Prompt Saver MCP Server

Prompt Saver - LLM Prompt Intelligence Platform

Live: https://promptsaver.online/

Chrome extension: Add to Chrome — type // in Claude, ChatGPT or Gemini to insert a saved prompt.

A prompt management tool for saving, versioning, and searching LLM prompts. Built with Next.js, Neon Postgres, and a warm stone/teal design system.

Features (MVP - Phase 1)

• Prompt Authoring: Create and edit prompts with automatic versioning
• Multi-LLM Testing: Execute prompts against multiple LLM providers from a single interface
• Prompt Library: Full-text search and intelligent categorization of prompts
• Workspace-Based Organization: Organize prompts within dedicated workspaces

MCP Server (Claude Code Integration)

Prompt Saver runs a remote MCP server at /api/mcp, so a Claude Code session can search, read, and save your prompts without leaving the terminal.

Connect

1. Sign in at https://promptsaver.online/, then click Settings and generate a token. The raw token is shown exactly once — copy it immediately. Only its SHA-256 hash is stored, so a lost token can't be recovered; revoke it on the same page and create a new one.

2. The tokens page shows the registration command with your token filled in. It looks like:

   claude mcp add --transport http prompt-saver --scope user \
     https://promptsaver.online/api/mcp \
     --header "Authorization: Bearer ps_..."
   

   --scope user registers the server once for every project rather than just the current one.

Tools

Once connected, Claude Code can call five tools against your prompt library:

• search_prompts(query, limit?) — searches title, description, content and tags. Returns summaries only (id, title, description, tags, updated_at) — never full bodies. limit defaults to 20 and is capped at 50.
• get_prompt(id) — fetches the full text of one prompt.
• create_prompt(title, content, description?, tags?) — saves a new prompt along with its first version.
• update_prompt(id, ...) — updates a prompt's draft in place, without creating a new version.
• save_version(id, content, change_summary?) — saves an immutable new version of an existing prompt.

There is no delete tool.

Favourite prompts as slash commands

Any prompt marked as a favourite (the star in the web app) is also registered as a slash command, named from its title — "Daily Planning" becomes /mcp__prompt-saver__daily-planning. Archived favourites are excluded. Each command takes one optional context argument, appended to the prompt body:

/mcp__prompt-saver__daily-planning auth refactor

Favourites are read once, when the session connects. Starring a prompt does not add its slash command to a session that's already running — open a new session, or run /mcp to reconnect, to pick up newly starred prompts.

Cold starts

The database backing this app (Neon Postgres) scales its compute to zero when idle. The first MCP request after a period of inactivity may take noticeably longer while it wakes back up; subsequent requests are fast.

Chrome extension

The Chrome extension lives in extension/. It lets users save prompts from any webpage or AI chat interface.

Setup and development

cd extension
npm install
npm run dev

The development build is unpacked and ready to load into Chrome. Configuration requires the web app's NEXT_PUBLIC_EXTENSION_IDS environment variable to contain the extension's ID (visible in chrome://extensions/ when unpacked). Set it to * to allow any well-formed extension ID. That's useful while unpacked IDs change, but any extension can then ask a signed-in user to connect (the connect page shows the requesting ID), so use an explicit list in production.

API

The extension calls these endpoints on the web app's /api/v1/prompts route:

All endpoints require a bearer token prefixed with ps_.

For privacy details, see /privacy.

Technology Stack

• Frontend: Next.js 16, React 18, TypeScript (strict mode)
• Styling: Tailwind CSS (WCAG 2.1 AA accessible)
• Storage: Neon Postgres via Drizzle ORM (server-side, per-user isolated)
• Authentication: Google OAuth via NextAuth.js
• Testing: Jest + React Testing Library
• Code Quality: ESLint, Prettier, TypeScript strict mode

Prerequisites

• Node.js 18.17+ or 20.x
• npm 9+ (or use npm ci with --legacy-peer-deps)

Setup

1. Clone and Install

git clone <repository-url>
cd prompt-saver
npm install --legacy-peer-deps

2. Configure Environment Variables

Create .env.local based on .env.example:

cp .env.example .env.local

Required variables:

NEXTAUTH_SECRET=your-secret-key-here
NEXTAUTH_URL=http://localhost:3000
GOOGLE_CLIENT_ID=your-google-client-id
GOOGLE_CLIENT_SECRET=your-google-client-secret
DATABASE_URL=postgresql://...-pooler.../neondb?sslmode=require
DATABASE_URL_UNPOOLED=postgresql://.../neondb?sslmode=require
ALLOWED_EMAILS=you@example.com

Warning: leaving ALLOWED_EMAILS unset lets anyone with a Google account sign in and get their own workspace. Always set it to a comma-separated allowlist of emails before deploying anywhere reachable.

