Postmark

What our check kept, up to 60 lines or 6 KB

# Postmark marketing site — robots.txt
# Crawl policy: AI crawlers are explicitly allowed. As a marketing site we want
# our content discoverable and citable by AI search/answer engines and assistants.
# Revisit this policy if crawl volume or usage becomes a concern.
#
# Usage policy: allowing the crawl is not the same as allowing every downstream
# use, so each group below also carries a Content-Signal directive declaring how
# the content may be used once fetched:
#
#   search=yes     — building a search index and serving search results
#   ai-input=yes   — retrieval-augmented generation, grounding, and generative
#                    AI search answers (i.e. being cited in an answer)
#   ai-train=no    — training or fine-tuning AI models
#
# The Content-Signal directives in this file use the syntax and vocabulary of a
# proposed IETF standard from the AI Preferences (aipref) working group and have
# the meanings set forth in that draft. See https://contentsignals.org/ and
# https://datatracker.ietf.org/doc/draft-romm-aipref-contentsignals/
#
# Under RFC 9309 a crawler obeys only its single most-specific matching group, so
# the directive is repeated in every group rather than declared once under "*".
# Nothing here grants permission beyond these signals; to license this content,
# contact Postmark directly.

# --- AI crawlers: allowed ---

# OpenAI
User-agent: GPTBot
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /

User-agent: OAI-SearchBot
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /

User-agent: ChatGPT-User
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /

# Anthropic
User-agent: ClaudeBot
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /

User-agent: Claude-User
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /

User-agent: Claude-SearchBot
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /

# Legacy Anthropic token, superseded by ClaudeBot. Listed explicitly because
# RFC 9309 matches on the exact product token, so ClaudeBot does not cover it.
User-agent: Claude-Web
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /

# Google (AI/Gemini training — separate from Googlebot search)
User-agent: Google-Extended

How we test this:

• We read robots.txt and check it doesn't disallow / for the agents that fetch for a user or find sites for AI search: ChatGPT-User, OAI-SearchBot, Claude-User, Claude-SearchBot, Perplexity-User, PerplexityBot (no robots.txt counts as allowed).
• We show blocks on GPTBot (OpenAI model training), not scored; ClaudeBot (Anthropic model training), not scored; Google-Extended (Gemini training and grounding), not scored in v1; CCBot (Common Crawl's open dataset), not scored: blocking them is the site's own call.
• Whether Google-Extended should be scored is a rubric v2 question, and we'll announce it before changing anything.
• Then we fetch your homepage as LeaderfileBot and check it returns 2xx after redirects, with no challenge page.

How we test this:

• We fetch your homepage and your docs page as LeaderfileBot, our own scanner, and check neither answers with a challenge page, or a 401 or 403 that a normal browser gets past.
• One blocked page is a fail; both caps your score at 39.
• Firewalls often let in crawlers they can verify, so ChatGPT or Claude may still get in where our scanner can't.

How we test this:

• We look for your docs page: the first homepage link to a docs., dev. or developer(s). subdomain of your domain, or to a /docs or /developer(s) path; with none, we try https://docs.<host>/ then https://<host>/docs.
• It passes if that page returns 200.
• Board companies use a docs URL we confirmed by hand.

What our check kept, up to 60 lines or 6 KB

a link: https://postmarkapp.com/llms.txt

How we test this:

• We read your homepage and your docs page and look for a pointer to an llms.txt: a link to it, a <link> tag, a Link header with rel="llms-txt" or an X-Llms-Txt header, or a line on the page naming /llms.txt.
• It passes when one points at an llms.txt that answers with markdown links.
• AFDocs checks the same (llms-txt-directive).

