Changelog

This page tracks user-facing changes to Cosine CLI.

v2.0.1

Changes since v2.0.0-beta21 (published 2026-03-12).

New Features

Text Prediction in the Prompt

As you type, the prompt input now shows inline ghost-text completions. A predicted continuation appears after your cursor and can be accepted with Tab or the right arrow key. The overlay tracks your cursor position precisely as you move through text.

Session Resume

Sessions now persist between runs. When you launch the CLI, your last active session is automatically resumed so you can continue exactly where you left off. You can also explicitly resume a specific session by ID. The resume flow correctly prioritises remote-hosted sessions when running in cloud environments.

VNC Support for Remote Environments

Remote environments can now run and stream a VNC display, enabling the agent to operate GUI applications visually. This unlocks browser automation, desktop apps, and any workflow that requires a visible screen.

Safari Browser Support

Safari is now available alongside Chrome and Firefox as a browser option for agent-driven web tasks.

Auto-Update and Restart

The CLI now checks for updates in the background and prompts you to restart when a new version is ready. Homebrew-installed builds are updated automatically — no manual brew upgrade needed.

--prompt-file Flag

Pass a prompt from a file when starting the agent:

cos2 start --prompt-file ./task.md

Useful for longer or templated prompts and scripted agent invocations.

--mode and --reasoning Flags

Set the agent mode and reasoning level directly at startup without navigating the settings menu:

cos2 start --mode plan --reasoning high

Persistent Startup Flags

Flags passed to cos2 start (like --mode and --reasoning) are now saved and restored across sessions, so your preferred configuration carries over automatically.

Commands Menu Keyboard Shortcut

A keyboard shortcut has been added to open the commands panel directly, without navigating through submenus.

Ctrl+\ to Answer Now

Press Ctrl+\ at any point during agent reasoning to interrupt and get the agent’s current answer immediately, without waiting for the full response cycle to complete.

MCP Tool Count Display

When an MCP server connects, the TUI now shows exactly how many tools it loaded (e.g. Vercel MCP (14 tools)), making it easy to verify integrations are healthy at a glance.

Improved MCP Server Install UI

The interface for discovering and installing MCP servers from within the CLI has been redesigned for clarity.

Native Tool Search — Always On

The AI’s native tool-search capability is now enabled by default for everyone and persisted across restarts. The --enable-tool-search flag has been removed since the behaviour is now the default.

Collapsible Changes View in the Overview Tab

The file-change summary in the Overview tab can now be collapsed and expanded, keeping the UI manageable when the agent has touched many files.

Transcript Overlay Improvements

The transcript view now opens anchored to the bottom of the conversation and preserves scroll position when you reopen it.

Auto-Generate Dockerfiles for Environments

When creating a new environment, Cosine can automatically generate a suitable Dockerfile based on your project’s language and tooling, rather than requiring you to write one from scratch.

Configurable Pod Size Per Environment

Each cloud environment can now be configured with its own compute size independently, so demanding environments get more resources without over-provisioning everything.

Remote PTY Sessions

Remote environments now support full interactive terminal sessions with proper PTY allocation, enabling interactive programs (REPLs, TUIs, prompts) to run correctly in the agent’s terminal.

Auto Git Configuration in Remote Environments

Git identity and authentication are automatically configured when spinning up a remote runtime session, so the agent can commit, push, and open PRs without requiring manual credential setup.

Environments Moved to Workspace Menu

The Environments submenu has been reorganised under the Workspace section in the navigation, grouping project-level settings in one place.

Logout from the CLI

You can now log out of your Cosine account directly from within the CLI without needing to touch configuration files.

Fixes

• Fixed large paste handling — pasting a large block of text into the prompt no longer hangs or drops characters.
• Fixed intermittent @filename mention search failures; file search now also runs asynchronously while you type so it no longer blocks input.
• Fixed TUI layout corruption caused by ANSI escape sequences in tool output.
• Fixed sidebar keyboard selection drift when the list updates while navigating.
• Fixed stale Anthropic todo items without IDs failing to clear.
• Fixed multiple scroll position bugs in the chat timeline that caused the view to jump unexpectedly when new content arrived.
• Fixed thinking block markdown rendering styles in the timeline.
• Fixed over-counted context token usage that was causing premature compaction.
• Fixed Plan mode context being rebuilt too eagerly after tool calls, causing unnecessary latency.
• Fixed repeated streamed tool-call argument chunks being incorrectly stripped, which produced truncated tool inputs.
• Fixed the agent to handle malformed tool-call payloads gracefully rather than entering an error state.
• Fixed MCP OAuth flow bugs in the connection flow and TUI OAuth UI components.
• Fixed the code edit tool to normalise indentation when matching, so edits succeed across codebases with mixed tabs and spaces.
• Fixed the Anthropic-provider edit tool to enforce exact string matching and prevent incorrect partial matches.
• Fixed tool registration failures in Plan mode that caused certain tools to be unavailable during planning.
• Fixed the remote gitops push-to-branch and PR creation flow, including correct git identity and auth handling.
• Fixed remote task history resume not correctly restoring conversation state in the Platform view.
• Fixed a trailing blank row appearing at the bottom of the TUI under certain terminal sizes.
• Fixed remote todo list display and subagent token graphs not rendering correctly in remote sessions.
• Updated all remaining user-facing “checkpoint” references to “commit” for consistency.

