Gemini Code Assist 4.0 – New Features, Agent Mode and Faster Edits

Introduction

Since its mid‑August launch, Gemini Code Assist has been on a rapid release cadence, delivering weekly updates that reshape how developers interact with code. From deeper project awareness to inline diffs and a new agent‑mode workflow, the tool is quickly becoming a central part of the VS Code and IntelliJ ecosystems. This article walks through every notable change from the late‑August rollout through the early‑October release, highlighting the most impactful enhancements for individual developers and teams.

August 2023 – Foundations and Early Enhancements

Telemetry Control (August 26)

• The VS Code extension now lets Gemini Code Assist telemetry override the IDE’s global telemetry toggle. Enabling logs in Gemini will collect data even when VS Code telemetry is disabled—an essential detail for administrators concerned with auditability.

Full Remote Codebase Awareness (August 27‑29)

• The assistant can now ingest an entire remote repository, not just the files currently open in the editor. This enables queries such as “What does this repository do?” and returns answers drawn from the whole codebase.
• Markdown documentation (architecture notes, runbooks, ADRs) is also indexed, allowing the model to respect project‑specific conventions without extra prompting.

September 2023 – Context Management and Dashboarding

Repository Targeting (September 3)

• Use the @ syntax in prompts to prioritize a specific remote repository. This is handy for multi‑repo environments (e.g., a Go backend and a TypeScript front‑end) where you need the assistant to focus on one service at a time.

Usage Dashboard (September 4)

• A built‑in dashboard displays activity volume, usage trends, and adoption metrics—useful for team leads and administrators monitoring overall engagement.

IntelliJ Enhancements (September 9)

• Attach terminal output directly to a chat, allowing the assistant to reason about build failures or flaky tests.
• Regenerate button provides a quick way to request a fresh answer when the first response falls short.

September 10‑11 – Agent Mode and Workflow Polishing

Cloud Run Deploy Command (September 10)

• A custom slash command /deploy (forward/deploy) builds, containers, pushes, and publishes a Cloud Run service, returning a public URL. This streamlines demo creation and internal previews.

Chat Workflow Improvements (September 11)

• Edit a previous prompt and regenerate a response based on the edit.
• Delete a single prompt/response pair without erasing the entire conversation.
• Release channels let users opt into preview builds for early‑access features while keeping a stable GA channel for production use.

Late September – Inline Diff, Checkpoints and Context Indicators

Inline Diff (September 23)

• General Availability of inline diffs in VS Code: additions appear in green, deletions in red, letting developers review changes without leaving the editor. This has become a frequent, hour‑by‑hour productivity booster.

Checkpoint & Prompt Library (September 23 – IntelliJ)

• Revert to checkpoint restores files to their pre‑suggestion state, providing a safety net for AI‑generated edits.
• Saved prompts can be accessed via the @ picker, enabling reusable workflows such as “add logging” or “generate unit tests.”

Sign‑In Convenience (September 23)

• A copy‑and‑paste sign‑in link works in locked‑down environments where the native flow may be blocked.

September 26 – Predictive Editing

Next‑Edit Predictions (VS Code 2.51.0 preview)

• The editor now suggests the next block of code in the gutter. Users can accept, dismiss, or ignore the suggestion, which is especially helpful for repetitive boilerplate (e.g., large React forms or config files). While not perfect, it can shave many keystrokes when it lands correctly.

Ongoing Maintenance (Late September)

• Minor performance and stability updates for both VS Code (v250.0 Z) and IntelliJ (v1.31.3) keep the experience smooth while the core diff and checkpoint features mature.

October 2023 – Shift to Agent Mode

Deprecation of Classic Tools (October 2‑14)

• Traditional tool‑name shortcuts are being retired. Agent mode—now in preview—replaces them, connecting to external services through MCP (Model‑Control‑Plane) servers. This aligns Gemini with other AI platforms (e.g., Claude) and standardizes integration patterns.
• Existing workflows that relied on the old tool names will need a brief migration to the new agent‑mode setup.

IntelliJ Updates (October 8)

• Next‑edit predictions arrive in IntelliJ, mirroring the VS Code experience for Java and Kotlin boilerplate.
• Chat code suggestions now appear inside a preview block, improving readability and allowing users to collapse or expand snippets as needed.

Feature Deep‑Dive

Inline Diff and Checkpoints

• Inline diff visually distinguishes added (green) and removed (red) lines directly in the editor.
• A checkpoint indicator appears next to the chat pane; a single click restores the code to its pre‑edit state, eliminating the fear of accidental overwrites.

Context Control with “@” Picker

• Typing @ followed by a repository name forces the assistant to draw context from that specific remote, ideal for multi‑service architectures.

Usage Dashboard

• An organization‑level view shows request counts, adoption curves, and peak usage periods—valuable for engineering managers tracking AI‑assisted development.

Next‑Edit Predictions

• A gutter badge signals the next probable code block. Users can cycle through suggestions, accept the best fit, or continue typing manually.

What These Changes Mean for Developers

• Safer editing – Inline diffs and checkpoint rollback give confidence when applying AI‑generated code.
• Smarter context – Full remote repository awareness and markdown indexing ensure answers respect project‑specific conventions.
• Faster workflows – Next‑edit predictions and preview blocks reduce the back‑and‑forth between the editor and chat window.
• Unified integrations – Agent mode with MCP servers provides a consistent way to call external services, positioning Gemini alongside competing AI assistants.

Conclusion

The October release marks a clear transition: agent mode becomes the default interaction model, while inline diffs, checkpoints, and preview‑style chat sharpen daily productivity. For teams, the new usage dashboard and code‑customization visibility add much‑needed observability. Collectively, these upgrades make Gemini Code Assist a more reliable, context‑aware, and developer‑friendly AI companion.

Developers looking to modernize their workflow should explore the new inline diff, checkpoint rollback, and next‑edit prediction features—especially if they work across multiple repositories or maintain extensive internal documentation.