Kiro

Reasoning Controls and Cloud Sessions Configure thinking and effort from /model and start V3 cloud sessions before connecting a repository. This release brings reasoning controls into /model and lets V3 cloud sessions start before you connect a repository. Improvements add clearer live progress, smoother streaming, and more efficient fullscreen scrolling. Reliability fixes cover models, sessions, tools, and non-interactive runs. Reasoning controls in /model Open /model to switch models and configure the selected model's thinking and effort in one place. The panel shows only the options supported by that model and saves your choices for future sessions. /model is now the primary interface for reasoning settings. In V2, bare /effort is a legacy command: it shows a deprecation warning and opens the Effort setting in /model ; /effort <level> remains supported. In V3, /effort continues to open its own picker. Learn more -> Cloud sessions before repository connection (V3) You can start a cloud session before connecting a repository. Run /repo when you're ready to attach one. If no source provider is connected, Kiro opens the connection screen, where the repository is marked as optional.

Spec Review Mouse Support and Automatic Stream Recovery This release brings mouse support to the spec review screen. Under the hood, a stream idle watchdog, automatic retries with backoff, and a 60-minute streaming timeout mean a dropped connection or a throttled request no longer hangs or ends your turn. Mouse support in spec review The spec review screen now supports the mouse: scroll to navigate the document and click to position the cursor. Press m to toggle mouse support on or off. Learn more -> Automatic recovery from stream and network failures Turns no longer hang on a stalled response stream: an idle watchdog warns after 60 seconds of silence and cancels at 300, while throttling, 5xx errors, and connection drops are retried automatically with backoff. Streaming responses also get a 60-minute timeout by default, so long responses are no longer cut off. Tune all of it with the api.streamIdleSoftTimeout , api.streamIdleHardTimeout , and api.timeout settings. Learn more -> Improvements Fixes Patches

Spec Review Mouse Support and Automatic Stream Recovery This release brings mouse support to the spec review screen. Under the hood, a stream idle watchdog, automatic retries with backoff, and a 60-minute streaming timeout mean a dropped connection or a throttled request no longer hangs or ends your turn. Mouse support in spec review The spec review screen now supports the mouse: scroll to navigate the document and click to position the cursor. Press m to toggle mouse support on or off. Learn more -> Automatic recovery from stream and network failures Turns no longer hang on a stalled response stream: an idle watchdog warns after 60 seconds of silence and cancels at 300, while throttling, 5xx errors, and connection drops are retried automatically with backoff. Streaming responses also get a 60-minute timeout by default, so long responses are no longer cut off. Tune all of it with the api.streamIdleSoftTimeout , api.streamIdleHardTimeout , and api.timeout settings. Learn more -> Improvements Fixes Patches

Spec Review Mouse Support and Automatic Stream Recovery This release brings mouse support to the spec review screen. Under the hood, a stream idle watchdog, automatic retries with backoff, and a 60-minute streaming timeout mean a dropped connection or a throttled request no longer hangs or ends your turn. Mouse support in spec review The spec review screen now supports the mouse: scroll to navigate the document and click to position the cursor. Press m to toggle mouse support on or off. Learn more -> Automatic recovery from stream and network failures Turns no longer hang on a stalled response stream: an idle watchdog warns after 60 seconds of silence and cancels at 300, while throttling, 5xx errors, and connection drops are retried automatically with backoff. Streaming responses also get a 60-minute timeout by default, so long responses are no longer cut off. Tune all of it with the api.streamIdleSoftTimeout , api.streamIdleHardTimeout , and api.timeout settings. Learn more -> Improvements Fixes Patches

Spec Review Mouse Support and Automatic Stream Recovery This release brings mouse support to the spec review screen. Under the hood, a stream idle watchdog, automatic retries with backoff, and a 60-minute streaming timeout mean a dropped connection or a throttled request no longer hangs or ends your turn. Mouse support in spec review The spec review screen now supports the mouse: scroll to navigate the document and click to position the cursor. Press m to toggle mouse support on or off. Learn more -> Automatic recovery from stream and network failures Turns no longer hang on a stalled response stream: an idle watchdog warns after 60 seconds of silence and cancels at 300, while throttling, 5xx errors, and connection drops are retried automatically with backoff. Streaming responses also get a 60-minute timeout by default, so long responses are no longer cut off. Tune all of it with the api.streamIdleSoftTimeout , api.streamIdleHardTimeout , and api.timeout settings. Learn more -> Improvements Fixes Patches

