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Environment Variables

The LangGraph Cloud Server supports specific environment variables for configuring a deployment.

BG_JOB_ISOLATED_LOOPS

Set BG_JOB_ISOLATED_LOOPS to True to execute background runs in an isolated event loop separate from the serving API event loop.

This environment variable should be set to True if the implementation of a graph/node contains synchronous code. In this situation, the synchronous code will block the serving API event loop, which may cause the API to be unavailable. A symptom of an unavailable API is continuous application restarts due to failing health checks.

Defaults to False.

BG_JOB_TIMEOUT_SECS

The timeout of a background run can be increased. However, the infrastructure for a Cloud SaaS deployment enforces a 1 hour timeout limit for API requests. This means the connection between client and server will timeout after 1 hour. This is not configurable.

A background run can execute for longer than 1 hour, but a client must reconnect to the server (e.g. join stream via POST /threads/{thread_id}/runs/{run_id}/stream) to retrieve output from the run if the run is taking longer than 1 hour.

Defaults to 3600.

DD_API_KEY

Specify DD_API_KEY (your Datadog API Key) to automatically enable Datadog tracing for the deployment. Specify other DD_* environment variables to configure the tracing instrumentation.

If DD_API_KEY is specified, the application process is wrapped in the ddtrace-run command. Other DD_* environment variables (e.g. DD_SITE, DD_ENV, DD_SERVICE, DD_TRACE_ENABLED) are typically needed to properly configure the tracing instrumentation. See DD_* environment variables for more details.

LANGCHAIN_TRACING_SAMPLING_RATE

Sampling rate for traces sent to LangSmith. Valid values: Any float between 0 and 1.

See LangSmith documentation for more details.

LANGGRAPH_AUTH_TYPE

Type of authentication for the LangGraph Cloud Server deployment. Valid values: langsmith, noop.

For deployments to LangGraph Cloud, this environment variable is set automatically. For local development or deployments where authentication is handled externally (e.g. self-hosted), set this environment variable to noop.

LANGSMITH_RUNS_ENDPOINTS

For Bring Your Own Cloud (BYOC) deployments with self-hosted LangSmith only.

Set this environment variable to have a BYOC deployment send traces to a self-hosted LangSmith instance. The value of LANGSMITH_RUNS_ENDPOINTS is a JSON string: {"<SELF_HOSTED_LANGSMITH_HOSTNAME>":"<LANGSMITH_API_KEY>"}.

SELF_HOSTED_LANGSMITH_HOSTNAME is the hostname of the self-hosted LangSmith instance. It must be accessible to the BYOC deployment. LANGSMITH_API_KEY is a LangSmith API generated from the self-hosted LangSmith instance.

LOG_LEVEL

Configure log level. Defaults to INFO.

N_JOBS_PER_WORKER

Number of jobs per worker for the LangGraph Cloud task queue. Defaults to 10.

POSTGRES_URI_CUSTOM

For Bring Your Own Cloud (BYOC) deployments only.

Specify POSTGRES_URI_CUSTOM to use an externally managed Postgres instance. The value of POSTGRES_URI_CUSTOM must be a valid Postgres connection URI.

Postgres:

  • Version 15.8 or higher.
  • An initial database must be present and the connection URI must reference the database.

Control Plane Functionality:

  • If POSTGRES_URI_CUSTOM is specified, the LangGraph Control Plane will not provision a database for the server.
  • If POSTGRES_URI_CUSTOM is removed, the LangGraph Control Plane will not provision a database for the server and will not delete the externally managed Postgres instance.
  • If POSTGRES_URI_CUSTOM is removed, deployment of the revision will not succeed. Once POSTGRES_URI_CUSTOM is specified, it must always be set for the lifecycle of the deployment.
  • If the deployment is deleted, the LangGraph Control Plane will not delete the externally managed Postgres instance.
  • The value of POSTGRES_URI_CUSTOM can be updated. For example, a password in the URI can be updated.

Database Connectivity:

  • The externally managed Postgres instance must be accessible by the LangGraph Server service in the ECS cluster. The BYOC user is responsible for ensuring connectivity.
  • For example, if an AWS RDS Postgres instance is provisioned, it can be provisioned in the same VPC (langgraph-cloud-vpc) as the ECS cluster with the langgraph-cloud-service-sg security group to ensure connectivity.

REDIS_URI_CUSTOM

For Bring Your Own Cloud (BYOC) deployments only.

Specify REDIS_URI_CUSTOM to use an externally managed Redis instance. The value of REDIS_URI_CUSTOM must be a valid Redis connection URI.

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