# Sidekick

Sidekick is a simple but versatile agentic framework written in Go 1.25. It provides a robust architecture for building AI assistants with hierarchical orchestration, native Model Context Protocol (MCP) integration, and a rich terminal user interface (TUI).

## Features

*   **Hierarchical Orchestration:** Support for complex agent topologies, including coordinators and specialized subagents.
*   **Model Context Protocol (MCP):** Native integration for calling external tools via MCP, supporting `stdio`, `sse`, and `http` transports (via `mark3labs/mcp-go`).
*   **Intelligent Buffering:** Automatically buffers large tool outputs to prevent context window exhaustion, returning file pointers for significant payloads.
*   **Rich Terminal UI:** A beautiful, responsive TUI built with Charmbracelet's BubbleTea and Lipgloss, featuring status bars, role-based formatting, and dynamic viewports.
*   **Advanced Prompt Templating:** Define complex, multi-line system prompts using TOML. Support for Go's `text/template` engine allows you to compose modular prompts from reusable snippets.
*   **Internal Tools:** Built-in tools for file I/O (`read_file`, `write_file`, `grep_file`, `edit_file`) and an optional, secure `shell_exec` tool for running POSIX shell commands.
*   **Configuration Driven:** Easily configure models, agents, tools, and MCP servers via a declarative `config.toml` file.

## Internal Tools

Sidekick includes a set of internal tools that are always available to agents. These tools provide common file operations and system access.

### File Tools
- `read_file`: Read a file with optional line windowing.
- `write_file`: Overwrite a file with new content.
- `grep_file`: Regex search with surrounding context.
- `edit_file`: Replace a string or block of lines in a file.

### shell_exec Tool

The `shell_exec` tool allows an agent to run arbitrary POSIX shell commands and receive combined stdout/stderr output. 

**Security Warning:** This tool is extremely powerful and potentially dangerous. It is **disabled by default** and must be explicitly enabled for each agent in `config.toml`.

To enable `shell_exec` for an agent, add `enable_shell_exec = true` to its configuration:

```toml
[agents.coordinator]
role = "COORDINATOR"
model_id = "default"
enable_shell_exec = true # Security: explicitly enabled
toolsets = ["filesystem"]
```

## Installation

### Prerequisites

*   Go 1.25 or higher.

### Installing the Library

To use Sidekick as a framework in your own Go projects:

```bash
go get codeberg.org/luxferre/sidekick-ng
```

### Installing the TUI

To install the Sidekick TUI binary globally:

```bash
go install codeberg.org/luxferre/sidekick-ng/cmd/sidekick-tui@latest
```

Alternatively, you can build it locally from the source using the provided `Makefile`:

```bash
make
```

Or manually:

```bash
git clone https://codeberg.org/luxferre/sidekick-ng.git
cd sidekick-ng
go build -o bin/sidekick-tui ./cmd/sidekick-tui
```

## Configuration

Sidekick relies on two primary configuration files: `config.toml` for system settings and `prompts.toml` for advanced system prompt management.

**Important:** When running the TUI, the binary expects `config.toml` and `prompts.toml` to be present in the directory from which the command is executed.
### `config.toml`

This file defines your models, MCP servers, and agent profiles.

```toml
tool_response_threshold = 10000 # Bytes after which tool results are buffered to files

[models.default]
model_id = "env:DEFAULT_MODEL_ID"
endpoint = "env:DEFAULT_MODEL_ENDPOINT"
api_key = "env:DEFAULT_MODEL_API_KEY"
temperature = 0.0
max_tokens = 4096

[mcp_servers.filesystem]
transport = "stdio"
command = "npx"
args = ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"]

[mcp_servers.remote_tools]
transport = "sse"
url = "https://api.example.com/mcp"
auth_token = "env:MCP_API_KEY" # Optional Bearer token
headers = { "X-Custom-Header" = "value" } # Optional custom headers

[agents.coordinator]
role = "COORDINATOR"
model_id = "default"
system_prompt = "You are the primary coordinator agent." # This can be overridden by prompts.toml
subagents = ["researcher"]
toolsets = ["filesystem"]
```

### `prompts.toml`

Use this file to define complex, multi-line system prompts. If an entry here matches an agent's ID in `config.toml`, it will override the inline `system_prompt`. It uses Go's `text/template` engine, allowing you to compose prompts dynamically.

```toml
base_identity = """
You are a highly capable agentic assistant built on the Sidekick framework.
Always be professional, concise, and helpful.
"""

coordinator = """
{{template "base_identity"}}

You are the COORDINATOR agent. Your primary responsibility is to understand the 
user's request and delegate tasks accordingly.
"""
```

## Usage

### Running the TUI

1.  Ensure you have `config.toml` (and optionally `prompts.toml`) in your current directory.
2.  Set any necessary environment variables defined in your config (e.g., `DEFAULT_MODEL_API_KEY`).
3.  Run the TUI:

```bash
./bin/sidekick-tui
```
*   **Input:** Type your messages at the bottom prompt.
*   **Send:** Press `Enter` to send a message.
*   **Quit:** Press `ctrl+c` to exit.
*   **Scrolling:** Use the mouse wheel or arrow keys to scroll through the conversation history.

### Running the Sidekick MCP Server

Sidekick can also act as an MCP server, allowing other LLM-powered applications to leverage its agentic capabilities.

1.  Configure the `mcp_listener` in `config.toml`:

```toml
[mcp_listener]
transport = "sse" # "stdio" or "sse"/"http"
port = 8080      # for sse/http
```

2.  Run the MCP server:

```bash
./bin/sidekick-mcp
```

The server provides a `query` tool that routes requests to your coordinator agent, maintaining conversation history if provided.

### Using the Framework Programmatically

```go
package main

import (
  "context"
  "fmt"
  "log"

  "codeberg.org/luxferre/sidekick-ng"
)

func main() {
  // 1. Load Configuration
  cfg, err := sidekick.LoadConfig("config.toml")
  if err != nil {
    log.Fatal(err)
  }

  // 2. Load and Apply Prompts (Optional)
  tmpl, _ := sidekick.LoadPrompts("prompts.toml")

  // 3. Initialize Agent
  agentCfg := cfg.Agents["coordinator"]
  
  // Apply template override if exists
  if tmpl != nil && tmpl.Lookup("coordinator") != nil {
    if rendered, err := sidekick.RenderPrompt(tmpl, "coordinator"); err == nil {
      agentCfg.SystemPrompt = rendered
    }
  }

  agent := sidekick.NewAgent("coordinator", agentCfg, cfg)

  // 4. Run the Agent Loop
  ctx := context.Background()
  result, err := agent.Run(ctx, "What files are in the /tmp directory?")
  if err != nil {
    log.Fatal(err)
  }

  fmt.Println(result)
}
```

## Credits

Created by Luxferre in 2026, released into the public domain with no warranties.