msime-windows/PRIVACY.md

Privacy

Metasequoia IME for Windows converts keystrokes, composition text and candidates locally, using the shared C++ engine and the SQLite dictionaries installed under %LOCALAPPDATA%\metasequoiaime\. Local conversion never contacts the network. This document describes the optional online features that do, exactly what each one sends, and how to turn each one off.

Every claim below is checkable against this repository. Where a default matters, the file and key that set it are named.

Network features

Cloud candidates are enabled by default, and the installer asks before the first install. general.cloud_candidates is true in the shipped installer/default_config/config.default.toml, and server/src/config/ime_config.cpp also defaults to true when the key is absent. A first install shows a wizard page naming this feature and its endpoint, with the box checked; clearing it writes cloud_candidates = false into the config that install creates. Upgrades skip that page, because by then the config belongs to the user. While a composition is active, the typed spelling is sent over HTTPS to Google's input-tools service (https://inputtools.google.com/request) to fetch one extra candidate. Google receives that spelling, the IP address and standard request metadata. No committed text, dictionary content, learned frequencies, settings or account data are sent. This is the one online feature that needs no credential, so it is the one that is actually live on a fresh install. Turn it off in 设置 → 输入 → 云候选, or set cloud_candidates = false under [general] in %LOCALAPPDATA%\metasequoiaime\config.toml.

AI candidate suggestions require a token you supply. [ai_assistant] enabled ships as true, but the shipped token values are placeholders and the runtime rejects placeholders, so no request is made until a real token is entered. Once configured, the segmented spelling and the surrounding composition context are sent to the provider's Chat Completions endpoint — DeepSeek, OpenAI, SiliconFlow or Groq, per [ai_assistant] provider. That provider's own privacy terms then apply. Set enabled = false to disable it outright.

Candidate translation requires credentials you supply. [tencent_tmt] enabled ships as true with placeholder credentials, so nothing is sent until real Tencent Cloud keys are entered. Once configured, candidate text that the local dictionaries could not gloss is sent to https://tmt.tencentcloudapi.com. Translations are display metadata and never change the text that is committed.

Voice input requires a token you supply. [voice_input] voice_input ships as true with a placeholder ASR token, so the hotkeys do nothing over the network until a real token is entered. Once configured, recorded audio is uploaded to the configured endpoint — Doubao (wss://openspeech.bytedance.com/...), OpenAI, SiliconFlow or Groq. If text polishing is enabled, the returned transcript is additionally sent to the configured Chat Completions endpoint.

The update check runs only when you press the button. 设置 → 关于 → 检查更新 fetches https://msime.app/update.json and compares the version. There is no background or scheduled update check, and the request carries no identifier beyond the IP address and a cache-busting timestamp.

No telemetry

There is no analytics, telemetry, crash reporting, or usage measurement that leaves this machine. The input method does not record, store or transmit what you type: the only records it can keep are the optional local counters described below, and those cover character classes, activity time and candidate-choice counts, never text. No third-party SDK for those purposes is linked, and there is no endpoint that receives usage data. This is verifiable: searching the server/, windows/, ui/, ui-html/ and installer/ trees for telemetry, analytics, sentry, matomo, posthog, amplitude, mixpanel, crashpad and breakpad returns nothing.

Local input statistics (built-in, off by default)

The input method can show a local typing summary in 设置 → 统计. This is a built-in capability, not a separately distributed tool: statistics.enabled is false in the shipped installer/default_config/config.default.toml, so a fresh install records nothing, and 设置 → 统计 lets you turn recording on.

While enabled, the input method records only counters in a local SQLite database: per-day and per-hour counts of five character classes (Chinese, Latin, digits, punctuation, other), the time counted as actively typed, and two further counters of candidate choices — how many commits were made from the Chinese candidate list and how many of those selected the first candidate of the first page. Those two counters power the "first-word hit rate" card and let you measure ranking quality locally; they carry no text and no way to reconstruct any wording. The counts come from text the input method commits to the document and from printable keystrokes it leaves for the application to insert; the second half is a keystroke-level approximation and can slightly over-count (for example an input field that rejects or truncates the character). No text, spelling, candidates, application name or window title is stored, and the counters are carried to the Server process over a session-scoped local named pipe only. The database is <DataDir>\stats.db, where <DataDir> is the data directory chosen at install time (default %LOCALAPPDATA%\metasequoiaime); it makes no network requests and uploads nothing.

Turning the switch off stops new recordings; existing counters are kept until they are deleted. To remove them, use the controls in 设置 → 统计: the automatic retention policy (keep the last 30 / 90 / 180 / 365 days) deletes expired days on the next write after midnight, and the "clear all statistics" button immediately wipes every record, including today's. statistics.retention in config.toml stores the policy and defaults to forever, which never deletes automatically; an invalid value falls back to forever so a broken config cannot delete data. Deleting stats.db works too.

Local data

Settings live in %LOCALAPPDATA%\metasequoiaime\config.toml. Learned word frequencies and user-created words are stored in %LOCALAPPDATA%\metasequoiaime\msime_user.db. Diagnostic logs are written to %LOCALAPPDATA%\metasequoiaime\log\ and record process lifecycle and error conditions, not typed content. Clipboard history is disabled by default (clipboard_history = false); when enabled it records copied text locally and is cleared as soon as it is switched off.

API tokens are stored in plain text in config.toml. This differs from the other platforms — macOS and iOS use the Keychain, and Linux uses the desktop Secret Service — and it means anything able to read that file can read the tokens. Use provider tokens scoped to this purpose, and treat the file as a secret when backing up or syncing the profile directory.

All of these files sit in the current user's profile and are protected only by that account's permissions.

Uninstall

Uninstalling deletes %LOCALAPPDATA%\metasequoiaime and %PROGRAMDATA%\metasequoiaime in full, including the user dictionary, settings and any installed skins. Back up msime_user.db first if you want to keep learned words. An in-place upgrade behaves differently: it preserves msime_user.db, config.toml, config.base.toml and the skins directory, and replaces everything else.

General

Metasequoia IME does not sell or share personal data, and installing or using it does not create an account. If a future release adds another network-backed feature, this notice must be updated before that feature ships.

Security or privacy concerns should be reported privately as described in the organisation SECURITY.md.