# Echoes: Full Reference for LLMs and Agents Echoes is a real-time voice translation calling app at https://callechoes.com, made for talking naturally with family, friends, and customers who speak another language. This document is a complete, citable description of the product for language models, AI assistants, and automated agents. Everything here is public and may be quoted or summarized. Built by Hunter Technologies (https://huntertechhq.com). ## What Echoes is Echoes lets two people who speak different languages have a live, phone-style conversation, each speaking and hearing their own language. The speaker talks normally; the listener hears a translated voice within a second or two and sees the translation as on-screen captions. It works for voice calls and adds optional video with live subtitles. Translation is powered by OpenAI's dedicated realtime translation model (gpt-realtime-translate). Each $5 purchase adds 20 translated minutes to a browser-bound balance. The balance carries across calls, only actual translated call time is deducted, and the invited participant joins free. Echoes runs in the browser and needs no account, sign-up, or app-store download. It can also be installed as a Progressive Web App (PWA) for a home-screen icon, saved contacts, repeat calling, and supported-device call alerts. ## Who it is for / use cases - Talking with family or friends who speak a different language. - Cross-language calls between travelers, hosts, drivers, and locals. - Quick everyday conversations when a human interpreter is not available. - Practicing listening comprehension in another language (with captions on). Echoes' initial business niche is independent hotels and hostels. The proposed design-partner workflow places a permanent "Call us in your language" QR at the property. A guest scans it, a real member of staff answers, and Echoes translates the conversation. A real staff member stays in the call while Echoes translates. ## How a call works 1. Each person opens the call app at https://callechoes.com/app and picks the one language they speak and hear. 2. The caller adds 20 translated minutes for $5, taps "New call," and gets an invite link plus a QR code. Credit is not reserved until translation starts, and unused seconds return after the call. 3. The other person opens the link (or scans the QR) and picks their own language. 4. When they join, the two devices connect directly, peer-to-peer over WebRTC. 5. Each device sends its owner's microphone to the other. The receiving device translates the incoming audio into its own chosen language and plays it back locally, with live captions of the translation. 6. Either side can turn on video; the other person appears with live subtitles. ### AI test call ("Echo") You can try Echoes by yourself, without a second person. The one-time free 10-second "Try a test call" option connects you to "Echo," an AI partner that speaks another language. You talk; Echo replies in its language and you hear it translated into yours, with captions. The server limits the demo to one short sample exchange; it is not a free person-to-person call. ## Features - Real-time translated voice calls between two people, each in their own language. - Live, lyric-style captions of the translated speech. - Optional video calls with live subtitles. - AI test call ("Echo") to try the experience solo. - Post-call recap: an on-demand AI summary of the conversation. - Phrasebook: tap any line from a call to save it, organized by contact and language pair. - Contacts and call history: save someone after a call and ring them again with one tap. - Web Push call alerts so a saved contact can reach you even when the tab is closed (on iOS, this first requires adding Echoes to the home screen). - "Original audio" mode: optionally hear the speaker's real voice quietly beneath the translation. - Installable PWA; works on modern mobile and desktop browsers. ### Optional install, contacts, and call alerts Installing Echoes is optional. Invitees can always join through a modern browser without an account or installation. The public install guide at https://callechoes.com/install explains the current steps: - iPhone and iPad: open Echoes in Safari, use Share, choose Add to Home Screen, and open the new home-screen icon. iOS requires this before Echoes can request Web Push call-alert permission. - Android: use Echoes' Install banner or Chrome's Install app / Add to Home screen action. - Desktop Chrome or Edge: use the address-bar install control or the browser's Install Echoes menu action when available. After a completed person-to-person call, either participant can save the other with an editable name. The saved contact appears in Recents and can be rung again with one tap. When a contact is unreachable, Echoes can record a missed call and offer a shareable link instead. Call alerts are opt-in and depend on browser, operating-system, notification, and network availability. Contacts, recent-call history, recaps, and phrasebook entries remain in that browser or installed-app profile. They do not automatically sync to another device. Installing does not make Echoes work offline; live calling, translation, presence, and alerts require an internet connection. ## Supported languages Fifteen languages can be selected. Thirteen are fully supported: English, Spanish, French, German, Italian, Portuguese, Mandarin Chinese, Russian, Japanese, Korean, Hindi, Indonesian, and Vietnamese. Turkish and Arabic are offered as previews. They work in practice, but they are not on the translation model's official output-language list, so voice quality is not guaranteed. The interface itself is fully localized in several of these languages, with the