Add kiro-acp-bridge (ACP adapter adding config options to Kiro CLI)

[AbduRahmanS]

Adds an ACP adapter that fronts Kiro CLI and exposes its model, reasoning-effort and agent selection as session config options.

Relationship to the other Kiro PRs

I found five open Kiro-related PRs while preparing this, so to be explicit about scope:

PR	What it adds	Distribution
#33, #209, #561	Kiro CLI itself (id kiro)	Kiro binaries — blocked on macOS/Windows archives
#482	Kiro Gateway — OpenAI/Anthropic-compatible gateway	npx
#575 (this)	Adapter adding config options on top of Kiro CLI	npx

This does not compete with #33 / #209 / #561 — it complements them. Those distribute Kiro; this makes Kiro's model, effort and agent selection reachable by clients that use session config options. I'd be glad to see one of them merge and would happily reference it.

Display name is deliberately "Kiro Bridge", not "Kiro", so it cannot be mistaken for a first-party entry.

Why it exists

Kiro CLI speaks ACP natively, but an older dialect: model selection goes through session/set_model plus a models block on session/new, and session/set_config_option returns -32601. Clients that have moved to session config options therefore show no model, effort or agent selector when talking to it directly. This adapter translates:

Surface	Mapping
Models	configOptions, category: "model"
Agents (Plan, Guide, user-defined)	configOptions, category: "mode"
Reasoning effort	configOptions, category: "thought_level"
Kiro slash commands + user skills	available_commands_update
Context usage	usage_update from measured token counts
Saved sessions	session/list

Notes for reviewers

Platform coverage. npx distribution sidesteps the .dmg/.msi problem that has held up the binary-based Kiro entries — this works on macOS, Linux and Windows. The trade is that it requires kiro-cli already installed, whereas #561 downloads it. Different tradeoff, not a better one.

Effort is per-model and re-queried on every model change. Kiro's GPT models expose an extra none level, Claude models do not, and auto has no effort axis at all — in that case the option is withdrawn rather than shown empty.

Authentication. Kiro's auth surface is state-dependent: with a signed-in CLI initialize returns authMethods: [], and it advertises kiro-login when authentication is required (as #561 notes). This adapter always advertises an ACP Terminal Auth method backed by kiro-cli login, because a client must decide what to render from one response without knowing the auth state — and because kiro-cli may be absent entirely, which is this CI's condition since the package ships via npx and does not bundle Kiro. initialize completes in that case rather than failing, so the handshake still offers a way forward.

Credits. Kiro bills in abstract credits, deliberately not written to usage_update.cost since ACP's Cost requires an ISO 4217 currency. Only genuine overage charges populate it.

Requirements

Node >= 22 and an installed, authenticated Kiro CLI. Two pinned runtime dependencies: @agentclientprotocol/sdk@1.4.0 and zod@3.25.76.

Verification

• 199 unit tests against fixtures captured from real Kiro traffic
• six end-to-end suites driving the built adapter through a simulated client against a live kiro-cli
• CI on Linux and macOS across Node 22 and 24, including a job asserting initialize advertises an auth method with no kiro-cli present
• the published npm artifact installed into a clean directory and driven through a full handshake

build_registry.py accepts the entry locally (Added agent: kiro-acp-bridge v0.1.0). I could not complete verify_agents.py --auth-check on my machine — npm exec stalls on its confirmation prompt without a TTY — but the invariant it checks is covered by the CI job above.

Repository: https://github.com/AbduRahmanS/kiro-acp-bridge
npm: https://www.npmjs.com/package/kiro-acp-bridge