# Update and Retire Templates

Templates are identified by namespace, name, and version. Load an existing template by ID when an update or lifecycle operation must target one exact definition.


# Load a template by ID

Pass `resource_template_id` or `process_template_id` to the corresponding builder:

``` python
with namespace.build_resource_template(
    resource_template_id=resource_template.id,
) as builder:
    model = builder.get_model(update=True)
```

``` python
with namespace.build_process_template(
    process_template_id=process_template.id,
) as builder:
    model = builder.get_model(update=True)
```

`update=True` reloads current backend state before reading the model. Save only changes that are safe for that existing version.


# Create a new version

Do not mutate structure referenced by existing resources or process runs. Create a new template with the same name and a new version, then define the changed structure there:

``` python
with namespace.build_resource_template(
    name="Detector File",
    type_names=["file", "detector-data"],
    version="2.0",
) as builder:
    builder.add_properties({
        "file": [
            {"name": "path", "type": "str", "default": ""},
            {"name": "sha256", "type": "str", "default": ""},
            {"name": "format", "type": "str", "default": "unknown"},
        ],
    })
```

The same rule applies to process templates: bump `version` when changing slots, directions, steps, or parameters. Template ID, creation and modification timestamps, and version are protected identity fields and cannot be changed through the model.


# Activate a template

After checking a definition, mark it active:

``` python
with builder:
    builder.finalize()
```

Activation changes lifecycle status; it does not change template structure.


# Archive a template

Archive versions that should no longer be selected for new work:

``` python
builder.archive()
```

Archiving preserves historical references and does not delete resources or process runs that already use the template.