POSTERN·STORE
Postern Labs · the parameterized storefront

Say what you need. The store parameterizes.

Describe a need by voice or text — a concierge turns it into a structured query over the Postern catalog. Or set the filters by hand: all three paths run the same local, deterministic search.

MIC LIVE

● catalog local · search local · no account · no telemetry concierge:
interpreted as no filters yet — everything is listed
Security features (require all checked)

Manual filters never touch the network — this panel, the chips above and the concierge all drive the same local, deterministic search.

concierge

Catalog

compare

App

Compare

Settings

Only needed for the natural-language concierge. Stored only in this browser’s localStorage and sent only to api.anthropic.com — the Store has no server that could ever see it. Without a key, plain keyword search and manual filters work fully offline.

Key at rest (optional lock)

Locking seals the key with AES-256-GCM under a key derived from your passphrase (PBKDF2-SHA-256, 310,000 it. — the same construction as Chiave, our sign-in reference). localStorage then holds only ciphertext; you unlock once per session, and forgetting the passphrase means re-entering the key. Without a lock, the key sits readable in this browser’s localStorage — any code or person with access to this browser profile can read it.

Billed to your own Anthropic account at your account’s rates.

Speech-to-text engine
Erase everything

Wipes your API key and all settings from the browser. The Store never records what you searched or compared — there is nothing else to erase, and no server copy.

Privacy — who sees what

The Postern Store is a static page. There is no store server, no account, no telemetry, and no analytics — it does not track what you search, view, or “install”. The entire catalog ships inside this file; searching and comparing run locally. The honest ledger:

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The catalog, the search, the filters — this page only

All app data is embedded in this HTML file. Filtering, ranking, comparing, and plain keyword search are deterministic local code — a search sends nothing about your query anywhere unless you ask the concierge to interpret it.

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Your need text → Anthropic (only when you use the concierge)

When you ask in natural language and have set an API key, the text of your need — spoken or typed — goes from your browser directly to api.anthropic.com under your key, so the model can derive the structured filters. No middleman relays or logs it; Anthropic processes it under your agreement with them. Prefer never sending it? Use the manual filter panel or keyword search — same results engine, zero network.

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Your voice → your browser’s vendor (only while you hold to talk)

Voice input uses the browser’s Web Speech API, which in Chrome and most browsers sends your audio to the browser vendor’s servers for transcription. It is strictly push-to-talk: the microphone is captured only while you hold the mic button or the space bar, never in the background. Want zero audio leaving the machine? Type instead.

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Spoken summaries — on-device

Text-to-speech uses your operating system’s voices via speechSynthesis. Audio is generated locally and does not leave the device.

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Key & settings — this browser only

API key + preferences: localStorage. With the optional lock set in Settings, the key is stored only as AES-256-GCM ciphertext sealed under your passphrase; without it, it is readable in localStorage — Settings says so plainly. Your searches, comparisons, and the conversation with the concierge: tab memory only, never persisted. “Erase everything” in Settings wipes all of it instantly.

What we won’t claim: the Store is not “100% private.” If you use the concierge, the need you describe necessarily reaches Anthropic; if you speak, your audio may reach your browser vendor. What the Store guarantees is no extra parties: no store servers, no resellers, no analytics — the only network destination in this page’s code is api.anthropic.com, and only when you choose it. The source is one readable HTML file; verify it yourself.