Device names: where each comes from, and how to change them

Every firmware a plug runs during a conversion has a name, used two ways:

• its hostname, which your router shows in its list of devices;
• the name of its own network (its SSID), which the plug raises when it cannot join your Wi-Fi.

Each firmware uses one name for both. This page lists every name, where each is set, and everything that has to change to rename them. It was written after the 2026-10 renaming, which took every name off the S60, so that another rename can be done in one pass.

The names

The examples are for a plug whose Wi-Fi MAC is 12:34:56:ab:cd:ef (made up): CDEF is the last two bytes, upper case; abcdef is the last three, lower case. Each plug works its own out, so no two plugs share a name.

The names an earlier release used are still recognised (see Old names), and so are the ones Tasmota gives itself where its settings are lost (see Tasmota’s own names).

Where each name is set

The installer (bridge)

• archive/bridge/main/main.c: BRIDGE_NAME_FORMAT ("autoflash-recovery-%02X%02X", from esp_read_mac(..., ESP_MAC_WIFI_STA)), used for the hostname and the network. The page title, which the tool recognises the installer by, is in INDEX_HTML (“Autoflash bridge”), and the project and log tag are autoflash_bridge.
• POST /tasmota-settings saves the settings record the run sends for the interim Tasmota, the name already in it. On the home network the installer adds the Wi-Fi it joined with; on its own network it saves the record without Wi-Fi (since 4.4.4), so that Tasmota still starts under the name.
• A changed installer is a new version: PROJECT_VER in archive/bridge/CMakeLists.txt and BRIDGE_VERSION in main.c (a test keeps them equal). Build and wrap it as archive/bridge/README.md says, into artifacts/autoflash-bridge-<kind>-<version>.ota (the wrapper names the plug’s model, so there is one per kind of plug).

The interim Tasmota (D1)

• It is Tasmota’s own build (artifacts/tasmota32c3-bluetooth.bin), not changed. Its name comes from the settings record D1 sends: give_tasmota_the_wifi() in tools/autoflash_cli.py calls tasmota_settings.named(template, our_setup_network(ctx)) (tools/autoflash/tasmota_settings.py: SET_HOSTNAME, at most HOSTNAME_MAX characters, with the record’s checksum made again, as the installer checks it before saving).
• Tasmota names its own network after its hostname (WiFi.softAP(TasmotaGlobal.hostname, ...)), so one name does both.

The startup firmware

• Our build of Tasmota’s Safeboot. The pattern is WIFI_DEFAULT_HOSTNAME ("autoflash-recovery-%4X", Tasmota’s %4X being the MAC’s last four hex digits), written into the build’s user_config_override.h by tools/configure_imprintable_safeboot.py and tools/configure_recovery_safeboot.py.
• repartition/recovery-safeboot/persist-settings.patch saves the name, written out, with the Wi-Fi, for the official Tasmota after it. It has to be written out: at every start Tasmota replaces a stored hostname that has a % in it with its own compiled default (tasmota.ino).
• Published as artifacts/README.md says: the header from configure_imprintable_safeboot.py, the build from tools/build_recovery_safeboot.sh, then tools/sanitise_safeboot.py and tools/validate_imprintable_safeboot.py, into artifacts/autoflash-recovery-safeboot-imprintable.bin; a test checks the pattern is in the image (tests/test_published_artifacts.py).

