CLI V3 uses the same unified agent harness as Kiro IDE and Kiro Web. This brings shared agent-loop improvements to the terminal and lets supported .kiro configuration travel between surfaces. Some tools, commands, and configuration fields remain surface-specific; the tables below identify the supported V3 path.
Spec-driven development: The Spec agent brings structured development to the terminal. Define requirements, generate designs, execute task plans. Use /spec new <name> to start. Learn more →
Capability-based permissions: Declare structured policies in permissions.yaml for fine-grained, auditable control. One rule can allow or deny an entire category of operations across all tools. Learn more →
Enhanced hooks: Standalone .kiro/hooks/*.json files with two action types (shell commands and agent prompts), new triggers, and a versioned schema. Learn more →
Enhanced agent config: Tag-based tool selection, unified permissions block, Markdown format, inline MCP servers. Learn more →
Introspect subagent: Ask Kiro about its features and get documentation-grounded guidance inline. It can explain capabilities, help with custom agents, Hooks, and Steering, and suggest configuration for your workflow. Learn more →
Tangent: Branch your conversation into side-conversations that inherit your context, explore freely, then jump back to exactly where you left off. Use /tangent to branch. Learn more →
The table tracks current V3 support across core CLI workflows and capabilities that exist only on the shared harness. "Available" means the reader task has a supported V3 path; the interface or configuration format can still differ from V2.
| Area | V3 status | What is available now | Details |
|---|---|---|---|
| Chat and terminal UI | Available | Markdown rendering, tool cards, Preserve scrollback, live progress, and fullscreen chat | Terminal UI |
| Prompt input | Available | File references, image paths and clipboard images, queued messages, and multi-line editing | Working with images, File references |
| Settings and display | Available | Global and workspace settings, ASCII mode, custom busy indicators, shared or per-session history, and scrollback control | In-session settings, Settings reference |
| Models and reasoning | Available | Session model selection plus Thinking and Effort controls in /model, with explicit saved defaults | Models, Reasoning effort |
| Documentation help | Available | An introspect subagent answers questions about Kiro features and configuration inline | New features |
| Specs and Plan mode | Available | Guided Spec creation, automatic Plan handoff, in-terminal Spec review, and full-screen task execution | Specs |
| Tangent and rewind | Available; V3 expands Tangent | Rewind branches from an earlier turn; V3 adds named, nestable side-conversations | Tangent, Rewind |
| Custom agents | Available; migration required | Universal agent profiles, AI-assisted creation, editing, and /upgrade-agent | Custom agents, Upgrading agent configs |
| Permissions | Available; migration required | Capability rules, scoped persistent policies, granular approvals, and session-wide trust | Permissions |
| Hooks | Available; migration required | Standalone project Hooks, global Hooks, blocking triggers, and dynamic confirmation | Hooks |
| MCP servers | Available | Configuration hot reload, authentication controls, pre-registered OAuth clients, and current protocol support | MCP configuration |
| Sub-agents | Available | Parallel isolated work, prompt previews, the Ctrl+G monitor, and idle timeouts | Sub-agents, Terminal UI |
| Local sessions | Available | Resume, export, dashboard search and cleanup, response indexing, and full replay of saved tool results | Session management |
| Headless automation | Available | JSON Lines event output, saved agent and model defaults, interruption records, and required-MCP startup checks | Headless mode |
| Cloud sessions | V3 only | Managed sandbox sessions that keep running after disconnect, with local and cloud sessions in one dashboard | Cloud sessions |
| Voice input | Available | Local speech-to-text input with /voice | Voice mode |
| Configuration and Steering | Available | Nested AGENTS.md, the /config panel, and optional Configuration Sync for new local sessions | Configuration, Steering |
| Skills and Powers | Available | Skill discovery, IDE-installed Powers, and /powers listing | Skills, Powers |
| Code Intelligence and Knowledge | Available | LSP-backed code navigation and semantic knowledge indexes | Code Intelligence, Knowledge bases |
| Change | Previous (2.x) | New (V3) | Impact |
|---|---|---|---|
| Built-in AWS tool unavailable | CLI 2.x use_aws tool (preferred alias aws) | Use MCP servers for AWS access | High |
| Session format changed | V2 session store | V3 session store (not backward-compatible) | High. Use --v2 when you need to return to a V2 session |
| Hook format changed | CamelCase object embedded in the profile | PascalCase array definitions, inline or in standalone .kiro/hooks/*.json files | High |
| Hook trigger names | camelCase (agentSpawn) | PascalCase (SessionStart) | High |
| Persistent trust configuration changed | Per-tool toolsSettings rules | Capability-based permissions.yaml; session-wide trust uses --trust-all-tools or /tools trust-all | High |
| "Vibe" concept removed | N/A for CLI | "Default" mode is the standard name | Low |
Start V3 and run /upgrade-agent to convert supported agent fields, permissions, and object-form Hooks. Then review its diagnostics and make only the manual changes it reports or your workflow requires. Run it again after you change V2 trust settings so the generated V3 rules stay current.
permissions.yaml, behavioral changes.kiro/hooks/ files, trigger name mappingWhen you start an interactive V2 chat, Kiro CLI may offer to switch you to V3. The offer has three options:
| Option | What happens |
|---|---|
| Switch to V3 and upgrade my configs | Starts this session in V3, saves chat.agentEngine as v3, and upgrades your agent configs now and on later launches |
| Remind me later | Keeps this session in V2 and shows the offer again in about seven days |
| Don't ask again | Keeps this session in V2 and stops the offer |
Pressing Esc works like Remind me later. Remind me later, Don't ask again, and Esc leave your harness unchanged. You can still start V3 at any time with kiro-cli --v3.
V3 does not reproduce every legacy surface. These differences remain relevant when deciding whether to switch:
| Difference | V3 behavior | If you depend on the V2 behavior |
|---|---|---|
| Classic interface | The V3 harness runs in the terminal UI, not the legacy non-TUI interface | Continue using the classic interface until your workflow works in the terminal UI |
| Workspace checkpoints | The experimental /checkpoint feature remains classic-only; V3 provides /rewind for conversation branches | Use version control to restore files and /rewind to revisit an earlier turn |
V3 can resume its own sessions through /sessions, --resume, and --resume-id. V2 cannot open a V3 session because the stored session formats differ; that is a cross-version migration boundary, not a missing V3 resume capability.
kiro-cli doctor: check and fix common installation issueskiro-cli issue: file a bug report
What's new in CLI V3