Reasoning Controls and Cloud Sessions Configure thinking and effort from /model and start V3 cloud sessions before connecting a repository. This release brings reasoning controls into /model and lets V3 cloud sessions start before you connect a repository. Improvements add clearer live progress, smoother streaming, and more efficient fullscreen scrolling. Reliability fixes cover models, sessions, tools, and non-interactive runs. Reasoning controls in /model Open /model to switch models and configure the selected model's thinking and effort in one place. The panel shows only the options supported by that model and saves your choices for future sessions. /model is now the primary interface for reasoning settings. In V2, bare /effort is a legacy command: it shows a deprecation warning and opens the Effort setting in /model ; /effort <level> remains supported. In V3, /effort continues to open its own picker. Learn more -> Cloud sessions before repository connection (V3) You can start a cloud session before connecting a repository. Run /repo when you're ready to attach one. If no source provider is connected, Kiro opens the connection screen, where the repository is marked as optional.

Session Search Scope, V2 Harness Flag, and Unified Settings Keyboard Choose whether session search covers agent responses, run a single session on the V2 harness, and move through every settings menu with the same keys. This version lets you choose what session search covers, adds a flag that selects the V2 agent harness for a single run, and gives every settings menu the same keyboard behavior. Choose what session search covers In V3, /sessions search indexes session titles, your prompts, and agent responses, so you can find a session by what Kiro answered rather than only by what you asked. Open /settings and choose Session search to switch between Prompts only and Prompts and agent responses . Tool output is not indexed in either mode. If your local index currently covers prompts only, /sessions asks once before rebuilding it. Learn more -> Select the agent harness for a single run Pass --v2 to run one session on the V2 agent harness. It works on both kiro-cli and kiro-cli chat , and it takes precedence over a saved chat.agentEngine value without overwriting it, so your default stays as you set it. Learn more -> Improvements Fixes

October 5, 2026 Switch to 3.0 from Classic, Category-Based Hook Matching, and Steadier V3 Sessions 2.28.0 Switch an interactive Classic session to 3.0, match V3 Hooks by tool category, and improve reliability in long V3 sessions. Kiro CLI 2.28.0 offers Classic users a path to switch to 3.0 without leaving their terminal, lets V3 Hooks match tool categories, and makes long V3 chats more reliable. Switch to 3.0 from an interactive Classic session When you start an interactive Classic session on a host that can run 3.0, Kiro now offers to switch: choose Switch to 3.0 and upgrade my agent configs to save 3.0 as your default, upgrade your agent configurations, and rerun your command in 3.0. Decline, and Kiro reminds you again about once a week. Match Hooks by tool category in V3 In V3 sessions, Hooks that run before or after a tool can now match by category, such as shell, read, write, or a specific MCP server or tool, instead of only by internal tool ID. Improvements Fixes { PREVIOUS } Connect more MCP servers, relocate ~/.kiro, and remap the TUI { NEXT } Workflow Delegation, Live Steering Context, and Saved Prompt Commands

October 2, 2026 Claude Sonnet 5.5 Now Available Claude Sonnet 5.5 is now available with experimental support across the Kiro IDE , CLI , Crew , and Web for Pro, Pro+, Pro Max, and Power customers in us-east-1 (IAD) and eu-central-1 (FRA). It's Anthropic's fastest Sonnet model to date and a clear upgrade over Sonnet 5: output is more than 30% faster, real-world knowledge work approaches Opus 5.5 performance, and clearer writing makes it a stronger collaborator. Claude Sonnet 5.5 includes a 1M-token context window , adaptive thinking on by default, and a 1.3x credit multiplier . To load the latest model list, restart the IDE or CLI, run kirocrew restart for Crew, or refresh Web in your browser. Learn more -> { PREVIOUS } DeepSeek, MiniMax, and Qwen now available as open weight model options { NEXT } Claude Sonnet 4.6 is now available in Kiro