ATAK 5.6 DataSync incompatibility with OpenTakServer 1.6 (Plugin Update Server 404, MissionAPI/DataSync 401, no mission/alert visibility)

[Iture]

Description

I am running OpenTakServer 1.6 using the Docker setup from this repository, with nginx acting as a reverse proxy.
TLS mutual authentication works correctly, certificates are accepted, and CoT routing between EUDs works as expected.

Important:
EUD‑to‑EUD communication works perfectly through the server.
I can successfully send:

• points / markers
• CASEVAC requests
• other CoT events

All these messages are delivered correctly to other devices.

However, ATAK 5.6 (with the DataSync plugin) cannot interact with OpenTakServer 1.6 beyond basic map tile loading. Several DataSync‑related features do not work:

• Plugin Update Server returns 404 Not Found
• /MissionAPI and /DataSync return 401 Unauthorized
• Missions do not load in ATAK
• Icons/positions do not appear on the map (despite CoT routing working)
• Alerts and CASEVAC tasks do not appear in the GUI
• Data packages and mission content do not sync

The base map loads correctly, but all mission‑related and DataSync‑dependent features are non‑functional.

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Expected Behavior

ATAK 5.6 should be able to:

• Retrieve missions and mission content
• Display unit positions and icons on the map
• Synchronize alerts and CASEVAC tasks
• Access the Plugin Update Server
• Interact with the server using DataSync endpoints

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Actual Behavior

✅ CoT routing works

EUDs can exchange CoT messages through the server.
Sending points, markers, CASEVAC tasks, etc. works correctly.

❌ Plugin Update Server

ATAK requests legacy plugin update endpoints and receives 404 Not Found from nginx.
OTS 1.6 does not expose the expected legacy plugin update paths.

❌ MissionAPI / DataSync

ATAK 5.6 DataSync plugin attempts to call:

• /MissionAPI
• /DataSync

Both require session/token authentication (@auth_required()), which ATAK 5.6 does not support.
As a result, ATAK receives 401 Unauthorized.

❌ No mission/alert/CASEVAC visibility

Because DataSync cannot authenticate or reach the correct endpoints:

• Missions do not load
• Icons/positions do not appear in the GUI
• Alerts and CASEVAC tasks do not sync
• Data packages are not accessible

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Steps to Reproduce

1. Deploy OpenTakServer 1.6 using this Docker repository.
2. Configure nginx as reverse proxy with TLS client certificate verification.
3. Connect ATAK 5.6 using a valid .p12 certificate.
4. Observe:
   • CoT routing works (points, CASEVAC, markers delivered to other EUDs)
   • Map tiles load
   • Missions, alerts, CASEVAC, and icons do not appear
5. Check nginx logs:
   • Plugin update requests → 404
   • /MissionAPI and /DataSync → 401
6. Check OTS logs:
   • No entries for /MissionAPI or /DataSync (requests never reach backend)

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Diagnosis

• ATAK 5.6 DataSync plugin uses legacy TAK Server endpoints (/MissionAPI, /DataSync, plugin update paths).
• OpenTakServer 1.6 uses new REST endpoints (/api/missions, /api/data_packages) and requires token/session authentication.
• ATAK 5.6 does not support token‑based authentication and cannot use the new API.
• Therefore, DataSync functionality is effectively broken with OTS 1.6.

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Questions

1. Is ATAK 5.6 DataSync officially supported with OpenTakServer 1.6?
2. Is there a compatibility layer or legacy endpoint support planned?
3. Should /MissionAPI and /DataSync be reintroduced for backward compatibility?
4. Is there a recommended workaround for plugin update server compatibility?
5. Is there a known DataSync plugin version that works with OTS 1.6?

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Additional Information

• Environment: Docker deployment from this repository
• Reverse proxy: nginx
• TLS mutual authentication enabled
• CoT routing between EUDs works correctly
• Probably only DataSync‑related functionality is affected