m04-zero-cost SKILL.md skillA
m04-zero-cost from moeru-ai/auv is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add moeru-ai/auv/m04-zero-cost@git:20260725.8a8e541Pins git:20260725.8a8e541 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- moeru-ai/auv
- Path
.agents/skills/m04-zero-cost/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260725.8a8e541, committed Jul 25, 2026
- Size
- 4,731 bytes
- Repository stars
- 202
- License
- Apache-2.0
CRITICAL: Use for generics, traits, zero-cost abstraction. Triggers: E0277, E0308, E0599, generic, trait, impl, dyn, where, monomorphization, static dispatch, dynamic dispatch, impl Trait, trait bound not satisfied, 泛型, 特征, 零成本抽象, 单态化.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Zero-Cost Abstraction > **Layer 1: Language Mechanics** ## Core Question **Do we need compile-time or runtime polymorphism?** Before choosing between generics and trait objects: - Is the type known at compile time? - Is a heterogeneous collection needed? - What's the performance priority? --- ## Error → Design Question | Error | Don't Just Say | Ask Instead | |-------|----------------|-------------| | E0277 | "Add trait bound" | Is this abstraction at the right level? | | E0308 | "Fix the type" | Should types be unified or distinct? | | E0599 | "Import the trait" | Is the trait the right abstraction? | | E0038 | "Make object-safe" | Do we really need dynamic dispatch? | --- ## Thinking Prompt Before adding trait bounds: 1. **What abstraction is needed?** - Same behavior, different types → trait - Different behavior, same type → enum - No abstraction needed → concrete type 2. **When is type known?** - Compile time → generics (static dispatch) - Runtime → trait objects (dynamic dispatch) 3. **What's the trade-off priority?** - Performance → generics - Compile time → trait objects - Flexibility → depends --- ## Trace Up ↑ …
Read the whole file at its exact version.
How to install
mdr add moeru-ai/auv/m04-zero-cost@sha256:3a2eed8faf0a0087The line at the top of this page pins the label git:20260725.8a8e541, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_l3axua4zyf6sahee)
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Versions
The registry has recorded 1 version of this file, committed on Jul 25, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4731 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
moeru-ai/auv · 202 stars · license Apache-2.0 · pushed 2026-11-04 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_l3axua4zyf6sahee GET https://markdownregistry.com/api/v1/resolve?ref=moeru-ai/auv/m04-zero-cost GET https://markdownregistry.com/api/v1/blob/3a2eed8faf0a0087aa5c823d66341123cc6f43ef36d1767c3fdbcc86cf8b4b54
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.