# SDKs

This document tracks the feature support of the various SDKs, and aims to consolidate the expected behavior around environment variables and configuration loading.

## Environment Variables

Each SDK should support the following environment variables:

Variable, Description, Required, Default

`HATCHET_CLIENT_TOKEN`, The tenant-scoped API token to use., Yes, N/A
`HATCHET_CLIENT_HOST_PORT`, The host and port of the Hatchet server to connect to, in `host:port` format. SDKs should handle schemes and trailing slashes, i.e. `https://host:port, No, Automatically detected in new tokens.
`HATCHET_CLIENT_TLS_STRATEGY`, The TLS strategy to use. Valid values are `none`, `tls`, and `mtls`., No, `tls`
`HATCHET_CLIENT_TLS_CERT_FILE`, The path to the TLS client certificate file to use., Only if strategy is set to `mtls`, N/A
`HATCHET_CLIENT_TLS_CERT`, The TLS client key file to use., Only if strategy is set to `mtls`, N/A
`HATCHET_CLIENT_TLS_KEY_FILE`, The path to the TLS client key file to use., Only if strategy is set to `mtls`, N/A
`HATCHET_CLIENT_TLS_KEY`, The TLS client key to use., Only if strategy is set to `mtls`, N/A
`HATCHET_CLIENT_TLS_ROOT_CA_FILE`, The path to the TLS root CA file to use., Only if the server certificate is not signed by a public authority that's available to your environment, N/A
`HATCHET_CLIENT_TLS_ROOT_CA`, The TLS root CA to use., Only if the server certificate is not signed by a public authority that's available to your environment, N/A
`HATCHET_CLIENT_TLS_SERVER_NAME`, The TLS server name to use., No, Defaults to the `host` of the `host:port`
`HATCHET_CLIENT_TLS_MIN_VERSION`, The minimum TLS version. Valid values are `1.2` and `1.3`., No, `1.3`

The following environment variables are deprecated:

Variable, Description, Explanation

`HATCHET_CLIENT_TENANT_ID`, The tenant ID to use., This is now part of the token.

## Compatibility Matrices

### DAGs

Whether the SDKs support full DAG-style execution.

SDK, DAGs?, Notes

Go SDK, Yes
Python SDK, Yes
Typescript SDK, Yes

### Timeouts

Whether the SDKs support setting timeouts and cancelling after timeouts.

SDK, Timeouts?, Step cancellation?, Notes

Go SDK, Yes, Yes
Python SDK, Yes, Yes, If thread is blocking, this won't be respected
Typescript SDK, Yes, Unknown

### Middleware

Whether the SDKs support setting middleware.

SDK, Middleware?, Notes

Go SDK, Yes
Python SDK, No
Typescript SDK, No

### Separately Registering and Calling Actions

Whether the SDKs support separately registering and calling actions, instead of defining them inline in the workflows.

SDK, Supported?, Notes

Go SDK, Yes
Python SDK, No
Typescript SDK, No

### Custom Services

Whether the SDKs support defining services to logically separate workflows and actions.

SDK, Supported?, Notes

Go SDK, Yes
Python SDK, No
Typescript SDK, No

### Scheduled Workflows

Whether the SDKs support defining scheduled workflows.

SDK, Supported?, Notes

Go SDK, Yes
Python SDK, No
Typescript SDK, No