Local-first systems
COBOL Bridge
In development In development. Not released.
Decades of business records live in mainframe files laid out by COBOL copybooks. COBOL Bridge is a Rust library, in development, that reads those files exactly, on the machine where the data already is, so a migration does not have to begin by shipping everything to someone else's cloud.
- Status
- In development. No public release yet.
- Form
- Rust library, memory-safe
- Reads
- Copybook layouts, EBCDIC text, COMP-3 packed decimals
- Runs
- Locally, on your own hardware
| Field | Picture | Bytes (hex) | Value |
|---|---|---|---|
CUST-NAME | PIC X(4) | C1 C3 D4 C5 | ACME (EBCDIC) |
BALANCE | PIC S9(5)V99 COMP-3 | 12 34 56 7C | +12345.67 exact |
What it does
COBOL Bridge maps a copybook's fixed-width record layout onto native data structures, decodes EBCDIC text, and unpacks COMP-3 packed-decimal fields into exact decimal values. The same input file and copybook always produce the same output.
Who it helps
- Organizations moving data off a mainframe, or connecting mainframe data to modern systems, that cannot or will not send full datasets to a vendor first.
- Teams in regulated industries whose records must stay inside their own perimeter during analysis and migration.
Why the approach matters
- Decimals stay decimal. Packed decimals hold money and quantities exactly. Converting them through floating point silently changes values. COBOL Bridge keeps them exact.
- Local by default. Ingestion and analysis run where the data is. Nothing needs to cross a network to be read.
- Memory safety. Written in Rust, a memory-safe language, which rules out whole classes of bugs that hostile or malformed input exploits in older parsers.
Current availability
Being built
- Copybook layout parsing for fixed-width records.
- EBCDIC text decoding and COMP-3 packed-decimal decoding.
Planned
- Fingerprinting each record with Hashit, so a migrated dataset can be checked against its source, record by record.
- A documented, versioned release.
COBOL Bridge is not available for download or purchase. If you are planning mainframe work and want to discuss it, write to us.