chicago-transit-duckdb SKILL.md skillA
chicago-transit-duckdb from misterclean/ai-plugins is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add misterclean/ai-plugins/chicago-transit-duckdb@v1.0.0Pins v1.0.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- misterclean/ai-plugins
- Path
skills/chicago-transit-duckdb/SKILL.md- Versions recorded
- 1
- Latest version
- v1.0.0, committed Nov 1, 2026
- Size
- 7,821 bytes
- Repository stars
- 3
- License
- MIT
Analyze and efficiently query CTA bus, CTA L train, and Metra vehicle-position archives from chicagotransitalerts.app using DuckDB 2. Use for this position feed, recent Chicago transit data, route or line fleet deployment, sampling cadence, freshness, estimated coordinates, bus headways, movement diagnostics, JSON-to-Parquet conversion, incremental ingestion, or query-performance profiling. Apply even when the user gives only the subscription page or asks for the last several complete days. Do…
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
# Chicago Transit with DuckDB Turn the public daily position archive into a validated, repeatable analytical dataset. Prefer persistent native DuckDB tables for repeated local queries, minute summaries for fleet readouts, and sorted Parquet for portable storage. Treat historical benchmark results as measured evidence, not a guarantee for future workloads. ## Establish scope and evidence 1. Identify Chicago dates, modes, routes/lines, grain and requested output. Infer sensible defaults rather than requiring an implementation questionnaire. 2. Read [source-and-schema.md](references/source-and-schema.md) before ingestion or timestamp interpretation. Fetch the current index once; the subscription page is a discovery page, not the position dataset. 3. Select complete calendar days in `America/Chicago`. For “last seven complete days”, end yesterday in that timezone. Use a trusted client/session date as `--as-of` when supplied. Verify every requested file is published. State missing dates instead of silently substituting an older window. …
Read the whole file at its exact version.
How to install
mdr add misterclean/ai-plugins/chicago-transit-duckdb@sha256:eead2a8fbbd8a64aThe line at the top of this page pins the label v1.0.0, 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_gdtjipme4ma7oo55)
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Versions
The registry has recorded 1 version of this file, committed on Nov 1, 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 (7821 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
misterclean/ai-plugins · 3 stars · license MIT · pushed 2026-11-01 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_gdtjipme4ma7oo55 GET https://markdownregistry.com/api/v1/resolve?ref=misterclean/ai-plugins/chicago-transit-duckdb GET https://markdownregistry.com/api/v1/blob/eead2a8fbbd8a64ab5959f45dcb261125d23fdb471e57ea418fa249461fccbac
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.