# Browser extension

The Blekline extension masks prompts in-browser before send — complementary to MCP (IDE/agent path).

## Supported surfaces

ChatGPT, Claude, Gemini, Perplexity, Grok, Poe, DeepSeek (see extension manifest host permissions).

## Architecture

```
Content script → background.ts → @blekline/client → POST /api/mask
```

Enterprise private tenant: set `PLASMO_PUBLIC_BLEKLINE_APP_ORIGIN`.

## vs MCP

| Surface | Best for |
|---------|----------|
| Extension | Browser SaaS chat UIs |
| MCP server | Cursor, Claude Desktop, Codex |
| MCP proxy | Tool-call governance before Daytona |

Use both for full coverage: browser wedge + IDE ingress + runtime sandbox (Daytona).

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**Next steps:** [AI Enablement Stack](/docs/introduction/ai-enablement-stack) · [Quick start](/docs/introduction/quick-start) · [MCP Cursor setup](/docs/mcp/cursor) · [Open workspace](https://app.blekline.com) · [Report issue](https://github.com/Blekline/blekline-oss/issues/new?template=bug_report.yml)