Official Tasmota, and F4

• Tasmota’s own release (tasmota32c3.bin), not changed. Before F4 it runs on the startup firmware’s saved name.
• F4 (step_configure()) resets Tasmota’s settings to its own defaults (Reset 4), which would name it Tasmota’s way. Just before the reset it puts in a Berry driver, Device.at_next_save() in tools/autoflash/device.py, whose save_before_restart gives the final name (final_name(ctx, "tasmota"): TASMOTA_AP_PREFIX and the MAC’s last six hex digits), the template and Module 0 as the reset’s restart saves the rebuilt defaults: one restart, and no other name in between. Should that not take, the same goes in after the reset (Backlog Hostname ...; Module 0), costing a second restart.
• A name cannot be sent with Reset 4: Tasmota resets only once its queued commands are done, so a Hostname sent with it is applied first and then wiped - and, setting a restart of its own, cancels the reset.
• The driver runs once, and is never given a command that saves the settings itself: SaveData does (SettingsSaveAll), which calls the driver again - in the emulator, round and round until Tasmota’s stack overflowed and it restarted before saving, its settings lost.

The mover

• ESPHome/autoflash_mover.yaml: ESPHome names must be lower case and ESPHome’s own suffix is six hex digits, so the mover is built as autoflash-moving with name_add_mac_suffix and its on_boot writes autoflash-recovery-%02X%02X over that name before its Wi-Fi starts, and sets its own network to it.
• The two must be the same length: autoflash-moving (16) and ESPHome’s -xxxxxx (7) make 23, as autoflash-recovery-XXXX does. A new interim name means a new compiled name of the matching length.
• A changed mover is a new version (project: version:), built with esphome compile into artifacts/autoflash-mover-<version>.bin.

ESPHome, converted

• ESPHome/sonoff_s60.yaml: name: esphome with name_add_mac_suffix: true gives esphome-abcdef; on_boot sets its own network to App.get_name(). friendly_name says what plug it is.
• The file name and package_import_url stay as they are: they are built into plugs converted already, and Home Assistant adopts them by it.
• Rebuilt as ESPHome/README.md says, a new version each time: artifacts/esphome-<kind>-imprintable-<version>.bin and its bootloader, then IMAGE, its SHA-256 and size in tools/autoflash/esphome.py.
• Its Wi-Fi action (autoflash_wifi, WIFI_ACTIONS in esphome.py) and the Wi-Fi placeholders (AUTOFLASH-IMPRINT-SSID> and -PASS>, in tools/autoflash/imprint.py) are in the mover and the startup firmware too.

What the tool looks for

All in tools/autoflash_cli.py unless said:

• SETUP_SSID_PREFIX (autoflash-recovery-), named() and our_setup_network(): the interim name.
• final_name(ctx, firmware): tasmota-abcdef, esphome-abcdef.
• bridge_networks(), mover_networks(): the interim name and the old ones.
• setup_networks(), setup_network_hint(): a Tasmota’s own network - tasmota-abcdef, Tasmota’s own tasmota-ABCDEF- and ESP_ABCDF0. Not the interim name: the installer’s network, listed for a moment after it restarts into a Tasmota that has the Wi-Fi, was taken for Tasmota’s. The one Tasmota that does raise a network under the interim name (sent through the installer’s own network, so given no Wi-Fi: tasmota_named_alone) is looked for by it in finish_tasmota_setup(), once the installer has gone (installer_gone()), and found when a run is tried again by asking it (setup_network.tasmota_answers(): on its own network Tasmota’s page waits on a Wi-Fi scan, its status does not).
• esphome_networks(), esphome_network_hint(): ESPHome’s.
• TASMOTA_DEFAULT_NAME_RE and name_with_the_wifi(): a Tasmota under its own default name, given the Wi-Fi on its setup network, is named again in that restart (the same Berry driver as F4’s).
• tasmota_at_home() and note_setup_network(): the interim name is never kept as the plug’s own.
• tools/autoflash/setup_network.py: BRIDGE_PAGE_MARKERS, the installer’s page title, old and new.
• tools/autoflash/kinds.py: per kind of plug, ESPHome’s old names (esphome_legacy_setup_prefix, esphome_legacy_prefix) and its friendly name.
• tools/autoflash/prompts.py: find_ssid() takes a network by the names in the order given, with PROVISIONAL_PREFIX (ESP_) last and looked at again.
• tools/autoflash/output.py: the patterns that keep a plug’s name out of the report one shares.
• tools/flash_readout.py: the names it waits for while reading a stock plug.

