Deno is a runtime that executes JavaScript, TypeScript, and WebAssembly programs outside a browser. Developers use it for applications such as web servers, and the catalogue add-ons provide workflows and guidance for Deno projects.
Borrowing it
Nothing to install: this file belongs to denoland/deno. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/denoland/deno/main/.claude/skills/node-compat/SKILL.mdgit clone --depth 1 https://github.com/denoland/denoWrote 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/denoland/deno/node-compat)<a href="https://agentmods.dev/skills/denoland/deno/node-compat"><img src="https://agentmods.dev/badge/skills/denoland/deno/node-compat/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/denoland/deno/node-compat"><img src="https://agentmods.dev/badge/skills/denoland/deno/node-compat.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00037 | $0.01264 |
| Opus 5.5 | $0.00015 | $0.00506 |
| Sonnet 5.5 | $0.00007 | $0.00253 |
| Haiku 4.5 | $0.00004 | $0.00126 |
Grade A, and why
node-compat scanned grade A with 0 findings 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 188 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Node Compat Test
Work on Node.js compatibility test $ARGUMENTS.
Step 1: Build and run the test
./x build
./x test-compat $ARGUMENTS
If the test passes, report success and ensure test is specified in
tests/node_compat/config.jsonc.
Step 2: Diagnose the failure
Read the test file to understand what it tests:
# Tests live under tests/node_compat/test/
Use Grep and Read to find the test source, then analyze:
- What Node.js API or behavior is being tested?
- What is the actual error or assertion failure?
- Where is the relevant Deno implementation? Check
ext/node/(polyfills, ops, internal bindings),runtime/, orcli/.
Read the corresponding Node.js docs and/or source code to understand the expected behavior.
Step 3: Classify the failure
Determine which category this failure falls into:
A. Fixable bug
The Deno implementation is wrong or incomplete, but can be corrected. This includes:
- Missing method/property on a polyfill
- Wrong return value or error type
- Missing event emission
- Incorrect argument handling
- Hard-to-fix but still fundamentally implementable behaviors
Action: Fix the implementation (Step 4).
B. Inherent incompatibility
The test relies on Node.js internals or architecture that Deno fundamentally cannot or will not support:
internalBinding()calls to Node's C++ layer- Node.js-specific CLI flags (
--inspect,--prof, etc.) - V8 internals exposed through Node-specific APIs
- Node.js-specific build/addon tooling (node-gyp internals)
- Tests for Node.js's own test infrastructure
Action: Ignore the test with a reason (Step 5).
C. Not worth fixing
The test exercises an edge case or behavior that is technically possible but provides negligible value:
- Extremely obscure error message wording differences
- Node.js-specific deprecation warnings
- Behavior that no real-world code depends on
Action: Ignore or skip the test with a reason (Step 5).
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 First seen · 188 lines · 37 tokens per session scan A 49498c75721c
node-compat is a skill published in the GitHub repository denoland/deno (108,724 stars, last pushed today), licensed MIT. It adds 37 tokens to every session and 1,264 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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