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Update module reconfiguration lifecycle docs #5042

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Update module reconfiguration lifecycle docs
claude May 6, 2026
45c5ae7
Address review feedback: simplify table, clarify RPC naming, use reco…
claude May 26, 2026
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29 changes: 16 additions & 13 deletions docs/build-modules/module-reference.md
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Expand Up @@ -240,12 +240,15 @@ if __name__ == '__main__':

The default behavior when you don't implement a method:

| Behavior | Go | Python |
| ------------------------ | ------------------------------------------------------------ | ---------------------------------------------------------------------------------------- |
| Rebuild on config change | Default (`viam-server` destroys and re-creates the resource) | Default (`viam-server` destroys and re-creates the resource) |
| In-place reconfigure | Not supported for modular resources | Implement `reconfigure()` (called if your class satisfies the `Reconfigurable` protocol) |
| No-op close | Embed `resource.TriviallyCloseable` | Default on `ResourceBase` |
| Skip config validation | Embed `resource.TriviallyValidateConfig` | Default on `EasyResource` |
| To get this behavior | Go | Python |
| ---------------------- | ---------------------------------------- | ------------------------- |
| No-op close | Embed `resource.TriviallyCloseable` | Default on `ResourceBase` |
| Skip config validation | Embed `resource.TriviallyValidateConfig` | Default on `EasyResource` |

`viam-server` always rebuilds modular resources when their configuration
or dependencies change. It closes the existing resource instance and
creates a new one using the constructor. In-place reconfiguration is not
supported for modular resources in any language.

## Logging

Expand Down Expand Up @@ -331,13 +334,13 @@ defined in `proto/viam/module/v1/module.proto`:

All RPCs are initiated by `viam-server` and handled by the module:

| RPC | Purpose |
| --------------------- | -------------------------------------------------------- |
| `Ready` | Handshake: module returns its supported API/model pairs. |
| `AddResource` | Create a new resource instance from config. |
| `ReconfigureResource` | Update an existing resource with new config. |
| `RemoveResource` | Destroy a resource instance. |
| `ValidateConfig` | Validate config and return implicit dependencies. |
| RPC | Purpose |
| --------------------- | --------------------------------------------------------------------------------------------------------------------------- |
| `Ready` | Handshake: module returns its supported API/model pairs. |
| `AddResource` | Create a new resource instance from config. |
| `ReconfigureResource` | Rebuild an existing resource with new config (removes and re-creates the resource). The name is retained for compatibility. |
| `RemoveResource` | Destroy a resource instance. |
| `ValidateConfig` | Validate config and return implicit dependencies. |

The module also connects back to the parent `viam-server` to access other
resources (dependencies) on the machine.
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4 changes: 2 additions & 2 deletions static/include/components/apis/overrides/protos/sensor.Reconfigure.md
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@@ -1,2 +1,2 @@
Reconfigure this resource.
Reconfigure must reconfigure the resource atomically and in place.
Reconstruct this resource.
For modular resources, reconstruction destroys the existing resource instance and creates a new one using the constructor.
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