads may be rejected or timeout","Passing an invalid schema object itself may produce unexpected results","Network or payment authorization failures return HTTP 402 or 5xx errors"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, deterministic, dependency-free JSON validation step inside an automated pipeline or agent workflow — especially when you want to catch malformed or schema-violating payloads before they reach a database, downstream API, or LLM. It is ideal for validating webhook payloads, API inputs, or config objects against a known schema subset without spinning up a full JSON Schema library. Prefer it over general-purpose schema validators when you need a simple pay-per-call microservice with no infrastructure overhead.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T12:34:33.079Z","isFirstParty":false,"canonicalSlug":"preplayer-ai-json-schema-validator-1874e6e1"}