Documentation

CapyBro is a Windows tray utility that brings AI into your everyday text work without any extra steps. Select text in Word, Chrome, VS Code, Slack, Notepad — anywhere → press a global hotkey (Ctrl+Shift+E by default) → AI rewrites it according to your prompt → the new text is already in place of the selection.

No browser tabs, no copy-paste into ChatGPT and back, no manual prompts each time. Works offline-as-much-as-possible: one HTTPS request to OpenRouter (dozens of models via a single account — GPT-4o, Claude, Gemini, Llama, etc.), everything else local. Native .NET 8 / WPF, no Electron. Sits in the system tray and wakes up only on your hotkey.

Download

Get the latest release from GitHub Releases — file CapyBro-Setup-2.0.0.exe (~48 MB). Or visit capybro.app — the link is always fresh.

Run the installer

Launch the installer → 3-click wizard → done. The icon appears in the system tray near the clock. The installer is per-user — no admin rights required, installs into %LOCALAPPDATA%\CapyBro\.

Install via winget

Have Windows Package Manager (winget — built into Windows 11 and recent Windows 10)? This is the fastest path: one command in PowerShell or Terminal downloads and installs CapyBro from the official manifest.

Update any time with winget upgrade RomanTykhonenko.CapyBro, or remove it with winget uninstall RomanTykhonenko.CapyBro.

The first run starts a 4-step onboarding wizard:

1. Welcome + UI language — quick intro and a language picker (English / Українська / Русский). Switching here re-renders the whole wizard instantly so you can read the next steps in your language.
2. OpenRouter API key — paste a key from openrouter.ai/keys. The wizard pings /credits 400 ms after your last keystroke and shows a green checkmark or an error. No key handy? Skip — you can switch to Ollama in Settings → Provider later.
3. Hotkeys — three combinations at once: improvement (Ctrl+Shift+E), prompt menu (Ctrl+Shift+Q), undo (Ctrl+Shift+Z). Conflicts with already-registered system hotkeys are flagged on the spot.
4. Done — select text in any program, press the hotkey, watch the magic happen.

After onboarding: tray icon → Settings → Prompts tab. Create a few prompts for your scenarios: «Fix grammar», «Translate to English», «Make more formal», «Shorten to 100 words», «Explain simpler», etc.

System tray

After launch, a capybara icon lives in the system tray near the clock. Hover for the tooltip — CapyBro if you're on OpenRouter (default) or CapyBro · Ollama if the local provider is active. The app has no main window between hotkey runs; everything is reached through the tray.

• Left-click on the icon → opens the Settings window.
• Right-click on the icon → context menu with three items: Settings, History, Quit. «Quit» triggers a graceful shutdown — pending writes flush, in-flight HTTP requests cancel cleanly.

Settings window — four sidebar tabs

• General — provider, API key, default model, hotkeys, autostart, Pro license, experimental flags, Danger zone (Reset).
• Prompts — manage your prompt library and pick the default one. Pro users also get the Prompt Packs browser here.
• History — the last 50 improvements (visible when the History toggle is on — it is by default). Search, copy back the original or the improved text, delete individual entries, or clear everything.
• Statistics — Pro feature, visible to everyone but locked for free tier with a teaser panel. Headline numbers, by-model breakdown, 30-day activity chart, Reset.

The sidebar footer shows the version + capybro.app link, and (if you're on Ollama) a small outlined «Ollama» pill so you always know which backend is active.

All hotkeys are registered via Win32 RegisterHotKey with MOD_NOREPEAT, so they work globally over any application. Conflicts with system / other utilities are detected immediately: the onboarding wizard and Settings → General highlight conflicting hotkeys in red.

Create / edit your own scenarios: fix errors, translate, shorten, more formal, friendlier, technical style, marketing tone, etc. Each prompt can have:

• Its own model (overrides the default for this prompt only — toggle «Per-prompt model» in Additional features first).
• Per-provider model — if you keep both OpenRouter and Ollama configured, the prompt remembers a different model for each.
• Diff preview before applying (on by default — toggle off per-prompt or globally if you prefer instant paste).

Prompt menu (Ctrl+Shift+Q)

Toast with a list of your prompts. Arrows + Enter to select, Esc to cancel, digits 1-9 for quick access. The popover closes automatically when you click into another process (foreground-window polling).

Prompt packs (Pro)

Prompts tab → top-right button Prompt packs. Browse 5 curated packs — Legal / Marketing / Academic / Code review / Business — ~10 prompts each (~50 total). Click Install to copy the pack's prompts into your library; name clashes get a 2 / 3 suffix so nothing in your existing set is overwritten. An «Installed» badge marks packs you already added.

