Environment Variables

IGraph follows a zero-hardcoded-credentials principle — all sensitive information can only be injected via environment variables.

Variable List

Variable	Description	Required
IGRAPH_API_KEY	Shared key for LLM / Embedding	Required for online commands (LLM summary / vectorization)
IGRAPH_EMBEDDING_BASE_URL	Overrides embedding.baseURL config	Optional
IGRAPH_LLM_BASE_URL	Overrides llm.baseURL config	Optional

Priority

Environment variables > Project config file

When both an environment variable and a config file value exist, the environment variable takes precedence.

Setting Up

Temporary (Current Terminal Session)

export IGRAPH_API_KEY="sk-..."
export IGRAPH_EMBEDDING_BASE_URL="http://localhost:8080/v1"

Persistent

Add environment variables to your shell config file:

# ~/.bashrc or ~/.zshrc
export IGRAPH_API_KEY="sk-..."

WARNING

Never write API Keys to:

• .igraph/config.json config files
• Any file in the code repository
• MCP config files (.mcp.json, etc.)

IGraph actively scans for and rejects configs containing credential fields.

Behavior Without API Key

Command	Behavior
igraph build	Add --no-llm to run (skips summary and vectorization)
igraph rebuild	Add --no-llm to run
igraph query	Automatic fallback to FTS5-only full-text search
igraph eval	Automatic fallback to FTS5-only full-text search
igraph serve	MCP Server starts normally; igraph_explore falls back to FTS5-only
igraph init	No API Key needed
igraph status	No API Key needed
igraph register	No API Key needed

Credential Passing in MCP Server

When using igraph register, no env field is written to the MCP config. The API Key is inherited from the user's shell environment.

This means:

• Ensure you've run export IGRAPH_API_KEY in your terminal before starting the AI assistant
• Or add it to your shell config file for persistence