{ "openapi": "3.1.0", "info": { "title": "WarmInboxes deliverability API", "version": "2026-09-26", "description": "Live email deliverability checks: authentication records, DNS, blacklists, domain registration and mailbox provider. No key, no signup, CORS open. The same checks are available as MCP tools at /mcp and as browser tools on the site. These are read-only and change nothing. Ordering and managing inboxes and domains is a separate authenticated API at https://api.warminboxes.com/v1, documented at https://docs.warminboxes.com — this spec does not describe it.", "license": { "name": "Free to use", "url": "https://warminboxes.com/terms" } }, "servers": [ { "url": "https://warminboxes.com" } ], "externalDocs": { "description": "Tool catalogue", "url": "https://warminboxes.com/tools.json" }, "x-warminboxes-app-api": { "description": "The authenticated product API: ordering and managing inboxes and domains.", "url": "https://api.warminboxes.com/v1", "docs": "https://docs.warminboxes.com", "llms": "https://docs.warminboxes.com/llms.txt", "auth": "Authorization: Bearer $WIB_API_KEY" }, "paths": { "/.netlify/functions/check-deliverability": { "get": { "operationId": "check_deliverability", "summary": "Deliverability grade (A-F)", "description": "Grade a domain A-F for cold email readiness. Checks SPF, DKIM, DMARC, MX, blacklists and domain age together and returns a weighted score with a per-check breakdown and what to fix. Start here for open-ended \"is this domain any good\" questions.", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to grade, e.g. \"acme.com\". Not an email address.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-spf": { "get": { "operationId": "check_spf", "summary": "SPF record", "description": "Look up a domain's SPF record and validate it, including the recursive DNS lookup count that silently breaks SPF past 10.", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to check, e.g. \"acme.com\".", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-dkim": { "get": { "operationId": "check_dkim", "summary": "DKIM record", "description": "Find and validate a domain's DKIM signing key, including key strength. Leave selector empty to auto-scan 26 common selectors (google, selector1, k1, and the rest).", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to check, e.g. \"acme.com\".", "schema": { "type": "string" } }, { "name": "selector", "in": "query", "required": false, "description": "Optional DKIM selector. Omit to auto-scan common selectors.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-dmarc": { "get": { "operationId": "check_dmarc", "summary": "DMARC record", "description": "Look up and parse a domain's DMARC record: policy, subdomain policy, percentage, alignment and reporting tags, each explained.", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to check, e.g. \"acme.com\".", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-bimi": { "get": { "operationId": "check_bimi", "summary": "BIMI record", "description": "Validate a domain's BIMI record, the logo SVG, the VMC, and the DMARC enforcement level Gmail requires before it will show a brand logo.", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to check, e.g. \"acme.com\".", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-mta-sts": { "get": { "operationId": "check_mta_sts", "summary": "MTA-STS policy", "description": "Validate a domain's _mta-sts DNS record and its published policy file: mode, MX patterns, max_age and TLS-RPT.", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to check, e.g. \"acme.com\".", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-dns": { "get": { "operationId": "check_dns", "summary": "DNS records", "description": "Query any DNS record type for a domain: MX, TXT, A, AAAA, CNAME, NS, SOA, CAA.", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to query, e.g. \"acme.com\".", "schema": { "type": "string" } }, { "name": "type", "in": "query", "required": false, "description": "Record type, e.g. \"MX\", \"TXT\", \"A\". Defaults to MX if omitted.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-blacklist": { "get": { "operationId": "check_blacklist", "summary": "Blacklist / RBL check", "description": "Check a domain or IP against 20+ major email blacklists (Spamhaus, Barracuda, SORBS and others) and report which list it appears on.", "tags": [ "deliverability" ], "parameters": [ { "name": "input", "in": "query", "required": true, "description": "A domain or an IPv4 address.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-surbl": { "get": { "operationId": "check_surbl", "summary": "SURBL URI blacklist (bulk)", "description": "Check domains against the SURBL URI blacklist in bulk. URI blacklists list the domains that appear inside a message body, so a listed tracking or landing domain sends the whole email to spam however clean the sender is. Up to 100 domains per call.", "tags": [ "deliverability" ], "parameters": [ { "name": "domains", "in": "query", "required": true, "description": "Domains to check. Max 100. Comma-separated for more than one.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-nameservers": { "get": { "operationId": "check_nameservers", "summary": "Nameservers and DNS provider (bulk)", "description": "Get the NS records and the DNS provider behind one domain or a whole list. Useful for working out who actually controls a domain's DNS before trying to fix its records.", "tags": [ "deliverability" ], "parameters": [ { "name": "domains", "in": "query", "required": true, "description": "Domains to look up. Comma-separated for more than one.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-domain-expiry": { "get": { "operationId": "check_domain_expiry", "summary": "Domain registration and expiry", "description": "Get a domain's registrar, creation date, expiry date and days remaining, over RDAP with a WHOIS fallback for ccTLDs that publish no RDAP service. Domain age is one of the strongest cold-email risk signals.", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to look up, e.g. \"acme.com\".", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-google-domain": { "get": { "operationId": "check_google_domain", "summary": "Google Workspace tenancy", "description": "Tell whether a domain is already attached to a Google Workspace account, or is clear for a fresh Google tenant.", "tags": [ "deliverability" ], "parameters": [ { "name": "domain", "in": "query", "required": true, "description": "Domain to check, e.g. \"acme.com\".", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/check-cname": { "get": { "operationId": "check_cname", "summary": "CNAME chain", "description": "Follow a host's full CNAME chain and flag the mistakes that break a cold-email tracking domain. Pass expected to assert where the chain should end up.", "tags": [ "deliverability" ], "parameters": [ { "name": "host", "in": "query", "required": true, "description": "Hostname to follow, e.g. \"track.acme.com\".", "schema": { "type": "string" } }, { "name": "expected", "in": "query", "required": false, "description": "Optional target the chain should resolve to.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/verify-email": { "get": { "operationId": "verify_email", "summary": "Email verification (bulk)", "description": "Check email addresses for syntax, live MX records, disposable providers and role prefixes (info@, sales@). Does not open SMTP connections, so catch-all domains come back valid.", "tags": [ "deliverability" ], "parameters": [ { "name": "emails", "in": "query", "required": true, "description": "Email addresses to verify. Comma-separated for more than one.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } }, "/.netlify/functions/segment-esp": { "get": { "operationId": "segment_esp", "summary": "ESP segmentation (bulk)", "description": "Split a list of domains by the email provider behind them (Google, Microsoft, or a security gateway) from their MX records. Sending Google-to-Google and Microsoft-to-Microsoft is one of the larger levers on inbox placement.", "tags": [ "deliverability" ], "parameters": [ { "name": "domains", "in": "query", "required": true, "description": "Domains to segment. Comma-separated for more than one.", "schema": { "type": "string" } } ], "responses": { "200": { "description": "The live result, queried at call time and never cached.", "content": { "application/json": { "schema": { "type": "object" } } } }, "400": { "description": "A required parameter is missing or malformed.", "content": { "application/json": { "schema": { "type": "object" } } } } } } } } }