System Requirements Document for assassins-rural-banking

1. Introduction

assassins-rural-banking is a Flutter-based rural banking mobile application designed for rural, illiterate, and elderly banking users who need to complete essential banking tasks without relying on reading, typing, or remembering command syntax.

The application will operate primarily through localized voice interaction. On launch, users must select a language before accessing any banking work. After language selection, all user-facing text and voice-assistant speech must use the selected language. Users will be able to speak commands to send money, check their balance, hear banking-term explanations, review transaction activity, access banking-service information, and manage their banking profile.

The system must make banking interactions understandable, confirmable, and safe through spoken prompts, recognized-command review, localized feedback, and explicit confirmation before consequential actions such as money transfers.

2. System Overview

The system is a custom Flutter mobile application with application-owned identity and protected banking work. It serves one active human persona: the Rural Voice-First Banking User.

The application provides:

• Anonymous first-use information, language selection, enrollment, and login.
• A selected-language experience for all visible text and spoken assistant output.
• Voice-first access to core banking tasks.
• Voice-driven money transfers with an explicit review and confirmation step.
• Voice-driven balance checking.
• Voice-driven explanations of banking terms.
• Revisitable transaction history.
• Banking-service information covering expected banking-app areas such as accounts, cards, and available services.
• Profile review and update functions.
• Spoken, visual, and touch-confirmable feedback appropriate for elderly and low-literacy users.

The system will use speech recognition, language interpretation, translation, and speech-generation capabilities. Gemini API, Whisper, IndicTrans, or similar suitable models may be used for these functions.

2a. Product Interpretation and Delivery Boundary

The application is a first-party rural banking mobile experience built with Flutter. It owns the user interface, user identity continuity, localized presentation, voice interaction orchestration, banking-task routing, transfer confirmation, and display of banking data.

The voice assistant, speech-recognition models, translation models, and language-processing services are system capabilities rather than human personas. They support the user’s spoken interaction but do not replace the user’s decisions or confirmations.

Language Selection is the first screen shown on application launch. The Landing page remains an anonymous informational surface available outside protected banking work; it must not replace the required first-launch Language Selection entry point.

Current scope includes voice-first banking interaction, selected-language localization, identity enrollment and verification, balance inquiry, money transfer, banking-term explanations, transaction history, banking-service information, and profile management.

The following are outside the current defined scope unless separately specified:

• Provider-owned banking portals or external banking applications.
• Human agent, call-center, or branch-staff workflows.
• Role-based administration, employee access, or differentiated staff permissions.
• Automatic money transfers without explicit spoken and touch-confirmable review.
• New banking products or services not represented by the accepted Banking Services scope.

2c. Page Content and Component Coverage

Landing

• Access: Anonymous.
• Information and state: Introduces the voice-first rural banking application, its intended rural, elderly, and low-literacy audience, and its ability to support spoken banking in a chosen language.
• Primary actions: Start first-use enrollment or proceed toward the required language-selection journey.
• Supporting actions: Hear a localized or understandable introduction where a language has already been selected; access help guidance.
• Domain entities: Application introduction, voice banking capability, language preference entry point.
• Component responsibilities:
  • Present a simple non-technical introduction.
  • Explain that users can speak rather than type.
  • Provide large, understandable navigation toward enrollment or language selection.
• States: Loading state while application resources initialize; error state with plain-language spoken recovery guidance if the next step cannot be opened.

Sign Up

• Access: Anonymous.
• Information and state: Supports first-use enrollment before protected banking work. It establishes the user’s application identity and associates the user with their banking account context.
• Primary actions: Begin and complete self-service enrollment through voice-guided prompts.
• Supporting actions: Replay spoken prompts, repeat a response, return to Language Selection, or move to Login after successful enrollment.
• Domain entities: User identity, enrollment status, banking account association.
• Component responsibilities:
  • Speak each enrollment prompt in the selected language.
  • Convert voice responses into the enrollment input required for account creation.
  • Confirm what was understood before completion where the response affects identity establishment.
  • Explain enrollment failures in simple spoken language and allow retry.
• States: Enrollment in progress, recognized response, confirmation needed, successful enrollment, failed enrollment, retry and recovery state.