Tasmota’s own names

Tasmota’s compiled default, %s-%04d - its MQTT topic (tasmota_ABCDEF, written tasmota-ABCDEF) and four decimal digits of the chip ID - gives tasmota-ABCDEF-1234. The plug has it only where its settings are gone: in a Tasmota whose settings were erased by switching it off and on 7 times, and while it tests the Wi-Fi it is given on its setup network after that. The setup network itself then has that name, and the tool looks for it.

For a moment as Tasmota turns its own network on, before it names it, the network goes out as ESP_ and the plug’s access-point MAC (the Wi-Fi MAC plus one: ESP_ABCDF0). Tasmota’s WifiManagerBegin() turns the access point on first (WifiSetMode(WIFI_AP_STA), which ends with delay(100)) and names it after (WiFi.softAP()), so for those 100 ms it beacons under ESP-IDF’s default name. Seen at nearly every Tasmota setup-network start in the emulator, in both builds we install (the 15.6.0 release: 4 starts of 5). Calling WiFi.softAP() first - which turns the access point on and names it at once - ends it: built from the same commit, 8 starts of 8 without the change went out as ESP_ABCDF0 first, none of 8 with it, and the setup page still worked. That is a change to Tasmota (#25169), so it reaches plugs only with a Tasmota release that has it. Until then a computer can list that name for a minute after, and the tool never takes it over the real one (find_ssid()).

Old names

A plug a run of an older checkout left part way through goes by the name it had then, so the tool still looks for every one: Sonoff-Setup-XXXX (the installer 4.4.3, the mover 1.0.0 and ESPHome 1.1.0’s own networks), S60-OTA-Bridge-XXXX with the password s60-ota-bridge (installers before 4.4.3), s60-ota-bridge and sonoff-s60-mover-xxxxxx (hostnames), sonoff-s60-xxxxxx (ESPHome 1.1.0), the “S60 OTA Bridge” page, the S60-IMPRINT- placeholders and the s60_wifi action. Renaming again, add today’s names to these lists rather than replacing them.

Renaming: the checklist

1. Change the name where it is made (above): the installer, the mover, the startup firmware, the final ESPHome, and the tool’s constants for the interim Tasmota and F4. Keep the mover’s compiled name the length of the new interim name; keep every name within Tasmota’s 32 characters and ESPHome’s lower-case rule.
2. Add the old names to the lists in Old names, in the tool.
3. Rebuild every firmware whose name changed, each as a new version, and publish each artifact: the file in artifacts/, its line in SHA256SUMS, its row in artifacts/README.md, the path, SHA-256 and size where the tool pins it (BRIDGE_OTA, esphome.IMAGE, CONTROL_FILES in flash_readout.py), and THIRD_PARTY_NOTICES.md.
4. Update the tests that name them: tests/test_setup_networks.py, tests/test_published_artifacts.py, tests/test_tasmota_settings.py, tests/test_autoflash.py, tests/test_flash_readout.py.
5. Update the pages that name them: troubleshooting.md (“The plug’s own network”), what-happens.md, technical-details.md, the ESPHome and installer READMEs, and the changelog.
6. Test every name in the emulator, as testing.md says: each firmware’s hostname is in the emulator’s DHCP log (/run/autoflash-emu/dnsmasq.log in the container), the network it raises in /run/autoflash-emu/softap, and every network that went out in the plug’s serial log (WIFIAP: guest SoftAP <name> up). Run every route from stock and between the firmwares, and the routes through each firmware’s own network (the fault suite’s fallback scenarios). Run one plug with another MAC too, so a name made from the MAC is seen to follow it: a copy of a backed-up plug under captures/plugs/<mac>/ with the new MAC in efuse.bin (bytes 0x18-0x1D, in reverse order) and test_copy_of in its plug.json.