Kate Agent Plugin

An AI assistant integrated into Kate that replicates Zed Editor's agent functionality: LLM chat, tool execution, context from open buffers, and iteration loops.

✨ Features

🤖 LLM Chat with Streaming

• Real-time chat with token streaming support
• Compatible with any OpenAI-compatible API (OpenAI, Anthropic, Ollama, LM Studio, etc.)
• Flexible configuration: API key, base URL, model, system prompt

🔧 Tool Execution

The plugin automatically executes tools based on LLM instructions:

Tool	Description
ReadFile	Reads files from the filesystem
EditFile	Modifies files with applyable diffs
Grep	Searches patterns in the project
Terminal	Executes commands (sandboxed)
WebSearch	Searches via DuckDuckGo

Security sandboxing: Terminal commands block rm, curl, wget, sh, bash, cp, mv, python, perl, ruby for protection.

📚 Automatic Buffer Context

• Automatically detects files open in Kate
• Injects context into LLM prompts (limit: 2000 characters)
• Configurable toggle in settings

🔄 Intelligent REPL Loop

• LLM → Tool → Result → LLM (automatic cycle)
• Up to 20 iterations to prevent infinite loops
• Tool output displayed inline in the chat

💾 Conversation Persistence

• Automatic thread saving to JSON files
• Conversation history loading
• Path: ~/.config/kate/agents/

👤 Agent Profiles

Three modes for different scenarios:

Profile	Use
Write	Code writing, substantial changes
Ask	Questions, explanations, debugging
Minimal	Concise responses, reduced context

@-Mentions for Files and Web

• Type @ for file autocomplete
• Fuzzy search on project paths
• Support for URLs and web searches

📊 Diff Preview

• Side-by-side preview before applying changes
• Multi-file support
• Explicit user confirmation required

💾 Checkpoint Backups

• Timestamped backups before every modification: .bak.YYYYMMDD-HHMMSS
• Maximum 5 backups per file (oldest are deleted)
• Easy recovery of previous file versions

👻 Ghost Text (Inlay Hints)

• Inline suggestions while typing
• Accept with Tab key
• Implemented via KTextEditor InlineNoteProvider API

📋 Context Menu

• Right-click in editor → "Ask agent about this"
• Sends current selection to the agent

⚙️ Configuration Page

Accessible from: Settings → Configure Kate → Plugins → Kate Agent

Available settings:

• API Key
• Base URL (for self-hosted providers)
• Model (e.g., gpt-4, claude-3, llama3)
• Custom system prompt
• Buffer context toggle (enabled by default)

📦 Installation

Prerequisites

• Kate ≥ 23.08 (KTextEditor KF6)
• Qt 6.4+
• CMake 3.16+
• GCC/Clang with C++17 support

Build from source

cd kate-agent-plugin
cmake -S . -B build
cmake --build build -j$(nproc)
sudo cmake --install build

Manual installation

# Copy the library
sudo cp build/libkateagentplugin.so \
  /usr/lib/x86_64-linux-gnu/qt6/plugins/kf6/ktexteditor/

# Copy the metadata file
sudo cp src/kateagentplugin.json \
  /usr/lib/x86_64-linux-gnu/qt6/plugins/kf6/ktexteditor/

Enable in Kate

1. Open Kate
2. Go to Settings → Configure Kate → Plugins
3. Enable Kate Agent Plugin
4. Restart Kate
5. Press Ctrl+Alt+A to open the panel

🚀 Usage

API Configuration

1. Open the Agent panel (Ctrl+Alt+A)
2. Click the gear icon (⚙️)
3. Enter:
   • API Key: Your API key
   • Base URL: https://api.openai.com/v1 (or self-hosted)
   • Model: gpt-4o, claude-3-5-sonnet, llama3:70b, etc.
   • System prompt: (optional) customize behavior

Chat with the Agent

1. Type your request in the input field
2. Use @ to mention specific files
3. Select the profile (Write/Ask/Minimal)
4. Press Enter

The agent will respond and can:

• Read files
• Execute searches
• Modify code (with confirmation)
• Execute safe commands

Accept Ghost Text Suggestions

When the agent proposes changes:

• Tab: Accept the suggestion
• Esc: Reject
• Shift+Tab: Accept line by line

Create Checkpoints

Before important modifications:

1. Click the "checkpoint" icon in the panel
2. A timestamped backup will be created
3. Recover from file.bak.YYYYMMDD-HHMMSS

⚠️ Known Limitations

LSP Integration (NOT available)

Problem: The plugin cannot access Kate's integrated LSP Client.

What's missing:

• Jump to definition (CTRL+click)
• Cross-file symbol search
• Hover information
• Intelligent completion based on LSP

Current fallback:

• Regex search on open files
• Works only for symbols in documents currently open in Kate
• Does not index the entire project

Temporary solution:

1. Enable Kate's "LSP Client" plugin (Settings → Configure Kate → Plugins)
2. Install appropriate language servers (clangd, rust-analyzer, pylsp)
3. Kate will handle them internally (but my plugin cannot use them directly)

Future plan:

• Wait for KTextEditor to expose a public API for the LSP client
• Or implement a standalone LSP client (complex, not priority)

Other Limitations

Feature	Status	Notes
Multi-file edit (batch)	⚠️ Partial	Diff preview works, batch editing no
Codebase indexing	❌ No	Only open files, not entire project
LSP hover	❌ No	Requires exposed LSP API
Go to definition	❌ No	Requires real LSP
Test UI/E2E	⚠️ Partial	4/7 unit tests passing

🧪 Testing

# Run all tests
cd build
ctest --output-on-failure

# Specific tests
./tests/test_configmanager
./tests/test_checkpointmanager
./tests/test_editorcontext
./tests/test_threadjsonstorage

🔧 Development

Build with debug

cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug
cmake --build build -j$(nproc)

Local installation (without sudo)

# Install to ~/.local
cmake -S . -B build -DCMAKE_INSTALL_PREFIX=$HOME/.local
cmake --build build
cmake --install build

# Manually copy to ~/.local/lib/qt6/plugins/ktexteditor/

Debug logging

Set environment variable:

export KATEAGENT_DEBUG=1
kate