| name | codemation-plugin-development |
| description | Guides Codemation plugin package development, including `definePlugin(...)`, plugin sandboxes, custom nodes, custom credentials, and publishable plugin package structure. Use when building or updating a Codemation plugin package or the plugin starter template. |
| compatibility | Designed for Codemation plugin packages and the Codemation plugin starter template. |
| tags | plugin, node, package |
Codemation Plugin Development
Mental model
A Codemation plugin is an npm package with a codemation.plugin.ts composition root that calls definePlugin(...). It registers custom nodes and credential types, optionally declares MCP servers, and ships a sandbox app so the plugin is immediately testable. Consumers load the built JavaScript entry (package.json#codemation.plugin) — not TypeScript source. Plugin code follows the same defineNode / defineCredential patterns as app-level code; the plugin boundary is purely about packaging and distribution.
When to use / when NOT
Plugin authoring is a framework-author / non-managed task. Managed-mode agents work with credential slots and workflow DSL — they do not author or modify plugin packages.
Use this skill for published plugin packages, plugin starter work, and sandbox-driven plugin development. Do not use for ordinary consumer workflow-only changes.
Decision branches & gotchas
MCP servers in plugins: Plugin-declared mcpServers is a non-managed pattern for self-hosted / framework-author scenarios. In managed mode, MCP servers are loaded from the control plane — see codemation-mcp-capabilities for the managed path.
Publishing guardrail: package.json#codemation.plugin must point at runnable JavaScript (./dist/codemation.plugin.js). Do not rely on consumers TypeScript-loading plugin files from node_modules.
Read next when needed
- Read
references/plugin-anatomy.md for the full definePlugin(...) code, package layout, sandbox setup, MCP server declaration, binary payload rules, and publishing guidance.
- Read
references/plugin-structure.md for a concise package layout reference.
