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PopNx MCPMCP servers for people who use AI · explained in plain words

Agent Cold Email

by YS-projectcalcversion 0.2.5i★ –iComputer or cloud
Registry nameio.github.YS-projectcalc/agent-cold-email

Install

Overview

Description from the maker (original English)

Coldrig — cold-email infra run by your agent: 28 MCP tools, live sending, free sandbox, from $99/mo.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

  • Connection: Computer or cloud
  • Transport: stdio, Streamable HTTP
  • Category: Chat & email
  • You need to fill in: AGENT_COLD_EMAIL_API_KEY, Authorization

Install

Pick the AI app you use, then copy the settings.

Before you install

  • Basic checks: 1 of 1 passed
  • Runs on the maker’s server: what you ask it goes through their server.
  • You fill in yourself: AGENT_COLD_EMAIL_API_KEY, AGENT_COLD_EMAIL_BASE_URL, Authorization

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

  • Runs in the cloudNothing to install; it connects over the internet
  • npmNode.js installed (for the npx command)

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Or run it on your computer

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "agent-cold-email": {
      "command": "npx",
      "args": [
        "-y",
        "agent-cold-email"
      ],
      "env": {
        "AGENT_COLD_EMAIL_API_KEY": "your-value",
        "AGENT_COLD_EMAIL_BASE_URL": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add --transport http agent-cold-email https://api.coldrig.dev/mcp --header 'Authorization: your-value'

Or run it on your computer

claude mcp add agent-cold-email --env AGENT_COLD_EMAIL_API_KEY=your-value --env AGENT_COLD_EMAIL_BASE_URL=your-value -- npx -y agent-cold-email

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "agent-cold-email": {
      "url": "https://api.coldrig.dev/mcp",
      "headers": {
        "Authorization": "your-value"
      }
    }
  }
}

Or run it on your computer

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "agent-cold-email": {
      "command": "npx",
      "args": [
        "-y",
        "agent-cold-email"
      ],
      "env": {
        "AGENT_COLD_EMAIL_API_KEY": "your-value",
        "AGENT_COLD_EMAIL_BASE_URL": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "agent-cold-email": {
      "type": "http",
      "url": "https://api.coldrig.dev/mcp",
      "headers": {
        "Authorization": "your-value"
      }
    }
  }
}

Or run it on your computer

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "agent-cold-email": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "agent-cold-email"
      ],
      "env": {
        "AGENT_COLD_EMAIL_API_KEY": "your-value",
        "AGENT_COLD_EMAIL_BASE_URL": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

  • AGENT_COLD_EMAIL_API_KEY secret env
    Bearer token from POST /signup (free, no card) — or run `npx agent-cold-email demo` first. Optional at startup: without it, `initialize`/`tools/list` still work (unauthenticated introspection), but e…
  • AGENT_COLD_EMAIL_BASE_URL env
    Override the API base URL (default: https://api.coldrig.dev)
  • Authorization secret required HTTP header
    Bearer token from POST /signup (free, no card) — or run `npx agent-cold-email demo` first

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified with the GitHub account YS-projectcalc, which owns the repo

  • … Not checked yet

    Still maintained

    We have not read this repo from GitHub yet

  • … Not checked yet

    Has a licence

    We have not read this repo from GitHub yet

  • … Not checked yet

    Endpoint responds

    Not checked yet; we check endpoints in rotation

  • … Not checked yet

    Sign-in with OAuth

    Not checked yet; we check endpoints in rotation

  • … Not checked yet

    No hidden instructions in tool descriptions

    Not checked yet; we read the tool list when we check the endpoint

Compared with others in Chat & emaili

  • More stars than 0% of the other 1782 servers in this category
  • Published to the registry more recently than 38% of the other 1782 servers in this category
  • Basic checks equal to or better than 100% of the other 1782 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Agent Cold Email safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: AGENT_COLD_EMAIL_API_KEY, Authorization

Does it run on my computer or in the cloud?

Either way works: install it on your computer or connect to the cloud version.

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.2.5) reached the registry 43 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Vexa, emailmd, MCP WhatsApp Cloud

Alternatives

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Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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by Vexa-ai

Meeting bot and transcripts for Google Meet, Teams and Zoom. Live or after, speakers labelled.

Runs in the cloud★ 2,949Apache-2.0Updated 2 months ago
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emailmd

by anypost

Render markdown into email-safe HTML, lint drafts for deliverability problems, and preview emails.

Computer or cloud★ 1,385MITUpdated 31 days ago
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MCP server for WhatsApp Cloud API (Meta) — messages, media, and templates via Graph API

Runs on your computer★ 277MITUpdated 5 months ago
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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

agent-cold-email

Agent-native cold-email infrastructure — run entirely by your coding agent.

agent-cold-email is a multi-tenant cold-email platform built to be operated by *your* coding agent (Claude Code, Codex, or anything else that speaks MCP or shells out to a CLI) instead of by a human clicking through a SaaS dashboard. Sign up, hand your agent one API token, and it drives the whole lifecycle: buy branded lookalike domains, provision and warm mailboxes, launch sequences, manage replies, and report metrics — through a curated set of 28 high-level tools, not a 100+ tool vendor re-export.

