Native WebMCP census · September 20, 2026
Pen.dev — WebMCP observations
Tools observed on the website listed for Pen.dev, with default and experimental browser contexts shown separately.
- Roster identity
- Pen.dev · speedrun:70f8efdb-0078-4960-9e74-9cf4393d610b
- Program and cohort
- a16z Speedrun · SR005
- Roster observed
- 2026-09-20
- Official profile
- Official directory entry
- Listed website
- https://pencil.dev
- Browser
- 153.0.8010.50
Observation windows
The experimental mode enabled WebMCP and WebMCPTesting. Both modes used fresh logged-out contexts and a 1.5-second settled observation window.
| Context | Result | Final URL | Start / end |
|---|---|---|---|
| Default Chrome | Not observed in this window | https://www.pen.dev/ | 2026-09-20T21:26:01.842Z 2026-09-20T21:26:04.064Z |
| Experimental features enabled | Registration observed | https://www.pen.dev/ | 2026-09-20T21:49:35.562Z 2026-09-20T21:49:37.924Z |
Exact tool names
| Name | Default | Experimental |
|---|---|---|
open_editor | Not observed | Observed |
Evidence limits
Passive homepage observation only. No tool was invoked. Registration does not establish execution, product quality, task success or adoption. A tool absent from one window may appear in another context.
Names and metadata describe exposed interfaces. They do not prove that a tool performs the named action or belongs to the company’s core product rather than a hosting platform.
- Default Chrome source hash
a13198d96033ac580e0e444a91af4feb50d5994cff286daefe4d5876683e7d8f- Default Chrome tool frame origins
- No registration observed
- Experimental features enabled source hash
828c62e7b48a055244f7c214098b06db67b59b43b0c7bb379377a4f3f12e2e15- Experimental features enabled tool frame origins
- https://www.pen.dev