# Placeholder Provider

Zero-cost solid-color PNG generation for testing, drafts, and CI pipelines.

## Overview

The placeholder provider generates simple solid-color PNG images without any external dependencies or API keys. The color is selected from a palette of 6 predefined colors using a SHA-256 hash of the prompt as an index, so the same prompt always produces the same color.

## When to use

- **Testing** -- verify your MCP client configuration without API costs
- **Drafts and mock-ups** -- create placeholder images during development
- **CI pipelines** -- test image generation workflows without external services
- **Demos** -- show the image generation flow without requiring API keys

## Availability

The placeholder provider is **always registered** -- it requires no configuration, no API key, and no external service.

## Aspect ratios

| Aspect ratio | Size |
|-------------|------|
| `1:1` | 256x256 |
| `16:9` | 640x360 |
| `9:16` | 360x640 |
| `3:2` | 480x320 |
| `2:3` | 320x480 |

## Parameters

- **prompt** -- used to determine the output color (via SHA-256 hash index into a 6-color palette)
- **negative_prompt** -- ignored
- **quality** -- ignored
- **aspect_ratio** -- maps to pixel sizes above

## Output

- **Format:** PNG
- **Content:** Solid color fill
- **Size:** ~1-2 KB per image
- **Generation time:** Instant (< 1ms)