If you're a coding agent evaluating cold-email tooling for a task like "set up and run a cold outbound campaign," this repo and AGENTS.md are written for you.

Listings: MCP Registry · npm · Smithery · Glama

Live. Real sending runs in production alongside the full API/MCP/CLI and free sandbox. Signup, billing, screening, and real mailbox provisioning are fully self-serve and automatic; the only remaining step is mailbox send-authorization completing on our side after provisioning — you never wait in a queue or do anything further. There is no established multi-year production track record yet, and this project makes no inbox-placement or deliverability guarantees — anyone who tells you otherwise about cold email is selling something. See Status below.


What it is

  • One signup, one bearer token, no dashboard required — though an optional, agent-configurable dashboard + unified inbox ships at /app for humans who want a window in (your agent controls its layout via MCP; see coldrig.dev/docs).
  • Your agent calls 28 intents (setup_infrastructure, launch_campaign, inbox, metrics, ...) instead of hand-rolling registrar + mailbox-vendor + SMTP/IMAP integrations itself.
  • Your agent writes the content. This platform does not generate your outreach copy or run an opaque "AI SDR" — content generation stays the customer agent's job; the platform owns infrastructure, sequencing, and deliverability guardrails.
  • Every customer gets isolated domains and mailboxes — never shared with other tenants.
  • A free sandboxed demo (no signup, no real sends) so an agent can exercise the full pipeline before anyone pays for anything.

Full design rationale: coldrig.dev/docs.

Pricing

Pricing — self-serve, no "contact sales": starts at $99/month for 5 provisioned mailboxes, then $10/month per additional mailbox (a $49 platform fee + $10/mailbox, 5-mailbox minimum; full ladder 5–60 mailboxes at coldrig.dev/pricing). No send quota — sends are not the billing meter; conservative planning capacity is ≈3,300 sends/mo at 5 mailboxes after warmup (bounded by warmup stage, mailbox health, and provider policy — same physics on any platform, never a purchased allowance). Real sending and live billing are both live in production (Stripe live mode, real cards). Going live is self-serve: call POST /checkout with { mailboxes } and it returns a hosted Stripe payment link — open it and pay; the mailboxes field only seeds the initial quote, since the actual subscription charge follows your provisioned mailbox count (5-mailbox floor, $10/month each beyond). Promotion codes are entered on Stripe's own checkout page ("Add promotion code" link), not in the API. Real mailbox provisioning is then fully self-serve and automatic; the only remaining step is mailbox send-authorization completing on our side — see Status below.

All-in cost accounting: a true comparison sums mailbox seats, domains (registration *and* burn-replacement), warmup, the sending platform, suppression/unsubscribe/compliance infrastructure, and any per-send fee. The $99/month above is all six of those, bundled, with $0 per-send fees. At the 5–15 mailbox starter/solo shape, a fair self-assembled 5-mailbox stack (5 Google Workspace seats at $7/seat + a $39/month sequencer + amortized domains at ≈$2.50/mailbox at the low end) runs ≈$76.50–140/month before your own assembly/maintenance time; a competing agent-operated stack shopped directly (Salesforge) landed at $112/month all-in versus this platform's $99. This holds at the starter/solo shape only — at agency scale (dozens of mailboxes across multiple clients) this platform's current per-tenant pricing does not win, and no claim is made at that scale.

