Configuration

config/langgraph-config.yaml is the canonical runtime config. Loaded at server boot by graph/config.py::LangGraphConfig.from_yaml(). All fields have defaults; the YAML only needs to override what's changing.

Full example

model:
  provider: openai
  name: protolabs/agent
  api_base: http://gateway:4000/v1
  api_key: ""
  temperature: 0.2
  max_tokens: 4096
  max_iterations: 50

subagents:
  worker:
    enabled: true
    tools: [echo, current_time, calculator, web_search, fetch_url]
    max_turns: 20

middleware:
  knowledge: false
  audit: true
  memory: false

knowledge:
  db_path: /sandbox/knowledge/agent.db
  embed_model: nomic-embed-text
  top_k: 5

model

Key	Default	What
provider	openai	LangChain LLM provider. The template's graph/llm.py only uses openai (via LiteLLM gateway).
name	protolabs/agent	Gateway alias or direct model name.
api_base	http://gateway:4000/v1	OpenAI-compatible endpoint.
api_key	""	Falls back to the OPENAI_API_KEY env var.
temperature	0.2	Sampling temperature.
max_tokens	4096	Per-call output cap.
max_iterations	50	Upper bound on tool-call loops per task.

subagents

One entry per subagent name. Each entry matches a SubagentConfig in graph/subagents/config.py and a SubagentDef field in LangGraphConfig.

Key	Default	What
enabled	true	If false, the subagent is still registered but dispatches return "disabled" errors.
tools	[]	Allowlist. Tool names not listed here are invisible to this subagent.
max_turns	30	Recursion cap.

Adding a new subagent name to the YAML requires matching entries in graph/subagents/config.py::SUBAGENT_REGISTRY, graph/config.py::LangGraphConfig, and the from_yaml() loop. See Configure subagents.

middleware

Key	Default	What
knowledge	false	Inject retrieved knowledge into state before LLM calls. Requires a knowledge store — leave off until you add one.
audit	true	Append every tool call to /sandbox/audit/audit.jsonl.
memory	false	Memory middleware (experimental). Requires a knowledge store.

knowledge

Only read when middleware.knowledge is true.

Key	Default	What
db_path	/sandbox/knowledge/agent.db	SQLite file path.
embed_model	nomic-embed-text	Embedding model.
top_k	5	Results per query fed into state.

The template does not ship a knowledge store — the config keys are kept so a fork can flip the switch without rewiring every call site.