What our check kept, up to 60 lines or 6 KB

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">


  <url>
    <loc>https://postmarkapp.com/</loc>
    <changefreq>daily</changefreq>
    <priority>1.0</priority>
  </url>

  <url>
    <loc>https://postmarkapp.com/why</loc>
    <changefreq>monthly</changefreq>
    <priority>0.9</priority>
  </url>

  <url>
    <loc>https://postmarkapp.com/customers</loc>
    <changefreq>monthly</changefreq>
    <priority>0.5</priority>
  </url>

  <url>
    <loc>https://postmarkapp.com/dedicated-ips</loc>
    <changefreq>monthly</changefreq>
    <priority>0.5</priority>
  </url>

  <url>
    <loc>https://postmarkapp.com/write-for-us</loc>
    <changefreq>monthly</changefreq>
    <priority>0.5</priority>
  </url>

  <url>
    <loc>https://postmarkapp.com/customers/1password</loc>
    <lastmod>2019-07-09T16:44:17-04:00</lastmod>
    <changefreq>weekly</changefreq>
    <priority>0.3</priority>
  </url>
  <url>
    <loc>https://postmarkapp.com/customers/asana</loc>
    <lastmod>2018-07-17T08:22:01-04:00</lastmod>
    <changefreq>weekly</changefreq>
    <priority>0.3</priority>
  </url>
  <url>
    <loc>https://postmarkapp.com/customers/feature-upvote</loc>
    <lastmod>2019-03-20T20:27:34-04:00</lastmod>
    <changefreq>weekly</changefreq>
    <priority>0.3</priority>
  </url>
  <url>
    <loc>https://postmarkapp.com/customers/eternia-web-solutions</loc>
    <lastmod>2023-12-21T16:47:07-05:00</lastmod>
    <changefreq>weekly</changefreq>
    <priority>0.3</priority>
  </url>
  <url>
    <loc>https://postmarkapp.com/customers/livechat</loc>

How we test this:

• We fetch the Sitemap: URL from robots.txt, else /sitemap.xml, and check it returns 200 with a <urlset> or <sitemapindex> root element.

How we test this:

• We count the visible words in the raw HTML (no JavaScript run) of your homepage and your docs page, and check each has at least 150.
• With no docs page found (AR-FIND-02), the homepage is judged alone.

How we test this:

• We read your docs page and up to 7 more docs pages (the ones we read for other checks, then links on your docs page).
• A page fails when it answers 401 or 403 to a normal browser too, redirects to a sign-in page, or is a sign-in form with little else on it.
• A redirect counts as a sign-in when it adds one: a sign-in path the page didn't have, a login subdomain, or an identity provider's site such as Okta's when the page was on another site.
• A sign-up page, one whose title or main heading says sign up or create an account, isn't a login.
• A refusal only to automated readers is our scanner being blocked, not a login.
• A login on your docs page caps your score at 39; across the pages, a share of 25% or less caps it at 39, 50% or less at 59.

How we test this:

• We fetch /leaderfile-check-404, a page that shouldn't exist, and check it returns 404 or 410 after redirects.
• Off the board, if that address refuses automated readers, we try /leaderfile-check-404.html.

What our check kept, up to 60 lines or 6 KB

# Postmark

> Postmark is a reliable transactional and bulk email service that helps developers deliver and track application emails. It provides REST APIs, SMTP support, webhooks, and comprehensive email templates to replace traditional SMTP with a scalable, developer-friendly solution.

## Quick Start

To use Postmark for sending emails in your application:

1. Create a Postmark account and verify your sending domain or email address
2. Get your Server API Token from your Postmark server settings
3. Use the REST API or SMTP to send emails
4. Maximum email size is 10 MB (including attachments)
5. Maximum 50 recipients per email (To, CC, BCC combined)

### Authentication

All API requests require authentication using the `X-Postmark-Server-Token` header with your Server API Token:

```
X-Postmark-Server-Token: your-server-token-here
```

For testing without actually sending emails, use `POSTMARK_API_TEST` as your token.

