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

# Full specification

> SPEC.md and architecture

The full protocol specification and architecture are maintained in the repository as Markdown.

## SPEC.md

**[SPEC.md](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/SPEC.md)** covers:

* Design goals (protocol composability, deterministic execution, least-privilege, hierarchical orchestration, progressive context hydration)
* Core concepts (Context, Orchestrator, Executors)
* Runtime behavior: orchestrator vs executor, data flow, what is shared
* Shared input/output model
* Executor types (agent, tool, human)
* Nested orchestration
* Mounts (seed, focus, deep) and Ref objects
* Policies and protocols
* Orchestration strategies (single, sequential, delegate, swarm)
* Triggers, schemas, context inputs/outputs
* Security model

Use it as the authoritative protocol document when implementing runtimes or tooling.

### Host system configuration

Machine- and project-local **`ecp.config.yaml`** (system config) is specified in the same document: **[Host system configuration (`ecp.config.yaml`)](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/SPEC.md#L623)**. It covers the **`version`** field, the split between **configure** sections and the **`security`** mirror, MCP tool plugins, and A2A endpoint shape. The annotated example is **[config/ecp.config.example.yaml](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/config/ecp.config.example.yaml)**.

## ARCHITECTURE.md

**[ARCHITECTURE.md](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/ARCHITECTURE.md)** documents plugin registration and architecture decisions.

## Schema and types

* **JSON Schema:** `packages/spec/dist/ecp-context.schema.json` (generate with `npm run generate:schema`)
* **TypeScript types:** `packages/spec/src/types/ecp.ts` (single source of truth)

See [Schema reference](/reference/schema) for details.

## Repository

| Path                                                                                                                                                     | Description                                               |
| -------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------- |
| [spec.yaml](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/spec.yaml)                                                    | Canonical example Context                                 |
| [SPEC.md](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/SPEC.md)                                                        | Full protocol specification                               |
| [SETUP.md](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/SETUP.md)                                                      | Install, CLI, env, config                                 |
| [SPEC.md — Host system configuration](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/SPEC.md#L623)                       | Full **`ecp.config.yaml`** spec (v0.5+ `security` mirror) |
| [config/ecp.config.example.yaml](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/config/ecp.config.example.yaml)          | Annotated system config example (validated in repo tests) |
| [`ECPSystemConfig` (types.ts)](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/packages/runtime/src/engine/types.ts#L484) | TypeScript reference for system config                    |
| [ARCHITECTURE.md](https://github.com/executioncontrolprotocol/executioncontrolprotocol/blob/main/ARCHITECTURE.md)                                        | Plugin registration and architecture                      |
| [packages/spec/](https://github.com/executioncontrolprotocol/executioncontrolprotocol/tree/main/packages/spec)                                           | Types, JSON Schema, validators                            |
| [packages/runtime/](https://github.com/executioncontrolprotocol/executioncontrolprotocol/tree/main/packages/runtime)                                     | Execution engine                                          |
| [packages/cli/](https://github.com/executioncontrolprotocol/executioncontrolprotocol/tree/main/packages/cli)                                             | CLI implementation                                        |
| [examples/](https://github.com/executioncontrolprotocol/executioncontrolprotocol/tree/main/examples)                                                     | Example Context manifests                                 |