Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/spinabot/brigade/canvasnpx skills add spinabot/brigade --skill canvasgit clone --depth 1 https://github.com/spinabot/brigadeWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/spinabot/brigade/canvas)<a href="https://agentmods.dev/skills/spinabot/brigade/canvas"><img src="https://agentmods.dev/badge/skills/spinabot/brigade/canvas.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00043 | $0.01516 |
| Opus 5 | $0.00022 | $0.00758 |
| Sonnet 5 | $0.00009 | $0.00303 |
| Haiku 4.5 | $0.00004 | $0.00152 |
Grade A, and why
canvas scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
3. Test URL directly: `curl http://<hostname>:18793/__brigade__/canvas/<file>.html` How it starts
The opening of the file, as written. The whole thing — 205 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Canvas Skill
Display HTML content on connected Brigade nodes (Mac app, iOS, Android).
Overview
The canvas tool lets you present web content on any connected node's canvas view. Great for:
- Displaying games, visualizations, dashboards
- Showing generated HTML content
- Interactive demos
How It Works
Architecture
┌─────────────────┐ ┌──────────────────┐ ┌─────────────┐
│ Canvas Host │────▶│ Node Bridge │────▶│ Node App │
│ (HTTP Server) │ │ (TCP Server) │ │ (Mac/iOS/ │
│ Port 18793 │ │ Port 18790 │ │ Android) │
└─────────────────┘ └──────────────────┘ └─────────────┘
- Canvas Host Server: Serves static HTML/CSS/JS files from
canvasHost.rootdirectory - Node Bridge: Communicates canvas URLs to connected nodes
- Node Apps: Render the content in a WebView
Tailscale Integration
The canvas host server binds based on gateway.bind setting:
| Bind Mode | Server Binds To | Canvas URL Uses |
|---|---|---|
loopback |
127.0.0.1 | localhost (local only) |
lan |
LAN interface | LAN IP address |
tailnet |
Tailscale interface | Tailscale hostname |
auto |
Best available | Tailscale > LAN > loopback |
Key insight: The canvasHostHostForBridge is derived from bridgeHost. When bound to Tailscale, nodes receive URLs like:
http://<tailscale-hostname>:18793/__brigade__/canvas/<file>.html
This is why localhost URLs don't work - the node receives the Tailscale hostname from the bridge!
Actions
| Action | Description |
|---|---|
present |
Show canvas with optional target URL |
hide |
Hide the canvas |
navigate |
Navigate to a new URL |
eval |
Execute JavaScript in the canvas |
snapshot |
Capture screenshot of canvas |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago First seen · 205 lines · 43 tokens per session scan A ade2da6e4b7a
canvas is a skill published in the GitHub repository spinabot/brigade (3,391 stars, last pushed 2d ago), licensed MIT. It adds 43 tokens to every session and 1,516 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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