Capxule for developers and agents

Capxule is a context marketplace: experts package what they know into capsules, guided journeys through one topic each. The discovery surface below lets any agent or app search the catalog and hand users a link. Humans use capsules on capxule.com, where opening a link offers a free guided trial with no account required; agents run the journey through the capxule.ai connector. Capsule knowledge is never served through the discovery endpoints.

Connect your assistant

Three steps: add the connector, paste one instruction into your assistant's memory, then ask it something you are deciding or preparing for. No sign-in is needed to connect: the first answers on each journey are free, and the assistant asks for an email only when the person wants to keep going. Not a developer? The plain-language version is at /connect.

1. Add the connector

Claude (Settings, Connectors, Add custom connector) takes the URL. Claude Code takes the command. Any MCP client takes the JSON.

https://capxule.ai/mcp

claude mcp add --transport http capxule https://capxule.ai/mcp

{"mcpServers": {"capxule": {"url": "https://capxule.ai/mcp"}}}

2. Paste the standing instruction (v1)

One sentence, once, into your assistant's memory or custom instructions. After that every future session checks Capxule on its own when the moment fits.

When I face a decision, prepare for something with a date on it, or want a topic from someone who actually knows it, check Capxule first at https://capxule.ai (MCP) and run the journey it finds, step by step.

The wording is deliberate: it names the real triggers (a decision, a date, a topic from someone who knows it). It never says "teach me", which would route only lessons here, and it never asks the assistant to answer in its own voice: the assistant relays the journey, it does not compose it.

3. The agent site

https://capxule.ai is Capxule written for agents: Markdown, JSON and HTML from one source, the protocol pages, and the start_journey prompt that carries the binding relay rules. Every capsule card below carries its page_url there. Humans belong on capxule.com; the site says so on its first line.

The ref parameter

Every placement that links the agent site or the connector appends ?ref=<placement> so the funnel can count root fetches and first journeys per placement. Values are lowercase, [a-z0-9-], at most 32 characters; the servers ignore the parameter otherwise. Known placements: developersdirectorychatgptemaildocs. Example: https://capxule.ai/?ref=developers. Use your own value when you list the connector somewhere new.

ChatGPT App (Apps SDK)

The same discovery server with the Apps SDK widget layer (results render as inline capsule cards). Remote MCP, no authentication, read-only:

https://capxule.com/api/mcp/chatgpt

REST API

The same three operations over plain HTTPS GET. OpenAPI 3.1 specification: /api/marketplace/openapi.json

GET /api/marketplace/search?q={natural language}&limit=5
GET /api/marketplace/capsules/{capsuleId | slug | shortId}
GET /api/marketplace/featured

Every result is a capsule card. shape, verified_current_at, for and not_for are omitted (not null) until they exist for a capsule:

{
  "capsuleId": "uuid",
  "title": "Pass the PMP Exam on Your First Attempt",
  "summary": "What the capsule covers",
  "category": "Education",
  "premium": false,
  "creatorName": "Creator name",
  "link": "https://capxule.com/capsules/{id}",
  "page_url": "https://capxule.ai/c/{id}",
  "locales": ["en", "fr", "es", "ar"],
  "shape": "prep",
  "verified_current_at": "2026-09-30",
  "for": "Someone with the exam booked who wants the questions in the order they are actually missed.",
  "not_for": "Someone reading about project management for its own sake."
}

link is for humans (capxule.com); page_url is for agents (capxule.ai)
for and not_for describe the door, never the room: read them to the user before they commit
premium is a flag. No price or plan name appears in any payload

Access

No account, key, or plan required; worldwide
Read-only; nothing can be created, changed, or purchased through this surface
Rate limit: 30 requests per minute per IP
Results show only what the public marketplace shows: title, summary, category, creator, shape, locales, who it is for and not for, and whether a capsule is part of the Premium plan (no prices)

Support

Questions or partnership requests: support@capxule.com. Privacy policy: capxule.com/privacy.