ClickHouse Pydantic Config

Generate DBeaver database client configurations from Pydantic v2 models using mise [env] as Single Source of Truth (SSoT).

When to Use This Skill

Use this skill when:

Setting up DBeaver connections for ClickHouse databases
Generating database client configurations from environment variables
Managing local vs cloud ClickHouse connection profiles
Integrating ClickHouse with mise-based development workflows
Automating DBeaver data-sources.json generation

Critical Design Principle: Semi-Prescriptive Adaptation

This skill is NOT a rigid template. It provides a SSoT pattern that MUST be adapted to each repository's structure and local database situation.

Why This Matters

Each repository has unique:

Directory layouts (.dbeaver/ location may vary)
Environment variable naming conventions
Existing connection management patterns
Local vs cloud database mix

The SSoT principle is the constant; the implementation details are the variables.

Quick Start

# Generate local connection config
mise run db-client-generate

# Generate cloud connection config
mise run db-client:cloud

# Preview without writing
mise run db-client:dry-run

# Launch DBeaver
mise run dbeaver

Credential Prerequisites (Cloud Mode)

Before using cloud mode, obtain credentials via the skill chain:

Create/retrieve user: Use clickhouse-cloud-management skill to create read-only users or retrieve existing credentials from 1Password
Store in .env: Add to .env file (gitignored):

CLICKHOUSE_USER_READONLY=your_user
CLICKHOUSE_PASSWORD_READONLY=your_password

Generate config: Run mise run db-client:cloud

Skill chain: clickhouse-cloud-management → .env → clickhouse-pydantic-config

mise `[env]` as Single Source of Truth

All configurable values live in .mise.toml:

[env]
CLICKHOUSE_NAME = "clickhouse-local"
CLICKHOUSE_MODE = "local"  # "local" or "cloud"
CLICKHOUSE_HOST = "localhost"
CLICKHOUSE_PORT = "8123"
CLICKHOUSE_DATABASE = "default"

Scripts read from os.environ.get() with backward-compatible defaults—works with or without mise installed.

Credential Handling by Mode

Mode	Approach	Rationale
Local	Hardcode `default` user, empty password	Zero friction, no security concern
Cloud	Pre-populate from `.env`	Read from environment, write to gitignored JSON

Key principle: The generated data-sources.json is gitignored anyway. Pre-populating credentials trades zero security risk for maximum developer convenience.

Cloud Credentials Setup

# .env (gitignored)
CLICKHOUSE_USER_READONLY=readonly_user
CLICKHOUSE_PASSWORD_READONLY=your-secret-password

Repository Adaptation Workflow

Pre-Implementation Discovery (Phase 0)

Before writing any code, the executor MUST:

# 1. Discover existing configuration patterns
fd -t f ".mise.toml" .
fd -t f ".env*" .
fd -t d ".dbeaver" .

# 2. Test ClickHouse connectivity (local)
clickhouse-client --host localhost --port 9000 --query "SELECT 1"

# 3. Check for existing connection configs
fd -t f "data-sources.json" .
fd -t f "dataSources.xml" .

Adaptation Decision Matrix

Discovery Finding	Adaptation Action
Existing `.mise.toml` at repo root	Extend existing `[env]` section, don't create new file
Existing `.dbeaver/` directory	Merge connections, preserve existing entries
Non-standard CLICKHOUSE_* vars	Map to repository's naming convention
Multiple databases (local + cloud)	Generate multiple connection entries
No ClickHouse available	Warn and generate placeholder config

Validation Checklist (Post-Generation)

The executor MUST verify:

Generated JSON is valid (jq . .dbeaver/data-sources.json)
DBeaver can import the config (launch and verify connection appears)
mise tasks execute without error (mise run db-client-generate)
.dbeaver/ added to .gitignore

Pydantic Model

The ClickHouseConnection model provides:

Type-safe configuration with Pydantic v2 validation
Computed fields for JDBC URL and connection ID
Mode-aware defaults (cloud auto-enables SSL on port 8443)
Environment loading via from_env() class method

See references/pydantic-model.md for complete model documentation.

DBeaver Format

DBeaver uses .dbeaver/data-sources.json with this structure:

{
  "folders": {},
  "connections": {
    "clickhouse-jdbc-{random-hex}": {
      "provider": "clickhouse",
      "driver": "com_clickhouse",
      "name": "Connection Name",
      "configuration": { ... }
    }
  }
}

Important: DBeaver does NOT support ${VAR} substitution—values must be pre-populated at generation time.

See references/dbeaver-format.md for complete format specification.

macOS Notes

DBeaver binary: Use /Applications/DBeaver.app/Contents/MacOS/dbeaver (NOT open -a)
Gitignore: Add .dbeaver/ to .gitignore

Related Skills

Skill	Integration
`devops-tools:clickhouse-cloud-management`	Credential retrieval for cloud mode
`quality-tools:clickhouse-architect`	Schema design context
`itp:mise-configuration`	SSoT environment variable patterns

Python Driver Policy

For Python application code connecting to ClickHouse (not DBeaver), use clickhouse-connect (official HTTP driver). See clickhouse-architect for:

Recommended code patterns
Why NOT to use clickhouse-driver (community)
Performance vs maintenance trade-offs

Additional Resources

Reference	Content
references/pydantic-model.md	Complete model documentation
references/dbeaver-format.md	DBeaver JSON format spec

Troubleshooting

Issue	Cause	Solution
DBeaver can't connect	Port mismatch (8123 vs 9000)	HTTP uses 8123, native uses 9000 - check config
Credentials not loading	.env not sourced	Run `mise trust` or source .env manually
JSON validation fails	Invalid data-sources.json	Validate with `jq . .dbeaver/data-sources.json`
Cloud SSL error	Missing SSL on port 8443	Cloud mode auto-enables SSL - verify port is 8443
mise task not found	Missing task definition	Add task to mise.toml `[tasks]` section
.dbeaver/ in git	Missing gitignore entry	Add `.dbeaver/` to `.gitignore`
Connection ID conflict	Duplicate connection names	Each connection needs unique ID (random hex)
Config not updating	DBeaver caching	Restart DBeaver to reload data-sources.json

clickhouse-pydantic-config