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Overview ¶
Package epc decodes GS1 Electronic Product Code (EPC) binary identifiers — the data on UHF RAIN RFID (EPC Gen2 / ISO 18000-63) tags used pervasively in retail item-level tagging and supply-chain logistics. It turns the 96-bit EPC read from a tag into the GS1 identifiers it encodes: the company prefix, item reference, serial number, the canonical EPC URIs, and the reconstructed GTIN-14.
This is a whole RFID band the toolkit did not decode: PromptZero covers HF (ISO 14443 / 15693 / NDEF) and LF (EM4100 / HID / FDX-B / T5577), but not the UHF EPC layer. Reading a UHF tag needs a RAIN reader (out of scope — hardware), but the EPC binary an operator captures decodes entirely offline and deterministically here.
Wrap-vs-native: native. The EPC binary is a fixed bit-field layout with a per-partition split table and a GS1 mod-10 check digit; no third-party dependency is warranted. The SGTIN-96 layout, the partition table, and the SGTIN→GTIN reconstruction are taken from the GS1 EPC Tag Data Standard and verified byte-for-byte against its canonical worked example — 3074257BF7194E4000001A85 → urn:epc:tag:sgtin-96:3.0614141.812345.6789 (company prefix 0614141, item reference 812345, serial 6789) — not recalled.
Covered: the complete set of 96-bit schemes — SGTIN-96 (0x30, retail item), SSCC-96 (0x31, logistics unit), SGLN-96 (0x32, location), GRAI-96 (0x33, returnable asset), GIAI-96 (0x34, individual asset), and GID-96 (0x35, the General Identifier with no GS1 key). Each is fully field-decoded and verified against a worked vector (SGTIN/SSCC additionally reconstruct the GTIN-14 / SSCC-18 with a recomputed mod-10 check digit; the partition-based schemes are anchored against the epc-encoding-utils library used as an oracle). Plus SGTIN-198 (header 0x36): the 198-bit SGTIN whose serial is an alphanumeric 7-bit-ASCII string rather than a numeric value (internal/ sgtin198.go). Unsupported (reported, not guessed): the other 198-bit variants (GRAI-170 / GIAI-202 / SGLN-195) and any header outside 0x30-0x36.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type GIAI ¶ added in v0.471.0
type GIAI struct {
Filter int `json:"filter"`
Partition int `json:"partition"`
CompanyPrefix string `json:"company_prefix"`
AssetReference uint64 `json:"asset_reference"`
TagURI string `json:"tag_uri"`
PureIdentityURI string `json:"pure_identity_uri"`
}
GIAI is a decoded GIAI-96 EPC.
type GID ¶ added in v0.470.0
type GID struct {
GeneralManagerNumber uint64 `json:"general_manager_number"`
ObjectClass uint64 `json:"object_class"`
SerialNumber uint64 `json:"serial_number"`
TagURI string `json:"tag_uri"`
PureIdentityURI string `json:"pure_identity_uri"`
}
GID is a decoded GID-96 EPC (General Identifier).
type GRAI ¶ added in v0.471.0
type GRAI struct {
Filter int `json:"filter"`
Partition int `json:"partition"`
CompanyPrefix string `json:"company_prefix"`
AssetType string `json:"asset_type"`
SerialNumber uint64 `json:"serial_number"`
TagURI string `json:"tag_uri"`
PureIdentityURI string `json:"pure_identity_uri"`
}
GRAI is a decoded GRAI-96 EPC.
type Result ¶
type Result struct {
Scheme string `json:"scheme"`
SchemeHeader string `json:"scheme_header"`
SGTIN *SGTIN `json:"sgtin,omitempty"`
SSCC *SSCC `json:"sscc,omitempty"`
SGLN *SGLN `json:"sgln,omitempty"`
GRAI *GRAI `json:"grai,omitempty"`
GIAI *GIAI `json:"giai,omitempty"`
GID *GID `json:"gid,omitempty"`
Notes []string `json:"notes,omitempty"`
}
Result is the decoded EPC.
type SGLN ¶ added in v0.471.0
type SGLN struct {
Filter int `json:"filter"`
Partition int `json:"partition"`
CompanyPrefix string `json:"company_prefix"`
LocationReference string `json:"location_reference"`
Extension uint64 `json:"extension"`
TagURI string `json:"tag_uri"`
PureIdentityURI string `json:"pure_identity_uri"`
}
SGLN is a decoded SGLN-96 EPC.
type SGTIN ¶
type SGTIN struct {
TagSize int `json:"tag_size"` // 96 or 198
Filter int `json:"filter"`
Partition int `json:"partition"`
CompanyPrefix string `json:"company_prefix"`
ItemReference string `json:"item_reference"`
// SerialNumber is the numeric serial of an SGTIN-96. SerialString is the
// 7-bit-ASCII serial of an SGTIN-198; exactly one is meaningful per the
// tag size.
SerialNumber uint64 `json:"serial_number,omitempty"`
SerialString string `json:"serial_string,omitempty"`
GTIN14 string `json:"gtin14"`
TagURI string `json:"tag_uri"`
PureIdentityURI string `json:"pure_identity_uri"`
}
SGTIN is a decoded SGTIN EPC (Serialised Global Trade Item Number), either the 96-bit form (numeric serial) or the 198-bit form (alphanumeric serial).
type SSCC ¶ added in v0.469.0
type SSCC struct {
Filter int `json:"filter"`
Partition int `json:"partition"`
CompanyPrefix string `json:"company_prefix"`
SerialReference string `json:"serial_reference"`
SSCC18 string `json:"sscc18"`
TagURI string `json:"tag_uri"`
PureIdentityURI string `json:"pure_identity_uri"`
}
SSCC is a decoded SSCC-96 EPC (Serial Shipping Container Code).
Source Files