Build your own DocuSign.

# Build an original app inspired by DocuSign

You are an experienced product designer and full-stack engineer. Build a working, polished MVP from the brief below. Implement the core journeys end to end; a static mockup is not sufficient. Inspect the current environment, make sensible implementation decisions, and get started. Ask a question only if a missing answer genuinely blocks implementation.

Starting platform: Web. Explicit customized Product & audience and Tech stack requirements take precedence over this starting target.

## Product & audience
Build an original document-signing workflow called Signpath, inspired by DocuSign. A sender uploads a permitted PDF, places fields, invites a small ordered set of recipients, and retrieves the completed document with its activity record. The scope is a controlled workflow prototype; do not claim legal equivalence, qualified signatures, or cryptographic PDF certification.

## Design
Create an original document preparation canvas with page thumbnails, recipient-colored field outlines, a field inspector, and a clear sending review. The signer sees only their assigned fields, required-field progress, explicit consent, and a final review before submission. Keep keyboard entry and mobile PDF navigation usable.

## Features
1. Document preparation: validate bounded PDFs, preserve an immutable original, and place text, date, checkbox, and signature-appearance fields with page-relative coordinates. Record the exact document version sent.

2. Recipient workflow: define sender and recipient roles, optional sequential routing, expiring single-recipient invitations, and revoke/decline states. Use configured email delivery or copyable test invitations with an honest delivery status.

3. Signing session: authorize each invitation, collect required fields and explicit completion consent, and freeze the recipient’s submission atomically. Reused, expired, or revoked links cannot alter a completed envelope.

4. Completion and files: generate a final flattened PDF from the stored field values using a verified PDF engine. Save its content hash and allow only authorized recipients/senders to download it.

5. Activity and templates: record version, recipient events, timestamps, and document hashes in an append-only application audit log. Reuse field layouts as templates, and export an audit summary without representing it as a qualified certificate.

## Tech stack
Use TypeScript with a browser PDF viewer, a Python API and maintained PDF rendering/writing library, PostgreSQL, and private object storage. Separate invitation tokens from document IDs, hash stored tokens, and enforce recipient-scoped actions. Document any real e-signature provider integration separately from visible signature appearances.

## Data & behavior
Envelope {ownerId, state, originalHash, finalHash}; DocumentVersion {objectKey}; Recipient {order, state}; Invitation {tokenHash, expiresAt, revokedAt}; Field {recipientId, page, normalizedRect, type, required}; Submission {values, consentAt}; AuditEvent; Template. Freeze sent versions and completed field values.

Acceptance checks and scope:
Test two recipients signing in order, a revoked link, concurrent final submissions, required fields, rotated/multiple page PDFs, field placement after zoom, and reopening the exported PDF. Exclude legal-validity guarantees, identity verification services, notarization, qualified digital signatures, and arbitrary editing of signed documents.

## Originality and assets
The named product is a reference for general workflows only. Use an original product name, visual identity, wording, layout, and assets. Do not copy proprietary code, branded logos, distinctive screens, private APIs, paid templates, or protected media. Use original or appropriately licensed sample data and assets. Build from this brief rather than scraping the reference service. Do not imply affiliation with the referenced company.

## Implementation quality
- Make every visible control work, with clear loading, success, empty, validation, and failure states. Remove controls for unimplemented features.
- Support the target platform and responsive or resizable layouts where appropriate. Use platform-appropriate accessibility semantics, labels, keyboard operation, visible focus, sufficient contrast, and reduced-motion preferences. Provide alternatives for drag-only interactions.
- Validate inputs at the relevant boundary. Treat imported or user-generated content as untrusted; render it safely. Confirm destructive actions or offer undo.
- Keep state changes reliable across navigation and reloads. Never silently lose edits. Handle persistence and network errors with an actionable message.
- Keep the scope realistic. Prioritize the complete primary journey. If a custom Features section differs from the baseline, update the data model, design, and acceptance checks to match it; explicit custom requirements take precedence over baseline assumptions.
- Provide realistic original sample content and a useful empty state. Keep sample data clearly separate from user-created data.

## Delivery and verification
1. Inspect the repository and outline the implementation in a few sentences.
2. Implement the app and connect its actual data flow. Continue until the primary journey works.
3. Run appropriate checks and test the acceptance cases above on the target platform. Verify responsive layouts and keyboard navigation when browser tools are available. For native projects, build with the available SDK and test an emulator or device when possible; report any missing native verification honestly. For games, verify the rules and gameplay loop, not only the menus.
4. Fix observed failures, then provide the runnable result, setup/run instructions, a brief explanation of what is implemented, and any specific configuration or verification limits.

This is a focused MVP. Do not add billing, AI services, or unrelated features unless explicitly requested in the brief. Start building now.