cs2-masked-inspect (C#)

Pure C# library for encoding and decoding CS2 masked inspect links — no runtime dependencies, targets .NET 8+ and .NET 10+.

Installation

dotnet add package VlyDev.Cs2MaskedInspect

Usage

Deserialize a CS2 inspect link

using VlyDev.Cs2MaskedInspect;

// Accepts a full steam:// URL or a raw hex string
var item = InspectLink.Deserialize(
    "steam://run/730//+csgo_econ_action_preview%20E3F3367440334DE2FBE4C345E0CBE0D3..."
);

Console.WriteLine(item.DefIndex);   // 7  (AK-47)
Console.WriteLine(item.PaintIndex); // 422
Console.WriteLine(item.PaintSeed);  // 922
Console.WriteLine(item.PaintWear);  // ~0.04121
Console.WriteLine(item.ItemId);     // 46876117973

foreach (var s in item.Stickers)
    Console.WriteLine(s.StickerId); // 7436, 5144, 6970, 8069, 5592

Serialize an item to a hex payload

using VlyDev.Cs2MaskedInspect;

var data = new ItemPreviewData
{
    DefIndex   = 60,
    PaintIndex = 440,
    PaintSeed  = 353,
    PaintWear  = 0.005411375779658556f,
    Rarity     = 5,
};

string hex = InspectLink.Serialize(data);
// 00183C20B803280538E9A3C5DD0340E102C246A0D1

string url = $"steam://run/730//+csgo_econ_action_preview%20{hex}";

Item with stickers and keychains

using VlyDev.Cs2MaskedInspect;

var data = new ItemPreviewData
{
    DefIndex   = 7,
    PaintIndex = 422,
    PaintSeed  = 922,
    PaintWear  = 0.04121f,
    Rarity     = 3,
    Quality    = 4,
    Stickers   =
    [
        new Sticker { Slot = 0, StickerId = 7436 },
        new Sticker { Slot = 1, StickerId = 5144, Wear = 0.1f },
    ],
};

string hex = InspectLink.Serialize(data);
var decoded = InspectLink.Deserialize(hex); // round-trip

---

Gen codes

Gen codes are space-separated command strings used on CS2 community servers to spawn items.

Format:

!gen {defindex} {paintindex} {paintseed} {paintwear} [{s0_id} {s0_wear} ... {s4_id} {s4_wear}] [{kc_id} {kc_wear} ...]

• Stickers are always represented as 5 slot pairs (padded with 0 0 for empty slots)
• Keychains are appended without padding, only for present slots
• Float values have trailing zeros stripped (max 8 decimal places); 0.0 becomes "0"

Generate a Steam inspect URL from parameters

using VlyDev.Cs2MaskedInspect;

string url = GenCode.Generate(
    defIndex:   7,
    paintIndex: 474,
    paintSeed:  306,
    paintWear:  0.22540508f,
    rarity:     6);
// steam://rungame/730/76561202255233023/+csgo_econ_action_preview%200018...

Convert an ItemPreviewData to a gen code

using VlyDev.Cs2MaskedInspect;

var item = new ItemPreviewData
{
    DefIndex   = 7,
    PaintIndex = 474,
    PaintSeed  = 306,
    PaintWear  = 0.22540508f,
    Stickers   = [new Sticker { Slot = 2, StickerId = 7203 }],
};

string code = GenCode.ToGenCode(item);
// "!gen 7 474 306 0.22540508 0 0 0 0 7203 0 0 0 0 0"

string code2 = GenCode.ToGenCode(item, "!g"); // custom prefix

Parse a gen code string

using VlyDev.Cs2MaskedInspect;

var item = GenCode.ParseGenCode("!gen 7 474 306 0.22540508 0 0 0 0 7203 0 0 0 0 0");
Console.WriteLine(item.DefIndex);    // 7
Console.WriteLine(item.PaintIndex);  // 474
Console.WriteLine(item.PaintSeed);   // 306
Console.WriteLine(item.PaintWear);   // 0.22540508

var item2 = GenCode.ParseGenCode("7 474 306 0.22540508"); // prefix is optional

Convert an existing inspect link directly to a gen code

string code = GenCode.GenCodeFromLink("steam://rungame/730/76561202255233023/+csgo_econ_action_preview%20001A...");
// "!gen 7 474 306 0.22540508"

---

Validation

Use IsMasked() and IsClassic() to detect the link type without decoding it.

using VlyDev.Cs2MaskedInspect;

// New masked format (pure hex blob) — can be decoded offline
var maskedUrl = "steam://run/730//+csgo_econ_action_preview%20E3F3...";
InspectLink.IsMasked(maskedUrl);   // true
InspectLink.IsClassic(maskedUrl);  // false

// Hybrid format (S/A/D prefix with hex proto after D) — also decodable offline
var hybridUrl = "steam://rungame/730/.../+csgo_econ_action_preview%20S76561199323320483A50075495125D1101C4C4FCD4AB10...";
InspectLink.IsMasked(hybridUrl);   // true
InspectLink.IsClassic(hybridUrl);  // false

// Classic format — requires Steam Game Coordinator to fetch item info
var classicUrl = "steam://rungame/730/.../+csgo_econ_action_preview%20S76561199842063946A49749521570D2751293026650298712";
InspectLink.IsMasked(classicUrl);  // false
InspectLink.IsClassic(classicUrl); // true

