Environment variables

AIMU reads a small set of environment variables. All are loaded via python-dotenv — a .env file in your working directory is picked up automatically by the clients that need keys.

API keys

Variable	Used by	Required?
ANTHROPIC_API_KEY	AnthropicClient	Yes (for anthropic:* models)
OPENAI_API_KEY	OpenAIClient	Yes (for openai:* models)
GOOGLE_API_KEY	GeminiClient (text) and GeminiImageClient (Nano Banana)	Yes (for gemini:* models)

If missing, the text clients construct successfully but the first request raises an authentication error from the underlying SDK. GeminiImageClient raises RuntimeError at construction time with an actionable message instead.

Tool endpoints

Variable	Used by	Default
SEARXNG_BASE_URL	aimu.tools.builtin.search	http://localhost:8080
AIMU_IMAGE_MODEL	aimu.tools.builtin.generate_image (lazy singleton)	hf:stabilityai/stable-diffusion-xl-base-1.0

The built-in generate_image tool constructs its image client lazily on first call, picking the provider and model from AIMU_IMAGE_MODEL. Accepts any string supported by aimu.image_client() — "hf:<repo>" or "gemini:<id_or_alias>". Override per-agent by building your own tool with make_image_tool(client) instead of using the singleton.

MCP server storage paths

Variable	Used by	Default
MEMORY_STORE_PATH	python -m aimu.memory.mcp (SemanticMemoryStore server)	None (in-memory)
DOCUMENT_STORE_PATH	python -m aimu.memory.document_mcp (DocumentStore server)	None (in-memory)
PROMPT_CATALOG_PATH	python -m aimu.prompts.mcp (PromptCatalog server)	prompts.db in cwd

When unset, MCP servers run with ephemeral state — fine for tests, not for production.

.env file example

# Cloud API keys
ANTHROPIC_API_KEY=sk-ant-...
OPENAI_API_KEY=sk-...
GOOGLE_API_KEY=...

# Local search (SearXNG)
SEARXNG_BASE_URL=http://localhost:8080

# Image generation default (used by the built-in generate_image tool)
AIMU_IMAGE_MODEL=gemini:nano-banana

# MCP server storage
MEMORY_STORE_PATH=./.aimu/memory
DOCUMENT_STORE_PATH=./.aimu/docs
PROMPT_CATALOG_PATH=./.aimu/prompts.db

Place it in your project root. Don't commit it — add .env to .gitignore.

See also

• Provider matrix — which provider needs which key
• CLI — runnable python -m entry points that read these vars