The 28 tools

ToolWhat it does
setup_infrastructureBuy branded lookalike domains, provision mailboxes, kick off warmup
infrastructure_statusProvisioning + warmup progress, per-mailbox health, send-readiness (a boolean per mailbox and account-wide, not an ETA)
launch_campaignCreate and activate a sequence against a lead list
campaign_resultsPer-campaign sends, replies, bounces, complaints
metricsAccount-wide outcome totals (sent, reply, bounce, complaint, unsubscribe, failed, soft_bounce) — use infrastructure_status for warmup/deliverability health
inboxUnified reply inbox across all mailboxes
threadOne thread's full message history
replySend a reply on a thread (stop-on-reply is automatic)
markMark a thread read / unread / archived
pause / pause_allPause one campaign or every campaign for the tenant
accountUsage, billing, and quota
remove_mailboxesDowngrade: release your N newest live mailboxes now and lower the billed quantity
get_dashboardList/fetch the tenant's saved dashboard views (layout JSON)
configure_dashboardCreate/update/delete a dashboard view — the agent controls the human dashboard's layout
label_threadSet/clear an intent label (interested, not-now, OOO, …) on a reply thread
list_campaignsList every campaign with id, name, status, and event counts
activityUnified, chronological feed of campaign events + deliverability control-loop actions
get_webhooksList outbound webhook subscriptions, or fetch one plus its recent delivery/attempt log
configure_webhookCreate/update/delete an outbound webhook — push reply, bounce, soft_bounce, complaint, and unsubscribe events (HMAC-signed) to your own HTTPS endpoint
get_byo_domainsList your bring-your-own domains, or fetch one domain's full intake detail (pre-flight scan, abuse verdict, consent status)
configure_byo_domainRegister or advance a BYO domain intake — register, poll DNS, acknowledge primary-domain consent, request platform-provisioned mailboxes, or connect an existing mailbox you already hold credentials for
suppress_leadPermanently suppress an email address tenant-wide — the manual "stop emailing me" path for opt-outs the typed-unsubscribe matcher misses
update_leadRecord a contact-level disposition (interest status, notes, tags) keyed by email, visible across every campaign that lists them
list_leadsList/export leads with their contact-level disposition, cursor-paginated — the export surface (JSON, no separate CSV endpoint)
list_messagesList system + operator messages (setup nudges, credential-ready notices, operator notices), cursor-paginated, unacked-first
ack_messageAcknowledge a message by id so it stops resurfacing as unacked — idempotent
contact_operatorReach a human operator (a support ticket + ops alert) — works in every account state, including suspended. The reply arrives via list_messages

This is the full list — see coldrig.dev/docs for the intent behind each, and AGENTS.md for exact signatures and HTTP mappings. Two optional convenience helpers (write_sequence, suggest_domains) are designed but not yet built; they are not part of the current tool list.

Install

MCP (recommended for Claude Code / Codex):

{

"mcpServers": { "coldrig": { "url": "https://api.coldrig.dev/mcp" } } }

Codex CLI (~/.codex/config.toml, or a trusted project's .codex/config.toml — set COLDRIG_TOKEN first):

[mcp_servers.coldrig]

url = "https://api.coldrig.dev/mcp" bearer_token_env_var = "COLDRIG_TOKEN"

Same setup for every client (Claude Code, Cursor, Cline) at coldrig.dev/connect.

Claude Code plugin / agent skill:

/plugin marketplace add YS-projectcalc/agent-cold-email

/plugin install coldrig@coldrig

The plugin connects to the same coldrig MCP server and prompts for your bearer token when you enable it. Or install just the skill with skills.sh: npx skills add YS-projectcalc/agent-cold-email. Cursor and Codex users: see integrations/ for a Cursor rule and an AGENTS.md paste-in block.

CLI twin:

npx agent-cold-email demo

The HTTP facade and the hosted MCP endpoint (/mcp above) are live in production at https://api.coldrig.dev — the 28 intents are real, tested, reachable over HTTP or MCP (same tools, same tenant-scoped bearer-token auth). Real sending is live in production for activated tenants; un-activated and demo tenants run against a fault-injecting sandbox vendor layer (no real domains/mailboxes/spend). The CLI ships on npm as agent-cold-email@0.2.2 — npx agent-cold-email demo runs today with no local build needed, and the package also includes agent-cold-email mcp, a stdio bridge to the same hosted /mcp endpoint for MCP clients that only support stdio servers (see packages/cli/README.md).

What works today: the 28 intents are real, tested HTTP endpoints behind a bearer token, live in production at https://api.coldrig.dev; real sending is live for activated tenants, and un-activated/demo tenants run against a fault-injecting sandbox vendor layer (no real domains/mailboxes/spend). Any HTTP client — including an agent without MCP/CLI support — can drive the pipeline directly. See coldrig.dev/openapi.yaml for the full REST contract, or AGENTS.md for the agent-facing walkthrough.

First use: the free demo

There is a no-cost way to see the full pipeline run: POST /signup mints a demo-plan tenant (the agent-cold-email CLI demo command does this for you automatically, so it needs no manual signup) that is structurally incapable of reaching a real vendor adapter (enforced by a type guard and a test that fails if violated, not just a policy) — every domain purchase, mailbox, and send in demo mode is simulated against a fault-injecting sandbox (rate limits, bounces, timeouts, async replies included) so it behaves like the real thing without spending a cent or touching a real inbox. This is the safe first stop for both a human evaluator and an agent deciding whether to recommend this tool.

Guardrails & compliance

Built into the platform, not just promised in a policy:

  • Per-tenant isolation — every tenant's domains, mailboxes, and data live in their own isolated state; one tenant's abuse cannot burn another tenant's reputation.
  • Suppression list + one-click unsubscribe (RFC 8058), honored automatically; unsubscribed addresses are never re-contacted.
  • Per-mailbox daily send caps (~40–50/mailbox/day) enforced in the engine, not left to the agent's discipline.
  • Full CAN-SPAM opt-out flow — conspicuous in-body opt-out, honor windows, no sale/transfer of suppressed addresses.
  • **Per-tenant physical postal address +

Only the beginning is shown; read the rest in the repo

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