3. Run Development Server

npm run dev

Visit http://localhost:3000 in your browser.

Development

Scripts

# Start development server
npm run dev

# Build for production
npm run build

# Run production server
npm start

# Run tests
npm run test
npm run test:watch    # Watch mode
npm run test:coverage # With coverage

# Linting
npm run lint
npm run lint:fix

# Code formatting
npm run format
npm run format:check

# Type checking
npm run type-check

Project Structure

src/
├── app/              # Next.js App Router pages and layouts
├── components/       # React components
├── lib/              # Utilities, hooks, services, and business logic
│   ├── api/          # API response wrappers
│   ├── auth/         # Authentication logic
│   ├── db/           # Database repositories and schemas
│   ├── hooks/        # Custom React hooks
│   ├── services/     # Business logic services
│   └── utils/        # Helper utilities
└── types/            # TypeScript type definitions

tests/
├── unit/             # Unit tests for utilities and hooks
├── integration/      # Integration tests
└── contract/         # API contract tests

Code Quality Standards

TypeScript Strict Mode

• No any types without justification
• All implicit returns must be typed
• Strict null checking enabled
• Strict property initialization required

ESLint Rules

• 80%+ test coverage for all utilities and hooks
• Maximum function complexity: 10 cyclomatic points
• No console statements in production code (warning only)
• No unused variables or imports

Testing Requirements

• All utilities must have unit tests
• All components must have integration tests
• API routes must have contract tests
• TDD approach: write tests first, must fail before implementation

Performance Targets

• Core Web Vitals: LCP ≤2.5s, FID ≤100ms, CLS ≤0.1
• Version creation: <100ms (atomic)
• Search response: <200ms for 10k prompts
• API response time (p95): <200ms
• Concurrent LLM executions: 100+ parallel

Accessibility

• WCAG 2.1 AA compliance
• Responsive design (320px to 1920px+)
• Keyboard navigation support
• Screen reader friendly components

Deployment

Build

npm run build

Environment Variables (Production)

Set these in your deployment platform:

NEXTAUTH_SECRET=<generate-with-: openssl rand -base64 32>
NEXTAUTH_URL=https://your-production-domain.com
GOOGLE_CLIENT_ID=your-google-client-id
GOOGLE_CLIENT_SECRET=your-google-client-secret
DATABASE_URL=postgresql://...-pooler.../neondb?sslmode=require
DATABASE_URL_UNPOOLED=postgresql://.../neondb?sslmode=require
ALLOWED_EMAILS=you@example.com

Warning: leaving ALLOWED_EMAILS unset lets anyone with a Google account sign in and get their own workspace. Do not skip it.

CI/CD

GitHub Actions automatically runs on push and pull requests:

• TypeScript type checking
• ESLint linting
• Prettier formatting
• Jest test suite
• Next.js build verification

Tests must pass before merging to main branch.

Contributing

1. Create a feature branch from 001-prompt-platform
2. Follow the TypeScript strict mode guidelines
3. Write tests first (TDD approach)
4. Ensure all tests pass: npm test
5. Ensure linting passes: npm run lint
6. Submit a pull request

Architecture Decisions

Repository Pattern

Database access is confined to repository classes implementing the interfaces in src/lib/db/repositories/types.ts. Server Actions are the only callers; client components never touch the database.

Immutable Versions

PromptVersions are immutable by design - no in-place edits allowed. This enables clean audit trails and version history.

Workspace Isolation

Every user gets one private workspace, created on first sign-in. All queries are scoped to the workspace id returned by getCurrentContext() — never to a value supplied by the client.

Roadmap

• Phase 2: Foundational infrastructure (database, auth, API patterns)
• Phase 3: User Story 1 - Prompt Authoring & Versioning
• Phase 4: User Story 2 - Multi-LLM Execution & Testing
• Phase 5: User Story 3 - Prompt Library & Search
• Phase 6: User Story 4 - Collaboration & Sharing
• Phase 7: User Story 5 - Prompt Testing & Evaluation

License

MIT — see LICENSE.

Support

For issues or questions, please contact the development team.