Flatkey CLI Media Generation

Flatkey CLI Media Generation

Skill by ara.so — Devtools Skills collection.

Overview

Flatkey CLI is a terminal-first media generation tool for images, videos, audio, and text. It provides:

• Unified API key and credit balance across all media types
• Agent-friendly JSON mode with clean stdout/stderr
• Local file output with --output / -o
• Model and voice discovery through flatkey models and flatkey audio voices
• Dry-run support for request validation without spending credits
• Cross-platform npm package (macOS, Linux, Windows)

Built for media teams, AI agents, and programmatic generation workflows that need cost-effective batch testing without long queues.

Installation

Global install (recommended)

npm install -g @flatkey-ai/cli

Run without installing

npx @flatkey-ai/cli help --ai

Check version

flatkey --version
flatkey -v

Authentication

Environment variable (recommended for agents)

export FLATKEY_API_KEY=<your-key>

Save locally

flatkey onboard --api-key <your-key>

Pass inline

flatkey image generate --prompt "test" --api-key <your-key>

Get your API key from console.flatkey.ai/keys.

Image Generation

Basic image generation

flatkey image generate \
  --prompt "magazine cover, reflective typography, studio lighting" \
  --model gpt-image-2 \
  -o cover.png

Agent-friendly JSON mode

flatkey image generate \
  --prompt "minimalist product shot, white background" \
  --model nano-banana-pro-preview \
  --json \
  -o product.png

JSON output includes:

• media_url: temporary signed URL
• local_path: saved file path (if -o used)
• cost: credits spent
• model: model used

Upload local image for reference

# Get temporary signed URL for local image
flatkey image upload --file ./reference.png --json

Returns:

{
  "url": "https://temporary-media.flatkey.ai/...",
  "expires_in_seconds": 3600
}

Video Generation

Basic video generation

flatkey video generate \
  --prompt "8 second cinematic product reveal, glossy black background" \
  --model seedance2 \
  --ratio 16:9 \
  --resolution 720p \
  -o launch.mp4

Video with reference image

# Upload image first, then use in video
flatkey video generate \
  --model Seedance2.0-pro \
  --prompt "a sleepy kitten, soft window light" \
  --image ./reference.png \
  -o kitten.mp4 \
  --json

Video with first/last frame

flatkey video generate \
  --model veo-3 \
  --prompt "smooth camera transition" \
  --first-frame ./start.png \
  --last-frame ./end.png \
  --ratio 16:9 \
  --resolution 1080p \
  -o transition.mp4

Supported video options

Ratios: 16:9, 9:16, 4:3, 3:4, 21:9, 1:1

Resolutions: 480p, 720p, 1080p

Models: seedance2, veo-3, veo-3-fast, Seedance2.0-pro

Audio Generation

Text-to-speech

flatkey audio generate \
  --prompt "Hello, this is a test of the Flatkey speech API." \
  --voice-id EXAVITQu4vr4xnSDxMaL \
  --model eleven_multilingual_v2 \
  --stability 0.5 \
  --similarity-boost 0.75 \
  --style 0 \
  -o speech.mp3 \
  --json

Multilingual TTS

flatkey audio generate \
  --prompt "你好，这是 Flatkey 网关的语音测试。" \
  --voice-id EXAVITQu4vr4xnSDxMaL \
  --model eleven_multilingual_v2 \
  -o mandarin.mp3

List available voices

flatkey audio voices --json

Returns array of voices with:

• voice_id: ID to use in generation
• name: voice name
• labels: metadata (gender, age, accent, etc.)

Sound effects

flatkey audio sfx \
  --prompt "glass shattering on the floor" \
  --duration 3 \
  -o shatter.mp3 \
  --json

Music generation

flatkey audio music \
  --prompt "calm ambient piano, sad mood" \
  --music-length-ms 10000 \
  -o background.mp3 \
  --json

Text Generation

Basic text generation

flatkey text generate \
  --prompt "write 5 sharp headlines for a creator tool launch" \
  --model gpt-5.5 \
  -o headlines.txt \
  --json

Supported text models

• gpt-5.5
• Claude models
• Gemini models
• GLM models
• Grok models

Check live models:

flatkey models --type text --json

Model and Credit Management

List all available models

flatkey models --json

Filter by type

flatkey models --type image --json
flatkey models --type video --json
flatkey models --type audio --json
flatkey models --type text --json

Check credit balance

flatkey credits --json

Check service status

flatkey status --json

Agent Protocol

Use flatkey help --ai to get agent-specific guidance:

flatkey help --ai

Agent best practices

1. Always use --json flag for machine-readable output
2. Prefer FLATKEY_API_KEY environment variable over inline keys
3. Use --output / -o when file path matters
4. Call flatkey models --json before choosing a model
5. Call flatkey audio voices --json before choosing a voice
6. Use --dry-run to validate requests without spending credits
7. Upload local images with flatkey image upload before using in video

Dry-run validation

flatkey video generate \
  --prompt "fashion campaign hero shot" \
  --model seedance2 \
  --ratio 16:9 \
  --dry-run \
  --json

Returns request payload without executing generation.

