Shelly Cover - Position and Tilt sent as separate RPC calls, causing race condition

The problem

Shelly Cover: Position and Tilt sent as separate RPC calls, causing race condition

The problem

When a Shelly 2PM (Gen2+) has slat control enabled, Home Assistant sends pos and slat_pos as two separate Cover.GoToPosition RPC calls. The second call interrupts/overrides the first, resulting in only the tilt (slat) being executed while the cover position change is ignored.

The Shelly firmware supports both parameters in a single RPC call (Cover.GoToPosition?id=0&pos=100&slat_pos=100), which works correctly. The HA integration should combine them.

Environment

Home Assistant Core (latest as of March 2026)
Shelly 2PM Gen2 and Gen3 devices
Firmware: 1.7.x
Integration: built-in Shelly integration
Slat control enabled via device settings (slat.enable: true)

Reproduction steps

Enable slat control on a Shelly 2PM: Cover.SetConfig with "slat":{"enable":true}
Close the cover fully (position 0, tilt 0)
Create a scene in HA that sets the cover to current_position: 100 and current_tilt_position: 100
Activate the scene
Expected: Cover moves to position 100 AND tilt moves to 100
Actual: Only the tilt moves to 100, cover stays at position 0
Activating the scene a second time then correctly moves the cover (because tilt is already at target)

Root cause verification via curl

Direct RPC calls to the Shelly device confirm the issue is about separate vs. combined calls:

Two simultaneous calls — FAILS (reproduces the HA behavior)

curl -s "http://<shelly-ip>/rpc/Cover.GoToPosition?id=0&pos=100" &
curl -s "http://<shelly-ip>/rpc/Cover.GoToPosition?id=0&slat_pos=100"

Result: Only slat moves, cover position is ignored.

Single combined call — WORKS

curl -s "http://<shelly-ip>/rpc/Cover.GoToPosition?id=0&pos=100&slat_pos=100"

Result: Both cover position and slat move correctly.

Sequential calls with delay — WORKS

curl -s "http://<shelly-ip>/rpc/Cover.GoToPosition?id=0&pos=100"
sleep 3
curl -s "http://<shelly-ip>/rpc/Cover.GoToPosition?id=0&slat_pos=100"

Result: Both execute correctly.

Shelly device configuration reference

The slat configuration is nested under slat in Cover.GetConfig:

{
  "id": 0,
  "name": "jalousie_buero",
  "motor": {"idle_power_thr": 2.00, "idle_confirm_period": 0.25},
  "maxtime_open": 90.00,
  "maxtime_close": 90.00,
  "slat": {
    "enable": true,
    "open_time": 1.50,
    "close_time": 1.50,
    "step": 20,
    "retain_pos": false,
    "precise_ctl": true
  }
}

Suggested fix

When both position and tilt_position need to be set, combine them into a single Cover.GoToPosition RPC call with both pos and slat_pos parameters, instead of issuing two separate calls.

Additional context

supported_features changes from 15 to 255 when slat control is enabled
The issue affects scenes, but individual service calls (cover.set_cover_position, cover.set_cover_tilt_position) work correctly when called manually one at a time
Approximately 15-20 cover devices are affected in a typical installation
Workaround: disable slat control on all devices and use small position values (e.g., current_position: 2) to simulate tilt

What version of Home Assistant Core has the issue?

2026.3.2

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

Shelly

Link to integration documentation on our website

No response

Diagnostics information

No response

Example YAML snippet

Anything in the logs that might be useful for us?

Additional information

No response

@bieniu

Hey there @bieniu, @thecode, @chemelli74, @bdraco, mind taking a look at this issue as it has been labeled with an integration (shelly) you are listed as a code owner for? Thanks!

Code owner commands

Code owners of shelly can trigger bot actions by commenting:

@home-assistant close Closes the issue.
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@home-assistant unassign shelly Removes the current integration label and assignees on the issue, add the integration domain after the command.
@home-assistant add-label needs-more-information Add a label (needs-more-information, problem in dependency, problem in custom component, problem in config, problem in device, feature-request) to the issue.
@home-assistant remove-label needs-more-information Remove a label (needs-more-information, problem in dependency, problem in custom component, problem in config, problem in device, feature-request) on the issue.

_{^{(message by CodeOwnersMention)}}

@Franklins59 Thanks for reporting this issue!

Before we dive in, please make sure this isn't a duplicate by searching through existing issues. Also check recently closed issues, as your problem might already be fixed but not yet released.

https://github.com/home-assistant/core/issues?q=%20label%3A%22integration%3A%20shelly%22%20
If your issue is related to Shelly generation 1 device, make sure you have configured CoIoT peer correctly.

If your issue is related to battery powered Shelly generation 2/3/4 devices, make sure you have configured Outbound WebSocket correctly.

Please enable Shelly debug logging, let it run for 10-15 minutes, and make sure to capture whatever problem you're having in the debug log.
Note: it is better to drag the log file into the comment (which will add it as an attachment) and not copy paste as it is hard to read logs in GitHub.

Finally, be sure to include diagnostics for the Shelly device you're having problems with.
_{^{(message by IssueContext)}}

shelly documentation
shelly source
_{^{(message by IssueLinks)}}

This is a duplicate of #148743, which was closed as stale without being fixed. I have now provided concrete curl test results proving the root cause: the integration sends pos and slat_pos as two separate RPC calls instead of combining them into a single Cover.GoToPosition call. The Shelly firmware supports both parameters in one call and works correctly when used that way.

The reason #148743 was not progressed is that this problem is outside of the Shelly integration, Shelly integration only adapts between Home Assistant services (open/close/set cover position/set tilt) to the device, we receive this from Home Assistant as two separate calls and I have not found a solution that can fix that.

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates.
Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍
This issue has now been marked as stale and will be closed if no further activity occurs. Thank you for your contributions.

Still on my task list, removing the stale one last time, hopefully to fix this before it become stale again

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Shelly Cover - Position and Tilt sent as separate RPC calls, causing race condition #165902

The problem

Shelly Cover: Position and Tilt sent as separate RPC calls, causing race condition

The problem

Environment

Reproduction steps

Root cause verification via curl

Two simultaneous calls — FAILS (reproduces the HA behavior)

Single combined call — WORKS

Sequential calls with delay — WORKS

Shelly device configuration reference

Suggested fix

Additional context

What version of Home Assistant Core has the issue?

What was the last working version of Home Assistant Core?

What type of installation are you running?

Integration causing the issue

Link to integration documentation on our website

Diagnostics information

Example YAML snippet

Anything in the logs that might be useful for us?

Additional information

Metadata

Assignees

Labels

Type

Fields

Projects

Milestone

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Development

Shelly Cover - Position and Tilt sent as separate RPC calls, causing race condition #165902

Description

The problem

Shelly Cover: Position and Tilt sent as separate RPC calls, causing race condition

The problem

Environment

Reproduction steps

Root cause verification via curl

Two simultaneous calls — FAILS (reproduces the HA behavior)

Single combined call — WORKS

Sequential calls with delay — WORKS

Shelly device configuration reference

Suggested fix

Additional context

What version of Home Assistant Core has the issue?

What was the last working version of Home Assistant Core?

What type of installation are you running?

Integration causing the issue

Link to integration documentation on our website

Diagnostics information

Example YAML snippet

Anything in the logs that might be useful for us?

Additional information

Activity

home-assistant commented on Mar 18, 2026

Franklins59 commented on Mar 19, 2026

thecode commented on Apr 5, 2026

issue-triage-workflows commented on Jul 4, 2026

issue-triage-workflows commented on Oct 4, 2026

thecode commented on Oct 6, 2026

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