Boundary Mapper
A lightweight tool for documenting integration contracts between systems.
Boundary Mapper is a structured approach to documenting the contracts between systems.
Most integration failures trace back to assumptions that were never made explicit. Boundary Mapper provides a minimal format for capturing what crosses each boundary, who owns each side, and what happens when things fail.
What it captures
For each system boundary:
- Owner — who is responsible for each side of the boundary
- Contract — what data crosses, in what format, under what constraints
- Failure modes — what happens when the boundary breaks
- SLA — what each side promises to the other
Format
The tool uses plain markdown files. No database. No service. The documentation lives next to the code it describes.
This is intentional. Integration contracts that live in a separate system become stale the moment they are written. Contracts that live next to the code have a chance of being maintained.