recommendation-engine SKILL.md skillA
recommendation-engine from secondsky/claude-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add secondsky/claude-skills/recommendation-engine@git:20260402.89c5e89Pins git:20260402.89c5e89 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- secondsky/claude-skills
- Path
plugins/recommendation-engine/skills/recommendation-engine/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260402.89c5e89, committed Apr 2, 2026
- First version recorded
- Dec 24, 2025
- Size
- 11,397 bytes
- Repository stars
- 247
- License
- MIT
Build recommendation systems with collaborative filtering, matrix factorization, hybrid approaches. Use for product recommendations, personalization, or encountering cold start, sparsity, quality evaluation issues.
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
# Recommendation Engine
Build recommendation systems for personalized content and product suggestions.
## Recommendation Approaches
| Approach | How It Works | Pros | Cons |
|----------|--------------|------|------|
| Collaborative | User-item interactions | Discovers hidden patterns | Cold start |
| Content-based | Item features | Works for new items | Limited discovery |
| Hybrid | Combines both | Best of both | Complex |
## Collaborative Filtering
```python
import numpy as np
from scipy.sparse import csr_matrix
from sklearn.metrics.pairwise import cosine_similarity
class CollaborativeFilter:
def __init__(self):
self.user_similarity = None
self.item_similarity = None
def fit(self, user_item_matrix):
# User-based similarity
self.user_similarity = cosine_similarity(user_item_matrix)
# Item-based similarity
self.item_similarity = cosine_similarity(user_item_matrix.T)
def recommend_for_user(self, user_id, n=10):
scores = self.user_similarity[user_id].dot(self.user_item_matrix)
# Exclude already interacted items
already_interacted = self.user_item_matrix[user_id].nonzero()[0]
…Read the whole file at its exact version.
How to install
mdr add secondsky/claude-skills/recommendation-engine@sha256:2f65682b700ea156The line at the top of this page pins the label git:20260402.89c5e89, 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_nuwow3acxsu3rheq)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Dec 24, 2025 and Apr 2, 2026, about one every 100 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260402.89c5e89 latest | 2026-04-02 | 89c5e89 | 11,397 B | A | view · diff |
| git:20251224.ba827ce | 2025-12-24 | ba827ce | 11,383 B | A | view |
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 (11397 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
secondsky/claude-skills · 247 stars · license MIT · pushed 2026-10-31 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_nuwow3acxsu3rheq GET https://markdownregistry.com/api/v1/resolve?ref=secondsky/claude-skills/recommendation-engine GET https://markdownregistry.com/api/v1/blob/2f65682b700ea156531786e868d97bb2521cc3f73e2737ce4218d9b932c395a1
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.