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Emailactive

Postmark API for coding agents

View Agent Bench results API docs

Postmark pairs mature transactional-email primitives with concrete agent instructions and a safe test token. It is a strong choice when delivery workflows matter more than a broad marketing suite.

#3of 7
Email API agent readiness

Completed a clean Agent Bench setup run and publishes an official agent skill, build spec, test token, and mature SDKs.

Last checked Aug 17, 2026 4 primary sources All Them APIs setup result
Agent Bench evidence

1m 21s Agent Bench setup run with 0 recorded errors.

All Them APIs measured an autonomous setup run using Claude Code · Opus 4.6.

All Them APIs · Email setup

Claude Code · Opus 4.6

Setup run completed

Postmark completed the setup run without a recorded error and required one human interruption.

Time
1m 21s
Errors
0
Interruptions
1
Cost
$0.56
This setup result is separate from the task-performance score.
View Agent Bench results
Agent verdict

Can a coding agent use Postmark? Yes.

Postmark now publishes an agent-ready build spec and an official skill alongside direct SDK installation. The test token makes payload validation unusually straightforward.

Agent guidance plus mature SDKs
Review fit, workflows, and caveats

Good fit

  • Operational and transactional email
  • Teams that separate email by application or stream
  • Agents that benefit from a copyable build spec

Check before shipping

  • A sender signature or domain must be confirmed
  • No first-party MCP server found
  • Different token types apply to server and account operations

Common workflows

  • Send transactional email
  • Send template-based messages
  • Process inbound email
  • Track delivery with webhooks
Recommended setupOfficial Node.js SDK
Coding agent skillnpx skills add ActiveCampaign/postmark-skills

Installs Postmark's published integration guidance for compatible coding agents.

Node.js / TypeScriptnpm install postmark

Set POSTMARK_SERVER_TOKEN in the server environment and use the official ServerClient.

Open official setup documentation
Reference

API limits and source records

Base URL, authentication, pricing, SDKs, rate limits, and checked documentation.

API basics
Base URL
https://api.postmarkapp.com
Authentication
Server token and Account token
Free tier
Developer plan and test token available; see current pricing
Credit card
Not required
Rate limit
Endpoint dependent; batch and recipient limits are documented per operation
Testing
POSTMARK_API_TEST validates send payloads without delivering email
7 official SDKs
Node.js / TypeScriptPythonRubyPHP.NETJavaRails
4 checked sources
API overviewbase URL · token types · RESTGet startedagent skill · build spec · SDK installationSend with APIsend endpoint · test token · sender requirementsOfficial librariesofficial SDKs
Pricing, status, and alternatives
PricingStatusChangelogGitHubResendMailgunLoops

See something inaccurate?

Email faizank@docsalot.dev with the API name and an official source link.