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# Tend — Voice-First Family Care Circle for Alexa+

> **Amazon Developer Hackathon (Build, Ship, Shape)**  
> **Primary Track:** Alexa+  
> **Mini Challenges:** AWS Builder & Open Source

Tend is an ambient, voice-first family care circle living inside Alexa+, engineered specifically for families supporting an aging parent. Without requiring parents to adopt complex smartphone apps, Tend empowers elders to log routines ("Alexa, tell Tend I took my morning pills") and allows adult children to stay informed ("Alexa, how's Mom doing today?").

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## Key Highlights

- **Alexa+ Native MCP Implementation:** Exposes 8 focused voice tools conforming to the official Model Context Protocol (spec `2025-11-25`).
- **Sub-500ms Latency ($p95 < 250\text{ ms}$):** Zero LLM calls in the synchronous voice request path. Spoken briefings are built deterministically from $\le 4$ DynamoDB queries.
- **Enterprise-Grade Auth & Security:** Full OAuth 2.1 authorization code flow with PKCE `S256`, RFC 9728 Protected Resource Metadata (PRM), and bare `401 Unauthorized` unauthenticated responses.
- **Interactive Multimodal Care Board:** Supports Alexa screen devices via the MCP App specification (`ui://tend/care-board`) styled according to [`DESIGN.md`](./DESIGN.md).
- **Asynchronous Intelligence (AWS Builder):** Scheduled EventBridge triggers an async Lambda digest worker utilizing Amazon Bedrock (Converse API) to summarize longitudinal trends into pre-cached insights.
- **Open Source Conformance Tool:** Includes `alexa-mcp-check` (`packages/conformance`), an Apache-2.0 automated test suite that validates any MCP server against Alexa+ protocol, auth, and voice linter standards.

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## Codebase Architecture & MCP SDK References

As required by the Alexa+ hackathon criteria, the official `@modelcontextprotocol/sdk` is directly integrated and utilized:

- **Official MCP SDK Server Import:** [`apps/mcp-server/src/server.ts`](./apps/mcp-server/src/server.ts#L1)  
  `import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";`
- **Streamable HTTP Stateless Transport:** [`apps/mcp-server/src/index.ts`](./apps/mcp-server/src/index.ts#L2)  
  `import { WebStandardStreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/webStandardStreamableHttp.js";`
- **Server Initialization & Capabilities:** [`apps/mcp-server/src/server.ts`](./apps/mcp-server/src/server.ts#L22-L33)  
  Initializes `McpServer` declaring `tools` and `resources` capabilities for specification version `2025-11-25`.
- **Tool Registrations:** [`apps/mcp-server/src/server.ts`](./apps/mcp-server/src/server.ts#L36-L230)  
  Registers all 8 voice tools with Zod input schemas and spoken response envelopes.
- **MCP App Multimodal Resource:** [`apps/mcp-server/src/server.ts`](./apps/mcp-server/src/server.ts#L232-L255)  
  Registers `ui://tend/care-board` resource rendering interactive care board HTML.
- **OAuth 2.1 & RFC 9728 Handlers:** [`apps/mcp-server/src/oauth.ts`](./apps/mcp-server/src/oauth.ts)
- **Core Domain & Repositories:** [`packages/core/src/index.ts`](./packages/core/src/index.ts)
- **Open Source Conformance CLI:** [`packages/conformance/src/cli.ts`](./packages/conformance/src/cli.ts)
- **AWS CDK v2 Infrastructure:** [`infra/cdk/src/index.ts`](./infra/cdk/src/index.ts)
- **Care Console UI Application:** [`apps/console/src/index.ts`](./apps/console/src/index.ts)

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## Monorepo Setup & Quickstart

Tend uses `pnpm` workspaces (Node 22+ recommended):

```bash
# 1. Install dependencies across all packages
pnpm install

# 2. Run complete verification gate (typecheck + lint + test + conformance)
pnpm verify

# 3. Start Tend MCP Server & Echo Show Care Board (Terminal 1)
pnpm --filter @tend/mcp-server start
# -> Listening at http://localhost:3000
# -> Live Care Board: http://localhost:3000/board
# -> Streamable HTTP: http://localhost:3000/mcp

# 4. Start Tend Care Console UI (Terminal 2)
pnpm --filter @tend/console start
# -> Running at http://localhost:3001
```

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## License

Tend is open-source software licensed under the [Apache License, Version 2.0](./LICENSE).