Chalk Labs
Need help deploying legacy-code?
Chalk Labs sets up agents like this inside real teams: connected to your tools, tested on your data, with a human in the loop where it matters.
Install
Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.
npx agentmarket install skill/omarsiwy-legacy-code
Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.
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About
Use cases: writing
Reviews
Write a reviewNo reviews yet. Installed it? Reviews come from verified installers only. How reviews work
Permissions
What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.
- Tools
- No tools found
- Secrets
- None asked for
- Install scripts
- None found
Network hosts it talks to 1
codeload.github.com· found in install command
Files it touches
~/.claude/skills/legacy-code
What's inside
- Skill name
legacy-code- Description
- Safely modify code that lacks tests. Applies the Legacy Code Change Algorithm — find seams, write characterization tests, break dependencies, then change. Use when modifying untested code, adding features to legacy systems, breaking dependencies for testability, wrapping or sprouting new behavior alongside old code, writing characterization tests, or when user mentions "legacy code", "no tests", "untested", "seam", or "safe refactor".
- License
- unknown
- Instructions
- 83 lines in SKILL.md · view on GitHub
Files (2)
- REFERENCE.md
- SKILL.md
The license isn't open source, so the instructions aren't shown here. Read SKILL.md on GitHub
More from OmarSiwy/NixOSConfig
- 0.542score
branchless
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Replace a data-dependent branch with arithmetic or a select.
SkillBFreshness: B★ 1Claude Code +9 - 0.542score
data-oriented-design
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Data-oriented design for code layout, architecture, and performance.
SkillBFreshness: B★ 1Claude Code +9 - 0.542score
simd-loops
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Turn a hot scalar loop into SIMD.
SkillBFreshness: B★ 1Claude Code +9 - 0.542score
api-design
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Design and evaluate system-level APIs against the five characteristics of reusable components.
SkillBFreshness: B★ 1Claude Code +9 - 0.542score
expert-research-access
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Read paywalled papers (IEEE, Elsevier, Springer, Wiley, ACS, JSTOR, PMC, SciFinder) through the research-gateway MCP server using institutional SSO.
SkillBFreshness: B★ 1Claude Code +9 - 0.497score
clean-room-pseudocode-pipeline
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Reimplement a codebase function-by-function through a strict clean-room pseudocode handoff.
SkillCFreshness: C★ 1Claude Code +9 - 0.492score
refactoring-patterns
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Fowler-based refactoring and enterprise patterns.
SkillCFreshness: C★ 1Claude Code +9 - 0.492score
pragmatic-programmer
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Pragmatic Programmer decision heuristics for code changes.
SkillCFreshness: C★ 1Claude Code +9 - 0.472score
diagnosing-bugs
OmarSiwy
Diagnosis loop for hard bugs and performance regressions.
SkillCFreshness: C★ 1Claude Code +9 - 0.467score
domain-modeling
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Build and sharpen a project's domain model.
SkillCFreshness: C★ 1Claude Code +9 - 0.467score
codebase-design
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Shared vocabulary for designing deep modules.
SkillCFreshness: C★ 1Claude Code +9 - 0.456score
implement
OmarSiwy
Implement a piece of work based on a spec or set of tickets.
SkillCFreshness: C★ 1Claude Code +9
Signals
- Stars
- 1
- Forks
- 0
- Open issues
- 0
- Last commit (this folder)
- Jul 22, 2026 (3 months ago)
From GitHub (fetched Oct 24, 2026).
Details
- License
- License unknown
- Repository
- github.com/OmarSiwy/NixOSConfig
- First seen
- Oct 24, 2026
- Last checked
- Oct 24, 2026
- Source
- GitHubgithub-graphql
More from OmarSiwy
- 0.542score
expert-research-access
OmarSiwy
Read paywalled papers (IEEE, Elsevier, Springer, Wiley, ACS, JSTOR, PMC, SciFinder) through the research-gateway MCP server using institutional SSO.
SkillBFreshness: B★ 1Claude Code +9 - 0.542score
data-oriented-design
OmarSiwy
Data-oriented design for code layout, architecture, and performance.
SkillBFreshness: B★ 1Claude Code +9 - 0.542score
simd-loops
OmarSiwy
Turn a hot scalar loop into SIMD.
SkillBFreshness: B★ 1Claude Code +9 - 0.542score
api-design
OmarSiwy
Design and evaluate system-level APIs against the five characteristics of reusable components.
SkillBFreshness: B★ 1Claude Code +9 - 0.542score
branchless
OmarSiwy
Replace a data-dependent branch with arithmetic or a select.
SkillBFreshness: B★ 1Claude Code +9 - 0.497score
clean-room-pseudocode-pipeline
OmarSiwy
Reimplement a codebase function-by-function through a strict clean-room pseudocode handoff.
SkillCFreshness: C★ 1Claude Code +9
Done for you
Rather not set it up yourself?
Chalk Labs scopes, builds and runs agents for your team: the task audit, the eval harness, the integrations and the weekly ops report. Fixed scope, priced before we start.
See how we build AI agents →Read the case studies
Chalk Labs is a two-founder AI and growth studio. We build AI agents, CRMs and MVPs for Web3 and AI companies, and have shipped 50+ product and token launches.
- launches shipped
- 50+
- launches shipped
- media placements
- 500+
- media placements
- founders on every account
- 2
- founders on every account
Press we've placed: Forbes · CoinDesk · Decrypt · Cointelegraph · The Block
Rahil Jain, Co-founder, Chalk Labs. Ex-Goldman Sachs engineer. You talk to the person who builds it.
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Cite this page
legacy-code skill. Agent Mart. https://agentmart.dev/skills/omarsiwy-legacy-code (last updated 2026-10-24)