{"uid":"cap_ElFPmkoPdUv05Y1f_8U5r","slug":"lookproof-spf-flatten-b23d8883","name":"Lookproof SPF Flatten","description":"Check SPF, DMARC, DKIM, MTA-STS, DNSSEC and more, with results that explain what was found and why. Free browser checks and a pay-per-request API with x402.","url":"https://api.lookproof.dev/v1/mail/spf-flatten?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","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","title":"DomainInput","required":["domain"],"properties":{"domain":{"type":"string","title":"Domain","examples":["example.com"],"maxLength":1024,"minLength":1}},"additionalProperties":false}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_nrYN0waKSVO6ISAIkEtRf","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Unfolds and flattens a domain's full SPF policy into merged IPv4/IPv6 CIDR blocks by recursively following includes and redirects per RFC 7208 lookup limits","exampleAgentPrompt":"Can you flatten the full SPF policy for stripe.com and show me all the IPv4 and IPv6 blocks that are authorized to send email, including any sources per block and whether it hits the 10-lookup limit?","exampleUseCases":[{"title":"Firewall allowlist for outbound mail","prompt":"I need to build an IP allowlist for email from salesforce.com — can you flatten their entire SPF policy into all the actual IPv4 and IPv6 CIDR blocks so I know exactly which servers are authorized to send?"},{"title":"SPF lookup limit audit before deployment","prompt":"Before I publish our new SPF record for acmecorp.com, can you check whether following all the includes and redirects would exceed the 10-lookup or 2-void-lookup limits and flag any PermError conditions?"},{"title":"Identify mail providers from SPF","prompt":"I'm investigating who sends email on behalf of hubspot.com — can you expand their full SPF policy into flat IP blocks and show me which include sources each block came from?"}],"resultDescription":"A structured response containing merged IPv4 and IPv6 CIDR blocks representing all authorized senders, annotated with the SPF include or mechanism source for each block, separately listed exists/ptr/macro mechanisms, flags for overly broad blocks, lookup counts (DNS and void), and a PermError indicator if RFC 7208 limits are exceeded.","failureModes":["Domain does not exist or has no SPF record — returns error or empty result","SPF PermError encountered (exceeds 10 DNS lookups or 2 void lookups) — processing stops and error is flagged","Invalid domain input (malformed string) — validation error","SPF record has syntax errors — parse failure reported","Upstream DNS resolution timeout — lookup may fail or return partial results"],"whenToPreferThis":"Choose this endpoint when you need a complete, receiver-perspective flattening of an SPF policy into actual IP ranges — especially when debugging lookup limit issues, building firewall allowlists, auditing authorized senders, or verifying RFC 7208 compliance. Prefer this over simple SPF record readers when you need recursive resolution of includes/redirects with CIDR merging and source attribution.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:40:06.420Z","isFirstParty":false,"canonicalSlug":"lookproof-spf-flatten-b23d8883"}