# Environment configuration

> Reference for the environment variables that configure Temporal Clients, including the Temporal CLI.

This page lists every environment variable that configures a client, including SDK
[Temporal Clients](/encyclopedia/temporal-client) and the Temporal CLI, along with its TOML configuration key and the
equivalent CLI flag.

For how to use these variables and configuration files together, refer to
[Environment configuration](/develop/environment-configuration).

When the same setting comes from more than one place, the highest precedence wins:

1. A CLI flag passed explicitly on the command line.
2. An environment variable.
3. A value in a TOML configuration file.

Every variable below lists the clients that read it. `Read by: every client` means every SDK and the Temporal CLI.

## Configuration file variables

### `TEMPORAL_CONFIG_FILE`

Path to the TOML configuration file. Defaults to `temporal.toml` in a platform-specific directory.

- TOML key: none
- CLI flag: `--config-file`
- Read by: every client

### `TEMPORAL_PROFILE`

Name of the configuration profile to load. Defaults to `default`.

- TOML key: none
- CLI flag: `--profile`
- Read by: every client

## Connection variables

### `TEMPORAL_ADDRESS`

Host and port of the Temporal Frontend Service, such as `localhost:7233`.

- TOML key: `profile.<name>.address`
- CLI flag: `--address`
- Read by: every client

### `TEMPORAL_NAMESPACE`

Temporal Namespace to connect to.

- TOML key: `profile.<name>.namespace`
- CLI flag: `--namespace`
- Read by: every client

### `TEMPORAL_API_KEY`

API key for authentication. When set, TLS is enabled by default.

- TOML key: `profile.<name>.api_key`
- CLI flag: `--api-key`
- Read by: every client

### `TEMPORAL_CLIENT_AUTHORITY`

Overrides the `:authority` gRPC header. This is a Go SDK extension with no equivalent in other clients and no CLI flag
of its own.

- TOML key: `profile.<name>.authority`
- CLI flag: none
- Read by: Go

## TLS variables

### `TEMPORAL_TLS`

Set to `true` to enable TLS, `false` to disable it. The TOML key inverts the value: `disabled = true` turns TLS off.

- TOML key: `profile.<name>.tls.disabled`
- CLI flag: `--tls`
- Read by: every client

### `TEMPORAL_TLS_CLIENT_CERT_PATH`

Filesystem path to the client's public TLS certificate. Cannot be combined with `TEMPORAL_TLS_CLIENT_CERT_DATA`.

- TOML key: `profile.<name>.tls.client_cert_path`
- CLI flag: `--tls-cert-path`
- Read by: every client

### `TEMPORAL_TLS_CLIENT_CERT_DATA`

Raw PEM data for the client's public TLS certificate. Cannot be combined with `TEMPORAL_TLS_CLIENT_CERT_PATH`.

- TOML key: `profile.<name>.tls.client_cert_data`
- CLI flag: `--tls-cert-data`
- Read by: every client

### `TEMPORAL_TLS_CLIENT_KEY_PATH`

Filesystem path to the client's private TLS key. Cannot be combined with `TEMPORAL_TLS_CLIENT_KEY_DATA`.

- TOML key: `profile.<name>.tls.client_key_path`
- CLI flag: `--tls-key-path`
- Read by: every client

### `TEMPORAL_TLS_CLIENT_KEY_DATA`

Raw PEM data for the client's private TLS key. Cannot be combined with `TEMPORAL_TLS_CLIENT_KEY_PATH`.

- TOML key: `profile.<name>.tls.client_key_data`
- CLI flag: `--tls-key-data`
- Read by: every client

### `TEMPORAL_TLS_SERVER_CA_CERT_PATH`

Filesystem path to the Certificate Authority certificate used to verify the server. Cannot be combined with
`TEMPORAL_TLS_SERVER_CA_CERT_DATA`.

