{"uid":"cap_CC5DYmMTCrEVdIR62AY5a","slug":"fastx402-json-semantic-diff-5a635566","name":"FastX402 JSON Semantic Diff","description":"200 pay-per-call tools for AI agents, from $0.001 per request in USDC on Base or Solana with x402. No account, no API key.","url":"https://fastx402.tools/json-diff-semantic?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["before","after"],"properties":{"after":{"type":"string","description":"Second JSON object or array"},"before":{"type":"string","description":"First JSON object or array"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"added":{"type":"array","items":{"type":"object","properties":{"path":{"type":"string"},"value":{"type":"string"}}}},"removed":{"type":"array","items":{"type":"object","properties":{"path":{"type":"string"},"value":{"type":"boolean"}}}},"summary":{"type":"string"},"modified":{"type":"array","items":{"type":"object","properties":{"path":{"type":"string"},"after":{"type":"integer"},"before":{"type":"integer"}}}}}}}}}},"responseSchema":{"type":"json","example":{"added":[{"path":"status","value":"active"}],"removed":[{"path":"active","value":true}],"summary":"2 modified, 1 added, 1 removed","modified":[{"path":"age","after":31,"before":30},{"path":"tags[1]","after":"moderator","before":"user"}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_KPcWoPgdJ39DA6v3XrgI7","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Compares two JSON objects or arrays and returns a structured semantic diff showing added, removed, and modified fields with their paths and values.","exampleAgentPrompt":"Compare these two JSON objects and tell me what fields were added, removed, or changed — before: {\"age\":30,\"tags\":[\"admin\",\"user\"],\"active\":true} and after: {\"age\":31,\"tags\":[\"admin\",\"moderator\"],\"status\":\"active\"}.","exampleUseCases":[{"title":"API response change detection","prompt":"I have two versions of an API response and I need to know exactly what changed — before: {\"price\":99,\"inStock\":true,\"label\":\"Basic\"} and after: {\"price\":109,\"inStock\":true,\"label\":\"Standard\",\"discount\":0.1}. Can you diff them semantically?"},{"title":"Config file drift tracking","prompt":"My deployment config changed between releases. Before it was {\"replicas\":2,\"env\":\"staging\",\"debug\":true} and now it's {\"replicas\":4,\"env\":\"production\",\"debug\":false,\"timeout\":30}. What are all the differences?"},{"title":"User profile update audit","prompt":"A user's profile record was updated. Can you compare the old version {\"name\":\"Alice\",\"role\":\"viewer\",\"active\":false} with the new one {\"name\":\"Alice\",\"role\":\"editor\",\"active\":true,\"verified\":true} and summarize what changed?"}],"resultDescription":"A JSON object listing added fields (path + new value), removed fields (path + old value), and modified fields (path + before value + after value), plus a human-readable summary string such as '2 modified, 1 added, 1 removed'.","failureModes":["Malformed JSON in 'before' or 'after' params causes parse error","Missing required 'before' or 'after' query parameters returns validation error","Very large or deeply nested JSON may hit size limits","Non-JSON strings passed as parameters return error"],"whenToPreferThis":"Use this endpoint when you need a structured, path-level semantic diff of two JSON objects or arrays — especially when you want to programmatically consume the diff (added/removed/modified lists with field paths) rather than a raw text comparison. Prefer this over generic text diff tools when working with API payloads, config objects, or any structured data where field-level change tracking matters.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T07:42:40.248Z","isFirstParty":false,"canonicalSlug":"fastx402-json-semantic-diff-5a635566"}