[Feature]: Add Kiro CLI ACP provider support

[mfroembgen]

Before submitting

• I searched existing issues and did not find a duplicate.
• I am describing a concrete problem or use case, not just a vague idea.

Area

apps/server

Problem or use case

Kiro CLI supports ACP through kiro-cli acp, but T3 Code does not currently expose Kiro as a provider.

I also did not find Kiro in the current ACP Registry, so users cannot get it through the generic registry path today either.

Prior-art check:

• No open or closed issue matched Kiro, kiro-cli, or Kiro ACP.
• Agent Client Protocol Support #203 and Introduce an ACP adapter layer for providers #315 cover generic ACP support/adapter discussion, but not a Kiro-specific feature.
• chore: kiro cli coming soon #2228 was only a disabled Kiro placeholder and was closed as obsolete.
• [codex] Fix Kiro ACP image attachment errors #2793 contained Kiro provider work, but was closed as a cross-repo PR and redirected to a fork.
• ACP implementation bringing 31 CLI tools into t3code #2684 is an open ACP Registry PR, but Kiro is not currently included in the registry.

Proposed solution

Add a small, first-class Kiro ACP provider integration that launches:

kiro-cli acp

and maps the basic ACP session loop into T3 Code: readiness checks, session start, prompt streaming, tool/step updates, cancellation, and model selection where Kiro advertises it.

This could be implemented as a dedicated built-in provider or as an explicitly supported ACP Registry/custom ACP path if maintainers prefer that architecture.

Why this matters

Kiro users could use their Kiro subscription, custom agents, MCP setup, and CLI-native behavior inside T3 Code's existing GUI, threads, and project/worktree workflow.

Smallest useful scope

A first pass only needs to:

• detect kiro-cli
• start kiro-cli acp
• create a session
• send prompts and render streamed assistant output
• show tool calls/tool updates in the existing step UI
• support cancellation and clean shutdown
• show a helpful setup error when Kiro is missing or not authenticated

Resume, custom agents/modes, image attachments, richer permissions, and deeper model/mode UX can come later.

Alternatives considered

• Generic ACP Registry only, but Kiro is not currently in the ACP Registry.
• Reopen chore: kiro cli coming soon #2228, but that was only a placeholder.
• Reopen [codex] Fix Kiro ACP image attachment errors #2793, but a fresh issue is cleaner because that PR mixed a full provider implementation with unrelated changes and was closed as cross-repo.

Risks or tradeoffs

• Could duplicate some generic ACP Registry work if ACP implementation bringing 31 CLI tools into t3code #2684 lands first.
• Kiro-specific modes, permissions, images, and session loading need careful mapping.
• Desktop PATH/auth probing needs to work outside a normal shell environment.

Examples or references

• Kiro CLI: https://kiro.dev/docs/cli/
• Kiro ACP: https://kiro.dev/docs/cli/acp/
• Generic ACP support request: Agent Client Protocol Support #203
• Generic ACP adapter-layer request: Introduce an ACP adapter layer for providers #315
• Obsolete Kiro placeholder PR: chore: kiro cli coming soon #2228
• Closed Kiro provider PR: [codex] Fix Kiro ACP image attachment errors #2793
• Open ACP Registry PR: ACP implementation bringing 31 CLI tools into t3code #2684

Contribution

• I would be open to helping implement this.

[whoisaldo]

This would be awesome, especially because Kiro has free student plans!

[TinBane]

Kiro also has launched promotions for existing AWS companies to try and push use.
One concern I have is that kiro seems to want to do some things differently. It's designed to use certain cycles to plan things out, and it has "powers" which are plugins. Not sure how much any of that bothers T3, but hoping we could get the basics working well, pretty quickly.

I might have a crack at it, as I'm about to start a free trial.

[TinBane]

I've opened #13360 with a first pass at this.

It's intentionally minimal: Kiro as a built-in provider that launches kiro-cli acp as a thin flavor on the shared AcpAdapterV2, like Grok and Antigravity. It has a status check (installed, logged in, models) that never opens a session, clear setup errors, streaming, tool steps, approvals, cancel, resume, images, model switching, and clean shutdown of Kiro's launcher and its chat child. It targets the v2 orchestrator branch.

I have more working locally but held it back on purpose, hoping a small, provable first version is easier to accept:

• Kiro's planner as T3 plan mode (stopping the turn at the plan hand-off so Kiro doesn't start editing)
• context % and credit usage, with auto-resume when credits reset, and /compact
• Kiro slash commands and subagents ("crews")
• a custom Kiro agent setting (--agent)
• stripping the DeepSeek tool-call marker some Kiro models leak into text
• end-of-turn questions (Kiro has no ask-user tool; it ends its turn with a fenced block T3 turns into the existing question card)
• an env-gated live test against the real CLI

Happy to send any of these as small follow-up PRs.

[TinBane]

@juliusmarminge following up on your note on #13360: could you confirm whether Kiro as a built-in provider is a direction you'd accept, and at what scope?

Why I think it's worth it: Kiro is AWS's coding agent, and AWS is actively pushing it into companies that already run on AWS, including trial promotions for existing customers. That means a growing number of developers will have a Kiro seat from work rather than a Claude or Codex subscription, and this discussion is already one of the most upvoted provider requests here.

Proposed scope: a thin flavor on the shared ACP adapter now on main, the same pattern as Grok and Antigravity. Status check (installed / signed in / models, without opening a session), streaming, tool steps, approvals, cancel, resume, images, and model switching. About 800 non-test lines in one commit, retargeted to main. Kiro-only extras (plan mode, credits, subagents, slash commands) stay out unless you want them later as separate PRs.

If you'd rather take a different shape (smaller, user-configured ACP instead of built-in, or not at all), that answer helps too.

[tinuva]

@TinBane see @juliusmarminge 's PR at #14693

[m4rcelpl]

Hi @juliusmarminge,

I'd like to contribute additional Kiro CLI V3 functionality and agree
on the direction and scope before opening a PR.

I've reviewed #14693. It already covers model selection, reasoning
effort and agent selection, so I'd like to coordinate with that work.

The additional capabilities I have prototyped are:

• Manual context compaction through Kiro's _kiro/session/compact extension.
• Displaying Kiro's reported context utilization.
• Login, cancellation of login, and logout from T3 provider settings,
  with credentials remaining owned by the CLI.
• Displaying credit usage and limits reported by Kiro.

The implementation reuses the shared ACP adapter, with Kiro-specific
behavior at the driver boundary. It targets the V3 engine and would
be adapted to the existing Kiro integration.

The prototype has been tested against Kiro CLI 2.29.1, with focused
backend tests and a recorded compaction replay. Automated browser
verification is incomplete; UI evidence still needs to be collected.

Would you accept contributions in this direction?
Would you prefer patches coordinated with #14693, or follow-up PRs
after it merges?

For scope, would you approve starting with manual compaction and its
context indicator? Are login and credit usage also welcome as separate
follow-ups, or would you prefer a different grouping?

I'm happy to adapt the prototype to the scope and architecture you approve.