Performance

• Reduced environment boot time through a refactored bootstrap sequence that parallelises more initialisation work.
• The grep tool now streams results in chunks, preventing memory pressure and crashes when searching large codebases.
• @mention file lookup now runs asynchronously so typing in the prompt is never blocked while results load.
• Provider-side context compaction is now available, reducing context window pressure in long sessions.
• Improved scrolling performance through long conversations, particularly in sessions with many tool calls or large outputs.

v2.0.0-beta21

Changes since v2.0.0-beta20 (published 2026-03-10).

New Features

• Added GitHub Copilot sign-in with cos login-with-copilot, so you can connect your Copilot account from the CLI and use Copilot-backed models directly in Cosine.
• You can now queue follow-up prompts while a run is still active. Nudges and queued prompts are shown separately, and queued items stay visible in the timeline until they run.
• Added /link-project so you can attach another project to the current session, with an option to save that linked project for future sessions in the same workspace.
• Tool approvals are now more informative: edit-like tool calls can show a diff preview before approval, and approval cards use clearer user-facing descriptions.
• Expanded the model picker with updated model options, including GPT 5.4, GPT 5.4 1M, and GitHub Copilot-backed choices, while making model selection behave more consistently across settings and task prompts.

Fixes

• Fixed image path detection so pasted paths still work when they are quoted or followed by trailing punctuation.
• Fixed remote runtime host override handling so custom hosts are respected more consistently.
• Fixed remote runtime configuration selection and write-location issues.
• Fixed queued prompt handling so stacked items lay out correctly and stale completion events do not accidentally drain the queue.
• Fixed interrupted-run UI so cancellations are shown more cleanly.

v2.0.0-beta19

Changes since v2.0.0-beta18 (published 2026-03-07).

New Features

• Added a diff viewer to the Git Session Manager so you can inspect checkpoint changes without leaving the CLI.
• Swarm mode now lets you turn QA verification agents on or off with /swarm-qa or from the command menu.
• Subagents now share MCP and LSP context more reliably with their parent session, reducing setup friction in Swarm workflows.
• Added initial support for sandbox-backed remote environments in managed runtime flows.

Changed

• The project initialization dialog now includes a “No, not this time” option so you can skip setup and continue immediately.

Fixes

• Fixed ANSI terminal rendering issues.
• Fixed shifted number and symbol keys in VS Code terminal input.
• Fixed nested subagents appearing under the wrong parent in the Agents panel.
• Fixed UI state bleed-through between active and background agents in multi-agent sessions.
• Fixed a background-task scheduling issue that could cause Swarm runs to return early.

v2.0.0-beta18

Changes since v2.0.0-beta17 (published 2026-03-05).

New Features

• Added Lua plugin support with cos plugin install, cos plugin list, and cos plugin remove, plus a plugin runtime that can subscribe to agent events, queue nudges, make HTTP requests, and perform sandboxed file operations.
• Added plugin documentation covering installation, the Lua API, lifecycle, and example plugins.
• Added xhigh reasoning support for GPT-5.4 in the CLI reasoning-effort controls.
• Swarm can now nudge active work and surface semi-async subagent progress so long-running tasks feel more responsive.

Changed

• cos update now automatically runs the installer for non-Homebrew installs, reducing the manual steps after an upgrade.
• The slash-command menu has been cleaned up for faster navigation and clearer command discovery.
• Plugin logs are now surfaced in the CLI panels so plugin activity is easier to inspect while debugging.
• Lumen and Devstral have been removed from the CLI model picker.

Fixes

• Resolved a subagent hang that could affect VS Code-hosted CLI sessions backed by CLI2.

beta15

Changes since beta14 (published 2026-03-04).

New Features

• Added automatic task name derivation from user prompts in the Agents sidepanel to make multi-agent sessions easier to scan.
• Expanded CLI2 event coverage to improve telemetry and product insights.

