cs0618-hunter

cs0618-hunter is a skill for Claude Code, Codex from joslat/maf-doctor. It costs 85 tokens per session (731 once invoked), scanned A, original, MIT.

A tool and procedure for finding obsolete API warnings in .NET builds. An API is a programming interface, and obsolete means a library or project marks it as no longer recommended for use.

In plain words
What is it for?
Use it to run a .NET build, collect CS0618 and CS0246 diagnostics, identify the affected calls, and match obsolete-API warnings with their canonical fixes.
Why use it?
It uses the compiler's actual build warnings, which can reveal indirect obsolete calls, unexpected overload choices, and obsolete code marked inside the project itself. It then connects the warnings to known fixes in a registry.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to run a .NET build, collect CS0618 and CS0246 diagnostics, identify the affected calls, and match obsolete-API warnings with their canonical fixes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/joslat/maf-doctor/cs0618-hunter
Install

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.

Any agent
npx skills add joslat/maf-doctor --skill cs0618-hunter
Clone the repo
git clone --depth 1 https://github.com/joslat/maf-doctor

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for cs0618-hunter

README.md
[![agentmods](https://agentmods.dev/badge/skills/joslat/maf-doctor/cs0618-hunter/github.svg)](https://agentmods.dev/skills/joslat/maf-doctor/cs0618-hunter)
Your own site
<a href="https://agentmods.dev/skills/joslat/maf-doctor/cs0618-hunter"><img src="https://agentmods.dev/badge/skills/joslat/maf-doctor/cs0618-hunter/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.

agentmods 80×15 button for cs0618-hunter

Your own site · 80×15
<a href="https://agentmods.dev/skills/joslat/maf-doctor/cs0618-hunter"><img src="https://agentmods.dev/badge/skills/joslat/maf-doctor/cs0618-hunter.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 85 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 731 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00085 $0.00731
Opus 5 $0.00043 $0.00365
Sonnet 5 $0.00017 $0.00146
Haiku 4.5 $0.00009 $0.00073

Measured 11d ago against content hash 2c7e79a622dd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

cs0618-hunter 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 11d 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.

.github/skills/cs0618-hunter/SKILL.md · 49 lines

How it starts

The opening of the file, as written. The whole thing — 49 lines — stays where its author put it; the contents beside it link to each section on GitHub.

cs0618-hunter — compiler ground-truth for obsolete API usage

⚡ Prefer the MCP tool. The maf-autopilot MCP server exposes MafRunCs0618Hunt(projectPath) — it shells dotnet build, parses every CS0618 / CS0246 diagnostic, joins each one to its canonical fix in the obsolete-API registry, and returns a structured report. The procedural walkthrough below is preserved for when you need to run the steps manually (offline, debugging the tool itself, etc.).

Why the compiler stays authoritative

[email protected] was the first release to surface [Obsolete] in member listings (PR #318 closes issue #316); this repository pins 0.9.1. That's an excellent pre-build static check, but three classes of obsoletion remain compiler-only:

  1. Transitive obsoletions — the API your code calls isn't obsolete, but it forwards to one that is.
  2. Overload-resolution surprises — a more-specific overload was added in a minor release and your literal types now bind to it.
  3. Project-local [Obsolete] — types your team marked obsolete in this solution. Static inspection of NuGet packages can't see those.

For all three, dotnet build | Select-String "warning CS0618" is the only authoritative answer.

Manual fallback workflow

When MafRunCs0618Hunt is unavailable:

# Step 1: get the baseline
dotnet build 2>&1 | Select-String "warning CS0618"

# Step 2: for each warning, look up the canonical fix in the registry
# (the LLM should call MafRegistryLookup with the matching entry ID,
#  or open .github/skills/maf-obsolete-api-registry/registry.yaml)

# Step 3: apply the fix; re-run the build; confirm the warning is gone

# Step 4: move on to the next warning. Never batch.

# Step 5: declare done only when:
dotnet build 2>&1 | Select-String "warning CS0618" | Measure-Object | Select-Object -ExpandProperty Count
# returns 0.

Read the full file on GitHub · 49 lines

Changes

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.

  1. 11d ago First seen · 49 lines · 85 tokens per session scan A 2c7e79a622dd

Subscribe to this mod's changes

cs0618-hunter is a skill published in the GitHub repository joslat/maf-doctor (14 stars, last pushed 24d ago), licensed MIT. It adds 85 tokens to every session and 731 once invoked, about $0.0004 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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