Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add nimadorostkar/Claude-Skills-collection --skill legacy-modernizationgit clone --depth 1 https://github.com/nimadorostkar/Claude-Skills-collectionWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/legacy-modernization)<a href="https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/legacy-modernization"><img src="https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/legacy-modernization/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/legacy-modernization"><img src="https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/legacy-modernization.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00040 | $0.00954 |
| Opus 5 | $0.00020 | $0.00477 |
| Sonnet 5 | $0.00008 | $0.00191 |
| Haiku 4.5 | $0.00004 | $0.00095 |
Grade A, and why
legacy-modernization scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Legacy Modernization
Purpose
Replace a legacy system incrementally, keeping it in production the entire time. The failure mode this skill exists to prevent is the two-year rewrite that ships nothing and is cancelled.
When to Use
- A system that works but resists change.
- Migrating off an unsupported framework, runtime, or vendor.
- Extracting a service from a monolith.
- Any proposal that starts with "we should just rewrite it".
Capabilities
- Characterization testing to capture undocumented behavior.
- Seam identification and dependency breaking.
- Strangler-fig migration behind a routing facade.
- Data migration with dual writes and backfills.
- Sequencing work so every step is independently shippable.
Inputs
- The legacy system, its deployment, and its actual traffic patterns.
- The concrete pain: what change is expensive, and how expensive.
- Constraints: uptime requirements, data volume, compliance, team capacity.
Outputs
- A migration plan of independently shippable increments.
- Characterization tests covering the behavior being preserved.
- A facade or router that lets old and new coexist.
- A decommissioning checklist for the old path.
Workflow
- Resist the rewrite — Establish what the current system does that a rewrite would have to rediscover. This list is always longer than expected, and it is the argument.
- Pin the behavior — Characterization tests at the outermost boundary you can reach: HTTP, CLI, batch output. Record what it does, bugs included.
- Introduce a facade — Put a routing layer in front of the capability. Every request now flows through a point you control.
- Carve off one capability — Choose the smallest one with clear boundaries. Implement it in the new system. Route a percentage of traffic to it.
- Compare, then cut over — Run both and diff the outputs (shadow mode) until you trust the new path. Then flip the route.
- Delete the old path — Immediately. A migration that leaves both paths alive has doubled the maintenance burden, not reduced it.
- Repeat — Next capability. Each cycle ships.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 12d ago First seen · 97 lines · 40 tokens per session scan A d144ced0d250
legacy-modernization is a skill published in the GitHub repository nimadorostkar/Claude-Skills-collection (26 stars, last pushed 24d ago), licensed MIT. It adds 40 tokens to every session and 954 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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