## Pricing

- [Pricing](https://postmarkapp.com/pricing.txt): Plans, pricing by volume, per-1,000 overage rates, feature highlights, optional add-ons (dedicated IPs, custom retention, DMARC monitoring), and pricing FAQs

## API Reference

- [TypeScript transactional email recipe](https://postmarkapp.com/developer/integration/official-libraries#typescript): Install, shared client, template send, batch handling, webhook payload validation, and repair guide — complete TypeScript path from setup to production
- [Send a receipt with templates](https://postmarkapp.com/developer/api/templates-api#send-a-receipt-with-templates): Task-first TypeScript examples for receipts, welcome emails, and other structured transactional sends using `TemplateAlias` and `TemplateModel`
- [Webhook protection guide](https://postmarkapp.com/developer/webhooks/webhooks-overview#protecting-your-webhook): Node/TypeScript HTTP Basic Authentication, IP allowlisting, payload shape validation, event parsing, Express route setup, and idempotency pattern — Postmark does not sign webhooks with HMAC
- [Batch send with partial-failure handling](https://postmarkapp.com/developer/user-guide/send-email-with-api/batch-emails): TypeScript `Promise.allSettled` batch example with per-recipient `MessageID` and error reporting
- [Send a single email](https://postmarkapp.com/developer/api/email-api#send-a-single-email): POST to `/email` endpoint
- [Send batch emails](https://postmarkapp.com/developer/api/email-api#send-batch-emails): POST to `/email/batch` endpoint  
- [Send with templates](https://postmarkapp.com/developer/api/templates-api#email-with-template): POST to `/email/withTemplate` endpoint
- [Send batch with templates](https://postmarkapp.com/developer/api/templates-api#send-batch-with-templates): POST to `/email/batchWithTemplates` endpoint
- [Send bulk emails](https://postmarkapp.com/developer/api/bulk-email): POST to `/email/bulk` endpoint for broadcast streams
- [Template management](https://postmarkapp.com/developer/api/templates-api): Create, edit, list templates via API
- [Bounce API](https://postmarkapp.com/developer/api/bounce-api): Manage bounced emails and reactivate addresses
- [Message tracking](https://postmarkapp.com/developer/api/messages-api): Search and retrieve message details
- [Stats API](https://postmarkapp.com/developer/api/stats-api): Get delivery, open, and click statistics
- [Webhooks](https://postmarkapp.com/developer/webhooks/webhooks-overview): Configure real-time event notifications
- [Delivery webhook](https://postmarkapp.com/developer/webhooks/delivery-webhook): TypeScript handler, idempotency key guidance, and Express route for delivery events
- [Bounce webhook](https://postmarkapp.com/developer/webhooks/bounce-webhook): TypeScript handler distinguishing hard and soft bounces, and Express route for bounce events
- [Server management](https://postmarkapp.com/developer/api/servers-api): Create and configure servers
- [Domain management](https://postmarkapp.com/developer/api/domains-api): Verify domains and configure DKIM/SPF

## Core Concepts

### Message Streams

Postmark separates emails into two types of Message Streams:
- **Transactional**: One-to-one emails triggered by user actions (welcome emails, password resets, order confirmations)
- **Broadcast**: Bulk emails for newsletters, announcements, marketing campaigns

Specify the stream using the `MessageStream` field in your API calls. Most API endpoints default to "outbound" (transactional) stream.

### Key Limitations

How we test this:

• We read llms.txt at your site root and, if your docs live on another host, at your docs root, and check one returns 200, isn't HTML and has at least one markdown link.
• Off the board, we also try your docs. host and /docs/llms.txt.
• We read the first 2 MB: a larger file is judged on that part, and the result says "read the first 2 MB; the file is larger".

How we test this:

• We read the llms.txt AR-READ-07 passes on (the first with markdown links) and fetch up to 12 of its links, spread through the file, two at a time.
• A link is broken when it answers 404 or 410, or its host doesn't exist.
• A 2xx after redirects resolves, and so does an answer like 400, 405 or 406 that shows the address is there (an MCP endpoint answers a plain GET with 405).
• A refusal, a 429 or a server error isn't judged.
• The credit is the share that resolve, halved when the file runs to 50,000 characters or more, and nothing past 100,000: AFDocs' size bands.
• With no llms.txt it isn't counted: AR-READ-07 counts that.

How we test this:

• On each docs page we read (up to 7) we count the characters of visible text in the raw HTML, and of its Markdown copy if it has one, and judge the page by the larger of the two: an agent reading either may be cut off.
• Under 50,000 passes, up to 100,000 is half, more fails: AFDocs' bands, from the limits agents cut pages at.
• The credit is the average across the pages.