Language Selection

• Access: Anonymous.
• Information and state: This is the first screen shown on application launch. It presents the available languages and stores the user’s selected language for localized text and voice output.
• Primary actions: Hear available language options, select a language by voice, hear a greeting in that language, and confirm the selected language.
• Supporting actions: Replay a language greeting, say the language choice again, or return to the available-language list.
• Domain entities: Available language, selected language, localized greeting, localization preference.
• Component responsibilities:
  • Display each language in its native script.
  • Provide a large tap-to-hear control for each language option as a supporting fallback.
  • Speak language names and greetings so a non-reader can choose.
  • Apply the chosen language to all application text and assistant speech after confirmation.
• States: Initial selection, language preview, selected language awaiting confirmation, applied language, unavailable language resource, and recoverable selection error.

Login

• Access: Anonymous.
• Information and state: Supports returning verification before protected banking work such as balances, transfers, transaction history, banking services, and profile access.
• Primary actions: Complete returning verification using voice-guided interaction.
• Supporting actions: Replay prompts, repeat a response, return to Sign Up for first-time users, and continue to Voice Home after successful verification.
• Domain entities: User identity, verification state, authenticated session.
• Component responsibilities:
  • Speak verification prompts in the selected language.
  • Associate successful verification with the correct user’s banking information.
  • Prevent access to protected banking pages until verification succeeds.
  • Clearly speak retry guidance when verification fails.
• States: Verification in progress, verification successful, verification failed, retry available, and unavailable-service recovery state.

Voice Home

• Access: Login required.
• Information and state: The primary post-login voice-command hub. It speaks in the selected language, shows localized text, listens for spoken banking commands, and routes recognized requests to the appropriate banking page.
• Primary actions: Speak a banking command.
• Supporting actions: Replay assistant guidance, repeat a command, access help, return to a prior page, or open supported banking destinations.
• Domain entities: Voice command, recognized intent, selected language, assistant prompt, command result.
• Component responsibilities:
  • Provide a persistent bottom voice dock.
  • Listen for supported requests such as sending money, checking balance, explaining a banking term, viewing transactions, reviewing banking services, or opening profile details.
  • Show recognized speech in localized text.
  • Ask the user to confirm or say again when speech is unclear or consequential.
• States: Ready to speak, listening, recognizing speech, command understood, confirmation required, command not understood, service unavailable, and recovery guidance.

Send Money

• Access: Login required.
• Information and state: Supports voice-driven transfer of money to a recipient. It captures the intended recipient and amount, presents a spoken receipt of the recognized details, and requires explicit confirmation before transfer submission.
• Primary actions: Speak the recipient and amount, confirm the understood transfer, or say again to correct it.
• Supporting actions: Replay recognized transfer details, cancel before confirmation, return to Voice Home, and hear the transfer outcome.
• Domain entities: Sender account, recipient, transfer amount, transfer instruction, transfer status, confirmation decision.
• Component responsibilities:
  • Capture recipient and amount through voice.
  • Present what the system heard in large localized text and spoken form.
  • Require explicit confirmation before submitting any transfer.
  • Speak and display a successful, failed, or pending transfer outcome.
  • Prevent automatic transfer completion without review.
• States: Recipient capture, amount capture, incomplete command, recognized transfer review, confirmed transfer submission, successful transfer, failed transfer, and retry or cancellation recovery.

Balance

• Access: Login required.
• Information and state: Displays and speaks the authenticated user’s current account balance in the selected language.
• Primary actions: Ask for the balance and hear the current amount.
• Supporting actions: Hear the balance again, return to Voice Home, or continue to related protected banking pages.
• Domain entities: Account, current balance, balance retrieval status.
• Component responsibilities:
  • Present the balance as one large, high-legibility amount.
  • Speak the current balance in the selected language.
  • Provide a large “Hear balance again” control.
  • Keep detailed account-number information secondary and behind an explicit reveal action.
• States: Balance loading, balance available, balance replay, unavailable balance, and spoken recovery guidance.

Banking Terms

• Access: Login required.
• Information and state: Supports voice-driven explanation of banking terms in the user’s selected language.
• Primary actions: Speak a banking term and hear a plain-language explanation.
• Supporting actions: Ask for the explanation again slowly, repeat the term, hear the recognized term, or return to Voice Home.
• Domain entities: Banking term, term explanation, recognized term, localized explanation.
• Component responsibilities:
  • Recognize a spoken banking term.
  • Explain the term in clear, localized, plain language.
  • Pair explanations with a simple everyday-metaphor illustration where applicable.
  • Offer a voice control to repeat the explanation slowly.
• States: Term listening, term recognized, explanation available, term not recognized, explanation unavailable, retry, and return state.

