Copyleaks

Build me a focused AI detection + plagiarism workflow for the personal core of Copyleaks. Requirements:

- Use exactly this stack: Next.js 15 + TypeScript + SQLite. Model source documents, editable pages or notes, internal links, revisions, and exports; retain source IDs and timestamps.
- Paid product context: AI-content and plagiarism detection for documents, schools, and businesses. Build only this DIY scope: Analyze user-supplied text with a labelled heuristic or user-selected detector, show evidence and uncertainty, and export a reviewable report.
- For AI detection + plagiarism, import a user-supplied document and preserve its original text and hash.
- Run a clearly labelled heuristic or user-selected detector and record its model/version, score, and evidence spans.
- Let the user review uncertain passages and export a report with limitations and source excerpts.
- Use a local web page with input, progress, review, and export views. Required input or access: OpenAI API key in .env. Keep credentials in .env.
- Acceptance: with one labelled sample, show the input, saved intermediate state, and exported result; verify this invariant: A classifier score cannot be presented as proof of authorship; a failed detector run remains unknown and never overwrites source text.
- Out of scope: vendor-managed prompt and quality tuning; proprietary models or classifiers. Keep this a personal, inspectable workflow.
- Include a README with setup, a sample input, required keys or permissions, data location, and the supported scope.

# AGENTS.md — Build guide for Copyleaks

## Project scope
Build a private AI detection + plagiarism workspace that sends user text to one chosen model, stores versions, applies reusable instructions, and exports Markdown.

Catalogue verdict: no. Do not mistake the interface for the product. Copyleaks's durable value is model, data, workflow, which a solo one-shot build cannot reproduce responsibly. The prompt therefore builds only the closest honest personal consolation tool.
Use the implementation prompt below to define the deliverable. Complete each phase's acceptance checks before extending the scope.

## Working agreement
- Inspect the repository and its existing instructions before choosing paths, dependencies or commands. Keep one coherent stack and explain changes to the proposed architecture.
- Plan a vertical slice that accepts a real input and produces the useful output described below. Persist only the state the prompt calls for; respect memory-only and upstream-managed workflows. Use fixtures only when they are clearly labelled.
- After scaffolding, document the actual install, development, check and build commands in README and keep them synchronized with the package or project manifest. Do not report commands as successful unless they ran.
- Work in small steps. At handoff, list implemented flows, checks actually performed, remaining blockers, and any credentials or provider setup the owner must supply.
- Do not publish, spend money, contact customers, delete source data or run irreversible migrations without the project owner's authorization.

## Prerequisites
- OpenAI API key in .env
- Node.js 22
- SQLite database
- Explicit README warning that this is a consolation build, not a production replacement

## Stack and architecture
- Use exactly this stack: Next.js 15 + TypeScript + SQLite.
- Model source documents, editable pages or notes, internal links, revisions, and exports; retain source IDs and timestamps.
- Interface for this AI detection + plagiarism workflow: a local web page with input, progress, review, and export views.

## Security and data integrity
- A classifier score cannot be presented as proof of authorship; a failed detector run remains unknown and never overwrites source text.
- Keep API keys and OAuth secrets in .env; redact them from logs, generated files, and error responses.
- State the practical limit: vendor-managed prompt and quality tuning.

## Agent implementation rules
- Project rule, data: Model source documents, editable pages or notes, internal links, revisions, and exports; retain source IDs and timestamps.
- Project rule, behavior: For AI detection + plagiarism, import a user-supplied document and preserve its original text and hash.
- Project rule, recovery: A classifier score cannot be presented as proof of authorship; a failed detector run remains unknown and never overwrites source text.

## Optional agent skills and references
No installable skill is listed for this guide; use the project rules and the stack documentation.

Read the linked SKILL.md and its dependencies before adding a skill. Select only the skills matching this project's runtime and task; their documentation does not supply API access, credentials or approval to perform external actions. Pin the reviewed revision where the tool supports it. Follow the chosen agent's documented project-level installation mechanism.

## Distribution ideas
These are optional planning notes. Obtain the owner's approval before publishing or contacting anyone.
- Demonstrate this AI detection + plagiarism operation with sample or user-owned data: For AI detection + plagiarism, import a user-supplied document and preserve its original text and hash.
- Show a concrete result or export: Let the user review uncertain passages and export a report with limitations and source excerpts.
- State the practical limit: vendor-managed prompt and quality tuning.

## Engineering roadmap
1. Phase 1, architecture and data: Use exactly this stack: Next.js 15 + TypeScript + SQLite. Model source documents, editable pages or notes, internal links, revisions, and exports; retain source IDs and timestamps.
2. Phase 2, implement: For AI detection + plagiarism, import a user-supplied document and preserve its original text and hash.
3. Phase 3, implement: Run a clearly labelled heuristic or user-selected detector and record its model/version, score, and evidence spans.
4. Phase 4, review and output: Let the user review uncertain passages and export a report with limitations and source excerpts.
5. Phase 5, recovery and acceptance: Verify this invariant with a saved fixture: A classifier score cannot be presented as proof of authorship; a failed detector run remains unknown and never overwrites source text. State the practical limit: vendor-managed prompt and quality tuning.

## Paid-product capabilities outside this build
- vendor-managed prompt and quality tuning
- proprietary models or classifiers
- brand-trained workflows
- team governance and integrations

## Implementation prompt
Build me a focused AI detection + plagiarism workflow for the personal core of Copyleaks. Requirements:

- Use exactly this stack: Next.js 15 + TypeScript + SQLite. Model source documents, editable pages or notes, internal links, revisions, and exports; retain source IDs and timestamps.
- Paid product context: AI-content and plagiarism detection for documents, schools, and businesses. Build only this DIY scope: Analyze user-supplied text with a labelled heuristic or user-selected detector, show evidence and uncertainty, and export a reviewable report.
- For AI detection + plagiarism, import a user-supplied document and preserve its original text and hash.
- Run a clearly labelled heuristic or user-selected detector and record its model/version, score, and evidence spans.
- Let the user review uncertain passages and export a report with limitations and source excerpts.
- Use a local web page with input, progress, review, and export views. Required input or access: OpenAI API key in .env. Keep credentials in .env.
- Acceptance: with one labelled sample, show the input, saved intermediate state, and exported result; verify this invariant: A classifier score cannot be presented as proof of authorship; a failed detector run remains unknown and never overwrites source text.
- Out of scope: vendor-managed prompt and quality tuning; proprietary models or classifiers. Keep this a personal, inspectable workflow.
- Include a README with setup, a sample input, required keys or permissions, data location, and the supported scope.

## Completion evidence
Demonstrate the prompt's acceptance scenarios against the scoped workflow. Include setup from a clean checkout and failure recovery. Check persistence across restart and export/restore only for the state the prompt says to store; for memory-only tools, confirm that temporary content is discarded as specified. Record actual results and remaining limitations. A detailed plan alone does not establish a working replacement.