# MCP KNOWLEDGE BASE

## OVERVIEW

Tier 1 of three-tier MCP system: 3 built-in remote HTTP MCPs.

**Three-Tier System**:
1. **Built-in** (this directory): websearch, context7, grep_app
2. **Claude Code compat**: `.mcp.json` with `${VAR}` expansion
3. **Skill-embedded**: YAML frontmatter in skills

## STRUCTURE

```
mcp/
├── index.ts        # createBuiltinMcps() factory
├── websearch.ts    # Exa AI web search
├── context7.ts     # Library documentation
├── grep-app.ts     # GitHub code search
├── types.ts        # McpNameSchema
└── index.test.ts   # Tests
```

## MCP SERVERS

| Name | URL | Purpose | Auth |
|------|-----|---------|------|
| websearch | mcp.exa.ai/mcp?tools=web_search_exa | Real-time web search | EXA_API_KEY |
| context7 | mcp.context7.com/mcp | Library docs | CONTEXT7_API_KEY |
| grep_app | mcp.grep.app | GitHub code search | None |

## THREE-TIER MCP SYSTEM

1. **Built-in** (this directory): websearch, context7, grep_app
2. **Claude Code compat**: `.mcp.json` with `${VAR}` expansion
3. **Skill-embedded**: YAML frontmatter in skills (handled by skill-mcp-manager)

## CONFIG PATTERN

```typescript
export const mcp_name = {
  type: "remote" as const,
  url: "https://...",
  enabled: true,
  oauth: false as const,
  headers?: { ... },
}
```

## USAGE

```typescript
import { createBuiltinMcps } from "./mcp"

const mcps = createBuiltinMcps()  // Enable all
const mcps = createBuiltinMcps(["websearch"])  // Disable specific
```

## HOW TO ADD

1. Create `src/mcp/my-mcp.ts`
2. Add to `allBuiltinMcps` in `index.ts`
3. Add to `McpNameSchema` in `types.ts`

## NOTES

- **Remote only**: HTTP/SSE, no stdio
- **Disable**: User can set `disabled_mcps: ["name"]` in config
- **Context7**: Optional auth using `CONTEXT7_API_KEY` env var
- **Exa**: Optional auth using `EXA_API_KEY` env var
