Model Context Protocol (MCP) is an open standard.
Through it an agent reaches external systems: databases, APIs, trackers, anything.
EONYX ships an MCP client built on the official Go SDK, modelcontextprotocol/go-sdk.
Servers are described in eonyx.json, and their tools appear to the model next to the built-in ones.

Hooks are shell commands that run around a tool call.
One before it, one after it.
They bolt on formatting, auditing and guardrails without touching the agent’s code.

EONYX also runs headless: it does the task and exits.
That is what scripts, pipes and CI need.
Predictable output, JSON events, meaningful exit codes.

Features are nice.
Seeing them work is better.
A few practical scenarios: how to phrase the task, and which technique to switch on.
The prompts are deliberately plain.