- TOML key: `profile.<name>.tls.server_ca_cert_path`
- CLI flag: `--tls-ca-path`
- Read by: every client

### `TEMPORAL_TLS_SERVER_CA_CERT_DATA`

Raw PEM data for the Certificate Authority certificate used to verify the server. Cannot be combined with
`TEMPORAL_TLS_SERVER_CA_CERT_PATH`.

- TOML key: `profile.<name>.tls.server_ca_cert_data`
- CLI flag: `--tls-ca-data`
- Read by: every client

### `TEMPORAL_TLS_SERVER_NAME`

Overrides the server name used for Server Name Indication (SNI) in the TLS handshake.

- TOML key: `profile.<name>.tls.server_name`
- CLI flag: `--tls-server-name`
- Read by: every client

### `TEMPORAL_TLS_DISABLE_HOST_VERIFICATION`

Disables server hostname verification. Use with caution. Not every SDK applies this setting.

- TOML key: `profile.<name>.tls.disable_host_verification`
- CLI flag: `--tls-disable-host-verification`
- Read by: every client

## gRPC metadata variables

### `TEMPORAL_GRPC_META_*`

Sets gRPC headers. The part after `_META_` becomes the header key, so `TEMPORAL_GRPC_META_SOME_KEY` sets `some-key`.

- TOML key: `profile.<name>.grpc_meta`
- CLI flag: `--grpc-meta`
- Read by: every client

## Codec Server variables

### `TEMPORAL_CODEC_ENDPOINT`

Endpoint for a remote Codec Server. SDKs that read this variable do not apply the codec by default, so it is intended
mostly for CLI use.

- TOML key: `profile.<name>.codec.endpoint`
- CLI flag: `--codec-endpoint`
- Read by: every client except Java

### `TEMPORAL_CODEC_AUTH`

Authorization header value sent to the remote Codec Server.

- TOML key: `profile.<name>.codec.auth`
- CLI flag: `--codec-auth`
- Read by: every client except Java

## `temporal env` preset variables

The Temporal CLI supports a second configuration mechanism alongside TOML configuration files. `temporal env` stores
named key-value presets in `temporal.yaml`, and the variables below select which preset the CLI reads.

Both mechanisms work. The `temporal config` command that manages TOML configuration files is currently experimental,
while `temporal env` is not.

### `TEMPORAL_ENV`

Name of the active `temporal env` preset. Defaults to `default`.

- TOML key: none
- CLI flag: `--env`
- Read by: Temporal CLI

### `TEMPORAL_ENV_FILE`

Path to the preset file. Defaults to `temporal.yaml` in the CLI configuration directory.

- TOML key: none
- CLI flag: `--env-file`
- Read by: Temporal CLI

## Legacy TLS variables

The Temporal CLI reads an older set of TLS variable names for compatibility. When any of them is set, it overrides the
corresponding value from the configuration file and from the preferred variable. These names have no CLI flag and no
TOML key of their own.

### `TEMPORAL_TLS_CERT`

Superseded by `TEMPORAL_TLS_CLIENT_CERT_PATH`.

- Read by: Temporal CLI

### `TEMPORAL_TLS_CERT_DATA`

Superseded by `TEMPORAL_TLS_CLIENT_CERT_DATA`.

- Read by: Temporal CLI

### `TEMPORAL_TLS_KEY`

Superseded by `TEMPORAL_TLS_CLIENT_KEY_PATH`.

- Read by: Temporal CLI

### `TEMPORAL_TLS_KEY_DATA`

Superseded by `TEMPORAL_TLS_CLIENT_KEY_DATA`.

- Read by: Temporal CLI

### `TEMPORAL_TLS_CA`

Superseded by `TEMPORAL_TLS_SERVER_CA_CERT_PATH`.

- Read by: Temporal CLI

### `TEMPORAL_TLS_CA_DATA`

Superseded by `TEMPORAL_TLS_SERVER_CA_CERT_DATA`.

- Read by: Temporal CLI