{ "version": "0.2.0", "rubricVersion": "0.9", "target": "https://resend.com", "host": "resend.com", "https": true, "measured": { "origin": "https://resend.com", "host": "resend.com", "https": true, "url": "https://resend.com/" }, "redirect": null, "scannedAt": "2026-10-20T17:05:52.735Z", "durationMs": 6780, "requests": 60, "score": 86.3, "parts": { "standards": { "score": 98.8, "share": 0.7, "points": { "earned": 90.875, "available": 92 }, "counts": { "pass": 19, "warn": 2, "fail": 0, "na": 7, "total": 28 } }, "conventions": { "score": 57.1, "share": 0.3, "points": { "earned": 4, "available": 7 }, "counts": { "pass": 4, "warn": 0, "fail": 3, "na": 1, "total": 8 } } }, "previous": null, "level": 5, "levelName": "Agent-native", "levelBlurb": "The action surface is discoverable, its auth is described, and its status is published.", "levelCeiling": 5, "verdict": "Agent-native", "confidence": 100, "confidenceLabel": "high", "fingerprint": "4fae6b60df53d147252d8cfe5d83d782ecf051ec4fe4576599a90e7e59d7cf32", "modules": { "commerce": { "inScope": false, "signals": [] }, "agentApi": { "inScope": true, "kinds": [ "mcp", "oauth", "rest-api" ], "signals": [ { "kind": "rest-api", "evidence": "Link rel=\"api-catalog\" on the homepage" }, { "kind": "rest-api", "evidence": "/.well-known/api-catalog lists 1 linkset entry" }, { "kind": "rest-api", "evidence": "/openapi.json is an OpenAPI 3.0 document" }, { "kind": "oauth", "evidence": "/.well-known/oauth-protected-resource names resource https://api.resend.com" }, { "kind": "oauth", "evidence": "/.well-known/oauth-authorization-server names issuer https://api.resend.com" }, { "kind": "mcp", "evidence": "/.well-known/ai-catalog.json lists an MCP server card" } ] } }, "isCommerce": false, "commerceSignals": [], "blocked": null, "blockedNote": null, "deadline": { "ms": 60000, "reached": false }, "profile": { "id": "saas", "identified": true, "declared": false, "ambiguous": [], "evidence": [ "SaaS / software product (score 7), matched: SoftwareApplication schema; A pricing page responds; A documentation path responds." ], "scores": [ { "id": "saas", "score": 7, "signals": [ "SoftwareApplication schema", "A pricing page responds", "A documentation path responds" ] }, { "id": "api", "score": 5, "signals": [ "An OpenAPI document responds", "A documentation path responds" ] }, { "id": "publisher", "score": 3, "signals": [ "The homepage links a blog index", "Subscription copy" ] }, { "id": "services", "score": 2, "signals": [ "A contact path responds", "A pricing path responds" ] } ] }, "categories": [ { "id": "discoverability", "label": "Discoverability", "score": 100, "counted": true, "pass": 6, "warn": 0, "fail": 0, "na": 0, "total": 6, "unscored": { "present": 0, "defective": 0, "absent": 1 } }, { "id": "content", "label": "Content", "score": 98.6, "counted": true, "pass": 8, "warn": 1, "fail": 0, "na": 1, "total": 10, "unscored": { "present": 1, "defective": 0, "absent": 0 } }, { "id": "botaccess", "label": "Crawler access", "score": 100, "counted": true, "pass": 1, "warn": 0, "fail": 0, "na": 0, "total": 1, "unscored": { "present": 1, "defective": 1, "absent": 0 } }, { "id": "protocol", "label": "API and agent", "score": 97.5, "counted": true, "pass": 4, "warn": 1, "fail": 0, "na": 1, "total": 6, "unscored": { "present": 0, "defective": 4, "absent": 2 } }, { "id": "commerce", "label": "Commerce", "score": null, "counted": false, "pass": 0, "warn": 0, "fail": 0, "na": 5, "total": 5, "unscored": { "present": 0, "defective": 0, "absent": 0 } } ], "checks": [ { "id": "reachable", "category": "discoverability", "module": "core", "tier": "essential", "weight": 3, "conditional": false, "label": "Readable homepage", "why": "The homepage is the first URL every agent requests. An error or an empty page gives it nothing to read.", "skill": "agent-access", "standards": [], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "HTTP 200 text/html, 410 KB, 2121 words of visible text.", "evidence": "HTTP 200 · text/html · 410 KB", "fix": null, "part": "standards" }, { "id": "robots-txt", "category": "botaccess", "module": "core", "tier": "essential", "weight": 2, "conditional": false, "label": "robots.txt crawl policy", "why": "Crawlers read robots.txt before they fetch a page (RFC 9309). Its Sitemap line tells them where the URL list is.", "skill": "robots-txt", "standards": [ "RFC 9309" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "/robots.txt has 1 group and 1 rule across all groups, and 1 Sitemap line.", "evidence": "HTTP 200 · text/plain · 143 bytes · User-agent: * Allow: / Content-Signal: ai-train=yes, search=yes, ai-input=yes Sitemap: https://resend.com/sitemap.xml Host: https://resend.