test(thinking): require executable reasoning contract per plugin

AGENTS.md

@@ -13,6 +13,7 @@ Guest SDK, first-party plugins, catalog, and `.kxp` packaging for the Kinetix ga
 - Plugins are untrusted by the host; never rely on host leniency for malformed output.
 - Provider-specific behavior must be backed by official documentation or observed upstream behavior.
 - Do not invent model capabilities, pricing, token limits, or credential behavior.
+- Reasoning behavior needs executable proof: adapter and model-source plugins ship `thinking-contract.json` (`docs/thinking-contract.md`); `provides.thinking_translation` without it fails CI.
 - Publishing: a signed release does not make a catalog entry installable; follow `README.md`.
 
 ## Validation

README.md

@@ -107,6 +107,8 @@ scripts/sync_host_contract.py            # copy from $KINETIX_DIR or ../kinetix
 scripts/sync_host_contract.py --check    # CI: fail on drift
 ```
 
+Plugins that provide a provider adapter or model source must pin their reasoning behavior with a `thinking-contract.json`; `provides.thinking_translation = true` without a passing contract fails CI. See [Plugin thinking contract](docs/thinking-contract.md).
+
 Before adding host imports or another plugin runtime, read the [WASM capability security contract](docs/wasm-capability-security-v1.md) and run its consumer conformance fixtures.
 
 See [MIGRATION.md](MIGRATION.md) for the original extraction boundary and source revision.

adapter-conformance/src/lib.rs

@@ -12,6 +12,9 @@ use kinetix_plugin_sdk::schema::{Disposition, SchemaMode, SchemaProfile};
 use serde::Deserialize;
 use serde_json::{json, Value};
 
+mod thinking;
+pub use thinking::{check_model_source_contract, check_thinking_contract, CANONICAL_LEVELS};
+
 const REQUEST_TEXT: &str = include_str!("../../wit/fixtures/plugin-adapter/v1/requests/text.json");
 const REQUEST_IMAGE: &str =
     include_str!("../../wit/fixtures/plugin-adapter/v1/requests/image.json");