What is using-email-templates?

A guide for using Mailtrap email templates, which are reusable email designs managed outside application code. It covers filling templates with Handlebars values, a syntax for inserting changing data into messages.

Use it when creating, editing, sending, or testing Mailtrap-hosted transactional or promotional emails. It covers template UUIDs, variables, API management, and preview sends.

It keeps email design separate from sending logic and helps avoid mistakes with template identifiers, variables, API requests, and previews.

using-email-templates — Skill for Claude Code and Codex by mailtrap

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add mailtrap/mailtrap-skills --skill using-email-templates

Clone the repo

git clone --depth 1 https://github.com/mailtrap/mailtrap-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/mailtrap/mailtrap-skills/using-email-templates.svg)](https://agentmods.dev/skills/mailtrap/mailtrap-skills/using-email-templates)

Your own site

<a href="https://agentmods.dev/skills/mailtrap/mailtrap-skills/using-email-templates"><img src="https://agentmods.dev/badge/skills/mailtrap/mailtrap-skills/using-email-templates.svg" alt="Measured on agentmods" height="20"></a>

Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,202 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00049	$0.01202
Opus 5	$0.00024	$0.00601
Sonnet 5	$0.00010	$0.00240
Haiku 4.5	$0.00005	$0.00120

Measured 7d ago against content hash d11639391ed1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

using-email-templates scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

### Example (`curl`) — template send

skills/using-email-templates/SKILL.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Using Mailtrap email templates

Overview

Templates are edited in the Mailtrap UI, referenced by UUID from your app, and filled with Handlebars data at send time. The same template can be used with transactional and bulk (promotional) streams; pick the stream when you integrate.

Before generating SDK code: read the README of the relevant SDK repository linked below for current method signatures. Do not rely on memory.

Before generating API request bodies: use the official docs and examples below—request shapes belong in the API reference, not in guesses (including when using AI-assisted coding).

Template management via API (create/update/list outside the UI): Templates API.

Related skills: authorizing-api-requests (tokens, env vars, auth headers), sending-emails (bases and streams), testing-with-sandbox (preview sends without live delivery).

When to use

When sending or testing emails with Mailtrap-hosted templates (UUID in the send payload)
Creating or editing templates in the UI
Templates CRUD via Templates API (automations, provisioning)
API body using template_uuid and template_variables
Handlebars conditionals, loops, escaped vs unescaped HTML

Quick reference

API operations

In the developer docs, open:

Transactional – Send email (including template) (https://send.api.mailtrap.io)
Bulk – Send email (including template) (https://bulk.api.mailtrap.io)

Request body variant is typically EmailFromTemplate in the interactive reference.

Authorization

Send with Authorization: Bearer $MAILTRAP_API_TOKEN on the matching stream host (send.api.mailtrap.io or bulk.api.mailtrap.io). Token scope, storage, and the alternative Api-Token header are covered in skill authorizing-api-requests.

Read the full file on GitHub · 103 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

7d ago First seen · 103 lines · 49 tokens per session scan A d11639391ed1

Subscribe to this mod's changes

using-email-templates is a skill published in the GitHub repository mailtrap/mailtrap-skills (10 stars, last pushed 1mo ago), licensed MIT. It adds 49 tokens to every session and 1,202 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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using-email-templates