…", "fix": null, "part": "standards" }, { "id": "sitemap-xml", "category": "discoverability", "module": "core", "tier": "essential", "weight": 2, "conditional": false, "label": "XML sitemap", "why": "A sitemap lists the URLs a site wants crawled. Google says a small, well-linked site may not need one.", "skill": "sitemap", "standards": [], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "Sitemap index https://resend.com/sitemap.xml parses and lists 12 child sitemaps. This scan does not read the child sitemaps.", "evidence": "HTTP 200 · application/xml · 942 bytes · root ", "fix": null, "part": "standards" }, { "id": "llms-txt", "category": "discoverability", "module": "core", "tier": "recommended", "weight": 1, "conditional": false, "label": "/llms.txt published and well-structured", "why": "A 2024 proposal for a markdown index of a site. Google Search does not use it.", "skill": "llms-txt", "standards": [ "llmstxt.org" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "/llms.txt opens with H1 \"Resend\", with 19 H2 link sections and 58 links, 8.1 KB. The scan requested 13 links it names, and each answered 2xx. Not requested: 18 links on another origin and 25 same-origin links (the scan samples up to 6).", "evidence": "HTTP 200 · text/plain · 8.1 KB · headings: Resend | When to use Resend | Setup | Command line tool | MCP Server | Skills | Documentation | Support | OpenAPI spec …", "fix": null, "part": "conventions" }, { "id": "link-headers", "category": "discoverability", "module": "core", "tier": "recommended", "weight": 1, "conditional": false, "label": "Discovery via Link response headers", "why": "A Link header (RFC 8288) points a client at a resource before it parses the HTML.", "skill": "link-headers", "standards": [ "RFC 8288" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "The homepage Link header names the API catalog at /.well-known/api-catalog (rel=api-catalog). It does not name /llms.txt, the OpenAPI document at /openapi.json, and a markdown variant of the homepage.", "evidence": "link: ; rel=\"api-catalog\"", "fix": null, "part": "conventions" }, { "id": "canonical", "category": "discoverability", "module": "core", "tier": "recommended", "weight": 2, "conditional": false, "label": "Canonical URL", "why": "A canonical link names the one URL a page is known by. Google treats it and redirects as canonical signals.", "skill": "canonical", "standards": [ "RFC 6596" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "Canonical https://resend.com/ matches the page reached.", "evidence": "", "fix": null, "part": "standards" }, { "id": "http-caching", "category": "discoverability", "module": "core", "tier": "recommended", "weight": 1, "conditional": false, "label": "HTTP caching of the homepage", "why": "Cache-Control says how long the homepage may be reused. A validator lets a crawler ask whether it changed, and a 304 answer skips the body.", "skill": "http-caching", "standards": [ "RFC 9111", "RFC 9110" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "The homepage sends Cache-Control \"public, max-age=0, must-revalidate\" and ETag, and a request with If-None-Match was answered HTTP 304 Not Modified.", "evidence": "Cache-Control: public, max-age=0, must-revalidate · ETag: W/\"p2p9rpm6398zxl\" · Last-Modified: (none) · conditional GET with If-None-Match: HTTP 304", "fix": null, "part": "standards" }, { "id": "indexing-directives", "category": "discoverability", "module": "core", "tier": "essential", "weight": 2, "conditional": false, "label": "Homepage indexable: no noindex directive", "why": "A noindex in a meta tag or in a response header keeps the page out of search results. Bing keeps it out of Copilot too.", "skill": "indexing-directives", "standards": [], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "No noindex: the homepage states and , and none of them asks to leave the page out.", "evidence": " · ", "fix": null, "part": "standards" }, { "id": "not-found-status", "category": "discoverability", "module": "core", "tier": "recommended", "weight": 1, "conditional": false, "label": "A real 404 for a missing page", "why": "A URL that does not exist answers 404 or 410 (RFC 9110). A 200 there makes every mistyped link look like a page.", "skill": "not-found-status", "standards": [ "RFC 9110" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "/aws-probe-5a36f3ef766b, a path that does not exist, answered HTTP 404.", "evidence": "HTTP 404 · text/html · first 16 KB read", "fix": null, "part": "standards" }, { "id": "structured-errors", "category": "discoverability", "module": "core", "tier": "recommended", "weight": 1, "conditional": false, "label": "Structured errors for JSON requests", "why": "An agent that asks for JSON and gets an HTML error page has to read a page meant for people. RFC 9457 defines a JSON error format.", "skill": "problem-details", "standards": [ "RFC 9457" ], "status": "fail", "points": 0, "counted": true, "excluded": null, "detail": "Not used: /aws-probe-5a36f3ef766b, asked for JSON, answered HTTP 404 with an HTML page, not a JSON error.", "evidence": "HTTP 404 · text/html · first 16 KB read", "fix": "{\n \"type\": \"about:blank\",\n \"title\": \"Not Found\",\n \"status\": 404,\n \"detail\": \"Nothing is published at this address.