decompiler-mcp

Instructions for using DecompilerServer to inspect .NET assemblies, which are compiled libraries used by applications such as Unity games. Decompiling means examining compiled code to understand its types and methods.

In plain words
What is it for?
Use it to investigate third-party DLLs, Unity or RimWorld assemblies, game binaries, and differences between assembly versions.
Why use it?
It provides an orderly way to load assemblies, find symbols, inspect members, and compare versions without guessing names.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/pardeike/decompilerserver/decompiler-mcp
Any agent
npx skills add pardeike/DecompilerServer --skill decompiler-mcp
Clone the repo
git clone --depth 1 https://github.com/pardeike/DecompilerServer

Made for: Claude Code, Codex.

Per session 77 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 920 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00077 $0.00920
Opus 5 $0.00039 $0.00460
Sonnet 5 $0.00015 $0.00184
Haiku 4.5 $0.00008 $0.00092

Measured 2d ago against content hash 94403822317c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

decompiler-mcp 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 2d 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.

skills/decompiler-mcp/SKILL.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

DecompilerServer MCP

Use DecompilerServer as the primary source of truth for loaded .NET assemblies. Do not guess member IDs or fall back to shell scans after one failed symbol lookup; use the discovery and diagnostic tools first.

Default Workflow

  1. Load or confirm context:
    • load_assembly with assemblyPath, or gameDir plus assemblyFile for Unity layouts.
    • list_contexts or status to confirm loaded and registered aliases and the current context. Passing contextAlias activates a registered alias on demand.
    • Use get_server_stats only when cache, index, or performance diagnostics matter.
  2. Discover symbols:
    • Use search_symbols first for fragments or when unsure whether a name is a type or member.
    • Use resolve_member_id first for fully-qualified or XML-doc-like guesses such as Namespace.Type.Member, Namespace.Type:Member, or M:Namespace.Type.Member.
    • Use search_types when looking only for types.
    • Use search_members when looking only for methods, fields, properties, or events.
  3. Inspect type surface:
    • Use list_members or get_members_of_type after resolving a type.
    • Prefer mode: "signatures" for orientation and mode: "full" only when extra metadata is needed.
  4. Read code:
    • Use get_decompiled_source for complete focused source.
    • Use plan_chunking and get_source_slice for large types or methods.
  5. Analyze relationships:
    • Use find_callers, find_callees, and find_usages for call/use questions.
    • Use find_base_types, find_derived_types, get_overrides, and get_implementations for inheritance questions.
    • Use get_il before proposing transpiler anchors; suggest_transpiler_targets should be treated as a real-IL hint list, not a substitute for reading IL.
  6. Compare versions:
    • Use compare_contexts for structural alias-level overview.
    • Use compare_symbols for type/member drill-down.
    • Use compare_symbols with compareMode: "body" only for method bodies.

Read the full file on GitHub · 54 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2d ago First seen · 54 lines · 77 tokens per session scan A 94403822317c

Subscribe to this mod's changes

decompiler-mcp is a skill published in the GitHub repository pardeike/DecompilerServer (93 stars, last pushed 16d ago), licensed MIT. It adds 77 tokens to every session and 920 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.

Related

Other skills, from other repositories

geometry-and-math

Use this skill when using Phaser 4 math and geometry utilities. Covers vectors, rectangles, circles, triangles, polygons, random number generation, angles, distance, interpolation, and snapping. Triggers on: Vector2, Rectangle, Circle, math, distance, angle, random, lerp.

phaserjs/phaser · 64 tokens

text-and-bitmaptext

Use this skill when displaying text in Phaser 4. Covers Text game objects, BitmapText, web fonts, text styling, word wrap, alignment, padding, and dynamic text content. Triggers on: Text, BitmapText, this.add.text, font, word wrap, text style.

phaserjs/phaser · 64 tokens

unity-mcp-orchestrator

Orchestrate Unity Editor via MCP (Model Context Protocol) tools and resources. Use when working with Unity projects through MCP for Unity - creating/modifying GameObjects, editing scripts, managing scenes, running tests, or any Unity Editor automation. Provides best practices, tool schemas, and workflow patterns for…

CoplayDev/unity-mcp · 72 tokens

gameobject-component-destroy

Destroy one or more Components from a target GameObject. Missing (null) components are skipped — they cannot be destroyed. Use 'gameobject-find' and 'gameobject-component-get' to identify the components first.

IvanMurzak/Unity-MCP · 49 tokens

assets-create-folder

Create a new folder under a parent folder inside 'Assets/'. The parent path must start with 'Assets/' and every intermediate folder in it must already exist. Refreshes the AssetDatabase at the end and returns the GUID(s) of the created folder(s).

IvanMurzak/Unity-MCP · 55 tokens

assets-prefab-save

Save the currently opened prefab edit stage back to its prefab asset without exiting the stage. Pair with 'assets-prefab-open' to enter the edit mode first.

IvanMurzak/Unity-MCP · 37 tokens