What Is an AI Agent?
Short answer
An AI agent is software that uses a language model to complete a task by taking actions, not just by answering. It plans steps, uses tools such as a browser, terminal, email or database, checks the results and continues until the task is done or it needs help. A chatbot replies to you; an agent works on your behalf.
Chatbot vs agent
Evidence: Editorial assessment| Chatbot | AI agent | |
|---|---|---|
| Output | A reply | A completed task (files changed, email sent, record updated) |
| Tools | Usually none, or search | Terminal, browser, apps, APIs |
| Steps | One turn at a time | Many steps, planned and checked |
| Risk | Wrong information | Wrong actions, which need permissions and review |
Examples in 2026
- Coding agents: Claude Code works in the terminal, IDEs and on GitHub and handles git workflows; OpenAI Codex runs in the terminal; Gemini CLI is a free terminal agent.
- Workflow agents: Lindy, Zapier AI and n8n run multi-step business workflows.
- Computer-use agents: Anthropic's background computer use in Claude was reported in September 2026; OpenAI reported ChatGPT Work and an Agents API beta.
How agents connect to tools
Many agents use the Model Context Protocol (MCP), an open standard for connecting AI applications to tools and data sources. See MCP explained.
Where agents fail
Evidence: Editorial assessment- They can take confident wrong actions: an agent that edits code can also break it.
- Instructions hidden in web pages or documents (prompt injection) can steer browsing agents.
- Long tasks cost more than chat, because each step uses the model again.
- They need clear stopping points: require approval before sending, paying or deleting.
Common questions
Is ChatGPT an AI agent?
ChatGPT is primarily a chatbot, but OpenAI ships agent features alongside it, including Codex for coding. The difference is whether it acts on your behalf with tools.
Are AI agents safe?
They are as safe as the permissions you give them. Start with read-only access, approve risky actions, keep logs and review results.
What is the best AI agent?
It depends on the job. See our comparison of the best AI agents for coding, support and workflows.
Sources
- anthropics/claude-code on GitHub · checked 5 October 2026
- openai/codex on GitHub · checked 5 October 2026
- google-gemini/gemini-cli on GitHub · checked 5 October 2026
- ThursdAI release log, September 2026 · checked 5 October 2026
- modelcontextprotocol/modelcontextprotocol on GitHub · checked 5 October 2026