ClickHouse Agent

PyPI pydantic-ai-slim mcp-clickhouse

AI agent for ClickHouse database analysis via MCP (Model Context Protocol).

A single MCP server (mcp-clickhouse) driven by a single agent instance. Access restriction is performed via explicit allow-lists you pass per call (allowed_tables, allowed_databases), rather than managing multiple keys or fan-out across multiple agents.

Features

• Query ClickHouse databases using natural language with AI models
• Structured output: analysis, confidence, sql_used
• Easy connection management (predefined or custom)
• Conversational context with message-history pruning/summarization
• No CLI or external .env required — configure at runtime
• Access restriction via per-call allow-lists (allowed_tables, allowed_databases)
• Streamable results via run_stream()
• Persistent MCP server mode via async with ClickHouseAgent()
• Parallel queries via run_batch()
• Lifecycle reset via reset()
• Query result cache via enable_cache=True
• Typed exception hierarchy for reliable error handling
• Optional structlog integration (pip install ".[logging]")

Supported Providers

Provider	Key env var	Notes
Google Gemini	GOOGLE_API_KEY	Default
OpenAI	OPENAI_API_KEY
Anthropic	ANTHROPIC_API_KEY
Grok	GROK_API_KEY	Free tier, high rate limits
Mistral	MISTRAL_API_KEY
Cohere	CO_API_KEY

Local Development (Docker)

The fastest way to get started — no cloud ClickHouse account needed:

# Start ClickHouse with seeded demo data (orders + products)
docker compose up -d

# Install the package with dev dependencies
pip install -e ".[dev]"

# Run the examples (set your Google API key first)
GOOGLE_API_KEY=... python examples/example_minimal.py
GOOGLE_API_KEY=... python examples/example_stream.py
GOOGLE_API_KEY=... python examples/example_0_11.py
GOOGLE_API_KEY=... python examples/example_integration.py

The docker/init.sql file seeds demo.orders (25 orders, May 2026) and demo.products (10 products across Electronics, Sports, Home, Books) automatically on first start.

Quickstart

import asyncio
from agent.clickhouse_agent import ClickHouseAgent
from agent.config import config

config.set_ai_model("openai:gpt-4o-mini")
config.set_model_api_key("openai", "your_api_key_here")
config.set_clickhouse(host="localhost", port="8123", user="default", password="", secure="false")

async def main():
    agent = ClickHouseAgent()
    result = await agent.run(
        allowed_tables=["orders", "products"],
        allowed_databases=["demo"],
        query="give me some insights on the recent data",
    )
    print("Analysis:", result.analysis)
    print("Confidence:", result.confidence)
    print("SQL used:", result.sql_used)

asyncio.run(main())

Persistent server (multiple queries)

Use the context manager to keep the MCP subprocess alive across calls — avoids subprocess startup overhead on every query:

async def main():
    async with ClickHouseAgent() as agent:
        r1 = await agent.run(query="how many orders were placed last week?")
        r2 = await agent.run(query="which products are selling fastest?", message_history=r1.messages)

Parallel queries

async with ClickHouseAgent() as agent:
    results = await agent.run_batch(
        ["how many orders?", "total revenue?", "top 5 products?"],
        allowed_databases=["demo"],
    )
    for r in results:
        print(r.analysis)

Query result cache

agent = ClickHouseAgent(enable_cache=True)
result = await agent.run(query="how many orders?", allowed_databases=["demo"])
# identical call returns instantly from cache (stateless queries only)

Lifecycle reset

agent = ClickHouseAgent()
await agent.run(query="...")
await agent.reset()          # tear down MCP subprocess
await agent.run(query="...")  # re-initializes on next call

Switching providers

All providers use the same interface — just swap the model string and key:

# Anthropic Claude 4
config.set_ai_model("anthropic:claude-sonnet-4-6")
config.set_model_api_key("anthropic", "your_key")

# Google Gemini
config.set_ai_model("google:gemini-3.1-flash-lite")
config.set_model_api_key("google", "your_key")

# Grok (free tier, high rate limits — good for testing)
config.set_ai_model("grok:llama-3.3-70b-versatile")
config.set_model_api_key("grok", "your_key")

Message History & Summarization

Pass message_history between calls for multi-turn conversations. When token usage exceeds summarize_config.token_limit, older messages are automatically summarized into a compact form by a separate summarizer agent.

summarize_config.set_token_limit(10000)
summarize_config.set_ai_model("google:gemini-3.1-flash-lite")

Output

Each call to ClickHouseAgent.run() returns a RunResult:

Field	Description
analysis	Natural-language result text from the model
confidence	Confidence level (1–10)
sql_used	List of SQL strings executed during the run
messages	Full (possibly pruned/summarized) message history
new_messages	Only messages created in the latest turn
last_message	The last message in the conversation
usage	Token/usage statistics for the run

Error Handling

All errors raise from a typed hierarchy so you can catch at the right level:

from agent.exceptions import ClickHouseMCPError, MCPConnectionError, AgentExecutionError

try:
    result = await agent.run(query="...")
except MCPConnectionError:
    # MCP subprocess failed to start or connection dropped
    ...
except AgentExecutionError:
    # Agent logic failed during the run
    ...
except ClickHouseMCPError:
    # Any library error
    ...

Requirements

• Python 3.10+
• An AI provider API key (Google, OpenAI, Anthropic, Grok, Mistral, or Cohere)

All dependencies are managed via pyproject.toml.

Roadmap

✅ Done (0.11.x)

• MCP integration via pydantic_ai.mcp.MCPServerStdio
• SQL generation/execution via MCP tools
• Schema inspection (databases/tables/columns)
• Config-driven connections (playground/local/custom)
• Access restriction via per-call allow-lists (allowed_tables, allowed_databases)
• Runtime provider/model selection and API key management
• Structured outputs (ClickHouseOutput) and RunResult with sql_used
• Message history pruning/summarization
• Streaming results via run_stream()
• Persistent MCP server via async with ClickHouseAgent()
• Typed exception hierarchy
• Local development via Docker (docker compose up -d)
• ruff linting, Python 3.13 support, CI hardened
• Async batch queries via run_batch()
• reset() for lifecycle control
• Query result cache (enable_cache=True)
• structlog optional dep (pip install ".[logging]")

✅ 0.12 — Stable

• API locked — no breaking changes without a major version
• All known bugs resolved
• py.typed check added to CI
• mypy agent/ added to CI matrix
• Updated to mcp-clickhouse 0.4.0; list_databases tool now enforced by allowed_databases allow-list
• Default model updated to google:gemini-3.1-flash-lite

🔭 Post-1.0 — Future

• FastAPI standalone deployment option

Contributing

Open an issue or pull request for features or fixes.