> ## Documentation Index
> Fetch the complete documentation index at: https://executioncontrolprotocol.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Packages

> Map of ECP (Execution Control Protocol) npm packages: types, core, hosts, CLI, MCP, policies, extensions, and harnesses.

# Packages

Public packages under the `@executioncontrolprotocol` scope:

| Package                                              | Role                                                                    |
| ---------------------------------------------------- | ----------------------------------------------------------------------- |
| `@executioncontrolprotocol/types`                    | Protocol types and generated JSON Schemas                               |
| `@executioncontrolprotocol/core`                     | Fluent API, environment, in-memory engine (runtime-agnostic main entry) |
| `@executioncontrolprotocol/node`                     | Node runtime host                                                       |
| `@executioncontrolprotocol/browser`                  | Browser runtime host (not the demo UI)                                  |
| `@executioncontrolprotocol/cli`                      | `ecp` CLI                                                               |
| `@executioncontrolprotocol/mcp`                      | MCP server adapter around an `Ecp`                                      |
| `@executioncontrolprotocol/policies`                 | Budget, approval, state-control, registry-control                       |
| `@executioncontrolprotocol/format-toon`              | TOON format extension                                                   |
| `@executioncontrolprotocol/format-eql`               | EQL format extension                                                    |
| `@executioncontrolprotocol/format-mermaid`           | Mermaid format extension                                                |
| Model / platform extensions                          | `chrome-ai`, `ollama`, `openai`, `claude`, memory, secrets, …           |
| `@executioncontrolprotocol/harnesses-browser-nano`   | Browser nano (EQL) harness                                              |
| `@executioncontrolprotocol/harnesses-browser-coding` | Browser coding (Fluent/TS) harness                                      |

## Core subpaths

| Subpath                                  | Use                                                      |
| ---------------------------------------- | -------------------------------------------------------- |
| `@executioncontrolprotocol/core`         | Browser-safe main API                                    |
| `@executioncontrolprotocol/core/compile` | `compileWorkflowSource` (Node; browser condition → wasm) |
| `@executioncontrolprotocol/core/browser` | Browser authoring + wasm compile                         |
| `@executioncontrolprotocol/core/loaders` | Node file I/O for CLI                                    |
| `@executioncontrolprotocol/core/node`    | Loaders + compile convenience                            |
| `@executioncontrolprotocol/core/testing` | In-repo test extension stub                              |

**Compile stays on core subpaths**, not on runtime hosts. Extensions and harnesses depend on `types` + `core` only — never on `node`, `browser`, `cli`, or `mcp`.

## Apps vs hosts

The [browser demo](/getting-started/browser-demo) is a separate app that consumes `@executioncontrolprotocol/browser` and binds harnesses/providers. Vendor extensions live in [executioncontrolprotocol-extensions](https://github.com/GuillaumeCleme/executioncontrolprotocol-extensions).

## Next steps

* [Extensions](/guides/extensions)
* [Environments](/guides/environments)
* [Build from source](/getting-started/build-from-source)