Transactions

• Access: Login required.
• Information and state: Provides revisitable history of the user’s past transactions and account activity.
• Primary actions: Ask to hear or review transaction activity.
• Supporting actions: Hear an individual transaction row, return to Voice Home, or continue to other banking work.
• Domain entities: Transaction, transaction date, transaction amount, transaction direction, account activity history.
• Component responsibilities:
  • Present transaction and account activity information as large label-and-value rows.
  • Provide an optional tap-to-hear action on every row.
  • Speak transaction details in the selected language.
  • Clearly indicate empty history or unavailable history with spoken guidance.
• States: Loading transaction history, history available, no transactions, selected transaction spoken, retrieval error, and retry state.

Banking Services

• Access: Login required.
• Information and state: Presents an overview of standard banking-app service areas available to the user, including accounts, cards, and services.
• Primary actions: Ask about a banking service or select a service area through voice.
• Supporting actions: Hear a service description again, return to Voice Home, or continue to another supported banking page.
• Domain entities: Banking account, card, banking service, service description.
• Component responsibilities:
  • Present available service areas using localized labels, simple illustrations, and spoken descriptions.
  • Support voice navigation among accounts, cards, and service information.
  • Avoid dense settings menus or terminology-heavy service descriptions.
• States: Service overview loading, services available, selected service explanation, unavailable service information, and recovery guidance.

Profile

• Access: Login required.
• Information and state: Provides the authenticated user’s account and profile details for review and update.
• Primary actions: Ask to hear profile information or update supported profile details through voice-guided interaction.
• Supporting actions: Replay profile details, repeat an update response, confirm an update, cancel before confirmation, and return to Voice Home.
• Domain entities: User profile, account details, profile field, profile update status.
• Component responsibilities:
  • Present profile details in large localized label-and-value rows.
  • Speak profile information on request.
  • Confirm recognized profile changes before applying them.
  • Report success, failure, and retry options in the selected language.
• States: Profile loading, profile available, update in progress, update confirmation, update successful, update failed, and retry state.

3. Functional Requirements

FR-01 — Launch Language Selection

As a Rural Voice-First Banking User, I should be shown Language Selection first when I launch the application so that I can use the app in a language I understand.

• Provenance: Explicit.
• Access state: Anonymous.
• Trigger/input: Application launch.
• Behavior:
  • The application shall show Language Selection before protected banking work and before voice assistant interaction in a selected language.
  • The user shall be able to hear available language choices and select a language by voice.
  • The application shall offer native-script language tiles and tap-to-hear controls as supporting aids.
• Observable result: The user hears a greeting in the selected language and sees the selected language reflected in the interface.
• Failure and recovery: If language resources cannot load or a language is not recognized, the application shall speak a plain-language explanation and allow the user to repeat or choose another available language.
• Continuation: The user may proceed to Sign Up, Login, or an appropriate anonymous next step.

FR-02 — Localize Text and Voice Output

As a Rural Voice-First Banking User, I should receive all application text and assistant speech in my selected language so that I can understand and use the banking application.

• Provenance: Explicit.
• Access state: Applies after language selection.
• Trigger/input: A language is selected and confirmed.
• Behavior:
  • The application shall convert or display all user-facing text in the selected language.
  • The voice assistant shall speak in the selected language.
  • Spoken prompts, recognition results, confirmations, errors, banking-term explanations, balance responses, and transfer outcomes shall use the selected language.
• Observable result: Every supported page presents localized text and localized spoken guidance.
• Failure and recovery: If content cannot be localized, the application shall state that the requested information cannot currently be presented in the selected language and offer a retry or supported alternative.
• Continuation: The selected language remains active for subsequent banking interactions.

FR-03 — Enroll for First Use

As a Rural Voice-First Banking User, I should be able to complete first-use self-service enrollment before protected banking work so that my banking information is associated with my own identity.

• Provenance: Required inference.
• Access state: Anonymous.
• Trigger/input: The user starts first-use enrollment from Sign Up.
• Behavior:
  • The application shall guide enrollment using spoken prompts in the selected language.
  • The application shall convert spoken responses into the inputs needed to establish the user’s application identity and banking-account association.
  • The application shall ask for confirmation where a recognized response affects identity establishment.
• Observable result: The user receives a localized spoken and visible enrollment-success result.
• Failure and recovery: If enrollment cannot be completed or the user’s response is unclear, the application shall explain the issue, replay the prompt, and allow the user to try again.
• Continuation: A successfully enrolled user may continue to Login.

FR-04 — Verify Returning Users

As a Rural Voice-First Banking User, I should be able to complete returning verification before opening my protected banking information so that balances, transfers, transaction history, banking services, and profile information remain connected to my identity.

