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yeaight7yeaight7/agent-powerups/skills/search-before-building/SKILL.md

search-before-building

Skill6 starsChanged 4 months agoApache-2.0View on GitHub

Use when about to add a new helper, utility, or abstraction, a task sounds like a solved problem, a new external dependency is being considered, or custom code is proposed without checking what already exists.

1 other project uses a version of this.

Adopted by

Most recently taken up by

The file

We split this skill into the rules it gives an agent

10 rules. About 0 are common, 10 are distinctive, and 0 are very specific to this project.

  • ≈0

    Common · estimate

    Many files like this have a rule of this kind.

  • ≈10

    Distinctive · estimate

    This author's own choices. Worth a look.

  • 0

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Distinctive:

    Before implementing new functionality, verify it does not already exist and that the best option has been considered.

    line 8
  2. Distinctive:

    Run in order. Stop when you find a satisfactory answer.

    line 19
  3. Distinctive:

    Search the current codebase before anything else:

    line 23
  4. Distinctive:

    Check: Does equivalent logic already exist?

    line 30
  5. Distinctive:

    Search the relevant registry for the project language:

    line 34
  6. Distinctive:

    Check whether an MCP server already provides this capability:

    line 52
  7. Distinctive:

    Check the Agent Powerups catalog for MCP configs:

    line 59
  8. Distinctive:

    If a server covers the need, prefer configuring it over writing code.

    line 65
  9. Distinctive:

    Before adopting a package, verify:

    line 69
  10. Distinctive:

    If time-boxed, spend at most 5 minutes on Steps 1–2 before deciding.

    line 94

≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

Search Before Building

Before implementing new functionality, verify it does not already exist and that the best option has been considered.

When to Use

  • About to add a new helper, utility, or abstraction
  • Task says "add X" and X sounds like a solved problem
  • Considering a new external dependency
  • Agent proposes writing something from scratch without checking first

Four-Step Check

Run in order. Stop when you find a satisfactory answer.

Step 1 — Repo-first

Search the current codebase before anything else:

rg "<keyword>" src/ lib/ --type ts --type js -l
rg "<keyword>" --glob "*.py" -l

Check: Does equivalent logic already exist? Is it importable as-is, or would it need wrapper work?

Step 2 — Package registry

Search the relevant registry for the project language:

LanguageRegistrySearch method
TypeScript/JSnpmnpm search <keyword> or npmjs.com
PythonPyPIpip index search <keyword> or pypi.org
Gopkg.go.devweb search site:pkg.go.dev <keyword>
Rustcrates.iocargo search <keyword>

Score each candidate:

  • Maintenance: last commit < 1 year, open issues ratio
  • Popularity: weekly downloads or GitHub stars
  • License: MIT / Apache-2.0 / BSD preferred; check for GPL/commercial constraints
  • Size: avoid heavy packages for a single feature

Step 3 — MCP / tool servers

Check whether an MCP server already provides this capability:

# List currently configured MCP servers
cat .mcp.json 2>/dev/null || cat ~/.claude/settings.json | grep -A5 '"mcpServers"'

Check the Agent Powerups catalog for MCP configs:

apx list --type mcp-config

If a server covers the need, prefer configuring it over writing code.

Step 4 — Maintenance and license risk

Before adopting a package, verify:

  • Not abandoned (last release within 18 months)
  • License compatible with this project
  • No known critical CVEs (npm audit / pip-audit / cargo audit)
  • Dependency count is reasonable (< 20 transitive for small utilities)

Decision

FindingAction
Exact match in repoReuse — import and use; refactor only if the interface is incompatible
Exact external match, acceptable riskAdopt — install and use directly; do not wrap unless the API is hostile
Partial matchWrap — install, write a thin adapter; keep the adapter < 50 lines
Multiple weak matchesCompose — combine 2–3 small packages; document why
No suitable optionBuild — write custom code; document the gap search found

Constraint: Do Not Skip

This check is mandatory before:

  • Writing any utility over 20 lines that solves a generic problem
  • Adding a new external dependency
  • Configuring a new MCP server

If time-boxed, spend at most 5 minutes on Steps 1–2 before deciding.

Anti-Patterns

  • Repo-skip: Writing code without checking if an internal equivalent exists
  • Registry-skip: Adding a package without checking simpler alternatives
  • Over-wrapping: Encapsulating a library so heavily that the benefits are lost
  • Dependency bloat: Pulling in a 5 MB package for a single 10-line feature

Verification

  • The Step 1 repo search ran before any custom code was written
  • Registry candidates were scored on maintenance, popularity, license, and size
  • MCP/tool-server coverage was checked before writing new integration code
  • Any adopted package passed the abandonment, license, CVE, and dependency-count checks
  • The decision (reuse / adopt / wrap / compose / build) is recorded — and for build, the gap the search found is documented

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