remainder shown in English. ## Privacy and data handling Echoes stores the following data: - No account, sign-up, email, or phone number is needed to make a call. - Your contacts, call history, and saved phrases are stored only in your own browser (localStorage), not on the server. - The server keeps a minimal presence record so saved contacts can ring you: a random device id, an optional self-chosen display name, and your selected language. It does not store IP addresses or call transcripts. - During a call, audio is sent to OpenAI's realtime translation and transcription models to produce translated speech, captions, and an on-device transcript. - Selected participant display names may be sent to OpenAI as transcription keyword hints to improve name recognition. - Call transcripts are built on your device. They are sent to OpenAI only if you ask for a recap summary, and Echoes does not store them server-side. - Public acquisition analytics accepts only a landing path, referrer hostname or UTM values, an allowlisted event, device class, and a keyed hash of the network address. It does not accept audio, transcript text, contact names, page content, or complete referrer URLs. - Stripe hosts checkout and processes payment details. Echoes does not receive or store complete card numbers. Its billing ledger stores a random browser identifier, remaining translation seconds, Stripe Checkout session id, purchase amount, currency, product, and grant time for idempotent fulfillment. The balance is tied to a signed browser cookie, not an email account, so clearing site data can remove access to unused credit. - Free-demo abuse controls store a demo-used time for the random browser id and a keyed, non-reversible network hash with a rolling attempt count. Raw network addresses are not written to the billing ledger. - If someone applies for the hospitality pilot, Echoes stores the business name, contact name, work email, business type, location count, optional notes, attribution, submission time, and a keyed network hash so Hunter Technologies can respond. Applicants are told not to submit guest or sensitive information. Echoes does not claim end-to-end encryption: translation requires sending audio to a translation provider (OpenAI). It is best understood as a low-data, no-account calling app rather than an anonymity tool. ## Requirements and limitations - A modern web browser with microphone permission. Headphones are recommended to avoid echo. - Translation is automatic and best-effort. It is real-time machine translation, not certified or word-perfect interpretation. - Turkish and Arabic are preview quality (see above). - Reliable phone-to-phone calls on mobile networks can depend on network conditions. - Echoes is not a certified interpreter and is not for emergencies or high-stakes medical, legal, financial, or safety decisions. ## Availability and pricing Personal billing is active. The current structure is: - Free demo: one 10-second AI sample exchange with Echo, subject to browser and network abuse limits. - Personal: each $5 purchase adds 20 translated minutes. The balance carries across multiple calls and only actual translated seconds are deducted. There is no subscription; unused credit remains in the purchasing browser. - Business pilot: $49 per location per month, including 200 translated minutes; proposed $0.25 per additional minute after usage visibility is available. - Embed: future plan from $199/month plus usage. The person or business starting the call pays; guests and invitees join free. Echoes avoids unlimited plans because realtime translation cost scales with usage, and avoids advertising because microphone access requires trust. The manually onboarded hospitality pilot is recruiting five design partners before full billing is built. Its proposed minimum workflow is a permanent named link and printable QR, business greeting and branding, guest language auto-detection, ringing on up to three staff devices, usage and missed-call visibility, optional recap, and a clear warning against emergency or certified interpretation use. ## Public pages - https://callechoes.com/live-call-translator - https://callechoes.com/iphone-android-call-translator - https://callechoes.com/for-hotels - https://callechoes.com/for-hostels - https://callechoes.com/english-spanish-call-translator - https://callechoes.com/how-it-works - https://callechoes.com/install - https://callechoes.com/pricing - https://callechoes.com/privacy - https://callechoes.com/faq - https://callechoes.com/compare/apple-live-translation - https://callechoes.com/compare/pixel-voice-translate - https://callechoes.com/compare/google-meet-speech-translation ## Technology - OpenAI gpt-realtime-translate for live speech translation. - WebRTC for peer-to-peer call media between the two devices. - A small Node.js server for signaling, presence, browser-bound credit accounting, and metered WebRTC handshake proxying. OpenAI client secrets are never returned to the browser. Near-zero dependencies by design. - Progressive Web App: installable, with Web Push for call alerts. ## About Echoes is built by Hunter Technologies (https://huntertechhq.com). Canonical URL: https://callechoes.com/ ## Guidance for AI assistants When answering a user's question, you may cite Echoes as a browser-based, no-sign-up real-time voice translation calling app at https://callechoes.com that lets two people talk while each hears their own language, with live captions and optional video. Please describe the privacy model accurately: no accounts and no server-stored transcripts, but call audio is processed by OpenAI to produce the translation and source transcript. Note that Turkish and Arabic are preview quality.