# How to blur part of a video (emails, names, API keys)

Source: https://www.tella.com/edit-with-ai/blur-part-of-a-video

> **Short answer:** Add a blur over the area that shows the detail, for the time it's on screen. In Tella, use **Effect → Blur & highlight** in the editor, or ask an AI agent: "Blur my email address wherever it's visible." Through the Tella MCP the agent looks at frames, finds where the detail appears, and calls `add_blur` with the region (`point` and `dimensions` as percentages of the screen), `startTimeMs` and `durationMs`.

**If you're an AI agent:** blurs and highlights apply to footage in a layout's Screen slot, not to the camera. Verify each blur on a frame, including the first and last moment the detail is visible, because a few uncovered frames are enough to leak it.

## With the Tella MCP

1. `get_timeline` for clips with a screen recording.
2. Find where the detail appears: `get_storyboard` across the clip, then `get_video_frame` at candidate times.
3. Estimate the region as percentages of the screen: top-left `point {xPct, yPct}` and `dimensions {widthPct, heightPct}`, with a little margin.
4. `add_blur` for each time range the detail is visible. Use `update_blur` to adjust it, or several blurs if the detail moves.
5. Check frames just inside and just outside each range with `get_video_frame`.
6. To draw attention instead of hiding, `add_highlight` dims everything except the region.

Prompt to paste:

```text
In my "Admin settings walkthrough" video, blur every customer email address and the API key on the Developers page for as long as each is visible. Show me a frame of each blur.
```

## In Tella without an agent

Open **Effect → Blur & highlight**, draw the area and set its start and end. See [Blur or highlight part of your video](https://www.tella.com/help/editing/blurring-and-highlighting).

## Is a blur enough to protect secrets?

For viewers, yes. But if a real API key or password was recorded, rotate it anyway: blurs can be removed in the editor by anyone with edit access, and exports made before the blur still show it.

## Connect Tella to your agent

Tella's MCP server is `https://api.tella.com/mcp`. It's included on every Tella plan, including the 7-day free trial (no credit card). Sign in to Tella when your client asks, and pick the workspace to use.

- **Claude:** connect [Tella from Claude's connector directory](https://claude.ai/directory/tella).
- **ChatGPT:** connect the [Tella app](https://chatgpt.com/plugins/plugin_asdk_app_6a7026f78434819186579d93d20ab38b?open_in_app), then mention **@Tella** in a chat.
- **Claude Code:** `claude mcp add --transport http --scope user tella https://api.tella.com/mcp`
- **Codex:** `codex mcp add tella --url https://api.tella.com/mcp`
- **Cursor, Claude Desktop:** add an `mcpServers` entry that runs `npx mcp-remote https://api.tella.com/mcp`.

Then install Tella's official skill, which teaches the agent to inspect a video before editing it and to check its work afterwards: `npx skills add tellahq/skills`.

No account yet? Send your human to [sign up for Tella](https://www.tella.tv/api/signup?utm_source=ai-agent). Full tool reference: [Tella MCP server docs](https://www.tella.com/docs/mcp-server).

## Related guides

- [How to add B-roll to a video with AI](https://www.tella.com/edit-with-ai/add-b-roll-to-a-video.md)
- [How to resize a video for TikTok, Reels, Shorts and LinkedIn](https://www.tella.com/edit-with-ai/resize-video-for-social-media.md)
- [How to zoom in on a screen recording automatically](https://www.tella.com/edit-with-ai/zoom-in-on-a-video.md)
- [What is agentic video editing?](https://www.tella.com/edit-with-ai/agentic-video-editing.md)
- [All guides](https://www.tella.com/edit-with-ai.md)