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name: bitcoin-hardware-trezor description: | Trezor hardware wallets: Model T, Model One, Trezor Safe 3, Safe 5, Safe 7. Trezor Suite, trezorctl, USB protocol, BIP32 derivation, passphrase support, Shamir Backup. USE WHEN: integrating with Trezor, supporting Trezor in app, troubleshooting Trezor signing. allowed-tools: Read, Grep, Glob

Trezor Hardware Wallets

Trezor (SatoshiLabs, Czech Republic) was the first hardware wallet (2014). Open-source firmware + open-source software.

Models

Model	Year	Notes
Trezor One	2014	Original, no touchscreen, OLED display
Trezor Model T	2018	Touchscreen, Shamir Backup support
Trezor Safe 3	2023	Secure Element, BIP-39 + Shamir
Trezor Safe 5	2024	Touch, Secure Element, color display
Trezor Safe 7	2025	Dual SE (TROPIC01 + EAL6+), BLE, color touch

Years are launch years. Safe 3 shipped with firmware 2.6.3 (15 November 2023), Safe 5 with 2.7.2 (14 June 2024), Safe 7 with 2.9.3 (21 October 2025). Current firmware line is 2.12.4 (19 August 2026).

Trezor Safe 7 (launched 21 October 2025) is the first consumer device to ship Tropic Square's TROPIC01, a transparent and auditable secure element, alongside an EAL6+ Optiga element and an STM32U5 MCU - three independent layers from separate vendors. Firmware updates, device authentication and boot use the post-quantum SLH-DSA-128 signature scheme.

TROPIC01 disclosure (3 June 2026): Ledger Donjon reported a successful laser fault-injection attack against TROPIC01 (Tropic Square was informed in late January 2026); Tropic Square then identified a follow-on method targeting the chip's PIN protection. Trezor's response states that PIN, funds and wallet backup on the Safe 7 stay safe because only one of the three independent layers is affected, and that a hardware-level fault attack cannot be remediated by a firmware update.

Connection

• USB (HID protocol).
• Safe 7 adds Bluetooth 5.0+ pairing; USB and BLE both run the open-source Trezor Host Protocol (THP) (as of September 2026).
• Trezor Suite (desktop app) / web (Trezor Bridge).
• Third-party: Sparrow, Specter, Wasabi, BlueWallet, Electrum.

Derivation

Default BIP44/49/84/86 paths. Configurable via Suite or third-party wallet.

Passphrase ("25th word")

Trezor supports BIP39 passphrase:

• Optional 1-50 character string.
• Combined with seed via PBKDF2 (BIP39 standard).
• Trezor doesn't store the passphrase; entered each session.
• Hidden wallets: each unique passphrase = different wallet.

Shamir Backup (Model T, Safe 3, Safe 5, Safe 7)

SLIP-39:

• M-of-N share threshold.
• Each share: 20-33 BIP39-style words from a different wordlist.
• Multiple groups for hierarchical recovery.

Firmware verification

• Open-source firmware on GitHub.
• Trezor Suite verifies firmware signature on connect.
• DIY users can build + flash custom firmware.

API

trezorctl (CLI):

trezorctl get-public-key -n "m/84'/0'/0'"
trezorctl btc sign-tx -c bitcoin "$(cat tx.json)"

trezor-connect (web): JavaScript SDK for browser apps.

PSBT support

Trezor signs PSBT v0 (BIP174). Pass PSBT to device, user confirms, device returns signed PSBT.

Multi-sig PSBT: Trezor can sign as one party in a multisig.

Common issues

• Bridge not running: web wallets fail to find device. Restart Bridge.
• Wrong derivation path: tools default to legacy if unspecified; force m/84'/0'/0' for native segwit.
• Passphrase mistype: empty wallet shown. No way to recover — must remember exact passphrase.

See also

• hwi/SKILL.md
• psbt-flows/SKILL.md
• ../wallets/backup/SKILL.md
• ledger/SKILL.md