HTTP API

This HTTP API provides an interface for interacting with the Overvis MC252 device. All requests are made to paths starting with /api. The API supports GET and POST methods, some of which require authorization.

General Principles

• All data is transferred in JSON format.
• Successful responses use the 200 OK status.
• Errors are handled with appropriate HTTP statuses (400 Bad Request, 404 Not Found, 503 Service Unavailable, etc.).
• API request errors additionally contain a JSON object: { "error": "error code", "message": "error text" }.
• HTTP keep-alive is supported.
• Access to the API uses 3 access levels:
  • 🟩 0 - Guest
  • 🟨 1 - Power User
  • 🟥 2 - Administrator

Authorization

Authorization via API

To perform protected requests, you must complete the authorization procedure:

1. Get a salt at /api/login/salt/.
2. Log in via /api/login/ by sending a SHA1 password hash: login + password + salt.
3. All subsequent requests must include the session token Bearer xxxxxxxxxx in the Authorized header.

Logout is performed via /api/cmd/logout/. After successful authorization, the user receives access level 🟨 1 (Power User).

Authorization via Front Panel Button

Press the button on the front panel of the MC252 device once. After this, a user with Guest rights temporarily receives access level 🟨 1 (Power User) for 10 minutes.

Authorization via VPN Cloud

All requests coming from the VPN cloud automatically receive access level 🟥 2 — Administrator.

Endpoints Summary

GET Requests

Path	Purpose	Access Level
/api/version/	Device firmware version	🟩 0
/api/login/salt/	Get salt for password hashing	🟩 0
/api/identify/	Physical device identification	🟨 1
/api/state/get/?key&...	Get current device state by key (or all)	🟨 1
/api/settings/active/get/?key&...	Get active settings by key (or all)	🟨 1
/api/settings/saved/get/?key&...	Get saved settings by key (or all)	🟨 1
/api/modbus/resp/?tid=...	Get Modbus response by tid	🟨 1
/api/modbus/find/result/?list	Get Modbus device search result	🟨 1
/api/modbus/class-find/result/	Get Modbus template search result	🟨 1

POST Requests

Path	Purpose	Access Level
/api/login/	User authentication	🟩 0
/api/cmd/logout/	End session	🟨 1
/api/cmd/memory/card_eject/	Safe SD card ejection	🟨 1
/api/cmd/time/sync/	Time synchronization	🟨 1
/api/cmd/time/set/	Set time	🟨 1
/api/cmd/reboot/	Reboot device	🟨 1
/api/cmd/callback/reconnect/	Reconnect to cloud server via Modbus	🟨 1
/api/cmd/updates/download/	Download available updates	🟨 1
/api/cmd/updates/program/	Apply update	🟨 1
/api/cmd/settings/reset/	Reset settings to factory defaults	🟨 1
/api/cmd/settings/import/	Import configuration	🟨 1
/api/cmd/settings/export/	Export current settings	🟨 1
/api/cmd/gsm/sms-test/	Send test SMS	🟨 1
/api/activation/	License or device activation	🟨 1
/api/card/file/info/	Get file info on SD card	🟨 1
/api/card/file/read/	Read file from SD card	🟨 1
/api/card/file/write/	Write file to SD card	🟨 1
/api/card/remove/	Remove file from SD card	🟨 1
/api/card/dir/	Get list of files and directories	🟨 1
/api/settings/saved/set/	Change configuration parameters	🟨 1
/api/modbus/req/	Send Modbus request	🟨 1
/api/modbus/find/start/	Start Modbus device search on RS-485	🟨 1
/api/modbus/find/stop/	Stop/cancel Modbus device search on RS-485	🟨 1
/api/modbus/class-find/search-meta-info/	Get meta info from search template	🟨 1
/api/modbus/class-find/start/	Start template Modbus device search	🟨 1
/api/modbus/class-find/stop/	Stop/cancel template Modbus device search	🟨 1