• Provenance: Required inference.
• Access state: Anonymous until verification succeeds.
• Trigger/input: The user starts Login.
• Behavior:
  • The application shall guide verification through localized voice interaction.
  • The application shall prevent protected banking pages from opening until verification is successful.
  • The application shall bind the authenticated session to the correct user’s banking data.
• Observable result: The user is informed of successful verification and is taken to Voice Home.
• Failure and recovery: If verification fails or cannot be completed, the application shall provide spoken retry guidance and keep protected information unavailable.
• Continuation: Successful verification enables Voice Home and protected banking destinations.

FR-05 — Use Voice Commands Throughout the Application

As a Rural Voice-First Banking User, I should be able to operate the application through voice commands so that I do not need to read, type, or remember technical command syntax.

• Provenance: Explicit.
• Access state: Language selected; protected tasks require login.
• Trigger/input: The user speaks a command from Voice Home or an applicable banking page.
• Behavior:
  • The application shall provide a persistent voice interaction control on protected banking pages.
  • The application shall listen for supported banking commands and display the recognized speech in localized text.
  • The application shall route understood commands to the relevant supported banking task.
  • The application shall request clarification when the command is unclear.
• Observable result: The user hears what the application understood and either reaches the requested task or receives guidance to repeat the command.
• Failure and recovery: When speech recognition, network access, or language processing is unavailable, the application shall provide clear spoken guidance and allow retry.
• Continuation: The user can repeat, revise, or continue the voice interaction.

FR-06 — Send Money by Voice

As a Rural Voice-First Banking User, I should be able to send money by speaking the recipient and amount so that I can complete a transfer without typing.

• Provenance: Explicit.
• Access state: Login required.
• Trigger/input: The user asks to send money and speaks the intended recipient and amount.
• Behavior:
  • The application shall capture the spoken recipient and amount.
  • The application shall show and speak a full-width spoken receipt of the recognized transfer details.
  • The application shall provide explicit choices to confirm the transfer or say the details again.
  • The application shall submit the transfer only after the user explicitly confirms the recognized transfer details.
• Observable result: The user receives a localized spoken and visible transfer result, including successful, failed, or pending status where applicable.
• Failure and recovery: If the recipient or amount is unclear, the transfer cannot be completed, or the service is unavailable, the application shall explain the issue, allow correction or retry, and prevent unintended transfer submission.
• Continuation: The user may return to Voice Home, review transactions, or initiate another supported banking task.

FR-07 — Check Balance by Voice

As a Rural Voice-First Banking User, I should be able to ask for my balance and hear it in my selected language so that I can understand my available banking information without reading complex screens.

• Provenance: Explicit.
• Access state: Login required.
• Trigger/input: The user asks for their balance.
• Behavior:
  • The application shall retrieve the authenticated user’s current account balance.
  • The application shall display the balance as a large value and speak it in the selected language.
  • The application shall provide a “Hear balance again” action.
• Observable result: The user hears and sees the current balance.
• Failure and recovery: If the balance cannot be retrieved, the application shall state that clearly, avoid presenting stale information as current, and allow retry.
• Continuation: The user may replay the balance, return to Voice Home, or continue to another protected banking page.

FR-08 — Explain Banking Terms by Voice

As a Rural Voice-First Banking User, I should be able to ask what a banking term means and hear a simple explanation in my selected language so that I can understand banking concepts.

• Provenance: Explicit.
• Access state: Login required.
• Trigger/input: The user speaks a banking term.
• Behavior:
  • The application shall recognize the requested banking term.
  • The application shall provide a plain-language, localized explanation.
  • The application shall support a request to explain the term again slowly.
  • The application shall use a simple everyday-metaphor illustration where applicable.
• Observable result: The user receives a spoken explanation and localized on-screen explanation of the requested term.
• Failure and recovery: If the term is not recognized or an explanation is unavailable, the application shall ask the user to say the term again or provide a clear spoken explanation of the limitation.
• Continuation: The user may ask another term, repeat the explanation, or return to Voice Home.

FR-09 — Review Transaction History

As a Rural Voice-First Banking User, I should be able to review and hear my past transactions and account activity so that I can understand my banking history.

• Provenance: Required inference from the accepted requirement to include other banking-app details.
• Access state: Login required.
• Trigger/input: The user asks to open or hear transactions.
• Behavior:
  • The application shall display the user’s past transactions and account activity in large, spaced label-and-value rows.
  • The application shall provide a tap-to-hear action for each transaction row.
  • The application shall speak selected transaction details in the selected language.
• Observable result: The user can hear and review available transaction history.
• Failure and recovery: If no transactions exist, the application shall state this clearly. If history cannot be retrieved, the application shall offer retry guidance.
• Continuation: The user may hear another transaction, return to Voice Home, or continue to supported banking work.

