> ## Documentation Index
> Fetch the complete documentation index at: https://docs.medera.info/llms.txt
> Use this file to discover all available pages before exploring further.

# Variables & Scopes

> Template resolution in canvas nodes

Canvas nodes resolve variables using `{{scope.path}}` template syntax. The runtime `Execution context.resolveVariable` is recursive and works across arrays, objects, and strings.

## Scopes

### `workflow.input`

Input parameters passed to the workflow at execution start. Frozen — cannot be mutated.

```text theme={"system"}
{{input.patient_id}}
{{input.deployment_id}}
{{input.clinical_context.chief_complaint}}
```

### `state.<name>`

State variables declared on the workflow's `start` node. Initialized from `state_variables.defaultValue`. Mutable during execution.

```text theme={"system"}
{{state.phq9_score}}
{{state.attempts}}
```

A `transform` node can write to state:

```yaml theme={"system"}
transform: output_to: state.phq9_score template: "{{nodes.intake_1.output.screeners.phq9.total}}"
```

### `nodes.<id>.output`

Output of a previously-executed node. Available as soon as the source node completes.

```text theme={"system"}
{{nodes.intake_1.output.transcript}}
{{nodes.intake_1.output.tasks[0].title}}
```

### `runtime.context`

Runtime context for the current execution.

| Path                       | Value                                           |
| :------------------------- | :---------------------------------------------- |
| `runtime.execution_id`     | `agent_workflow_executions.id`                  |
| `runtime.organization_id`  | Tenant ID (RLS-enforced)                        |
| `runtime.workflow_id`      | `agent_workflows.id`                            |
| `runtime.workflow_version` | Version executed                                |
| `runtime.trigger_type`     | `canvas_test` / `api` / `scheduled` / `webhook` |

### `tenant.secret`

Read-only access to tenant-configured secrets stored in your secret store (SSM / Vault). Resolved at execution time, never inlined into the workflow definition.

```| theme={"system"}
{{tenant.secret.epic_oauth_client_id}}
{{tenant.secret.aetna_payer_api_key}}
```

## Type safety

Variable references are type-checked against the source node's output schema at design time.

A `string` source cannot be assigned to a `number` sink.