What our check kept, up to 60 lines or 6 KB

<meta name="description" content="Send transactional and marketing emails and get them to the inbox on time, every time. Postmark is a fast and reliable email delivery service for developers.">

How we test this:

• We check your homepage's raw HTML (no JavaScript run) has a non-empty meta description or og:description.

What our check kept, up to 60 lines or 6 KB

<h2>Features</h2>
<h2>Postmark For</h2>
<h2>Postmark vs.</h2>
<h2>Features</h2>
<h2>Postmark For</h2>
<h2>Postmark vs.</h2>
<h3>Overview</h3>
<h3>Integration</h3>
<h3>User guide</h3>
<h3>API reference</h3>

How we test this:

• We check your docs page's raw HTML (no JavaScript run) has at least 2 headings (h1 to h3) with text and at least 150 visible words.
• Off the board, a docs page that comes back as markdown counts # to ### lines outside code blocks as its headings.

What our check kept, up to 60 lines or 6 KB

```json

How we test this:

• On your docs surface, we look for a code block that carries a language tag: language-* or lang-* on <pre> or <code>, code-language-* on any element (a code block's wrapper, say), or a data-language or data-lang attribute.
• In markdown files, a fenced block with a language (```ts) counts.
• If no page shows one, we read the markdown copy each HTML page declares (a <link rel="alternate" type="text/markdown">, or its URL plus .md listed in your llms.txt), since many docs sites add the language label with JavaScript.
• If none of the pages we read is a quickstart or SDK page, a miss isn't counted: it can't fail you or withhold your score.

What our check kept, up to 60 lines or 6 KB

res you need, at a price that makes sense. Start Free Trial No Credit Card Required How many emails do you send and receive each month? 10,000 emails Free $0.00 /mo Test your integration with 100 emails/month 100 emails/month. No overages allowed in this plan. Perfect for: Testing your integration Evalu

How we test this:

• We fetch the first homepage link with 'pricing' in its path, else /pricing (board companies: a pricing URL we confirmed by hand), and check it returns 200 and its raw text (no JavaScript run) shows a price or 'free' within 80 characters of month, mo, year or yr.
• Off the board, a pricing address that answers with JSON counts when it has a price field.

How we test this:

• On each docs page we read (up to 7), one Markdown answer with content passes the page: it answers Accept: text/markdown with text/markdown, declares a copy with <link rel="alternate" type="text/markdown"> that returns Markdown, or the address the page lands on, after redirects, ending in .md does (for one ending in a slash, both /page.md and /page/index.md).
• An empty answer doesn't count.
• The credit is the share of pages that pass.
• AFDocs, Cloudflare's isitagentready and is-agentic check it.

What our check kept, up to 60 lines or 6 KB

{
  "@context": "http://schema.org",
  "@type": "Organization",
  "url": "https://postmarkapp.com",
  "logo": "https://postmarkapp.com/images/logo-stamp-social.png",
  "name": "Postmark",
  "founder": [
    {
      "@type": "Person",
      "name": "Jason VandeBoom",
      "jobTitle": "CEO"
    }
  ],
  "foundingLocation": {
    "@type": "Place",
    "address": {
      "@type": "PostalAddress",
      "streetAddress": "1 North Dearborn St, 5th Floor",
      "addressLocality": "Chicago",
      "addressRegion": "IL",
      "postalCode": "60602",
      "addressCountry": "US"
    }
  },
  "location": {
    "@type": "Place",
    "address": {
      "@type": "PostalAddress",
      "streetAddress": "1 North Dearborn St, 5th Floor",
      "addressLocality": "Chicago",
      "addressRegion": "IL",
      "postalCode": "60602",
      "addressCountry": "US"
    }
  },
  "sameAs": [
    "https://x.com/postmarkapp",
    "https://discord.com/invite/cHzm4PYmvs",
    "https://www.linkedin.com/company/postmarkapp/",
    "https://www.youtube.com/@Postmarkapp"
  ]
}

How we test this:

• We check your homepage's raw HTML has an application/ld+json block that parses as JSON and has @type or @context.

What our check kept, up to 60 lines or 6 KB

{
    "linkset": [
        {
            "anchor": "https://api.postmarkapp.com/",
            "service-desc": [
                {
                    "href": "https://postmarkapp.com/swagger/server.yml",
                    "type": "application/yaml",
                    "title": "Postmark Server API"
