agentmail

agentmail is a skill for Claude Code from Ghosteken/agent-harness. It costs 31 tokens per session (2,260 once invoked), scanned A, a copy of agentmail, MIT.

An email service for AI agents that provides real email addresses and an API for sending and receiving messages.

In plain words
What is it for?
Use it to create agent mailboxes, send or read email, receive inbound webhooks, and check the service's karma balance.
Why use it?
It lets agents use inboxes for sign-ups, verification codes, notifications, and other email workflows without a person handling each message.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the agent-harness plugin — 173 skills, 17 commands, 12 agents shipped together

Good fit Use it to create agent mailboxes, send or read email, receive inbound webhooks, and check the service's karma balance.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ghosteken/agent-harness/agentmail
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 Ghosteken/agent-harness --skill agentmail
Clone the repo
git clone --depth 1 https://github.com/Ghosteken/agent-harness

Made for: Claude Code.

Or install agent-harness, the plugin that ships this one along with the rest of its 173 skills, 17 commands, 12 agents.

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.

agentmods badge for agentmail

README.md
[![agentmods](https://agentmods.dev/badge/skills/ghosteken/agent-harness/agentmail/github.svg)](https://agentmods.dev/skills/ghosteken/agent-harness/agentmail)
Your own site
<a href="https://agentmods.dev/skills/ghosteken/agent-harness/agentmail"><img src="https://agentmods.dev/badge/skills/ghosteken/agent-harness/agentmail/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for agentmail

Your own site · 80×15
<a href="https://agentmods.dev/skills/ghosteken/agent-harness/agentmail"><img src="https://agentmods.dev/badge/skills/ghosteken/agent-harness/agentmail.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,260 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 100% copy Near-identical to another mod 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00031 $0.02260
Opus 5.5 $0.00012 $0.00904
Sonnet 5.5 $0.00006 $0.00452
Haiku 4.5 $0.00003 $0.00226

Measured 1mo ago against content hash a68e8fc0b2b0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

agentmail 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 1mo 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.

curl -X POST https://api.theagentmail.net/v1/accounts \
Origin

This is a copy

100% identical to agentmail — 92 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

archive/skills-community/agentmail/SKILL.md · 258 lines

How it starts

The opening of the file, as written. The whole thing — 258 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AgentMail — Email for AI Agents

AgentMail gives AI agents real email addresses (@theagentmail.net) with a REST API. Agents can send and receive email, sign up for services (GitHub, AWS, Slack, etc.), and get verification codes. A karma system prevents spam and keeps the shared domain's reputation high.

Base URL: https://api.theagentmail.net

When to Use

  • An AI agent needs a real inbox/outbox for signups, verification flows, or transactional communication.
  • You need to provision AgentMail accounts, send messages, read inbox contents, or register inbound webhooks.
  • You need to monitor karma usage or wire email events into agent automation.

Quick start

All requests require Authorization: Bearer am_... header (API key from dashboard).

Create an email account (-10 karma)

curl -X POST https://api.theagentmail.net/v1/accounts \
  -H "Authorization: Bearer am_..." \
  -H "Content-Type: application/json" \
  -d '{"address": "[email protected]"}'

Response: {"data": {"id": "...", "address": "[email protected]", "displayName": null, "createdAt": 123}}

Send email (-1 karma)

curl -X POST https://api.theagentmail.net/v1/accounts/{accountId}/messages \
  -H "Authorization: Bearer am_..." \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["[email protected]"],
    "subject": "Hello from my agent",
    "text": "Plain text body",
    "html": "<p>Optional HTML body</p>"
  }'

Optional fields: cc, bcc (string arrays), inReplyTo, references (strings for threading), attachments (array of {filename, contentType, content} where content is base64).

Read inbox

# List messages
curl https://api.theagentmail.net/v1/accounts/{accountId}/messages \
  -H "Authorization: Bearer am_..."

# Get full message (with body and attachments)
curl https://api.theagentmail.net/v1/accounts/{accountId}/messages/{messageId} \
  -H "Authorization: Bearer am_..."

Check karma

curl https://api.theagentmail.net/v1/karma \
  -H "Authorization: Bearer am_..."

Read the full file on GitHub · 258 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.

  1. 1mo ago First seen · 258 lines · 31 tokens per session scan A a68e8fc0b2b0

Subscribe to this mod's changes

agentmail is a skill published in the GitHub repository Ghosteken/agent-harness (4 stars, last pushed yesterday), licensed MIT. It adds 31 tokens to every session and 2,260 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to agentmail, differing in 92 lines, and is treated as a copy.

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