# Variables

Store readable configuration shared by Workflows in an Environment, and understand when changed values take effect.

Last updated: 2026-10-18

A Variable holds a non-secret configuration value for an Environment. Use it for values such as an
API's base URL, a destination identifier or a processing threshold. A Workflow reads it as
`vars.NAME`, for example `vars.API_URL`.

Use a [Secret](/configuration/secrets) for an API key, password or token. Variable values are
readable through configuration tools by callers with the required access, including Agents.

## Names and values

The name belongs to the Workspace; the value belongs to an [Environment](/configuration/environments). Use uppercase names with
underscores, such as `API_URL`.

| Name | Staging value | Production value |
| --- | --- | --- |
| `API_URL` | `https://sandbox.example.com` | `https://api.example.com` |
| `DESTINATION_ID` | `test-inbox` | `customer-inbox` |

Every Workflow using `vars.API_URL` in staging reads the staging value. There is no separate
Workflow-level override. Setting a value in one Environment does not supply it in another.

A name has a fixed kind throughout the Workspace. If `API_URL` is a Variable, it cannot also be a
Secret in production. Choose the kind based on whether the value is sensitive.

## When a change takes effect

Typenode captures the Environment's Variable values when it accepts a Run. That Run keeps those
values, including when it resumes after waiting or makes another attempt.

Updating a Variable affects later Runs without republishing. It does not replace the value in a
Run already accepted. Because the value is shared within the Environment, the change affects later
Runs of every Workflow that references it.

For example, changing `API_URL` while a Run waits for input leaves that Run using its original URL
when it resumes. A new Run uses the changed URL.

## Missing and empty values

A name existing in the Workspace does not mean it has a value in every Environment. Check the
Environment you will run in.

In Workflow code, reading an unset Variable produces `undefined`; an empty string is a set value.
Typenode also checks configuration requirements before work starts, so a missing required value
can prevent a Run from starting. Supply required values explicitly rather than expecting another
Environment to provide them.