                },
                {
                    "href": "https://postmarkapp.com/swagger/account.yml",
                    "type": "application/yaml",
                    "title": "Postmark Account API"
                }
            ],
            "service-doc": [
                {
                    "href": "https://postmarkapp.com/developer",
                    "type": "text/html",
                    "title": "Postmark API documentation"
                },
                {
                    "href": "https://postmarkapp.com/api-explorer",
                    "type": "text/html",
                    "title": "Postmark API Explorer"
                }
            ],
            "status": [
                {
                    "href": "https://status.postmarkapp.com/",
                    "type": "text/html",
                    "title": "Postmark system status"
                }
            ]
        }
    ]
}

How we test this:

• We fetch five standard .well-known files and check at least one returns 200 with valid JSON: oauth-authorization-server (RFC 8414), oauth-protected-resource (RFC 9728), openid-configuration, api-catalog (RFC 9727) and agent-card.json (A2A).
• This list is ours: AgentReady v2.0 doesn't name one.
• Off the board, on a miss, we also read oauth-protected-resource on the mcp., api. and docs. hosts of your domain, where that metadata usually lives, and it counts only with its resource field.

What our check kept, up to 60 lines or 6 KB

- [sendEmail](#sendemail)

How we test this:

• Passes when AR-ACT-03 passes (your docs surface names your own MCP server, not just a mention or a blog post about one; on the board, only an MCP server with a tool that acts on the product: send, manage or query, not only search docs, since AgentReady calls this "the interface an agent acts through"), or when your docs surface shows a CLI install: brew install, npm i -g, npm install -g, pipx install, uv tool install, go install, az extension add, or curl ... | sh (or | bash).
• A mention of MCP that isn't your own server, with no CLI install, isn't counted.
• For board companies, the CLI half counts only a command of the product's own CLI that we confirmed by hand, like az communication email send or twilio email:send, on the pages we read or on the docs page that shows it: an install alone could be any tool (an MCP setup guide installing pnpm, say).
• For a product inside a larger platform, the platform's MCP server or CLI counts when its docs show it covers the product.
• An MCP server earns both this check and AR-ACT-03, because AgentReady lists them as two items.
• If none of the pages we read is a quickstart or SDK page, a miss isn't counted: it can't fail you or withhold your score.

How we test this:

• We look for an OpenAPI or Swagger document: for board companies, a URL we confirmed by hand; then up to 2 links on your docs surface whose URL mentions openapi or swagger, or whose link text does for a .json or .yaml file (files on other sites count when your docs link them; an address written out in your llms.txt or another text file counts as a link, and its line as the link text); then /openapi.json and /openapi.yaml on your host and your docs host.
• Off the board, a .json or .yaml link under an llms.txt heading that names OpenAPI counts as a link to a spec, or, where that section has none, a link with no file extension, and on a miss we also try those two on the docs., developers. and api. hosts of your domain.
• It passes if one parses as JSON or YAML with an openapi or swagger key and at least one path.
• A spec over 10 MB counts as couldn't check.

What our check kept, up to 60 lines or 6 KB

npm install postmark
pip install postmark-python

How we test this:

• On your docs surface we look for an npm install (npm, yarn, pnpm or bun) and a pip install (pip, poetry or uv) of a named package.
• Both must appear, on any of the pages (AgentReady: npm and PyPI).
• Off the board, uv tool install and pipx install also count as a pip install.
• Off the board, if one is missing we also read the markdown copy each HTML page declares (a <link rel="alternate" type="text/markdown">, or its URL plus .md listed in your llms.txt), then up to 2 pages your llms.txt names for that language.
• AgentReady v2.0 asks for SDKs and a CLI here; this check tests the npm and PyPI half, and a CLI counts under AR-ACT-10.
