Introduction
Comparing AI Agents: Claude vs Gemini vs Codex on OpenACP is a topic that every modern developer should understand. As AI coding agents become increasingly integrated into development workflows, having the right tools and knowledge becomes essential. In this comprehensive guide, we will explore everything you need to know about this subject, from basic concepts to advanced techniques that will help you get the most out of OpenACP.
OpenACP is a free, open-source bridge that connects 28+ AI coding agents to your favorite messaging platforms — Telegram, Discord, and Slack. Built on the Agent Client Protocol (ACP), it provides a universal interface for controlling AI agents from anywhere, on any device. Whether you are working from your desk or coding on the go from your phone, OpenACP makes it possible to interact with powerful AI coding assistants through the chat apps you already use every day.
The rise of AI-powered coding tools has transformed how developers write, debug, and maintain code. Tools like Claude Code from Anthropic, Gemini CLI from Google, and Codex from OpenAI represent the cutting edge of AI-assisted development. However, each of these tools typically requires its own interface, its own terminal session, and its own workflow. This fragmentation creates friction that slows developers down and makes it harder to leverage multiple AI agents effectively.
This is where OpenACP comes in. By providing a unified bridge between these diverse AI agents and your messaging platforms, OpenACP eliminates the need to constantly switch between terminals, browser tabs, and IDE windows. Instead, you can send a message to your AI agent from Telegram, Discord, or Slack and receive the results in real time, complete with streaming output, tool call visibility, and permission controls.
Understanding the Core Concepts
Before diving into the specifics, it is important to understand the fundamental architecture that makes OpenACP work. At its core, OpenACP acts as a bridge with three main components: the messaging platform adapter, the session manager, and the agent instance.
The messaging platform adapter handles communication with Telegram, Discord, or Slack. Each platform has its own adapter that translates platform-specific features into a common internal format. For Telegram, this means forum topics per session, streaming message updates, and inline permission buttons. For Discord, it means thread-based sessions with slash commands and button interactions. For Slack, it uses Socket Mode with channel-based sessions and thread organization.
The session manager is responsible for creating, tracking, and persisting sessions. Each session represents a single conversation between a user and an AI agent working on a specific project directory. Sessions support auto-naming, where the agent summarizes the conversation after the first message to generate a descriptive topic title. Sessions also persist across restarts, so you never lose your context.
The agent instance wraps the actual AI coding agent as a subprocess using the ACP protocol. When you send a message, OpenACP forwards it to the agent, which then reads your codebase, writes code, runs commands, and streams the results back through the messaging platform in real time.
The ACP Protocol
The Agent Client Protocol (ACP) is an open standard that defines how tools communicate with AI coding agents. Think of it like the Language Server Protocol (LSP), which standardized how editors communicate with language servers for features like autocomplete and go-to-definition. ACP does the same thing for AI coding agents, standardizing the communication layer so that any ACP-compatible agent can work with any ACP-compatible client.
This means that when a new AI coding agent is released and registered on the ACP Registry, it automatically becomes available in OpenACP without any code changes. You simply run openacp agents install agent-name and start using it immediately.
Getting Started and Setup
Setting up OpenACP is straightforward. The entire process takes less than five minutes and is guided by an interactive setup wizard that walks you through each step.
npm install -g @openacp/cli
openacpWhen you run openacp for the first time, the setup wizard launches automatically. It will guide you through five steps: choosing your messaging platform (Telegram, Discord, Slack, or multiple), connecting your bot with token validation and auto-detection, picking a workspace directory where the agent will work, selecting your default AI agent from the 28+ available options, and choosing your run mode (foreground or daemon).
The wizard uses a polished CLI interface powered by @clack/prompts, making the setup experience smooth and professional. Each step includes validation to ensure your configuration is correct before proceeding.
Configuration Details
OpenACP stores its configuration in ~/.openacp/config.json, which is validated using Zod schemas to ensure type safety. You can override any setting using environment variables with the OPENACP_ prefix. For example, OPENACP_TELEGRAM_BOT_TOKEN overrides the Telegram bot token, and OPENACP_DEFAULT_AGENT overrides the default agent.
Key configuration options include allowedUserIds for access control, maxConcurrentSessions (default 20) for resource management, sessionTimeout (default 60 minutes) for automatic cleanup, and defaultAgent for setting your preferred AI coding agent.
