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Postscript API and MCP server

Postscript's API has no campaigns, segments or keywords, and its analytics connector only reads. Sign in to Postscript once in your own Cloud Browser, and your AI agent does the work there for you. The same tools work over MCP for agents and as a REST API for scripts.

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Not affiliated with Postscript.

Postscript's own API leaves this out. So we run one for you.

Postscript's own API, a GitHub MCP server and Cotlet compared
What you need Postscript's APIGitHub MCP serverCotlet
Campaigns, segments, keywords, replies No Partly Yes, 13 tools
Acts as you, signed in 24/7 No No Yes, Cloud Browser
Fixed for you when Postscript changes N/A No Yes, tested every 6h
Runs with your laptop off N/A No Yes, hosted

Checked Oct 23, 2026. Sources: Postscript Help: Postscript MCP · Postscript Developers: API authentication · Postscript Developers: API reference · Postscript on Zapier

Your own Cloud Browser, on 24/7. Sign in once. We keep it connected.

  1. 01Sign in to Postscript in your own Cloud Browser

  2. 02Connect it for your agents

  3. 03Cotlet keeps it signed in and working

How do I connect Postscript to Claude, ChatGPT or my code?

AI agents connect over MCP, scripts call the REST API. Both reach the same 13 tools with one API key.

For AI agents: MCP

Add Cotlet to your agent once. Postscript and every other app you connect show up as its tools.

  • Claude
  • ChatGPT
  • OpenClaw
  • Hermes
  • GrokBot
  • Cursor
  • n8n
  • Any MCP client
  1. 1

    Add Cotlet to your agent

    Claude Code
    claude mcp add --transport http cotlet \
  https://cotlet.dev/mcp/v1 \
  --header "Authorization: Bearer $COTLET_API_KEY"
    Cursor
    {
  "mcpServers": {
    "cotlet": {
      "url": "https://cotlet.dev/mcp/v1",
      "headers": {
        "Authorization": "Bearer ${COTLET_API_KEY}"
      }
    }
  }
}
    Codex
    # ~/.codex/config.toml
[mcp_servers.cotlet]
url = "https://cotlet.dev/mcp/v1"
bearer_token_env_var = "COTLET_API_KEY"

    Paste the snippet for your client. The same server and key serve every app you connect, so you do this once.

For scripts: REST API

Every tool is an endpoint under /api/v1/postscript with its own method and path, such as POST /api/v1/postscript/campaigns, with the same API key. Our open-source repo has ready scripts to start from.

REST API docs

What can the Postscript API and MCP server do?

13 tools on your own Postscript account. Agents call them as operations of the MCP tools postscript_read and postscript_write; scripts call each one at its own REST endpoint, with the same inputs and answers.

API reference
Postscript tools in Cotlet's MCP server and REST API
Tool What it does Access
list_segments Segments of the shop from Messaging > Segments, with their Segment Size. read
list_campaigns Campaign flows from Messaging > Flow Builder, with status and the segments they include. read
get_message_analytics Message Analytics rows per campaign and automation: sends, clicks, orders, revenue and unsubscribes. read
list_keywords Opt-in keywords from Acquisition > Keywords, with their reply. read
find_subscriber Subscriber profile from Search, found by phone number, name or email. read
list_conversations Threads from Messaging > Conversations, filterable by state, topic and sentiment. read
create_segment Save a segment under Messaging > Segments from criteria joined with and or or. write
create_campaign Save a campaign flow draft with its segments and first Send Message block. Sends nothing. write
send_preview Text a preview of a campaign message to one phone number. writeasks first
schedule_campaign Activate a campaign flow immediately or at a date and time. writeasks first
stop_campaign End a running campaign flow with End campaign and Stop campaign. writeasks first
create_keyword Create an opt-in keyword with a reply, optionally with a coupon. writeasks first
reply_to_conversation Send a reply in a Conversations thread with Send Reply. writeasks first

Scroll the table for all 13 tools.

