Kiro Release Notes

This release introduces new spec workflows that let you design features architecture-first and fix bugs with structured root cause analysis. Supervised mode now lets you review changes at the hunk level for precise control. New hook triggers automate work around spec tasks, and MCP servers can now surface prompts, templates, and elicitation support directly in chat.

Design-First Feature Specs

A new Design-First workflow lets you start a feature spec from technical architecture instead of requirements. Provide a high-level or low-level design, pseudocode, or system diagram and Kiro derives feasible requirements from it. This is ideal when you have strict non-functional constraints, an existing design to port, or want to think through the architecture before defining user-facing behavior.
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Bugfix Specs

Specs now include a dedicated Bugfix workflow. Describe the issue you're seeing and Kiro walks you through root cause analysis, fix design, and regression prevention. The result is a bugfix.md that captures current behavior, expected behavior, and what must remain unchanged, giving the agent clear guardrails before it writes a single line of code.
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Hunk-Based Review in Supervised Mode

Supervised mode now presents file changes as individual hunks instead of full-file diffs. Each hunk is a logical group of related lines that you can independently accept, reject, or discuss with inline chat. You can also accept changes at the file level or accept all changes at once. This gives you precise control over exactly which parts of a change to keep.
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Pre and Post Task Execution Hooks

Two new hook triggers let you automate work around spec task execution.
Pre Task Execution fires before a task begins, so you can run setup scripts or validate prerequisites.
Post Task Execution fires after a task completes, letting you run tests, linting, or notify external systems automatically. Combine these with the existing hook actions to build end-to-end automation around your spec workflows.
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MCP Prompts, Resource Templates, and Elicitation

MCP servers can now provide prompts and resource templates that appear in the context provider (#) menu in chat. Select a prompt to insert pre-built instructions, or fill in a resource template's parameters to pull in specific content as context. During tool execution, servers can also request additional input from you through elicitation. Kiro supports elicitation so servers can request the information they need without interrupting your workflow.
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Kiro is now available in AWS GovCloud (US-East) and AWS GovCloud (US-West) regions, enabling government agencies and contractors to use Kiro within their compliance boundaries.

GovCloud Authentication

GovCloud Authentication
Authenticate using AWS IAM Identity Center with a GovCloud Start URL (containing us-gov-home). Kiro uses the same installer for both commercial and GovCloud regions—IAM Identity Center authentication automatically routes traffic to the appropriate region. Individual login methods like GitHub, Google, and AWS Builder ID are not available in GovCloud regions.
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Inference Routing

Inference Routing
For GovCloud customers, inference requests are processed using Amazon Bedrock in AWS GovCloud (US-West). Your content remains stored in the region where your Kiro profile was created, with all cross- region communication encrypted via TLS 1.2+.
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This release adds inline file references with @path syntax, dynamic model selection with tab completion, and estimated token usage visibility for tools. It also brings automatic skill loading, improved agent editing, and enhanced context management.

File and Directory References

Include file contents or directory trees directly in your messages using @path syntax. Content is expanded inline before sending, avoiding tool calls and saving tokens. Type @src/main.rs to inject file contents, or @src/ to show a directory tree. Tab completion and syntax highlighting help you reference files quickly.
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Dynamic Model Selection

The /model command now supports direct selection with tab completion and fuzzy matching. Type /model clau to see matching models, or /model claude-opus-4.6 to switch immediately. Ghost text hints appear as you type.
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Tool Context Insights

The /tools command now displays estimated token counts for each tool and totals per origin, helping you understand context window usage from MCP servers and native tools.
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This release adds support for signing in to Kiro IDE with Okta or Microsoft Entra ID credentials.

Enterprise SSO with Okta and Entra ID

Enterprise teams can now connect Okta or Microsoft Entra ID alongside AWS IAM Identity Center, giving organizations flexibility in how they manage user access. Developers sign in to the IDE with their existing corporate credentials. User and group synchronization happens automatically through SCIM provisioning. Configure your IdP once and it works across both Kiro IDE and CLI.

This release adds support for authenticating Kiro CLI with Okta or Microsoft Entra ID credentials.

Enterprise SSO with Okta and Entra ID

Enterprise teams can now connect Okta or Microsoft Entra ID alongside AWS IAM Identity Center for centralized access management. Developers authenticate the CLI with their existing corporate credentials through a browser-based OAuth flow. User and group synchronization happens automatically through SCIM provisioning. Configure your IdP once and it works across both Kiro IDE and CLI.

