Generation patterns
Create predictable or random serials safely with sequence, random, and year tokens.
A generation pattern combines fixed text with supported tokens. Serial Trail validates capacity before starting and checkpoints large batches so they can resume without gaps.
Supported tokens
| Token | Result | Example |
|---|---|---|
{SEQ:6} |
Zero-padded sequence | 000123 |
{RAND:8} |
Random characters | 7KQ2M9AX |
{YYYY} |
Four-digit year | 2026 |
Example: ESP-{YYYY}-{SEQ:6} produces ESP-2026-000001.
Choose sequence width carefully
The width is the batch's capacity. {SEQ:3} has only 1,000 values from 000 through 999; use a wider token for long-lived pools. Serial Trail refuses a batch that would overflow the width.
Random-token safety
Longer random tokens reduce collision probability. Existing serials remain protected by the merchant-level uniqueness constraint; a collision is retried and a batch fails loudly if it cannot complete safely.
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