FR-10 — Review Banking Services

As a Rural Voice-First Banking User, I should be able to hear and review available banking service areas so that I can understand the accounts, cards, and services provided through the application.

• Provenance: Required inference from the accepted requirement to include other banking-app details.
• Access state: Login required.
• Trigger/input: The user asks about banking services, accounts, or cards.
• Behavior:
  • The application shall provide a localized overview of available account, card, and banking-service information.
  • The application shall support voice navigation and spoken descriptions of service areas.
• Observable result: The user hears and sees understandable service information in the selected language.
• Failure and recovery: If a requested service description is unavailable, the application shall explain this in simple language and allow the user to choose another available service area.
• Continuation: The user may return to Voice Home or another available protected page.

FR-11 — Review and Update Profile Details

As a Rural Voice-First Banking User, I should be able to review and update my profile details through voice-guided interaction so that my account information can remain accurate.

• Provenance: Required inference from the accepted requirement to include other banking-app details.
• Access state: Login required.
• Trigger/input: The user asks to hear or update profile information.
• Behavior:
  • The application shall present profile information in localized, large label-and-value rows.
  • The application shall speak profile information when requested.
  • The application shall capture supported profile updates through voice-guided prompts.
  • The application shall require confirmation before applying a recognized profile change.
• Observable result: The user hears and sees profile information or a confirmed update result.
• Failure and recovery: If a profile change is unclear or cannot be applied, the application shall explain the problem, retain the prior information, and offer retry or cancellation.
• Continuation: The user may return to Voice Home after reviewing or updating profile details.

FR-12 — Provide Voice-First Accessibility Support

As a Rural Voice-First Banking User, I should receive large, understandable, spoken banking guidance so that I can use the app despite low literacy, limited reading confidence, or age-related usability needs.

• Provenance: Explicit.
• Access state: Applies across all pages.
• Trigger/input: The user opens or interacts with any application page.
• Behavior:
  • The application shall prioritize voice commands and spoken prompts.
  • The application shall use large user-facing text, clear labels, large touch targets, and understandable icons.
  • The application shall not require users to remember exact voice-command syntax.
  • The application shall pair status colors with icons, plain-language labels, and spoken feedback.
• Observable result: The user receives clear spoken and visual guidance for available actions, errors, confirmations, and outcomes.
• Failure and recovery: Errors shall not rely on color alone and shall include spoken recovery instructions.
• Continuation: The user can repeat prompts, say again, retry, cancel, or return to the previous supported step.

4. User Personas

Rural Voice-First Banking User

• Provenance: Required inference from the explicit target audience of rural, illiterate, and elderly people.
• Product context: This user accesses personal banking information and banking tasks through a mobile application but may be unable or unwilling to read dense text, type information, navigate complex menus, or remember command structures.
• Primary goal: Complete essential banking tasks independently through speech in a familiar language.
• Distinct accepted responsibilities:
  • Select a preferred language before using the application.
  • Complete first-use enrollment and returning verification.
  • Speak banking requests such as sending money, checking balance, reviewing transactions, learning banking terms, reviewing banking services, and managing profile information.
  • Review and explicitly confirm consequential transfer and profile-update details.
• Relevant inputs and decisions:
  • Select and confirm a language.
  • Speak a recipient and transfer amount.
  • Confirm or correct recognized transfer details.
  • Ask for a balance, transaction, banking-term explanation, or banking-service description.
  • Confirm or revise profile updates.
• Interactions with accepted participants: The user speaks to the application’s voice assistant and receives localized spoken output, recognition feedback, confirmations, and banking outcomes. The speech and language service is a system capability, not a human participant.
• Observable success: The user completes banking tasks, receives understandable spoken results in the selected language, and does not need to read, type, or memorize technical command syntax.

5. Core User Flows

Flow 1 — Select Language on First Launch

1. The Rural Voice-First Banking User launches the application.
2. The application opens Language Selection as the first screen.
3. The application presents available languages in native script and provides a spoken prompt asking the user to choose a language.
4. The user hears one or more language names or greetings and speaks the preferred language choice.
5. The application recognizes the language choice and plays a greeting in that language.
6. The application shows and speaks the recognized language selection.
7. The user confirms the selected language or asks to choose again.
8. The application applies the selected language to all user-facing text and future assistant speech.
9. If the selection is unclear or unavailable, the application explains the issue in a simple spoken form and returns the user to the available language choices.
10. The user continues to Sign Up, Login, or another permitted anonymous path.