{"uid":"cap_1dZu-r5mHP3pSqFokexCC","slug":"dkim-selector-fm3-lookup-eade57a0","name":"DKIM Selector fm3 Lookup","description":"DKIM public key for selector \"fm3\" of a domain: looks up fm3._domainkey.<domain> (TXT, Cloudflare DoH) and parses v=, k=, key type, public-key length, testing flag and whether the key is revoked (empty p=). Confirms that mail signed with the fm3 selector will verify. $0.01 per lookup.","url":"https://dns.intel.rallylive.ca/dns/dkim/fm3?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"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_4WufefpIf9AdKrSU-boiB","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":"Looks up and parses the DKIM public key for the 'fm3' selector of a given domain, returning key type, length, testing flag, and revocation status.","exampleAgentPrompt":"Check the DKIM configuration for the fm3 selector on fastmail.com — I want to know if the key is valid, what type it is, its length, and whether it's revoked or in testing mode.","exampleUseCases":[{"title":"Pre-send email authentication audit","prompt":"Before we send our campaign through Fastmail, can you verify that the fm3 DKIM selector on ourdomain.com is properly set up, not revoked, and has a strong enough key?"},{"title":"Diagnosing DKIM failures for fm3","prompt":"Our emails signed with the fm3 selector are being rejected — can you look up fm3._domainkey.example.com and tell me if the key is valid, revoked, or in testing mode?"},{"title":"Security audit of email signing keys","prompt":"I'm auditing the email security posture for acme.com — please check the fm3 DKIM selector and tell me the key type, public key length, and whether it's flagged as a test key."}],"resultDescription":"Returns parsed DKIM record details for the fm3 selector including: v= (version), k= (key type such as RSA), public key length in bits, whether the record is in testing mode (t=y flag), and whether the key is revoked (empty p= field), allowing confirmation that mail signed with fm3 will successfully verify.","failureModes":["Domain has no fm3._domainkey TXT record — returns not-found or empty result","DKIM record is revoked (empty p= field) — returns revoked status","DNS resolution failure via Cloudflare DoH — network or upstream error","Malformed TXT record that cannot be parsed — returns parse error","Domain does not exist — DNS NXDOMAIN response"],"whenToPreferThis":"Use this endpoint when you specifically need to validate the 'fm3' DKIM selector (commonly used by Fastmail and similar providers) for a domain. Prefer this over generic DNS TXT lookups when you need structured, pre-parsed DKIM fields (key type, length, revocation, testing flag) rather than raw DNS responses.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-20T00:59:10.079Z","isFirstParty":false,"canonicalSlug":"dkim-selector-fm3-lookup-eade57a0"}