How IntelliJ IDEA 2026.1 Turns the IDE into an Open AI Agent Platform

IntelliJ IDEA 2026.1 – AI Agent Platform

Agent Client Protocol (ACP) and AI integration

Version 2026.1 introduces the Agent Client Protocol (ACP), a standardized interface that allows any external AI agent implementing the protocol to be discovered, installed, and invoked from within the IDE. An ACP registry is built into the IDE, providing a searchable catalog of agents such as Codex, Cursor, GitHub Copilot, Claude, and others. Developers can mix agents in a single session—for example, using Cursor for refactoring, Codex for unit‑test generation, and Claude for code‑logic analysis—without writing custom plugins.

Unlimited smart assistance

New smart‑assistance actions, including “post‑edit suggestions”, no longer consume the JetBrains AI Pro quota. These suggestions can be applied to the current cursor location or propagated across an entire file, improving code consistency. The Spring runtime insight feature lets developers inspect injected beans, endpoint security settings, and property values at runtime without stopping the application. Kotlin‑specific JPA fixes address compatibility issues with Jakarta Persistence entities.

Language and platform support

Java 26 is supported from day one, including preview features such as pattern‑matching for switch, lazy constants, and other JEPs. Kotlin 2.3.20 is bundled, adding nested type aliases and exhaustive when ‑expression checks. A dedicated C/C++ support plugin provides advanced code assistance, real‑time quality analysis, and refactoring capabilities for native development.

Productivity enhancements

Command completion is extended to include AI actions and suffix templates, allowing developers to trigger AI‑driven operations directly from the command palette.

Git worktree integration enables creation of isolated worktrees for urgent fixes while AI agents operate on separate branches.

AI agents now have native database access; agents such as Codex and Claude can query and modify configured data sources, facilitating automated data‑processing workflows.

Stability and performance

The release resolves over 1,000 bugs and usability issues, including 334 user‑reported problems. Performance tuning eliminated 40 UI‑freeze scenarios, ensuring responsive interaction even with AI‑enhanced features active.

Collaboration changes

Code With Me real‑time collaboration is deprecated; 2026.1 is the last version with built‑in support. The feature will be extracted as a separate plugin and is scheduled for complete removal in early 2027.