coder/xum is a desktop application for running coding agents in isolated, parallel workspaces, either locally, through Git worktrees, or on remote servers over SSH. It helps developers manage multiple agents, models, code changes, reviews, costs, and agent status from one interface. The catalogue skills, instructions, agents, settings, and command define workflows for using Xum.
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 skills add coder/xum --skill generate-readme-screenshotsgit clone --depth 1 https://github.com/coder/xumWrote 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/coder/xum/generate-readme-screenshots)<a href="https://agentmods.dev/skills/coder/xum/generate-readme-screenshots"><img src="https://agentmods.dev/badge/skills/coder/xum/generate-readme-screenshots/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/coder/xum/generate-readme-screenshots"><img src="https://agentmods.dev/badge/skills/coder/xum/generate-readme-screenshots.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Server-Side Request Forgery · line 129 Code issues a request to a loopback, link-local, or private-range host. This can reach internal services not meant to be exposed and is a common SSRF pivot.Fix: Avoid requests to loopback/link-local/private hosts from skill code. If internal access is intended, document it and validate the target against an allowlist.
- medium Server-Side Request Forgery · line 191 Code issues a request to a loopback, link-local, or private-range host. This can reach internal services not meant to be exposed and is a common SSRF pivot.Fix: Avoid requests to loopback/link-local/private hosts from skill code. If internal access is intended, document it and validate the target against an allowlist.
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 5.1 | $0.00093 | $0.01933 |
| Opus 5.5 | $0.00037 | $0.00773 |
| Sonnet 5.5 | $0.00019 | $0.00387 |
| Haiku 4.5 | $0.00009 | $0.00193 |
Grade A, and why
generate-readme-screenshots 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 1mo 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.
> **Important:** `curl` may succeed when `bun fetch` fails (different DNS resolution). The source is not reproduced here
Licensed AGPL-3.0
The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.
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.
- 1mo ago Changed 9eaf159ec327
- 1mo ago First seen · 214 lines · 93 tokens per session scan A da7316406671
generate-readme-screenshots is a skill published in the GitHub repository coder/xum (2,062 stars, last pushed today), licensed AGPL-3.0. It adds 93 tokens to every session and 1,933 once invoked, about $0.0004 per session on Opus 5.5. 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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