CapyBro v2.0 supports two backends — switched with a single checkbox in Settings → Provider:

• OpenRouter (cloud, default) — fast, wide model selection (GPT-4o, Claude, Gemini, Llama, etc.), pay-as-you-go. Requires an API key from openrouter.ai/keys.
• Ollama (local) — for those who categorically don't want to send text to the cloud. Run ollama, pull any model (ollama pull gemma3), click «Refresh models» — the whole pipeline works offline.

How to switch to Ollama

1. Install Ollama and run ollama serve (usually auto-starts after install).
2. In a terminal: ollama pull gemma3 (or any other model from the library).
3. Settings → Provider → ✓ «Use local model (Ollama)». CapyBro runs a health check — if ollama serve isn't running, a warning toast appears and the checkbox reverts to OpenRouter.
4. Settings → Local models (Ollama) → click the refresh button. The list of pulled tags appears. Pick one.
5. Done — Ctrl+Shift+E works as always, but through the local backend.

History tab

Enabled by default. Stores the original / improved / prompt / model / time of the last 50 runs. The History tab has a search box (150 ms debounce), entries grouped into Today / Yesterday / This week / Older, and a detail viewer with copy-icon buttons for the original and the improved text. Delete an individual entry from the detail header, or wipe everything with the «Clear all» button.

Disabled in Settings → Additional features → uncheck «History». File: ~/.ai_text_improver_v2_history.json.

History export (Pro)

Top of the History tab — button Export. Pick CSV (spreadsheet-friendly: Timestamp, Original, Improved, Prompt, Model, HotkeyKind) or JSON (full structure). Useful for archiving, sharing with a team, or analysing your editing patterns externally.

Diff preview

Side-by-side comparison of original + AI result with change highlighting before anything touches your document. Three actions: Accept (paste), Regenerate (re-roll the same prompt), Reject (cancel and restore clipboard). Useful for long texts where you can't tell at a glance what changed.

On by default for every prompt — built-in and custom. Disable per-prompt via the checkbox in the Prompts editor, or globally via the master toggle in Settings → Additional features.

Edit result (top-right toggle): swap the right pane between read-only diff and an editable text box. Tweak the AI output by hand, then Accept ships your edited version (not the raw AI output) into the document.

Streaming toast

Streaming display of generation — you see the AI type. Doesn't block your work; you can keep doing whatever you want while the AI generates. The ✕ button cancels the request instantly. Toggle in Settings → Additional features.

Pro is a one-time payment ($9 via Gumroad). It unlocks five features on top of the free version. Every one of them is visible to free-tier users — with a small outlined «Pro» pill — so you can see exactly what you'd be unlocking. Clicking a locked action shows a toast pointing you to the purchase page.

1. History export to CSV / JSON

Already covered above. One-click export of all 50 history entries to a spreadsheet-friendly CSV or a full-fidelity JSON.

2. Settings backup & restore

Settings → General → Backup card. Save the whole config — prompts, models, hotkeys, language, feature flags — to a portable JSON file you can carry to another machine or stash as a snapshot before experimenting. Important: backups do not carry your API key or Pro license (for safety and portability — those are per-machine). Restore preserves the current machine's license token, so the backup itself stays portable.

3. Switch-model hotkey

Settings → General → Model switching card. Pin 2–3 models in slots, then press Ctrl+Shift+M (rebindable) anywhere to cycle through them. Provider-scoped: OpenRouter has its own set of pinned models, Ollama has its own — flipping providers preserves both. Works mid-run — the hotkey bypasses the single-in-flight guard, so if a model is being slow you can retry with another instantly.

4. Premium prompt packs

Five curated packs of ~10 prompts each (~50 total): Legal, Marketing, Academic, Code review, Business correspondence. Each prompt is trilingual (English / Українська / Русский). Browse and install from Prompts tab → top-right Prompt packs button. Installation merges into your existing prompts list — name conflicts get a 2 / 3 suffix so your custom set is never overwritten.

5. Usage statistics

A fourth tab in Settings. Three cards: Overview (total improvements, total characters, total spent, active-since date), By model (per-model run counts + spend), 30-day activity (a daily bar chart). Stats are recorded unconditionally for every successful improvement — they're counts only, no text — so you have data even if the History toggle is off. File: ~/.ai_text_improver_v2_stats.json. Reset with the button in the Overview card.

How to activate

1. Buy the key on Gumroad — see the pricing section on capybro.app.
2. Gumroad emails you a license key after purchase.
3. Settings → General → Pro License card → paste the key into the only input field → Activate. You don't need to type your email anywhere — the buyer email comes back from Gumroad automatically and shows up under the «Pro activated» status.
4. If the key checks out, the badge «✓ Pro activated» appears immediately, the «Supporter» badge lights up in the window title bar, and all five Pro features unlock.

