Parity Schema Check

Parity

Badger ships a parity subcommand that diffs the live agent’s behaviour against a declared schema. This translates the upstream’s PARITY.md pattern into a runtime check.

Why a runtime parity check?

A static parity table goes stale the moment the live code drifts. Encoding the contract as a schema and diffing it at runtime makes drift detectable in CI:

chimera badger parity --against PARITY.md
echo $?   # 0 = match; 1 = drift; 2 = usage error

Schema format

Three formats are accepted:

JSON

{
  "tools": ["bash", "read_file", "edit_file", "search"],
  "max_steps": 25,
  "slash_commands": ["help", "model", "tools", "parity", "rerun"],
  "model": "claude-sonnet-4-6",
  "rerun_on_failure": false
}

YAML-ish

model: claude-sonnet-4-6
max_steps: 25
rerun_on_failure: false
tools:
  - bash
  - read_file
  - edit_file
slash_commands:
  - help
  - parity

PARITY.md (Markdown with a fenced block)

# Parity schema

{“max_steps”: 25, “model”: “claude-sonnet-4-6”}

The first fenced code block is parsed.

Schema fields

Field	Type	Meaning
tools	list[str]	Tool names that must be present.
max_steps	int	Expected default --max-steps value.
slash_commands	list[str]	Slash command names the REPL must expose.
model	str	Expected default model id.
rerun_on_failure	bool	Expected default for the flag.

Only declared fields are enforced. The diff is asymmetric: live extras (tools or slash commands present live but absent from the schema) are reported informationally but never fail the check.

Output

Text (default)

$ chimera badger parity --against PARITY.json
badger parity: OK (live agent matches schema)

$ chimera badger parity --against PARITY.json
badger parity: FAIL
  missing tools (1): browser
  max_steps mismatch: expected=25 actual=50

JSON

chimera badger parity --against PARITY.json --output-format json

Returns a payload with expected, live, and report sub-objects so you can wire downstream tooling (CI, dashboards) against the structured output.

Auto-resolve

When --against is omitted, badger searches the working directory for PARITY.md, PARITY.json, PARITY.yaml, or parity.md (in that order). Pass --cwd to scope the search.

REPL: /parity

Inside the badger REPL, the /parity slash command runs the same check:

> /parity
badger parity: OK (live agent matches schema)
> /parity ./PARITY.json
...