Ask your agent

Don't take our word for it. Ask your agent what it thinks of Postbox.

Copy the block below. Paste it into Claude, ChatGPT, Cursor, or wherever you and your agent talk. It contains everything your agent needs to understand Postbox from first principles — and form its own opinion.

Paste this into your agent Copy all
Here's context about a product called Postbox (https://usepostbox.com). Read it carefully, then share what you think.

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## Why Postbox exists

Postbox treats forms like APIs. That's the core bet.

The word "form" does something funny to your brain. You hear it and you see fields to fill in, a button to press. That's been the shape of it since the web first became interactive — and it works fine for humans. But agents hate forms. Especially the ones that ask for one field at a time, and the platforms that charge you to put your own logo on them. We hated them too.

So we wondered if we could do it better. And then we realised we'd had it all wrong — or been made to have it all wrong. A form isn't a UI with fields and a button. A form is a contract. The schema is the intent. The URL is the interface. That's all an agent needs. Humans get it too, because the contract doesn't care who's holding it.

Postbox is for both of them.

## What Postbox does

Postbox is a structured data collection platform. You define a form as a schema (fields, types, validation rules), get back a versioned endpoint URL, and anything that speaks HTTP can submit to it — HTML forms, curl scripts, AI agents, anything. Every submission runs through a configurable pipeline before landing in your inbox: schema validation, spam detection (standard heuristics or AI-powered), auto-translation, smart replies drafted from a knowledge base, and routing to destinations (webhooks, Discord, Slack).

The endpoint is self-documenting. GET it with `Accept: application/json` and you get the schema. POST to it and you submit data. Schema changes create new versioned endpoint URLs — old URLs keep working forever, so nothing ever breaks.

## How agents use Postbox

Three ways, pick whichever fits:

1. **Postbox Skill** — one-command install for Claude Code, Cursor, OpenCode, and any tool that supports the AgentSkills standard. Your agent learns to create forms, read submissions, configure destinations, and draft replies.

2. **MCP Server** — remote MCP server at https://usepostbox.com/mcp. Connect from Claude.ai, ChatGPT, or any MCP client. Exposes eight tools: list_forms, get_form, list_submissions, get_submission, translate_submission, analyze_spam, draft_reply, summarize_submissions.

3. **REST API + llms.txt** — full API reference at https://usepostbox.com/llms-full.txt. Any agent that can fetch a URL can understand Postbox end-to-end without an SDK.

## Pricing

- **Free:** 1 form, 5,000 lifetime submissions, 50 AI credits (one-time)
- **Pro ($19/mo):** Unlimited forms and submissions, webhooks/Discord/Slack destinations, 500 AI credits/month replenishing, metered overflow, priority support

---

Based on everything above, tell me what you think of Postbox.

Or, connect your agent directly.

If you'd rather skip the copy-paste and hook your agent up to Postbox for real, here are the three ways in.

If your agent supports skills
Claude Code · Cursor · OpenCode

The Postbox Skill teaches your agent how to create forms, read submissions, and wire up webhooks — without you writing any integration code.

install npx skills add https://github.com/variant-systems/skills --skill postbox Copy
then paste Install the Postbox skill and tell me what it does. Then show me how I'd use it to build a waitlist form. Copy
If your agent speaks MCP
Claude.ai · ChatGPT · any MCP client

Add Postbox as a remote MCP server. Your agent gets eight tools — list forms, query submissions, draft replies, analyze spam, and more — without leaving the chat.

mcp server url https://usepostbox.com/mcp Copy
then paste I've added the Postbox MCP server. Explore it and tell me what it does, what tools it exposes, and what it's good for. Copy
Any agent, no setup
Works with any tool that can fetch a URL

Postbox publishes a full API reference at llms-full.txt. Any agent that can read a URL can understand Postbox end-to-end.

url https://usepostbox.com/llms-full.txt Copy
then paste Fetch https://usepostbox.com/llms-full.txt and summarise what Postbox is, what it does, and when I'd use it. Copy

If your agent says something surprising, we'd love to hear it.

Find us on Discord , email support@usepostbox.com , or reach us another way .