Context Mode MCP — Casos de uso, Instalar & Demo en vivo

Por qué usarlo

Características clave

98% context reduction via sandboxed tool execution
Per-session SQLite FTS5 index survives compaction
Automatic routing hooks (PreToolUse, PostToolUse, PreCompact, SessionStart)
12 platforms supported (Claude Code, Cursor, Codex, Gemini CLI, Copilot…)
'Think in code' paradigm — have the LLM write scripts, not process data itself

Demo en vivo

Cómo se ve en la práctica

context-mode-mcp.replay ▶ listo

0/0

Instalar

Elige tu cliente

~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "context-mode-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "context-mode"
      ]
    }
  }
}

Abre Claude Desktop → Settings → Developer → Edit Config. Reinicia después de guardar.

~/.cursor/mcp.json · .cursor/mcp.json

{
  "mcpServers": {
    "context-mode-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "context-mode"
      ]
    }
  }
}

Cursor usa el mismo esquema mcpServers que Claude Desktop. La configuración del proyecto prevalece sobre la global.

VS Code → Cline → MCP Servers → Edit

{
  "mcpServers": {
    "context-mode-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "context-mode"
      ]
    }
  }
}

Haz clic en el icono MCP Servers de la barra lateral de Cline y luego en "Edit Configuration".

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "context-mode-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "context-mode"
      ]
    }
  }
}

Mismo formato que Claude Desktop. Reinicia Windsurf para aplicar.

~/.continue/config.json

{
  "mcpServers": [
    {
      "name": "context-mode-mcp",
      "command": "npx",
      "args": [
        "-y",
        "context-mode"
      ]
    }
  ]
}

Continue usa un array de objetos de servidor en lugar de un mapa.

~/.config/zed/settings.json

{
  "context_servers": {
    "context-mode-mcp": {
      "command": {
        "path": "npx",
        "args": [
          "-y",
          "context-mode"
        ]
      }
    }
  }
}

Añádelo a context_servers. Zed recarga en caliente al guardar.

claude mcp add context-mode-mcp -- npx -y context-mode

Un solo comando. Verifica con claude mcp list. Quita con claude mcp remove.

Casos de uso

Usos del mundo real: Context Mode

Stop wasting context on raw tool output

👤 Heavy Claude Code users who hit compaction mid-session ⏱ ~15 min intermediate

Cuándo usarlo: You feel your agent "forget" after 30 minutes and burn $$ on re-reads.

Requisitos previos

Claude Code v1.0.33+ — brew upgrade claude-code or npm update -g @anthropic-ai/claude-code

Flujo

Install

/plugin marketplace add mksglu/context-mode
/plugin install context-mode@context-mode✓ Copiado

→ Plugin registers hooks + 6 sandbox tools
Verify

/context-mode:ctx-doctor✓ Copiado

→ All checks [x]
Use normally

Now do a big task that would normally blow context — e.g. analyze all .log files under /var/log✓ Copiado

→ ctx_execute used instead of raw Read; output indexed not dumped
Check savings

/context-mode:ctx-stats✓ Copiado

→ Per-tool reduction ratio reported

Resultado: Same task, 10x longer before compaction, and the agent remembers.

Errores comunes

Other MCPs bypass the routing — Pass their tool calls through ctx_batch_execute for consistent accounting

Combinar con: serena

Resume a long task seamlessly after the model compacts

👤 Devs on multi-hour agent sessions ⏱ ~5 min beginner

Cuándo usarlo: Your task is too big to fit in one context window.

Flujo

Start with --continue

[CLI flag] claude --continue✓ Copiado

→ Prior session's SQLite loaded
Observe

What did I last ask you about? What tasks are in progress?✓ Copiado

→ Accurate recap from FTS5 index, not hallucinated

Resultado: A genuinely resumable workflow.

Errores comunes

Forgetting --continue starts fresh — Persistence requires --continue; absence means deliberate fresh start

Combinaciones

Combínalo con otros MCPs para multiplicar por 10

context-mode-mcp + serena

Serena for semantic code nav, context-mode for keeping its output out of context

Use serena for the lookup, ctx_execute to post-process the results.✓ Copiado

context-mode-mcp + playwright

Page snapshot output stays sandboxed

Snapshot the page via playwright, let context-mode hold it — search it instead of dumping.✓ Copiado

Herramientas

Lo que expone este MCP

Herramienta	Entradas	Cuándo llamar	Coste
ctx_execute	code: str (js/python)	Run a script to process data; output only what's needed	free
ctx_batch_execute	ops: [{tool, args}]	Wrap multiple tool calls through the sandbox	free
ctx_index	content: str, tags?: []	Stash data for later retrieval	free
ctx_search	query: str	Retrieve from session index	free
ctx_fetch_and_index	url: str	Pull a URL, keep it out of context but searchable	free
ctx_stats	none	See how much context was saved	free

Coste y límites

Lo que cuesta ejecutarlo

Cuota de API: Local
Tokens por llamada: Dramatic reduction — quoted 98% on real sessions
Monetario: Free (ELv2 license)
Consejo: The bigger the session, the bigger the win — use on long tasks

Seguridad

Permisos, secretos, alcance

Almacenamiento de credenciales: Session SQLite in ~/.context-mode/

Salida de datos: None

SQLite persists across sessions only if you use --continue — otherwise it's wiped

Resolución de problemas

Errores comunes y soluciones

ctx-doctor shows missing hooks

Restart Claude Code fully after install; hooks register at startup

Verificar: Re-run /context-mode:ctx-doctor

Sandbox won't execute code

Node/Python runtime missing. Doctor tells you which. Install with brew/asdf.

Search returns nothing

Verify FTS5 built: sqlite3 ~/.context-mode/session.db "SELECT name FROM sqlite_master". Reinstall if broken.

Alternativas

Context Mode vs otros

Alternativa	Cuándo usarla	Contrapartida
Raw Claude Code (no plugin)	Short sessions that never hit compaction	No context saving
claude-mem	You want the memory layer without the sandbox-tool paradigm	Different tradeoff — memory only, no tool output sandbox

Más

Recursos

📖 Lee el README oficial en GitHub

🐙 Ver issues abiertas

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