The configuration supports hot-reload, meaning you can change settings without restarting OpenACP. This is particularly useful when running in daemon mode, as you can update agent preferences or security settings on the fly.
Advanced Features and Capabilities
OpenACP goes far beyond basic message forwarding. It includes a comprehensive set of features designed for professional development workflows.
Real-Time Streaming
When an agent is working on your request, you see everything in real time. This includes thinking indicators with elapsed time showing when the agent is reasoning about your request, text responses streamed as they are generated so you do not have to wait for completion, tool call status tracking showing pending, in-progress, and completed operations with visual progress indicators, and plan cards showing visual task progress with completed, in-progress, and pending items with a progress bar.
Permission Control
Security is built into OpenACP at every level. When an agent wants to perform a potentially dangerous action like writing a file or running a command, you receive a permission request with approve and deny buttons directly in your chat. This gives you full control over what the agent can do. For trusted workflows, you can enable auto-approve mode which automatically approves all permission requests.
Voice and Speech
OpenACP supports voice messages for hands-free coding. Send a voice message on Telegram and OpenACP transcribes it using Groq speech-to-text, then forwards the transcription to your AI agent. You can also enable text-to-speech responses using Edge TTS, which is completely free and requires no API key. Voice modes include off, next (one prompt only), and always on.
Session Transfer
One of OpenACP's most powerful features is session transfer. Using the /handoff command, you can move a session between your terminal and your chat platform. Start coding in your terminal, then continue from your phone while commuting. Or start a quick fix from Telegram and hand it off to your terminal for more complex work.
Working with Multiple Agents
OpenACP supports 28+ AI coding agents from the ACP Registry, giving you unprecedented flexibility in choosing the right tool for each task. The supported agents include Claude Code from Anthropic, Gemini CLI from Google, Codex CLI from OpenAI, GitHub Copilot, Cursor, Cline, goose from Block, Amp, Auggie CLI from Augment Code, Junie from JetBrains, Kilo, and Qwen Code from Alibaba, among others.
Each agent has its own strengths. Claude Code excels at complex reasoning and large codebases. Gemini CLI is strong at multi-modal understanding. Codex CLI is optimized for quick code generation. Having all of these available through a single interface means you can switch between agents based on the task at hand.
openacp agents # Browse all available agents
openacp agents install claude-code # Install a specific agent
openacp agents info claude-code # Show agent detailsYou can install multiple agents and choose which one to use when creating each session. The default agent is used when you do not specify one, but you can always override it for individual sessions.
Agent Distribution Types
Agents are distributed in three ways depending on the agent: npx for Node.js agents that are downloaded automatically on first use, binary for platform-specific executables downloaded to ~/.openacp/agents/, and uvx for Python agents that are also downloaded automatically. OpenACP handles all the installation and version management for you.
Developer Tools and Operations
OpenACP includes several tools designed to make development workflows smoother and more productive.
Tunneling and Port Forwarding
Access your local development server from anywhere without a public IP. OpenACP supports four tunnel providers: Cloudflare (the default, free and fast), ngrok for established tunnel infrastructure, bore for a lightweight open-source option, and Tailscale for private mesh networking. Creating a tunnel is as simple as running openacp tunnel add 3000 to expose your local port 3000 to the internet.
Built-in File Viewer
OpenACP includes a built-in file viewer powered by Monaco Editor, the same editor engine that powers VS Code. This viewer supports syntax highlighting for all major languages, diff view for comparing changes, and markdown preview. When an agent creates or modifies a file, you can view it directly from your chat using the View File or View Diff buttons.
Usage Tracking and Budgets
Keep your AI agent costs under control with OpenACP's built-in usage tracking. It tracks token counts per session, generates cost reports, and supports optional monthly budget limits with configurable warning thresholds. This is especially useful for teams where multiple developers share the same AI agent API keys.
Doctor Diagnostics
When something is not working right, openacp doctor runs a comprehensive health check on your system. It verifies your Node.js version, checks agent installations, validates your configuration, tests platform connections, and suggests fixes for any issues it finds.
Best Practices and Tips
After working extensively with OpenACP, here are some best practices that will help you get the most out of the platform.
