Configuration & Environment Variables

This reference lists all configuration options, environment variables, filesystem paths, and network settings for PromptBranch.

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Environment Variables

Client & Database Variables

Variable	Scope	Default Value	Description
PROMPTBRANCH_DB	Desktop / CLI / MCP	OS default path	Overrides the SQLite database file path.
PROMPTHUB_DB	Desktop / CLI / MCP	Unset	Deprecated fallback path override.
PROMPTBUILDER_DB	Desktop / CLI / MCP	Unset	Deprecated fallback path override.

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AI Provider Keys (Auto-Detected)

If set in your shell environment, PromptBranch displays a "Use environment key" quick-connect button in Settings → AI Providers:

Variable	Provider	Description
OPENAI_API_KEY	OpenAI	API key for OpenAI GPT models.
ANTHROPIC_API_KEY	Anthropic	API key for Anthropic Claude models.
GOOGLE_GENERATIVE_AI_API_KEY	Google	API key for Google Gemini models.

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Default Filesystem Paths by OS

Operating System	Default Database Path	Local Sync Identity & Keys
macOS	~/Library/Application Support/PromptBranch/library.db	~/Library/Application Support/PromptBranch/sync/
Linux	$XDG_CONFIG_HOME/promptbranch/library.db (defaults to ~/.config/promptbranch/library.db)	$XDG_CONFIG_HOME/PromptBranch/sync/ (defaults to ~/.config/PromptBranch/sync/)
Windows	%APPDATA%\PromptBranch\library.db	%APPDATA%\PromptBranch\sync\

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Network & Discovery Ports

• mDNS Service: _promptbranch._tcp advertised over UDP port 5353 (multicast DNS).
• Peer-to-Peer Sync: Each device listens on a local TLS port for paired peers; firewalls must allow inbound connections to it on your LAN.