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.
npx skills add resend/resend-skills --skill agent-email-inboxgit clone --depth 1 https://github.com/resend/resend-skillsWrote 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.
[](https://agentmods.dev/skills/resend/resend-skills/agent-email-inbox)<a href="https://agentmods.dev/skills/resend/resend-skills/agent-email-inbox"><img src="https://agentmods.dev/badge/skills/resend/resend-skills/agent-email-inbox/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.
<a href="https://agentmods.dev/skills/resend/resend-skills/agent-email-inbox"><img src="https://agentmods.dev/badge/skills/resend/resend-skills/agent-email-inbox.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk warn
- NVIDIA SkillSpector pass
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 | $0.00094 | $0.05386 |
| Opus 5.5 | $0.00038 | $0.02154 |
| Sonnet 5.5 | $0.00019 | $0.01077 |
| Haiku 4.5 | $0.00009 | $0.00539 |
Grade A, and why
agent-email-inbox 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 20d 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.
1. Server is running: `curl http://localhost:3000` should return a response Copies of this mod
2 near-identical copies found in the catalogue:
- agent-email-inbox — 98% identical, 302 lines differ
- agent-email-inbox — 98% identical, 306 lines differ
How it starts
The opening of the file, as written. The whole thing — 511 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AI Agent Email Inbox
Overview
This skill covers setting up a secure email inbox that allows your application or AI agent to receive and respond to emails, with content safety measures in place.
Core principle: An AI agent's inbox receives untrusted input. Security configuration is important to handle this safely.
The skill builds the agent on a Resend Inbox. An inbox groups email into threads, and your agent replies inside the thread with one call. Resend sets the recipients and the threading headers. If the user has no custom domain, or their plan has no inbox available, use Receiving without an inbox instead. The security levels are the same for both.
Why Webhook-Based Receiving?
Resend uses webhooks for inbound email, meaning your agent is notified instantly when an email arrives. This is valuable for agents because:
- Real-time responsiveness — React to emails within seconds, not minutes
- No polling overhead — No cron jobs checking "any new mail?" repeatedly
- Event-driven architecture — Your agent only wakes up when there's actually something to process
- Lower API costs — No wasted calls checking empty inboxes
Architecture
Sender → Email → Resend Inbox → inbox.email.received webhook → Your Server → AI Agent
↓
Security Validation
↓
Process or Reject → Reply in the thread
SDK Version Requirements
The inbox flow needs the Node.js SDK resend >= 6.34.1, which has resend.inboxes.* and the inbox.* webhook event types. Always install the latest SDK version. If the project already has a Resend SDK installed, check the version and upgrade if needed.
The Python SDK resend >= 2.50.0 also has the inbox methods. For the other languages, call the Inboxes API over HTTP until their SDK has inbox methods, or use Receiving without an inbox.
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 20d ago Changed b4aaeb24aeb4
- 23d ago Changed · +108 lines 493b670a4640
- 29d ago Changed · +2 lines 42d56b4c3098
- 2mo ago First seen · 401 lines · 94 tokens per session scan A 50df0c77dc31
agent-email-inbox is a skill published in the GitHub repository resend/resend-skills (212 stars, last pushed yesterday), licensed MIT. It adds 94 tokens to every session and 5,386 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-08-30.
agent-email-inbox compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| agent-email-inboxresend/resend-skills | Skill | 212 | yesterday | MIT | A | 94 | Claude Code |
| mem0-oss-to-platformmem0ai/mem0 | Skill | 68k | 2d ago | Apache-2.0 | A | 217 | Claude Code, Codex |
| azure-mgmt-botservice-dotnetmicrosoft/skills | Skill | 3.2k | yesterday | MIT | A | 78 | Claude Code |
| fastapi-router-pymicrosoft/skills | Skill | 3.2k | yesterday | MIT | A | 46 | Claude Code |
| dev-runtimelangwatch/langwatch | Skill | 5.0k | yesterday | Apache-2.0 | A | 172 | Claude Code |
| api-designericrisco/rsc-harness | Skill | 503 | 2d ago | MIT | A | 105 | Claude Code, Codex |
| migrate-segw-to-raparc-mcp/arc-1 | Skill | 252 | yesterday | MIT | A | 106 | Claude Code |