---

Validation rules

Deserialize() enforces:

Rule	Limit	Exception
Hex payload length	max 4,096 characters	ArgumentException
Protobuf field count	max 100 per message	InvalidOperationException

Serialize() enforces:

Field	Constraint	Exception
PaintWear	[0.0, 1.0]	ArgumentOutOfRangeException
CustomName	max 100 characters	ArgumentOutOfRangeException

---

How the format works

Three URL formats are handled:

1. New masked format — pure hex blob after csgo_econ_action_preview:

   steam://run/730//+csgo_econ_action_preview%20<hexbytes>
   

2. Hybrid format — old-style S/A/D prefix, but with a hex proto appended after D (instead of a decimal did):

   steam://rungame/730/.../+csgo_econ_action_preview%20S<steamid>A<assetid>D<hexproto>
   

3. Classic format — old-style S/A/D with a decimal did; requires Steam GC to resolve item details.

For formats 1 and 2 the library decodes the item offline. For format 3 only URL parsing is possible.

The hex blob (formats 1 and 2) has the following binary layout:

[key_byte] [proto_bytes XOR'd with key] [4-byte checksum XOR'd with key]

Section	Size	Description
key_byte	1 byte	XOR key. 0x00 = no obfuscation (tool links). Other values = native CS2 links.
proto_bytes	variable	CEconItemPreviewDataBlock protobuf, each byte XOR'd with key_byte.
checksum	4 bytes	Big-endian uint32, XOR'd with key_byte.

Checksum algorithm

var buffer   = new byte[] { 0x00 }.Concat(protoBytes).ToArray();
uint crc     = Crc32(buffer);
uint xored   = ((crc & 0xFFFF) ^ ((uint)protoBytes.Length * crc)) & 0xFFFFFFFF;
// stored as big-endian uint32

PaintWear encoding

PaintWear is stored as a uint32 varint whose bit pattern is the IEEE 754 representation of a float. The library handles this transparently — callers always work with float values.

---

Proto field reference

CEconItemPreviewDataBlock

Field	Number	Type	Description
AccountId	1	uint32	Steam account ID (often 0)
ItemId	2	uint64	Item ID in the owner's inventory
DefIndex	3	uint32	Item definition index (weapon type)
PaintIndex	4	uint32	Skin paint index
Rarity	5	uint32	Item rarity
Quality	6	uint32	Item quality
PaintWear	7	uint32*	float reinterpreted as uint32
PaintSeed	8	uint32	Pattern seed (0–1000)
KillEaterScoreType	9	uint32	StatTrak counter type
KillEaterValue	10	uint32	StatTrak value
CustomName	11	string	Name tag
Stickers	12	repeated Sticker	Applied stickers
Inventory	13	uint32	Inventory flags
Origin	14	uint32	Origin
QuestId	15	uint32	Quest ID
DropReason	16	uint32	Drop reason
MusicIndex	17	uint32	Music kit index
EntIndex	18	int32	Entity index
PetIndex	19	uint32	Pet index
Keychains	20	repeated Sticker	Applied keychains

Sticker

Field	Number	Type	Description
Slot	1	uint32	Slot position
StickerId	2	uint32	Sticker definition ID
Wear	3	float?	Wear (fixed32)
Scale	4	float?	Scale (fixed32)
Rotation	5	float?	Rotation (fixed32)
TintId	6	uint32	Tint
OffsetX	7	float?	X offset (fixed32)
OffsetY	8	float?	Y offset (fixed32)
OffsetZ	9	float?	Z offset (fixed32)
Pattern	10	uint32	Pattern (keychains)

---

Known test vectors

Vector 1 — Native CS2 link (XOR key 0xE3)

E3F3367440334DE2FBE4C345E0CBE0D3E7DB6943400AE0A379E481ECEBE2F36F
D9DE2BDB515EA6E30D74D981ECEBE3F37BCBDE640D475DA6E35EFCD881ECEBE3
F359D5DE37E9D75DA6436DD3DD81ECEBE3F366DCDE3F8F9BDDA69B43B6DE81EC
EBE3F33BC8DEBB1CA3DFA623F7DDDF8B71E293EBFD43382B

Field	Value
ItemId	46876117973
DefIndex	7 (AK-47)
PaintIndex	422
PaintSeed	922
PaintWear	≈ 0.04121
Rarity	3
Quality	4
Sticker IDs	[7436, 5144, 6970, 8069, 5592]

Vector 2 — Tool-generated link (key 0x00)

new ItemPreviewData { DefIndex = 60, PaintIndex = 440, PaintSeed = 353,
                      PaintWear = 0.005411375779658556f, Rarity = 5 }

Expected hex:

00183C20B803280538E9A3C5DD0340E102C246A0D1

---

Running tests

dotnet test

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Contributing

Bug reports and pull requests are welcome on GitHub.

1. Fork the repository
2. Create a branch: git checkout -b my-fix
3. Make your changes and add tests
4. Ensure all tests pass: dotnet test
5. Open a Pull Request

All PRs require the CI checks to pass before merging.

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Author

VlyDev — vladdnepr1989@gmail.com

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License

MIT © VlyDev