CapyBro collects ZERO telemetry by default — no analytics, crash reporting, or surveys. All network requests are only your requests to OpenRouter (one HTTPS call per hotkey). Nothing else goes anywhere.

PII redaction (experimental)

Settings → Additional features → PII masking automatically replaces before sending to the model: emails → <<EMAIL_n>>, phones → <<PHONE_n>>, URLs → <<URL_n>>, credit cards → <<CARD_n>>, IBAN → <<IBAN_n>>, full names (heuristic) → <<NAME_n>>. The original values are substituted back after the AI response — the model never sees your real PII.

CapyBro has three independent stores — settings, history, and statistics. Each one has its own one-click reset button inside the app. You don't have to delete files manually.

Reset settings (most common)

Settings → General → scroll to the bottom → Danger zone → Reset settings. A confirmation dialog appears. On YES, three things happen at once:

• The config file is overwritten with defaults — prompts, hotkeys, language, model lists, experimental flags all reset.
• Your OpenRouter API key is removed from Windows Credential Manager.
• Your Pro license (if any) is deactivated — the «Supporter» badge disappears, Pro-only features re-lock.

Clear history

Settings → History → Clear all. Wipes the 50-entry history JSON. Confirmation dialog before the action.

Reset statistics

Settings → Statistics → Reset statistics (top of the Overview card). Zeroes all counters and bucketed data. Pro-only — the tab is visible to everyone but the reset action requires an active license.

Disable autostart

Settings → General → System → uncheck «Run with Windows». Removes the HKCU\Software\Microsoft\Windows\CurrentVersion\Run\CapyBroV2 registry entry. The checkbox state is part of the config — so a Reset will leave the autostart entry alone if you'd previously enabled it.

See the onboarding wizard again

Reset does not bring back the onboarding wizard — the «onboarding completed» flag is part of the default config it writes. If you really want a fresh first-run experience, close the app (tray → Quit), open ~/.ai_text_improver_v2_config.json in a text editor, find "OnboardingCompleted": true and set it to false. Relaunch — the wizard appears again.

The hotkey doesn't react

1. Check whether this hotkey is taken by another utility (e.g., Snipping Tool Ctrl+Shift+S conflicts).
2. Settings → General → «Hotkeys» block. Conflicts are highlighted in red with a hint.
3. Change to something unique like Ctrl+Alt+Shift+E.

AI returns a translation instead of a fix (or vice versa)

Open the prompt in Settings → Prompts and rewrite it more explicitly («Fix grammar in the same language without translating»). The model follows what your prompt says — if it's ambiguous, the model picks for you.

Toast disappeared but new text didn't appear

• Check that the target program has focus on a text field. CapyBro pastes via clipboard + Ctrl+V — the field must accept paste.
• Some sandboxed apps (UWP / WSA) block keyboard automation. The result is still on your clipboard — paste with Ctrl+V manually.

How to undo a bad improvement

Press Ctrl+Shift+Z right after the unwanted result. CapyBro restores the original text from its in-memory cache (or the history file if you'd left history on). Works once — for older improvements, use the History tab and click the copy-original icon on the entry you want.

«Unknown publisher» warning on install

The installer is currently unsigned (SmartScreen accumulation period). Safe — click «More info» → «Run anyway». Or wait until the installer is signed with a certificate.

Settings window doesn't open

• The tray icon should be alive (not Windows-grey). If grey — the app crashed. Restart from the Start menu.
• Log: %USERPROFILE%\.ai_text_improver_v2*.log — the stack trace will be there.

Does it work on Windows 10?

Yes, minimum requirement — Windows 10 1809 (for WPF / DPI awareness). Most features gracefully degrade on older builds (Mica → solid background).

Does it work on macOS / Linux?

No. Depends on Win32 API (RegisterHotKey, SendInput, Credential Manager, NotifyIcon). A port is possible via another stack (Avalonia + alternative tray + keyring), but it's a from-scratch rewrite.

Wondering how CapyBro stacks up against other AI text tools? Side-by-side comparisons with feature tables and migration guides:

• CapyBro vs Grammarly — free, open-source alternative that works in any Windows app, not just browser and MS Office.
• CapyBro vs ChatGPT Desktop — same models (GPT, Claude, Gemini, via OpenRouter), but available on a global hotkey instead of a single chat window.
• CapyBro vs Slashit App — open-source alternative to the AppSumo lifetime deal, with local Ollama mode for privacy.

• Project: capybro.app · GitHub repo · Releases
• API provider: OpenRouter · API docs
• Local LLM: Ollama · Model library