Run Kiro CLI from anywhere you are

Kiro is the one agent on this list Happier has no install path for at all. There is no managed package, no release binary and no vendor recipe it can offer to run — you install kiro-cli the way AWS documents and Happier picks it up from your PATH afterwards.

It is also a built-in Agent Client Protocol provider, launched as kiro-cli acp on a transport profile written for it. That distinction matters more than it sounds: Happier has a generic door for any CLI that speaks the protocol, and Kiro does not go through it. The built-in entry declares up front that this CLI can load an existing session, that it advertises real modes and models, and that it will take images in a prompt — so the app renders those controls because the integration says they exist, not because it hopes. Kiro turns up in the ACP backends screen for the same reason, and you can safely leave it alone there; the provider page is the one to use.

Everything about identity stays with AWS. Happier holds no AWS credential for this one, launches the CLI as a subprocess, and lets it resolve your identity exactly as it does when you run it yourself; the provider page can start kiro-cli login on the computer you picked, which is a convenience rather than a broker. MCP servers you defined in Happier reach it as native tools rather than through the shell bridge, and resume is offered as experimental — a session identity Happier stored and can ask the CLI to pick up again, rather than a promise that it always will.

Kiro is AWS’s agentic development CLI, and its documentation is explicitly about the Agent Client Protocol — convenient, because that is the protocol Happier speaks to it over. happier kiro runs the kiro-cli binary in the repository you point it at.

Everything about your AWS identity stays where it already was. Happier starts the process on your own computer, carries the conversation to your other devices encrypted, and gets out of the way. There is no gateway between the CLI and AWS, and nothing about your account is copied anywhere.

The computer running it does not have to be the one in front of you. A development box, an EC2 instance or a machine in a cupboard is fine — install the Happier CLI there, start the session, and read it from a phone.

The iOS and Android apps, the desktop app for macOS, Windows and Linux, and app.happier.dev are all clients onto the Kiro CLI process running on your computer — not read-only mirrors. Answer a permission request, send the next instruction, browse the repository, read the diff. The transcript is end-to-end encrypted before it leaves your computer, so the server carrying it holds ciphertext.

Happier installs on the computer that already holds your repository, and happier kiro starts Kiro CLI there as an ordinary subprocess, in the directory you point it at, signed in the way you signed it in. There is no gateway between the agent and AWS, and no copy of your source anywhere else.

Happier looks for kiro-cli on your PATH and runs the copy you installed. There is no install path for it inside Happier at all: install it the way AWS documents, and Happier picks it up from there.

AWS’s own install and sign-in guide is at kiro.dev/docs/getting-started/installation/. Happier does not mirror it, because a copy of someone else’s install instructions is a copy that goes stale.

Configuration reference for the Happier side — Kiro CLI in the Happier docs.

Kiro CLI is one of 13 command-line coding agents Happier runs, and they share one session list, one permission inbox, one set of keyboard shortcuts and one MCP configuration.

You define an MCP server once and Kiro CLI receives it as native MCP inventory, next to whatever MCP servers it already had of its own.

That matters most on the days you are running more than one: sessions from different vendors side by side, and a notification tap opening the session that raised the request rather than the app’s front door. The full list is here.

Typing happier kiro in a terminal starts the session right where you are standing, and the same session is in the app at the same time. What you read in that shell is Happier’s own display of the session — the transcript, the permission prompts, the tool output — rather than Kiro CLI’s interface. Nobody has to give up the terminal to get a phone client.

There is no hand-off to Kiro CLI’s own TUI. That exists for Claude Code, Codex and OpenCode, and for Kiro CLI the session stays Happier’s on both ends. happier attach <session-id> lists the sessions on that computer and marks the ones it cannot reattach, rather than failing after you pick one.

The attach guide lists the cases instead of promising all of them.

One command on the computer that holds your code, then happier kiro in the repository you want to work in.

Walkthroughs are in the guides. All of it is MIT-licensed, and the relay is one you can run yourself.