First, choose the right agent for the job. If you are doing complex refactoring across many files, Claude Code's large context window and strong reasoning capabilities make it ideal. For quick bug fixes or simple code generation, Codex CLI or Gemini CLI might be faster. OpenACP makes it easy to switch between agents, so do not hesitate to use different agents for different tasks.
Second, use session management effectively. Give your sessions descriptive names or let the auto-naming feature handle it. This makes it much easier to find and resume sessions later. Also, be aware of the session timeout setting — if you are working on a long-running task, consider increasing it from the default 60 minutes.
Third, leverage the permission system wisely. Start with manual approval mode to understand what actions the agent is taking. Once you are comfortable with an agent's behavior on a particular project, you can enable auto-approve mode to speed up your workflow. But always be cautious when working on production code or sensitive files.
Fourth, take advantage of voice messages when you are on the go. Send a voice message from your phone describing what you want, and OpenACP will transcribe it and send it to your agent. This is perfect for quick fixes or code reviews while commuting.
Finally, consider running OpenACP in daemon mode for always-on availability. With openacp start, it runs as a background service that starts automatically on boot. This means your AI agents are always ready to help, whether you are at your desk or on your phone.
Comparison with Alternatives
Understanding how OpenACP compares to other solutions helps you make an informed decision about your AI coding toolkit.
Compared to Claude Code Channels, OpenACP offers several advantages. It is completely free and open-source under the MIT license, while Channels costs twenty dollars per month. OpenACP supports 28+ agents while Channels only works with Claude. OpenACP works on Telegram, Discord, and Slack, while Channels is limited to Slack. OpenACP is fully self-hosted with all data staying on your machine, while Channels uses a hybrid model. OpenACP supports voice messages and session transfer, which Channels does not offer.
Compared to using AI agents directly in the terminal, OpenACP adds the convenience of mobile access, multi-platform support, and a persistent session management layer. You can start a coding session from your terminal and continue it from your phone, something that is simply not possible with terminal-only agents.
Compared to IDE-integrated AI tools like Cursor or GitHub Copilot, OpenACP offers a fundamentally different workflow. Instead of being tied to a specific editor, OpenACP lets you interact with AI agents from any messaging platform. This is complementary to IDE integration — you might use Cursor at your desk and OpenACP on your phone.
Conclusion and Next Steps
As we have seen throughout this guide, the combination of OpenACP with modern AI coding agents represents a powerful evolution in how developers work with code. By bridging the gap between AI agents and messaging platforms, OpenACP makes AI-assisted development accessible from anywhere, on any device.
The open-source nature of OpenACP, built on the open Agent Client Protocol standard, ensures that you are never locked into a single vendor or platform. As new AI agents emerge and existing ones improve, they become available through OpenACP automatically via the ACP Registry.
Whether you are a solo developer looking to code from your phone, a team lead wanting to give your team access to AI coding tools through familiar chat platforms, or an enterprise architect evaluating AI development tools, OpenACP provides a flexible, secure, and cost-effective solution.
Getting started takes less than five minutes. Install OpenACP, connect it to your preferred messaging platform, and start coding with AI from anywhere.
npm install -g @openacp/cli
openacpFor more information, visit the OpenACP documentation, explore the GitHub repository, or follow @Open_ACP on Twitter for updates.
Frequently Asked Questions
What is OpenACP?
OpenACP is a free, open-source, self-hosted bridge connecting 28+ AI coding agents to Telegram, Discord, and Slack. It uses the Agent Client Protocol (ACP) for standardized communication.
How much does OpenACP cost?
OpenACP itself is completely free under the MIT license. You only pay for the AI agent API usage (e.g., Anthropic, OpenAI, Google API credits).
Which platforms does OpenACP support?
Telegram (forum topics, voice messages, streaming), Discord (threads, slash commands, buttons), and Slack (Socket Mode, channels, threads).
Is my code safe?
Yes. OpenACP is fully self-hosted. All data stays in ~/.openacp/ on your machine. Nothing is sent to any OpenACP server.
How many agents are supported?
28+ agents including Claude Code, Gemini CLI, Codex, Copilot, Cursor, Cline, goose, Amp, Junie, Kilo, Qwen Code, and more from the ACP Registry.