ml4t-data-export SKILL.md skillA
ml4t-data-export from ml4t/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add ml4t/skills/ml4t-data-export@git:20260901.c415df0Pins git:20260901.c415df0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- ml4t/skills
- Path
data/data-export/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260901.c415df0, committed Sep 1, 2026
- First version recorded
- May 28, 2026
- Size
- 4,370 bytes
- Repository stars
- 41
- License
- Apache-2.0
Export financial data in efficient columnar formats with schema enforcement. Use when persisting datasets for reproducible research or cross-pipeline sharing.
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
# Data Export
Saving financial data as CSV loses type information, bloats file size 5-10x, and makes every downstream read parse strings back into numbers - a tax paid on every pipeline run.
## The Problem
CSV is human-readable but machine-hostile: no type information (dates become strings, integers become floats), no compression (a 100MB Parquet file becomes 500MB CSV), no predicate pushdown (you must read the entire file to filter one column), and no schema enforcement (a renamed column breaks silently). For financial data pipelines where the same dataset is read hundreds of times by different notebooks, the cumulative cost of CSV is enormous in both time and correctness.
## The Pattern
### WRONG
```python
import pandas as pd
# CSV: no types, no compression, slow reads, 5x file size
df.to_csv("prices.csv", index=False)
# Every consumer must re-parse types
df = pd.read_csv("prices.csv", parse_dates=["date"]) # Hope the format matches
df["volume"] = df["volume"].astype(int) # Was saved as float because of NaN
```
### CORRECT
```python
import polars as pl
# Enforce schema before writing
SCHEMA = {
"timestamp": pl.Date,
"symbol": pl.Utf8,
"open": pl.Float64,
…Read the whole file at its exact version.
How to install
mdr add ml4t/skills/ml4t-data-export@sha256:fc229e910bc47d81The line at the top of this page pins the label git:20260901.c415df0, 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_4hzw6bfklnx22r4k)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between May 28, 2026 and Sep 1, 2026, about one every 96 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260901.c415df0 latest | 2026-09-01 | c415df0 | 4,370 B | A | view · diff |
| git:20260528.303089e | 2026-05-28 | 303089e | 4,380 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 (4370 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
ml4t/skills · 41 stars · license Apache-2.0 · pushed 2026-11-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_4hzw6bfklnx22r4k GET https://markdownregistry.com/api/v1/resolve?ref=ml4t/skills/ml4t-data-export GET https://markdownregistry.com/api/v1/blob/fc229e910bc47d81c7cf3aee5dee272e041de73fe7632964e2ff10ec80ecaeed
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.