Create Plugin

Create Plugin

Use this skill to create production-ready Canvas Plugins.

A Canvas Plugin is a bundle that combines:

• one plugin manifest at .canvas-plugin/plugin.json
• one or more bundled skills under skills/
• optional visual assets such as assets/icon.svg and assets/logo.svg
• optional connector recommendations for Composio, Canvas Email, and MCP servers
• optional marketplace metadata in a registry entry

Plugins should teach the agent which workflows belong together. They should not secretly install external services, write connector configuration, or store secrets.

Default Workflow

1. Clarify the plugin's audience, workflows, bundled skills, and connector recommendations.

2. Choose a stable plugin name in lowercase kebab-case.

3. Scaffold the plugin package:

   plugins/<plugin-name>/<version>/
   ├── .canvas-plugin/plugin.json
   ├── assets/
   │   ├── icon.svg
   │   └── logo.svg
   ├── connectors/
   │   └── optional-example.mcp.json
   ├── skills/
   │   └── <skill-name>/
   │       ├── SKILL.md
   │       └── agents/canvas.yaml
   └── LICENSE
   

4. Validate that every bundled skill has a unique name and a useful trigger-focused description.

5. Add connector recommendations only as metadata. The user must explicitly connect Composio apps, Canvas Email accounts, or MCP servers in the UI.

6. For a personal Canvas installation, call install_canvas_plugin_from_workspace with the package directory. To update an installed plugin, first call inspect_canvas_plugin, then call update_canvas_plugin_from_workspace with its version and checksum.

7. Use set_canvas_plugin_enabled to toggle it and remove_canvas_plugin to remove it. Removal deliberately stops when a materialized skill was edited, so the agent must preserve or resolve that user work explicitly.

8. Package or commit the plugin to the marketplace repository only after validation passes.

Manifest Template

Use this shape for .canvas-plugin/plugin.json:

{
  "name": "sales-operations",
  "version": "1.0.0",
  "description": "Coordinate sales workflows with CRM, email, and research connector recommendations.",
  "license": "MIT",
  "author": {
    "name": "Canvas Studios"
  },
  "source": "https://github.com/canvascoding/canvas-notebook-plugin-marketplace/tree/main/plugins/sales-operations/1.0.0",
  "skills": "./skills",
  "interface": {
    "displayName": "Sales Operations",
    "shortDescription": "Prepare account research and sales follow-ups",
    "category": "Sales",
    "brandColor": "#0F766E",
    "icon": "./assets/icon.svg",
    "logo": "./assets/logo.svg",
    "defaultPrompt": [
      "Use /sales-account-brief to prepare a target-account brief."
    ]
  },
  "connectors": {
    "composio": [
      {
        "toolkit": "hubspot",
        "label": "HubSpot",
        "recommended": true,
        "reason": "Use CRM records and company data during sales workflows."
      }
    ],
    "email": [
      {
        "kind": "mailbox",
        "label": "Sales inbox",
        "providers": ["gmail", "imap-smtp"],
        "recommended": true,
        "reason": "Read and send sales email through Canvas Email, not through Composio Gmail."
      }
    ],
    "mcp": [
      {
        "name": "sales-research",
        "label": "Sales Research MCP",
        "configPath": "./connectors/sales-research.mcp.json",
        "recommended": true,
        "env": ["SALES_RESEARCH_API_KEY"],
        "oauth": true,
        "reason": "Optional external research tools for account enrichment."
      }
    ]
  }
}

Connector Rules

Composio recommendations:

• Use Composio toolkit slugs such as hubspot, slack, or linear.
• Include label, reason, and recommended or required.
• Do not include API keys, connected-account IDs, trigger IDs, or user-specific secrets.
• Do not recommend Gmail through Composio for email workflows. Use Canvas Email.

Canvas Email recommendations:

• Use connectors.email[] for mailbox needs.
• Supported provider hints are gmail and imap-smtp.
• Explain why the mailbox is useful, but leave account connection to the UI.

MCP recommendations:

• Use connectors.mcp[] for optional MCP servers.
• Put example server config under connectors/*.mcp.json.
• List required environment variable names in env.
• Set oauth: true when OAuth may be required.
• Do not merge MCP config automatically.

Skill Bundling Rules

Each bundled skill should be narrow enough to be useful independently and clear enough to trigger correctly.

Use this skill layout:

skills/<skill-name>/SKILL.md
skills/<skill-name>/agents/canvas.yaml

SKILL.md frontmatter should include:

---
name: sales-account-brief
description: "Use this skill to prepare a target-account sales brief from CRM context, email context, and research notes."
license: "MIT"
metadata:
  version: "1.0.0"
---

agents/canvas.yaml should include UI metadata:

interface:
  display_name: Sales Account Brief
  short_description: Prepare a target-account sales brief
  brand_color: "#0F766E"
  icon_small: "./icon.svg"

Marketplace Registry Entry

When preparing an official marketplace entry, add the plugin to registry.json in the marketplace repo.

Required fields:

• name
• displayName
• description
• latestVersion
• versions[version].downloadUrl
• versions[version].packagePath
• versions[version].checksum
• versions[version].manifestPath

The checksum should be the Canvas Plugin package checksum, not a checksum of the whole git repository.

Validation Checklist

Before handing off:

• .canvas-plugin/plugin.json exists and is valid JSON.
• name is lowercase kebab-case.
• version is semantic, for example 1.0.0.
• skills points to a package-local directory.
• Every connectors.mcp[].configPath points to an existing file.
• Icons and logos are package-local image files.
• No secrets, tokens, personal account IDs, or generated local paths are committed.
• Local installation succeeds through the Canvas Plugin installer.
• Marketplace install succeeds from a registry archive when publishing to the store.