Backward compatibility

indexnowkit/console follows SemVer and the tiers of the core's docs/bc.md. Before 1.0, minor versions may contain breaking changes, listed under "Changed" in CHANGELOG.md.

Tier	Members
Call — signatures only grow by appended, defaulted parameters; pass anything past the first argument by name	CheckRunner, ConfigRunner, SubmitRunner, SubmitSubjectsRunner, ExplainRunner, KeyGenerateRunner (constructors and run()), ResultRenderer, Vocabulary (constructor: named arguments), ClassNameResolver, Definitions::*
Implement — methods are not added without a major version	SubjectLoaderInterface, ResultFormatterInterface
Value objects — final readonly, properties only appended with defaults	CommandDefinition, ArgumentDefinition, OptionDefinition, SubmitSubjectsOptions
Constants — referenced, not hard-coded	ExitCode::SUCCESS, FAILURE, INVALID, OptionDefinition::FLAG, VALUE, OPTIONAL_VALUE, LIST, CheckRunner::CONFIG_INVALID
Documents — the shape only grows by optional members	docs/check.schema.json, the JSON of check --json (status, environment, items[].{level, code, message, host}); the codes are the core's docs/check-codes.md

Command surface. The argument and option names, defaults and descriptions in Definitions are what the adapters render into their commands, so they are the public API of every adapter's CLI: an option is renamed only with a deprecation window on the adapter side. Descriptions and the printed texts of the runners are not API (they are written for humans and get improved); exit codes are.

Not covered: log and exception message texts, anything under tests/.

The package pins indexnowkit/core ^0.8: the runners take the core's Config, Checker, Adapter\SubmitterFactoryInterface and Submission\ResultSummary, so a core minor that changes them ships with a console minor.