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 ericrisco/rsc-harness --skill email-connectorgit clone --depth 1 https://github.com/ericrisco/rsc-harnessWrote 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/ericrisco/rsc-harness/email-connector)<a href="https://agentmods.dev/skills/ericrisco/rsc-harness/email-connector"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/email-connector/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/ericrisco/rsc-harness/email-connector"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/email-connector.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 97 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
- medium Data Exfiltration · line 97 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 | $0.00083 | $0.03281 |
| Opus 5.5 | $0.00033 | $0.01312 |
| Sonnet 5.5 | $0.00017 | $0.00656 |
| Haiku 4.5 | $0.00008 | $0.00328 |
Grade B, and why
email-connector scanned grade B 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.
Sends data to an external URLmediumData exfiltration
A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.
const r = await fetch('https://api.postmarkapp.com/email', { method: 'POST', How it starts
The opening of the file, as written. The whole thing — 278 lines — stays where its author put it; the contents beside it link to each section on GitHub.
email-connector — put transactional & bulk email on the wire
You wire the send. A welcome mail, a password reset, a receipt, a 4,000-row
digest — your job is the server code that hands it to a provider, makes it safe
to retry, and keeps the suppression list honest. You do not own the inbox
(SPF/DKIM/DMARC/reputation is ../email-deliverability/SKILL.md) and you do
not own the words (subject lines and growth are ../newsletter/SKILL.md,
launch copy is ../marketing/SKILL.md). Generic typed clients for any REST API
are ../api-connector-builder/SKILL.md; deciding when a multi-step sequence
fires is ../automation-flows/SKILL.md.
Stack as of June 2026: resend 6.12.4, @sendgrid/mail 8.1.6, Postmark via its
HTTP API, React Email 5.0 (React 19.2 / Next.js 16, Tailwind 4), Node 20+ / TS.
scripts/verify.sh is read-only and greps a target for the four invariants this
skill exists to hold: env-sourced key, idempotency, a single sendEmail() seam,
and a webhook signature checked on the raw body.
Step 1 — pick a provider
| Provider | Best default fit | Native idempotency | Template model | Batch cap | Pick when |
|---|---|---|---|---|---|
| Resend | Greenfield, React/Next shops | Yes — { idempotencyKey }, 24h, ≤256 chars |
React Email JSX via react: |
100/call | You want JSX templates and the least ceremony |
| SendGrid (Twilio) | High volume, marketing+txn mix | No — dedupe yourself | d- dynamic templates + dynamicTemplateData |
per-send personalizations |
You need 10k req/s scale or already on Twilio |
| Postmark | Pure transactional, deliverability-first | No — self-dedupe via your key + webhooks | Postmark server templates | per-stream | Receipts/resets must never queue behind marketing |
Idempotency support changes your strategy, not just your config — see Step 4.
Full per-provider matrix (auth header, SDK + version, single/batch signatures,
idempotency model, stream/subdomain model, dynamic-template syntax, webhook event
names, rate limits, when to pick each) plus a suppression-webhook handler skeleton
per provider is in references/providers.md.
What ships with it
4 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.
- 1mo ago First seen · 278 lines · 83 tokens per session scan B 99d385dfa55c
email-connector is a skill published in the GitHub repository ericrisco/rsc-harness (340 stars, last pushed today), licensed MIT. It adds 83 tokens to every session and 3,281 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it B with 1 finding (sends data to an external url). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
email-service-integration
Send reliable transactional emails (order confirmations, shipping updates) via SendGrid, SES, or Postmark with templates and deliverability best practices.
pipefy-members-email-webhooks
Use this skill when the user wants to manage pipe membership, send or read card inbox emails, use email templates, or manage webhooks.
building-mcp-servers
Authors an MCP server with the official SDK and gates.
dev-nextjs
Next.js development (App Router, Server Components, caching, streaming). Trigger when the user works with Next.js, modifies app/, pages/, next.config, or talks about RSC, Server Actions, Route Handlers, middleware.
dev-auth
Modern web auth implementation (better-auth, NextAuth/Auth.js, Clerk, Supabase Auth; migrating off the deprecated Lucia). Trigger when the user wants to add login, signup, sessions, OAuth, magic links, 2FA, or when existing auth code is detected to audit or migrate.
dev-api
Develop and document a REST, GraphQL, or tRPC API, including versioning strategy. Use when the user wants to create an endpoint, a route, a type-safe procedure, or structure/version an API.