• If none of the pages we read is a quickstart or SDK page, a miss isn't counted: it can't fail you or withhold your score.

What our check kept, up to 60 lines or 6 KB

All API requests require authentication using the `X-Postmark-Server-Token` header with your Server API Token:

How we test this:

• A stand-in: AgentReady asks for self-serve key generation with documented scopes, or OAuth metadata, and key sign-up can't be tested in code.
• It passes if OAuth metadata parses as JSON with the field its RFC requires (issuer for RFC 8414, resource for RFC 9728), or if your docs say "API key" or "API token" (also inside a placeholder like YOUR_API_KEY) within 200 characters of a documented auth header: an X-...-Key or X-...-Token header, a header named ...-Key or ...-Token, Authorization with Bearer, or "Bearer API key".
• The word "token" on its own doesn't count.
• For board companies we also read the authentication page their docs link.
• Off the board, OAuth metadata with its resource field on your mcp., api. or docs. host also counts.
• A board company whose API signs each request (like AWS Signature Version 4) or takes the key in the request body isn't counted: this stand-in can't judge that kind of auth either way.
• If none of the pages we read is a quickstart or SDK page, a miss isn't counted: it can't fail you or withhold your score.

How we test this:

• In the OpenAPI spec AR-ACT-02 finds, we count the operations with a non-empty operationId.
• The credit is the share that have one.
• With no spec, it isn't counted: AR-ACT-02 already counts that.

What our check kept, up to 60 lines or 6 KB

- [sendEmail](#sendemail)

How we test this:

• On your docs surface we look for your own MCP server and quote the line: your name next to "MCP" ("Acme MCP server"), "our" or "official" MCP server, or an mcp.<your domain> address.
• Any other mention of "MCP server" or "Model Context Protocol", like a directory or an explainer, isn't counted: it can't fail you and it earns no points, because we can't tell the server is yours.
• A mention in a link to a blog post, or on an llms.txt line that links to one, doesn't count at all: a post about building a server isn't one you ship.
• For board companies we read the MCP page their docs link and list the tools it documents: a server that only searches your docs counts here, as AgentReady describes an MCP server as a "standard tool protocol for docs search and actions".
• We don't probe /mcp or call any server.
• Off the board, OAuth metadata with its resource field on your mcp. host also counts: it's the server's own file.
• If none of the pages we read is a quickstart or SDK page, a miss isn't counted: it can't fail you or withhold your score.

How we test this:

• In the OpenAPI spec AR-ACT-02 finds, we count the operations that declare a 4xx, 5xx or default response with a schema, directly or through a $ref.
• The credit is the share that do.
• We note when they use application/problem+json (RFC 9457), the standard shape.
• With no spec, it isn't counted.
• The IETF's draft agent-friendly API profile, is-agentic and Alpic check it.

How we test this:

• We check your homepage's raw HTML, inline scripts included, contains modelContext (AgentReady names document.modelContext).
• External scripts aren't fetched.

What our check kept, up to 60 lines or 6 KB

{
  "$schema": "https://schemas.agentskills.io/discovery/0.2.0/schema.json",
  "skills": [
    {
      "name": "postmark",
      "type": "skill-md",
      "description": "Use when working with Postmark email platform - routes to specific sub-skills for sending emails, processing inbound email, managing templates, or configuring webhooks.",
      "url": "https://postmarkapp.com/.well-known/agent-skills/postmark/SKILL.md",
      "digest": "sha256:13464c46aedc1b118de4eb19ac1151811470b95b06ba79ceeac121aa52e87850"
    },
    {
      "name": "postmark-email-best-practices",
      "type": "archive",
      "description": "Use when asking about email deliverability, compliance (CAN-SPAM, GDPR, CASL), transactional email design patterns, list management, testing safely, or general email best practices — provider-agnostic knowledge with Postmark-specific guidance.",
      "url": "https://postmarkapp.com/.well-known/agent-skills/postmark-email-best-practices.tar.gz",
      "digest": "sha256:a32e16b4825c30fa0c589dc6ccb2f04d1b8bb56f467b283a907d96e1a396fcdc"
    },
    {
      "name": "postmark-inbound",
