Inspect links

Two kinds of links use the same csgo_econ_action_preview command. Their payload determines how they are resolved.

Embedded (masked) links

An embedded link contains a hex token carrying protobuf item data, a mask byte and a checksum. The item can be decoded locally.

import { createInspectUrl, analyzeUrl, decodeMaskedData } from 'cs2-inspect-lib'

const url = createInspectUrl({
  defindex: 7, paintindex: 44, paintseed: 661, paintwear: 0.15
})
const analysis = analyzeUrl(url)
if (analysis.hex_data) {
  console.log(decodeMaskedData(analysis.hex_data))
}

decodeMaskedData expects the complete hex token, including its framing and checksum, rather than bare protobuf bytes. Zero-mask links created by this library and checksum-valid nonzero XOR-mask links are supported. Historical unprefixed protobuf-plus-checksum input remains accepted. Legacy decoding does not authenticate the checksum; do not treat decoded data as proof of item ownership or authenticity.

Legacy inventory and market links

Legacy payloads reference an item held by Steam:

Payload	Meaning
S<owner>A<asset>D<inspect-token>	Inventory item
M<listing>A<asset>D<inspect-token>	Market listing

These require an authenticated Steam client and an available Game Coordinator. See Steam integration.

import { analyzeUrl, requiresSteamClient } from 'cs2-inspect-lib'

// Example format only; these IDs do not identify a real item.
const url = 'S76561198123456789A987654321D456789123'
console.log(analyzeUrl(url).url_type) // 'unmasked'
console.log(requiresSteamClient(url)) // true

Accepted input forms

The URL analyzer accepts a full steam://rungame/730/… link, a preview command, a hex token or a legacy S/M payload. Spaces and %20 separators are supported. normalizeUrl(url) returns the canonical Steam URL form.

validateUrl performs basic validation. Use analyzeUrl for actual format classification, and decode to verify that the payload can be read.

Working with item IDs

Decoded itemid values use bigint. Use decimal strings when writing JSON:

const json = JSON.stringify(item, (_key, value) =>
  typeof value === 'bigint' ? value.toString() : value
)