{"uid":"cap_2OIe0_K7drKMGjE4Y4-GP","slug":"json-schema-validator-2020-12-2102e749","name":"JSON Schema Validator (2020-12)","description":"Validates a JSON document against a JSON Schema (core 2020-12 keywords incl. $ref/$defs, anyOf/oneOf/allOf, formats) and returns every error with instance path, schema path and a plain-language message. Use it as an independent gate on structured LLM output before acting on it.","url":"https://jemeen-agent-services.onrender.com/v1/validate-json?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":null,"responseSchema":{"type":"json","example":{"valid":false,"errors":[{"keyword":"format","message":"must be a valid email","schemaPath":"#/properties/email/format","instancePath":"/email"}],"errorCount":1}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_BMJn0I5M9HKoFkIGfe-CT","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates a JSON document against a JSON Schema (Draft 2020-12) and returns detailed errors with instance paths, schema paths, and plain-language messages.","exampleAgentPrompt":"Check whether this JSON object is valid against my schema — it uses $ref, anyOf, and format constraints including email — and list every error with the exact field path and a plain-English explanation of what's wrong.","exampleUseCases":[{"title":"LLM output gate before action","prompt":"Before you process the structured JSON that the model just returned, validate it against our user-profile schema — it has required fields, email format checks, and oneOf branches — and only proceed if there are zero errors."},{"title":"API response contract check","prompt":"I just got a JSON response from a third-party API. Can you run it against our expected response schema and tell me every field that fails, including the exact path and what rule it broke?"},{"title":"Form submission data validation","prompt":"We collected this JSON form submission from a user. Validate it against our registration schema — which includes $defs for address and anyOf for phone-or-email — and give me a plain-English list of every problem so I can show it to the user."}],"resultDescription":"Returns a JSON object with a boolean 'valid' field, an 'errorCount' integer, and an 'errors' array. Each error includes 'keyword' (the failing schema keyword), 'instancePath' (dot/slash path to the offending value in the document), 'schemaPath' (path to the rule in the schema), and 'message' (plain-language description of the violation).","failureModes":["Malformed JSON input returns a parse error rather than validation errors","Invalid JSON Schema (e.g. bad $ref target) may cause schema compilation failure","Network timeout possible on first cold-start due to Render.com free-tier spin-up","Missing required request fields (document or schema) return a 4xx error","Complex schemas with deep $ref chains may hit processing limits"],"whenToPreferThis":"Choose this endpoint when you need a standalone, pay-per-call JSON Schema validator that supports the full Draft 2020-12 spec including $ref/$defs, anyOf/oneOf/allOf combiners, and format keywords — especially as an independent quality gate on LLM-generated structured output before acting on it. Prefer it over inline validation libraries when you need auditability, a neutral third-party check, or when running in an environment where installing dependencies is impractical.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-11-02T18:32:56.509Z","isFirstParty":false,"canonicalSlug":"json-schema-validator-2020-12-2102e749"}