Fixes

• Fixed additional Swarm mode issues to improve stability in parallel subagent workflows.

v2.0.0-beta13

Changes since v2.0.0-beta12 (published 2026-03-03).

Fixes

• Fixed update check functionality to properly detect and prompt for new CLI versions.
• Fixed Swarm mode bugs including subagent checkpointing issues that could cause state inconsistencies.
• Fixed terminal display issues where the terminal could appear white or unresponsive.
• Fixed backspace behavior in filter dialogs — Ctrl+H now works correctly as backspace.
• Fixed user question handling on subagents so prompts are properly routed when using parallel agent workflows.
• Improved Homebrew install detection on Windows CI environments.

v2.0.0-beta12

Changes since v2.0.0-beta10 (published 2026-02-25).

New Features

Swarm Mode

Swarm mode enables parallel agent workflows by allowing the primary agent to spawn and orchestrate multiple subagents simultaneously. When activated, the agent can delegate independent tasks to subagents that run in parallel, significantly speeding up complex multi-file operations. Subagents appear in the Agents panel (Ctrl+3 / Alt+3) indented under their parent, where you can monitor progress, view diffs, or kill individual agents. This is particularly useful for large refactoring tasks, cross-module changes, or when you need multiple independent investigations running concurrently.

Light Mode

The CLI now supports a complete light color theme alongside the existing dark theme. Light Mode provides better visibility in bright environments and reduces eye strain during daytime usage. The theme automatically applies to all UI components including the timeline, side panels, dialogs, and terminal views. You can switch between themes through the settings or use the quick toggle in the commands menu.

Rebase Quick Action in Git Session Manager

A new Rebase action has been added to the Git Session Manager, allowing you to quickly rebase your current branch without leaving the CLI interface. This streamlines common git workflows when working with agent-generated branches, making it easier to keep feature branches up to date with main before merging or continuing work.

Auto-Approve Plan Functionality

Plan mode now supports auto-approve, which automatically approves the generated plan without requiring manual confirmation for each step. This is ideal when you want the agent to create and execute a plan in one flow while still benefiting from the structured planning phase. The setting can be toggled per-session or configured globally for users who prefer the plan-then-execute workflow without interruptions.

Standardized Plan File Context Injection

Plan files are now injected into the agent’s context more consistently and reliably. When a plan is created, its content is properly formatted and made available to the agent throughout the session. This ensures the agent always has access to the full plan context when making edits, reducing drift between the intended plan and actual execution.

Open Terminal Action in the Terminal User Interface (TUI)

You can now open an interactive terminal session directly from the TUI using the new Open Terminal action. Accessible from the commands menu (/ or Ctrl+P), this creates a new shell session without leaving your current conversation. The terminal appears in the Terminals panel (Ctrl+2 / Alt+2) where you can switch between it and your chat session seamlessly.

Send Terminal Output to Model

Terminal output can now be sent directly back to the model as context. After running commands in an interactive terminal, you can capture the output and include it in your conversation with the agent. This eliminates manual copy-pasting when sharing command results, error messages, or logs with Cosine.

Implementation Plans in Chat Timeline

When the agent creates a plan, it now appears inline in the chat timeline as a structured implementation plan block. These plans are collapsible, show completion status, and can be referenced throughout the conversation. This makes it easier to track what the agent intends to do and check off items as they’re completed.

Native Gemini Streaming Responses

The CLI now supports native streaming responses from Google’s Gemini models. This provides real-time token-by-token output for Gemini-backed conversations, reducing perceived latency and allowing you to see responses as they’re generated rather than waiting for complete responses.

Improved Text Selection and Copy UI

Text selection in the timeline has been significantly improved. You can now select and copy text from assistant responses more reliably, with better visual feedback during selection. The copy UI has been updated to provide clearer confirmation when text is copied to the clipboard, making it easier to extract code snippets, explanations, or other content from agent responses.

Fixes

• Fixed hangs that could occur during websocket inference.
• Fixed rendering issues where output_text assistant messages could display incorrectly.
• Fixed message ordering in resumed sessions so tool execution blocks and assistant output are interleaved correctly.
• Fixed a ggrep mutex issue that could cause instability.
• Removed stray debug logs from the terminal popout dialog.
• Fixed stale tool definitions after model switches by invalidating cache correctly.
• Fixed terminal overlay responsiveness issues.
• Fixed dialog search behavior so Ctrl+H works as backspace.
• Fixed Linux CGO build/linking reliability by switching to external linker mode.

Performance

• Improved CLI2 CGO build speed by roughly 3x.
• Added improved generation/stream telemetry (including trace, latency, and TTFT capture) to improve performance observability.