\"\n}\n", "fixNote": "Send this with Content-Type: application/problem+json and the status 404 when a request for a missing path asks for JSON. Browsers can keep the HTML page (RFC 9457).", "part": "conventions" }, { "id": "llms-full", "category": "discoverability", "module": "core", "tier": "recommended", "weight": 1, "conditional": false, "label": "/llms-full.txt expanded context", "why": "A convention that puts a site's text in one file. The llms.txt proposal does not define it.", "skill": "llms-full-txt", "standards": [], "status": "fail", "points": 0, "counted": true, "excluded": null, "detail": "/llms-full.txt is a list of links, not page text: 56 link lines of 92 lines, 925 words in 9.2 KB.", "evidence": "HTTP 200 · text/plain · 9.2 KB · # Resend > Resend is the email API for developers. Send transactional and marketing emails at scale with a simple, mode…", "fix": null, "defect": true, "part": "conventions" }, { "id": "markdown-negotiation", "category": "content", "module": "core", "tier": "recommended", "weight": 1, "conditional": false, "label": "Markdown content negotiation", "why": "Some coding agents ask for text/markdown. Google Search does not use markdown.", "skill": "markdown-negotiation", "standards": [ "RFC 9110" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "The homepage serves text/markdown to `Accept: text/markdown, text/html;q=0.5`, with Vary: Accept, accept-encoding (HTTP 200).", "evidence": "HTTP 200 · text/markdown · Vary: Accept, accept-encoding · markdown body: yes", "fix": null, "part": "conventions" }, { "id": "headings", "category": "content", "module": "core", "tier": "essential", "weight": 2, "conditional": false, "label": "Semantic heading structure", "why": "Headings outline the page for screen readers and for any client that splits text by section.", "skill": "semantic-headings", "standards": [ "WCAG 2.2" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "1 H1, 14 H2s, and 12 H3s in an outline of 27 headings, with no skipped level.", "evidence": "outline: H1 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H3 H3 H3 H3 H3 H3 H3 H3 H3 H2 H3 H3 H3 H2 H2", "fix": null, "part": "standards" }, { "id": "meta", "category": "content", "module": "core", "tier": "essential", "weight": 2, "conditional": false, "label": "Title and description", "why": "The title and the description say what a page is about. Google uses them for the title link and the snippet.", "skill": "page-metadata", "standards": [], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "Title \"Resend · Email for developers\" (29 characters) and a description of 106 characters.", "evidence": "title (29 characters): Resend · Email for developers · description (106 characters): The best way to reach humans instead of spam folders. Deliver transactional and marketing emails at scale. · first H1: Email for developers", "fix": null, "part": "standards" }, { "id": "jsonld", "category": "content", "module": "core", "tier": "essential", "weight": 3, "conditional": false, "label": "JSON-LD structured data", "why": "Structured data names the entity a page describes. Google reads JSON-LD, Microdata and RDFa alike.", "skill": "structured-data", "standards": [ "schema.org" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "1 JSON-LD block parses, and the page entity, Organization \"Resend\", is stated under a schema.org @context.", "evidence": "JSON-LD: 1 blocks, 1 parsed · schema.org @context: yes · Microdata: 0 items · RDFa: 0 items · top-level types: Organization, WebSite, SoftwareApplication, WebPage, BreadcrumbList", "fix": null, "part": "standards" }, { "id": "lang", "category": "content", "module": "core", "tier": "recommended", "weight": 1, "conditional": false, "label": "Language declaration and multilingual access", "why": "The lang attribute names the language of the text. WCAG 3.1.1 requires it at level A. Google reads hreflang, not lang.", "skill": "language-declaration", "standards": [ "WCAG 2.2", "BCP 47" ], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "html lang=\"en\" is a well-formed BCP 47 tag, with no hreflang alternates.", "evidence": "html lang=\"en\" · alternates: none · content-language: (none)", "fix": null, "part": "standards" }, { "id": "no-js-fallback", "category": "content", "module": "core", "tier": "essential", "weight": 3, "conditional": false, "label": "Content that needs no JavaScript", "why": "Several AI crawlers do not run JavaScript. Text that appears only after scripts run is invisible to them.", "skill": "server-rendering", "standards": [], "status": "pass", "points": 1, "counted": true, "excluded": null, "detail": "14345 characters of text are in the HTML before any script runs.", "evidence": "static text: 14345 characters · inside