url-shortener SKILL.md skillA
url-shortener from pierry/harness-kit is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add pierry/harness-kit/url-shortener@git:20260615.091526bPins git:20260615.091526b in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- pierry/harness-kit
- Path
.claude/agents/system-architect/skills/url-shortener/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260615.091526b, committed Jun 15, 2026
- Size
- 13,396 bytes
- Repository stars
- 4
- License
- MIT
Design a URL shortener at scale (TinyURL / bit.ly style): short-code generation, redirect path, cache, partitioning, analytics, abuse. Topic playbook from the System Design series EP22. Use when the system is a link shortener, redirect service, or any read-heavy key-to-value lookup at scale. Sensors and evals gate.
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
Design a URL shortener. Topic playbook. The agent loads this reference and adapts it to the user's
real scale and product rules, then emits the SDD via the generic template.
Use when the problem is: a link shortener, a redirect service, vanity/branded short links, or any
read-dominated lookup of an opaque key to a stored value. Looks tiny, hides almost every core system
design theme: read>>write load, unique key generation, cache, partitioning, consistency, abuse,
analytics, multi-region.
Ask once if missing: target read QPS, custom-alias support, single vs multi-region, dedup policy
(same long URL = same code or not), edit/disable-after-create.
Read:
- guides/design-method.md
- guides/writing-style.md
- guides/templates/system-design.md
- guides/pipeline.md
Generate the SDD using the template, filled with the reference below, adapted to user scale.
Save to .claude/runtime/outputs/architect/design/{feature_id}.md.
Sensors: sensors/design-structure.md, sensors/design-rigor.md. Evals: evals/design-quality.md.
---
## Reference architecture (adapt, do not copy blindly)
One line: two very different flows share one product. **Create** is moderate write. **Resolve** is
…Read the whole file at its exact version.
How to install
mdr add pierry/harness-kit/url-shortener@sha256:cad5200bd0bc01b4The line at the top of this page pins the label git:20260615.091526b, 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_w46lj4guedfnr4ce)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Jun 15, 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 (13396 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
pierry/harness-kit · 4 stars · license MIT · pushed 2026-10-05 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_w46lj4guedfnr4ce GET https://markdownregistry.com/api/v1/resolve?ref=pierry/harness-kit/url-shortener GET https://markdownregistry.com/api/v1/blob/cad5200bd0bc01b4fbd208bc85911feb36e750152c75c028bcbe4c16ff205c9a
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.