Ask in plain words. Your agent does the rest.

All Postscript use cases

Is it safe to connect Postscript?

You sign in yourself in your own Cloud Browser, we never save your password, and anything that reaches your readers waits for your OK. The browser profile is encrypted in the EU. Independent scanners grade cotlet.dev A+.

Security overview

How much do the Postscript API and MCP server cost?

One price for both: a tool call costs the same over MCP or REST. Free 7-day trial with 2,000 credits, no card needed. Then one-time credit packs, no subscription, valid 12 months. Each call uses 10 credits, and your Cloud Browser uses 50 credits a day while Postscript is enabled for agents, so 20 calls a day come to 250 credits.

See full pricing
Cotlet credit packs: price, credits and calls at 10 credits each
Credits Price, one time Calls at 10 credits Per 1,000 credits
5,000 $29 500 $5.80
15,000 $79 1,500 $5.27
32,000 $149 3,200 $4.66
60,000 $249 6,000 $4.15

Only successful calls use credits; failed calls and timeouts cost nothing. At a balance of 0 calls pause, never a surprise charge. Authenticate with the Authorization: Bearer header.

Questions

Does Postscript have an API?

Postscript has an API and an official MCP server, but neither builds or sends campaigns (checked 23 Oct 2026). The MCP server is read-only: it pulls campaign, automation, popup and shop-wide analytics on Pro and Enterprise plans and "cannot create, edit, send, or delete anything". The API reference lists subscriber reads and updates, unsubscribe, redact and custom events.

How do I get access?

Sign up free, open Postscript under Integrations in the console and press Request access. Your free trial starts with your account, no card needed.

Is the MCP server different from the API?

No, only the way in. Cotlet builds each integration as a REST API and puts an MCP server on top, so both have the same 13 tools, the same inputs and answers, one API key and one price. AI agents such as Claude, ChatGPT or Cursor use MCP; scripts, cron jobs and HTTP steps in n8n, Make or Zapier use the REST API.

What is the Cloud Browser?

Your own Chrome that Cotlet runs for you in the EU, around the clock. You open it from the console, sign in to Postscript yourself and press Enable for agents. Your agent's calls go through it, from its IP with its cookies, so Postscript sees the browser you signed in with. Password saving is off and the profile is stored encrypted with AES-256-GCM.

Can my agent act without asking me?

Not on anything that reaches other people: send_preview, schedule_campaign, stop_campaign, create_keyword, reply_to_conversation wait for your OK by default. You can switch that off per tool for scheduled runs.

Do I need a Pro or Enterprise plan?

No. Postscript's official MCP server is available on Pro and Enterprise plans. Cotlet works in your own Postscript account, so it does not depend on that. Postscript's plan rules still apply: more than two keywords need the Growth, Professional or Enterprise plan, and two-way replies work for US and Canadian subscribers.

Does the agent skip Postscript's SMS rules?

No. Postscript still holds campaigns until waking hours in each subscriber's time zone, and it excludes unsubscribed people from every segment. Sending marketing texts needs the subscriber's prior express written consent under the TCPA, and you remain the sender. Every send waits for your OK by default.

Should I use a Postscript MCP server from GitHub instead?

Pick one if you want the code on your own computer and do not mind the upkeep: you install it, sign it in and fix it when Postscript changes. Pick Cotlet if you want it hosted and kept working for you.

Can I use it in n8n, Make or Zapier?

Yes. Add https://cotlet.dev/mcp/v1 in n8n's MCP Client node, or call the REST endpoints from an HTTP step in Make or Zapier.

Who runs Cotlet?

Cotlet is run by Take Group, a Polish software company working since 2019. Take Group runs about 3,200 websites on its own systems and has its own DevOps team for infrastructure security. We built and used integrations like this inside the company for years before opening them as Cotlet.

Is Cotlet affiliated with Postscript?

No. Cotlet is independent and not affiliated with Postscript.

Give your agent access to Postscript.

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