Common Patterns

Batch image generation

#!/bin/bash
PROMPTS=(
  "product shot, white background"
  "lifestyle photo, natural light"
  "close-up detail, macro lens"
)

for i in "${!PROMPTS[@]}"; do
  flatkey image generate \
    --prompt "${PROMPTS[$i]}" \
    --model gpt-image-2 \
    -o "output_$i.png" \
    --json
done

Video from uploaded reference

#!/bin/bash

# Upload reference image
UPLOAD_RESULT=$(flatkey image upload --file ./ref.png --json)
IMAGE_URL=$(echo $UPLOAD_RESULT | jq -r '.url')

# Generate video using uploaded image
flatkey video generate \
  --model seedance2 \
  --prompt "cinematic zoom in" \
  --image "$IMAGE_URL" \
  -o output.mp4 \
  --json

Multi-voice audio batch

#!/bin/bash

# Get available voices
VOICES=$(flatkey audio voices --json | jq -r '.[].voice_id' | head -3)

TEXT="This is a test of multiple voice synthesis."

for VOICE in $VOICES; do
  flatkey audio generate \
    --prompt "$TEXT" \
    --voice-id "$VOICE" \
    --model eleven_multilingual_v2 \
    -o "voice_${VOICE}.mp3" \
    --json
done

Check credits before generation

#!/bin/bash

CREDITS=$(flatkey credits --json | jq -r '.balance')

if (( $(echo "$CREDITS < 100" | bc -l) )); then
  echo "Low credits: $CREDITS"
  exit 1
fi

flatkey video generate \
  --prompt "test video" \
  --model veo-3-fast \
  -o test.mp4 \
  --json

Model discovery for specific type

#!/bin/bash

# Get all video models
VIDEO_MODELS=$(flatkey models --type video --json | jq -r '.[].id')

echo "Available video models:"
echo "$VIDEO_MODELS"

# Use first available model
FIRST_MODEL=$(echo "$VIDEO_MODELS" | head -1)

flatkey video generate \
  --prompt "test generation" \
  --model "$FIRST_MODEL" \
  -o test.mp4 \
  --json

Error Handling

JSON output structure

Success:

{
  "media_url": "https://...",
  "local_path": "./output.png",
  "cost": 5.2,
  "model": "gpt-image-2"
}

Error:

{
  "error": "Insufficient credits",
  "code": "INSUFFICIENT_CREDITS",
  "details": {...}
}

Common errors

Validate before generation

# Dry run to check request structure
flatkey image generate \
  --prompt "test" \
  --model gpt-image-2 \
  --dry-run \
  --json

# Check credits
flatkey credits --json

# Check model availability
flatkey models --type image --json

Advanced Configuration

Custom router URL (development only)

flatkey image generate \
  --prompt "test" \
  --base-url http://127.0.0.1:3000 \
  --json

Default routing endpoints

• Generation router: https://router.flatkey.ai
• Model registry: https://console.flatkey.ai/v1/available_models
• Voice registry: https://router.flatkey.ai/v1/voices

Troubleshooting

Command not found

# Check installation
npm list -g @flatkey-ai/cli

# Reinstall
npm install -g @flatkey-ai/cli

# Use npx
npx @flatkey-ai/cli --version

Progress animation interfering with output

Always use --json flag for agent workflows:

flatkey image generate --prompt "test" --json

This disables terminal animation and ensures clean stdout.

Local file not saving

Check -o / --output path permissions:

# Ensure directory exists
mkdir -p ./outputs
flatkey image generate --prompt "test" -o ./outputs/test.png

Video generation with image fails

Upload local image first:

# Wrong (local path)
flatkey video generate --image ./local.png --prompt "test"

# Correct (upload first)
UPLOAD=$(flatkey image upload --file ./local.png --json)
URL=$(echo $UPLOAD | jq -r '.url')
flatkey video generate --image "$URL" --prompt "test" --json

Model version mismatch

Always check live models before generation:

flatkey models --type video --json | jq -r '.[].id'

Model IDs can change. Use dynamic lookup in scripts.

Resources

• Website: flatkey.ai
• npm package: @flatkey-ai/cli
• API keys: console.flatkey.ai/keys
• Issues: github.com/flatkey-ai/flatkey-cli/issues