Environment Variables
This page documents the environment variables that provide configuration options to the Bittensor SDK.
General
BT_SUBTENSOR_CHAIN_ENDPOINT
The Subtensor chain endpoint address used when launching a local network (LocalNet).
This variable will be renamed or deprecated in Bittensor SDK version 10.
NEST_ASYNCIO
If the variable is set to 1, the nest_asyncio patch is applied to support nested asyncio event loops.
READ_ONLY
If set to 1, Bittensor is run in in read-only mode, and write-required operations are disabled (e.g., btlogging and bittensor-wallet).
Allows Bittensor to be run in read-only systems.
USE_TORCH
When set to 1, forces the use of PyTorch instead of NumPy for certain operations.
The SDK uses False if the variable is not set.
Subtensor
BT_CHAIN_ENDPOINT
The Subtensor node (RPC endpoint) URL to connect to Bittensor (overrides the default chain address).
The SDK uses bittensor.core.settings.DEFAULT_ENDPOINT if the variable is not set.
BT_NETWORK
The default Subtensor network name. Allows selecting the network (e.g., finney or testnet) during Subtensor initialization without specifying an explicit endpoint.
The SDK uses bittensor.core.settings.DEFAULT_NETWORK if the variable is not set.
Axon
BT_AXON_PORT
The port on which the local Axon server will listen for incoming connections.
The SDK uses 8091 if the variable is not set.
BT_AXON_IP
The local IP address (interface) used to start Axon.
The SDK uses "[::]" if the variable is not set.
BT_AXON_EXTERNAL_PORT
The external port of Axon advertised to other network peers.
The SDK uses None if the variable is not set.
BT_AXON_EXTERNAL_IP
The external IP address that Axon will share with other network participants.
The SDK uses None if the variable is not set.
BT_AXON_MAX_WORKERS
The maximum number of worker threads for the Axon server.
The SDK uses 10 if the variable is not set.
Logging
BT_LOGGING_DEBUG
When set to true or 1, enables DEBUG level message output.
BT_LOGGING_TRACE
When set to true or 1, enables the most verbose TRACE logging level.
BT_LOGGING_INFO
When set to true or 1, enables INFO level message output.
BT_LOGGING_RECORD_LOG
When set to true or 1, enables log file recording.
The SDK uses False if the variable is not set.
BT_LOGGING_LOGGING_DIR
Specifies the directory path for storing log files.
The SDK uses bittensor.core.settings.MINERS_DIR if the variable is not set.
PriorityThreadPoolExecutor
BT_PRIORITY_MAX_WORKERS
Maximum number of worker threads for the PriorityThreadPoolExecutor.
The SDK uses 5 if the variable is not set.
BT_PRIORITY_MAXSIZE
Maximum task queue size for the PriorityThreadPoolExecutor.
The SDK uses 10 if the variable is not set.
Wallet
BT_WALLET_NAME
Wallet name to use unless specified.
The SDK uses default if the variable is not set,
BT_WALLET_HOTKEY
Hotkey name to use unless specified.
The SDK uses default if the variable is not set,
BT_WALLET_PATH
The SDK uses bittensor.core.settings.WALLETS_DIR if the variable is not set.
Testing
FAST_BLOCKS
The SDK runs e2e tests in fast-block mode if the variable is not set.
USE_DOCKER
If set to 1 or true, uses the Docker-based LocalNet image for launching e2e tests.
The SDK uses False if the variable is not set.
LOCALNET_SH_PATH
Full path to the scripts/localnet.sh file in the cloned Subtensor repository used to launch the local chain (including for e2e tests if the Docker image is not used).
SDK skips running e2e tests if the variable is not set (used only together with the USE_DOCKER variable).
SKIP_PULL
Controls whether the Docker image used for end-to-end tests should be pulled from a remote container registry (e.g. GitHub Container Registry) before the test run. This is useful in CI pipelines where a custom image is built and should not be overwritten by a remote version.
- When
SKIP_PULL=0(default), the test framework runs docker pull to ensure the latest version of the image is used. - When
SKIP_PULL=1, the pull step is skipped. The tests will only run if the required Docker image is already available locally.