TL;DR — Claude Code sends its requests wherever one environment variable points. Aim that at a small local translator and it runs on the Kiro plan you already pay for. Full setup below, plus the two snags worth knowing about.

Claude Code and Kiro have something funny in common: underneath, they're powered by the same Claude models. Same brain. They just grew up speaking different dialects, so out of the box they can't hold a conversation.

I noticed this right as I was about to start a second subscription for Claude Code. My Kiro plan was already renewing every month, already serving the exact models Claude Code wanted to charge me for again. Paying twice to talk to the same thing felt absurd.

So instead of buying a second seat, I hired an interpreter. One small program that sits between them, listens to Claude Code, and relays everything to Kiro in a dialect it understands. Here's how to set it up, and what I learned doing it.

Why they can't just talk

Claude Code is more open-minded than people assume. It doesn't hard-code where it sends requests. It reads one environment variable, ANTHROPIC_BASE_URL, and ships everything to that address. Normally that's the official endpoint, but it'll happily send its requests anywhere you tell it to.

That's the opening. Point it somewhere local and the whole thing becomes possible.

Meet the interpreter

The catch is that Claude Code and Kiro phrase things differently. You can't just redirect one at the other and expect them to understand each other. You need a translator fluent in both.

That's kiro-gateway-next: a tiny proxy that runs on your own machine. A request arrives phrased one way and leaves phrased another:

Claude Code (phrases it for Anthropic) ──▶ kiro-gateway (rephrases it for Kiro) ──▶ your Kiro account

Claude Code gets a reply in the format it expects. Kiro receives a request it recognizes. The interpreter does the rephrasing in the middle, and the conversation just flows.

Setting it up, step by step

Six steps. About five minutes. None of it is more complicated than a git clone.

Step 1 — install Claude Code (version 2.1.29 or newer):

npm install -g @anthropic-ai/claude-code

Step 2 — bring in the interpreter and give it a clean workspace:

git clone --depth=1 https://github.com/coderhisham/kiro-gateway-next ~/kiro-gateway
cd ~/kiro-gateway
python3 -m venv .venv
.venv/bin/pip install -r requirements.txt

Step 3 — hand it your details. Create ~/kiro-gateway/.env:

PROXY_API_KEY="kiro-local-proxy-key"
KIRO_CLI_DB_FILE="/Users/<YOUR_USER>/Library/Application Support/kiro-cli/data.sqlite3"
SERVER_HOST="127.0.0.1"
SERVER_PORT="9000"

PROXY_API_KEY is a passphrase you pick yourself. KIRO_CLI_DB_FILE is where kiro-cli keeps your login on macOS.

Step 4 — start it up:

~/kiro-gateway/.venv/bin/python ~/kiro-gateway/main.py --port 9000 &

Step 5 — make sure it's awake:

curl http://127.0.0.1:9000/health

Step 6 — tell Claude Code where to send things. Create ~/.claude/settings.json:

{
  "env": {
    "ANTHROPIC_BASE_URL": "http://127.0.0.1:9000",
    "ANTHROPIC_API_KEY": "kiro-local-proxy-key"
  }
}

That key just has to match the passphrase from Step 3. It's local, and it never leaves your machine. Run claude, say yes when it asks about the key, and you're talking to Kiro.

Worth knowing: if your Kiro plan includes it, switch the model to claude-opus-4-8 and you get Opus 4.8 with a 1M-token context window. I gave it a codebase I'd normally have to explain in pieces. It read the whole thing at once.

The two snags nobody warns you about

It didn't go perfectly on the first try. Two things tripped me up, and both cost more time than the actual setup.

Snag one — names that run too long. I added a few MCP-heavy plugins and everything stalled with a blunt 400 Improperly formed request. No explanation, just a wall.

The reason: Kiro won't accept a tool name longer than 64 characters, and MCP servers love generating mouthfuls like mcp__github__check_if_a_repository_is_starred_by_the_authenticated_user. Count it. It's over the line.

Keep tool names short. And if it's just the sheer number of tools bloating the request, the gateway has a relief valve:

AUTO_TRIM_PAYLOAD=true

Snag two — a Rust build that fights Apple Silicon. One AWS plugin pulls in a Rust dependency that tried to cross-compile for x86 on my M-series Mac and fell over with a missing x86_64-apple-darwin target. One line fixes it, then restart Claude Code:

rustup target add x86_64-apple-darwin

Neither snag is the gateway's fault. They're the usual friction of getting two ecosystems to cooperate. Tutorials skip the errors, so consider this the heads-up I wish I'd had.

The one honest trade-off

I'm not going to pretend it's free of cost. There's a little latency. Your request takes a short detour through a local process and gets rephrased on the way, so it lands slightly slower than going direct. By the second hour I'd stopped noticing. If your work is timing-sensitive, run your own test before you rely on it.

And if anything misbehaves, turn on the logs:

DEBUG_MODE="errors"

It captures the full request and response for every failed call. That's how I tracked down the long-name issue instead of guessing.

Was it worth an evening?

Here's the math that settled it. Two subscriptions for one set of models, every month, indefinitely. Or one quiet evening, once, plus a little grumbling at Rust.

I took the evening. The interpreter has been running in the background ever since, my bill hasn't moved, and Claude Code is perfectly happy talking to Kiro without ever realizing the difference.

If you already pay for Kiro and you've been eyeing Claude Code, this is the easiest yes on the menu. Worst case, you lose a night to a tool name that's three characters too long. Best case, you forget the gateway is even there and just enjoy not paying twice for the same Claude.

You don't need a second subscription. You need a translator.

The interpreter is built on jwadow's kiro-gateway. AWS plugins come from awslabs.