Open weight models in Kiro IDE and Kiro CLI

You can now choose from three open weight models in the
Kiro IDE
and
Kiro CLI
. Available with experimental support on all plans, with sign-in via Google, GitHub, or AWS BuilderID. Inference runs in US East (N. Virginia). Restart your IDE to access them from the model selector.
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DeepSeek 3.2

0.25x credit multiplier. Best suited for agentic workflows and code generation. Handles long tool-calling chains, stateful sessions, and multi-step reasoning well.

Minimax 2.1

0.15x credit multiplier. Best suited for multilingual programming and UI generation. Delivers strong results across Rust, Go, C++, Kotlin, TypeScript, and others.

Qwen3 Coder Next

0.05x credit multiplier. Purpose-built for coding agents with 256K context and strong error recovery. Works especially well for long agentic coding sessions in the CLI.

Added support for Claude Opus 4.6 in eu-central-1 for users authenticating with IAM Identity Center — Anthropic's smartest model with state-of-the-art coding and agentic capabilities. Opus 4.6 plans more carefully, sustains tasks for longer, operates reliably in larger codebases, and catches its own mistakes through better debugging. Available with experimental support in both the Kiro IDE and Kiro CLI for Pro, Pro+, and Power tier subscribers with a 2.2x credit multiplier. Restart your IDE to access it from the model selector.

Added support for Claude Opus 4.6

Added support for Claude Opus 4.6 — Anthropic's most powerful model and the world's best for coding. Opus 4.6 excels on large-scale codebases and long-horizon projects, making it ideal for spec-driven development and sophisticated agents. Available with experimental support in both the Kiro IDE and Kiro CLI for Pro, Pro+, and Power tier subscribers with a 2.2x credit multiplier. Supported in us-east-1 for users authenticating with IAM Identity Center. Restart your IDE to access it from the model selector.

This release brings powerful new ways to customize and extend Kiro's agentic capabilities. Define your own specialized subagents, import portable skill packages from the community, and intercept tool invocations with new hook triggers. Enterprise customers also get new governance controls for web tools.

Custom Subagents

Define your own specialized agents to handle specific tasks in your workflow. Create a markdown file in ~/.kiro/agents (global) or .kiro/agents (workspace) with a system prompt and optional attributes like model selection, tool access, and MCP server integration. Kiro automatically selects the right custom agent based on its description, or you can invoke one explicitly.

Agent Skills

Import and create portable instruction packages following the open Agent Skills standard. Skills bundle instructions, scripts, and templates that Kiro activates on-demand when relevant to your task. Share skills across projects or import them from the community.

Pre and Post Tool Use Hooks

New hook triggers let you intercept agent tool invocations. Pre Tool Use hooks can block certain tools or provide additional context before execution. Post Tool Use hooks enable logging, code formatting, or follow-up instructions after a tool runs. Filter by tool categories (read, write, shell, web) or specific tool names with wildcard support.

Web Tools Governance

Pro-tier customers using IAM Identity Center can now control web tools access for their organization. Administrators can disable web search and web fetch tools from the AWS console under Settings > Shared settings.

Custom Extension Registry

Point Kiro at your organization's private extension registry instead of the default Open VSX marketplace. Configure a limited set of vetted extensions for your team by updating the extensionsGallery settings in product.json. Deploy across your organization using MDM or endpoint management.

This release adds Agent Client Protocol (ACP) support for integrating Kiro into ACP-compatible IDEs and clients, a Help Agent for instant CLI guidance, and a range of tool and configuration improvements.

ACP-compatible editors like JetBrains IDEs and Zed can now use Kiro as a custom agent. Run kiro-cli acp to start Kiro as an ACP-compliant agent that communicates over stdin/stdout using JSON-RPC. Kiro supports standard ACP methods plus extensions for slash commands, MCP tools, and session management.

Help Agent

Get instant answers about Kiro CLI without leaving your conversation. The built-in Help Agent uses documentation to answer questions about commands, tools, settings, and configuration — and can even create config files in .kiro/ for you. Use /help to switch to the Help Agent, or /help How do I configure MCP? to ask directly.

Enterprise Web Tools Governance

Administrators can now disable web_search and web_fetch tools organization-wide. Users see a notification in /tools when web access is disabled by their organization.

Subagent Access Control

New availableAgents and trustedAgents settings give fine-grained control over which agents can be spawned as subagents. Both support glob patterns like test-*.

Exit Codes & Startup Checks

Structured exit codes for scripting and automation. --require-mcp-startup ensures MCP servers are up before your session starts.