Supported Agents

Run Claude Code, Codex, Aider, or Kiro inside FTL sandboxes

FTL supports four coding agents, each running inside an isolated Docker sandbox with shadow credentials and zero-trust controls.

Available Agents

Claude Code

Anthropic’s recommended agent with stream-JSON output

Codex

OpenAI’s coding agent

Aider

Open-source AI pair programming tool

Kiro

AWS-powered coding agent with browser-based login

Agent Configuration

Selecting an Agent

Choose your agent during initial setup:

ftl setup

Or set the agent field in .ftlconfig:

.ftlconfig

{
  "agent": "claude-code",
  "tester": "claude-haiku-4-5-20251001"
}

Agent Requirements

Agent	Config Key	Required Credentials
Claude Code	"claude-code"	ANTHROPIC_API_KEY
Codex	"codex"	OPENAI_API_KEY
Aider	"aider"	OPENAI_API_KEY or ANTHROPIC_API_KEY
Kiro	"kiro"	AWS credentials + browser login

Agent-Specific Setup

Claude Code

Claude Code is the recommended agent with full stream-JSON output support.

1. Get API Key

   Obtain your Anthropic API key from console.anthropic.com

2. Save Credentials

   ftl auth ANTHROPIC_API_KEY sk-ant-...
   
3. Configure Project

   .ftlconfig

   {
     "agent": "claude-code",
     "tester": "claude-haiku-4-5-20251001"
   }
   

Docker Image: vvenne/ftl:latest

Codex

OpenAI’s Codex agent for code generation tasks.

1. Get API Key

   Obtain your OpenAI API key from the OpenAI platform

2. Save Credentials

   ftl auth OPENAI_API_KEY sk-...
   
3. Configure Project

   .ftlconfig

   {
     "agent": "codex",
     "tester": "claude-haiku-4-5-20251001"
   }
   

Docker Image: vvenne/ftl:codex

Aider

Open-source AI pair programming tool with flexible LLM backend support.

1. Get API Key

   Obtain an API key from either:

   • Anthropic: console.anthropic.com
   • OpenAI: OpenAI platform
2. Save Credentials

   ftl auth ANTHROPIC_API_KEY sk-ant-...
   # OR
   ftl auth OPENAI_API_KEY sk-...
   
3. Configure Project

   .ftlconfig

   {
     "agent": "aider",
     "tester": "claude-haiku-4-5-20251001"
   }
   

Docker Image: vvenne/ftl:aider

Kiro

AWS-powered agent requiring browser-based SSO authentication.

1. Configure AWS Credentials

   Set up AWS credentials using any standard method:

   # Option 1: AWS CLI
   aws configure
   
   # Option 2: FTL auth
   ftl auth AWS_ACCESS_KEY_ID AKIA...
   ftl auth AWS_SECRET_ACCESS_KEY ...
   ftl auth AWS_DEFAULT_REGION us-east-1
   
2. Configure Project

   .ftlconfig

   {
     "agent": "kiro",
     "tester": "claude-haiku-4-5-20251001"
   }
   
3. Run First Task

   ftl code 'your task here'
   
4. Complete Browser Login

   After the container starts, authenticate via browser:

   docker exec -it $(docker ps -q --filter ancestor=vvenne/ftl:kiro) kiro-cli login
   

   Credentials persist in the container until it is removed.

Docker Image: vvenne/ftl:kiro

Docker Images

FTL pulls the appropriate Docker image automatically based on your agent selection:

vvenne/ftl:latest   # Claude Code
vvenne/ftl:codex    # Codex
vvenne/ftl:aider    # Aider
vvenne/ftl:kiro     # Kiro
vvenne/ftl:full     # All agents

Local Fallback Builds

If Docker Hub is unavailable, FTL builds the image locally using the base Dockerfile plus agent-specific layers:

Codex Build Snippet

RUN npm install -g @openai/codex && npm cache clean --force

Aider Build Snippet

RUN pip3 install --break-system-packages aider-chat

Kiro Build Snippet (Architecture-Aware)

RUN apt-get update && apt-get install -y --no-install-recommends unzip \
  && ARCH=$(uname -m) \
  && if [ "$ARCH" = "x86_64" ]; then \
    curl -fsSL https://desktop-release.q.us-east-1.amazonaws.com/latest/kiro-cli.deb -o /tmp/kiro-cli.deb \
    && dpkg -i /tmp/kiro-cli.deb && apt-get install -f -y --no-install-recommends \
    && rm -f /tmp/kiro-cli.deb; \
  elif [ "$ARCH" = "aarch64" ]; then \
    curl -fsSL https://desktop-release.q.us-east-1.amazonaws.com/latest/kirocli-aarch64-linux.zip -o /tmp/kiro.zip \
    && unzip /tmp/kiro.zip -d /tmp/kiro-extract \
    && if [ -f /tmp/kiro-extract/install.sh ]; then PREFIX=/usr/local bash /tmp/kiro-extract/install.sh; \
    else find /tmp/kiro-extract -type f -name kiro-cli -exec install -m755 {} /usr/local/bin/kiro-cli \;; fi \
    && rm -rf /tmp/kiro.zip /tmp/kiro-extract; \
  fi \
  && rm -rf /var/lib/apt/lists/*

Switching Agents

To switch agents on an existing project:

1. Update Configuration

   Edit .ftlconfig to change the agent:

   .ftlconfig

   {
     "agent": "aider",
     "tester": "claude-haiku-4-5-20251001"
   }
   
2. Pull New Image

   Run setup to pull the new agent’s Docker image:

   ftl setup
   

   Select the new agent when prompted.

3. Configure Credentials

   Ensure the required API keys for the new agent are configured:

   ftl auth OPENAI_API_KEY sk-...
   

Persistent containers are keyed by project path, so switching agents will create a new container with the appropriate image.

Agent Behavior

Conversation History

Agent conversation history persists across tasks in /home/ftl/.claude/ inside the container. Follow-up instructions in the interactive shell continue the same conversation.

Pre-installed Dependencies

All agents have access to common Python and Node.js packages:

Python:

• stripe, requests, httpx, boto3
• openai, anthropic, pydantic
• python-dotenv, pytest

Node.js:

• TypeScript, ts-node, Jest
• Claude Code runtime (for all agents)

Warm Start Optimization

FTL runs claude --version in the background during boot to load Node.js modules into the Linux page cache, eliminating the 5-8s cold-start penalty on first task.