PromptVault

Open-source prompt versioning, evaluation, and management as an MCP server.

What is PromptVault?

PromptVault is a self-hosted tool for AI engineers and prompt engineers to:

• Version prompts like code with immutable versions and rollback support
• Evaluate prompts against datasets using LLM providers (OpenAI, Anthropic, Ollama)
• Access everything through an MCP server, CLI, or REST API

Quickstart

Install (no clone needed)

pip install pvlt

Or with uv/pipx:

uvx --from git+https://github.com/KrishBnsl/promptVault.git promptctl --help

Or with Docker:

docker run -p 8000:8000 -e GEMINI_API_KEY=your-key ghcr.io/krishbnsl/pvlt

From Source

git clone https://github.com/KrishBnsl/promptVault.git
cd promptVault
uv sync
cp .env.example .env
# Edit .env with your API keys

Create Your First Prompt

promptctl prompt create summarize \
  --content "Summarize the following article in {tone} style:\n\n{article}" \
  --description "Summarizes an article" \
  --variables '{"tone": "concise", "article": "string"}' \
  --model-config '{"provider": "openai", "model": "gpt-4o-mini", "temperature": 0.2}' \
  --tags "summarization,content"

Create a Dataset

echo '{"input": {"article": "AI is transforming..."}, "expected_output": "AI transforms..."}' > dataset.jsonl
promptctl dataset create article-summaries --file dataset.jsonl

Run Evaluation

promptctl eval run summarize --dataset article-summaries

Use with MCP (Claude Desktop)

Add to your Claude Desktop config:

{
  "mcpServers": {
    "pvlt": {
      "command": "promptctl",
      "args": ["serve"]
    }
  }
}

CLI Reference

promptctl prompt create <name> --content <text> [options]
promptctl prompt list [--tags TAGS] [--limit N]
promptctl prompt show <name> [--version N]
promptctl prompt versions <name>
promptctl prompt diff <name> <version-a> <version-b>
promptctl prompt rollback <name> --version N

promptctl dataset create <name> --file <jsonl-or-json>
promptctl dataset list

promptctl eval run <prompt-name> --dataset <dataset-name>
promptctl eval report <evaluation-id>

promptctl serve [--stdio|--http] [--port 8000]
promptctl web [--port 8080]

MCP Tools

Tool	Description
prompt_create	Create a new prompt with initial version
prompt_get	Retrieve a prompt version
prompt_list	List all prompts
prompt_versions	List all versions of a prompt
prompt_diff	Diff two prompt versions
prompt_rollback	Rollback to a previous version
dataset_create	Create a dataset
dataset_list	List datasets
dataset_get	Get dataset with items
evaluation_run	Run evaluation
evaluation_status	Check evaluation status
evaluation_report	Get evaluation report
evaluation_compare	Compare two evaluations

REST API

Base URL: http://localhost:8000/api

# Create a prompt
curl -X POST http://localhost:8000/api/prompts \
  -H "Content-Type: application/json" \
  -d '{"name": "test", "content": "Hello {name}"}'

# List prompts
curl http://localhost:8000/api/prompts

# Get a prompt
curl http://localhost:8000/api/prompts/test

Configuration

Copy .env.example to .env and configure:

PROMPTVAULT_DB_PATH=./promptvault.db
PROMPTVAULT_DEFAULT_PROVIDER=openai
OPENAI_API_KEY=sk-...
ANTHROPIC_API_KEY=sk-ant-...
GEMINI_API_KEY=...
OLLAMA_BASE_URL=http://localhost:11434

Architecture

┌─────────────┐   ┌─────────────┐   ┌─────────────┐
│   MCP Client │   │     CLI     │   │  REST Client │
│ (Claude etc) │   │ (promptctl) │   │ (curl, apps) │
└──────┬──────┘   └──────┬──────┘   └──────┬──────┘
       │                 │                 │
       ▼                 ▼                 ▼
┌─────────────────────────────────────────────────┐
│              PromptVault Core                   │
│  ┌─────────────┐ ┌──────────────┐ ┌──────────┐ │
│  │ Versioning  │ │ Evaluation   │ │ Storage  │ │
│  │ Engine      │ │ Engine       │ │ Layer    │ │
│  └─────────────┘ └──────────────┘ └──────────┘ │
│  ┌──────────────────────────────────────────┐  │
│  │        SQLite Database (local)           │  │
│  └──────────────────────────────────────────┘  │
└─────────────────────────────────────────────────┘

Documentation

📖 Full docs: https://krishbnsl.github.io/promptVault/

• Getting Started
• API Reference
• CLI Reference
• MCP Tools
• Agent Docs (llms.txt)

License

MIT License - see LICENSE for details.