      "type": "archive",
      "description": "Use when processing incoming emails with Postmark inbound webhooks — building reply-by-email, email-to-ticket, document extraction, or any workflow that receives and parses email.",
      "url": "https://postmarkapp.com/.well-known/agent-skills/postmark-inbound.tar.gz",
      "digest": "sha256:5f730336e1d08a6c56d07cacd90780bb5761e72b36b0492c22c41d9a0ba7304a"
    },
    {
      "name": "postmark-send-email",
      "type": "archive",
      "description": "Use when sending transactional or broadcast emails through Postmark — single sends, batch (up to 500), bulk, or template-based emails with support for attachments, tracking, and message streams.",
      "url": "https://postmarkapp.com/.well-known/agent-skills/postmark-send-email.tar.gz",
      "digest": "sha256:9e210a0bedec74e3abec60c9198fe5f294fb9be16c0df5ddb10346e8bf40eb1e"
    },
    {
      "name": "postmark-templates",
      "type": "archive",
      "description": "Use when creating, managing, or sending with Postmark server-side email templates — Handlebars syntax, layout inheritance, template validation, and cross-server pushing.",
      "url": "https://postmarkapp.com/.well-known/agent-skills/postmark-templates.tar.gz",
      "digest": "sha256:beb488f8fd291db6e552fd3a72ee5b02cc990a69046ebf375dca793a64dae779"
    },
    {
      "name": "postmark-webhooks",
      "type": "archive",
      "description": "Use when setting up Postmark webhooks for tracking email delivery, bounces, opens, clicks, spam complaints, or subscription changes — includes webhook configuration, payload handling, and security.",
      "url": "https://postmarkapp.com/.well-known/agent-skills/postmark-webhooks.tar.gz",
      "digest": "sha256:d481bccb758d339ba4b0e5e32ae8066dbeea98d90e218a04b2faa990defd04ea"
    }
  ]
}

How we test this:

• Any of three passes: /.well-known/agent-skills/index.json on your site or your docs (or one a Link header names) lists a skill whose file answers; your docs or llms.txt link a SKILL.md that answers with a name and a description; or your docs show a skills install command, on a page we read or on up to 3 pages your docs or llms.txt link about skills or your CLI.
• An install is npx skills add, claude plugin install, a git clone into a skills folder, or your own command line running plugin install or skills add right after the word skill.
• An index under a folder, like /developer/, may list its files from that folder.
• Cloudflare's isitagentready, agenticplug and Alpic check it.

How we test this:

• We look for OAuth authorization server metadata (RFC 8414): at /.well-known/oauth-authorization-server on your site, through the authorization_servers your protected-resource metadata (RFC 9728) names, and on your mcp. host.
• It passes when it lists S256 in code_challenge_methods_supported, has scopes_supported, and has a registration_endpoint or client_id_metadata_document_supported, as the MCP authorization spec asks.
• With no OAuth metadata, it isn't counted.

How we test this:

• On your docs surface we look for an install in each of four languages: TypeScript/JavaScript (npm, yarn, pnpm or bun), Python (pip, poetry or uv), Go (go get) and Java (a Maven <artifactId> or a Gradle implementation line).
• All four must appear.
• This shows how to install, not that a package is official.
• If none of the pages we read is a quickstart or SDK page, a miss isn't counted: it can't fail you or withhold your score.
• Ours, not AgentReady's.

How we test this:

• In the OpenAPI spec AR-ACT-02 found, we look for a POST operation on a path containing mail, email, message or send.
• No spec counts as a fail.
• Ours, not AgentReady's.

What our check kept, up to 60 lines or 6 KB

Start Free Trial No Credit Card Required How many emails do you send and receive each month? 10,000 emails Free $0.00 /mo Test your integration with 100 emails/month 100 emails/month. No overages allowed in this plan. Perfect for: Testing your integration Evaluating Postmark's deliverability Side projects with low

How we test this:

• On the pricing page AR-READ-11 reads, we look for "free" within 300 characters of a number followed by emails, messages or sends and a period (a month, a day, or 30 days), like "3,000 emails/month" or "4,000 sends in any rolling 30-day window", in the raw text (no JavaScript run).
• A one-time allowance with no period doesn't count.
• Ours, not AgentReady's.