compat

Compare two schema versions and detect breaking changes.

Usage

vexilc compat <old.vexil> <new.vexil> [--format <human|json>]

Options

Option	Default	Description
`--format <format>`	`human`	Output format: `human` or `json`

Example

$ vexilc compat v1/sensor.vexil v2/sensor.vexil
  ✓ field "flags" added at @2           compatible (minor)
  ✗ field "timeout" type u32 → u64      BREAKING (major)

Result: BREAKING — requires major version bump

JSON output

$ vexilc compat v1.vexil v2.vexil --format json

{
  "changes": [
    {
      "kind": "field_added",
      "declaration": "SensorReading",
      "field": "flags",
      "detail": "field \"flags\" added at @2",
      "classification": "minor"
    }
  ],
  "result": "compatible",
  "suggested_bump": "minor"
}

Exit codes

Code	Meaning
0	Compatible changes only
1	Breaking changes detected
2	Schema compilation error

The compat checker detects field additions, removals, type changes, ordinal changes, renames, deprecations, encoding changes, variant additions/removals, declaration additions/removals, namespace changes, and flags bit changes.