fix(coding-agent): honor provider compat in models.json closes #2062

packages/coding-agent/test/model-registry.test.ts

@@ -238,6 +238,125 @@ describe("ModelRegistry", () => {
 			}
 		});
 
+		test("provider-level compat applies to custom models", () => {
+			writeRawModelsJson({
+				demo: {
+					baseUrl: "https://example.com/v1",
+					apiKey: "DEMO_KEY",
+					api: "openai-completions",
+					compat: {
+						supportsUsageInStreaming: false,
+						maxTokensField: "max_tokens",
+					},
+					models: [
+						{
+							id: "demo-model",
+							reasoning: false,
+							input: ["text"],
+							cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+							contextWindow: 1000,
+							maxTokens: 100,
+						},
+					],
+				},
+			});
+
+			const registry = new ModelRegistry(authStorage, modelsJsonPath);
+			const compat = registry.find("demo", "demo-model")?.compat as OpenAICompletionsCompat | undefined;
+
+			expect(compat?.supportsUsageInStreaming).toBe(false);
+			expect(compat?.maxTokensField).toBe("max_tokens");
+		});
+
+		test("model-level compat overrides provider-level compat for custom models", () => {
+			writeRawModelsJson({
+				demo: {
+					baseUrl: "https://example.com/v1",
+					apiKey: "DEMO_KEY",
+					api: "openai-completions",
+					compat: {
+						supportsUsageInStreaming: false,
+						maxTokensField: "max_tokens",
+					},
+					models: [
+						{
+							id: "demo-model",
+							reasoning: false,
+							input: ["text"],
+							cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+							contextWindow: 1000,
+							maxTokens: 100,
+							compat: {
+								supportsUsageInStreaming: true,
+								maxTokensField: "max_completion_tokens",
+							},
+						},
+					],
+				},
+			});
+
+			const registry = new ModelRegistry(authStorage, modelsJsonPath);
+			const compat = registry.find("demo", "demo-model")?.compat as OpenAICompletionsCompat | undefined;
+
+			expect(compat?.supportsUsageInStreaming).toBe(true);
+			expect(compat?.maxTokensField).toBe("max_completion_tokens");
+		});
+
+		test("provider-level compat applies to built-in models", () => {
+			writeRawModelsJson({
+				openrouter: {
+					compat: {
+						supportsUsageInStreaming: false,
+						supportsStrictMode: false,
+					},
+				},
+			});
+
+			const registry = new ModelRegistry(authStorage, modelsJsonPath);
+			const models = getModelsForProvider(registry, "openrouter");
+
+			expect(models.length).toBeGreaterThan(0);
+			for (const model of models) {
+				const compat = model.compat as OpenAICompletionsCompat | undefined;
+				expect(compat?.supportsUsageInStreaming).toBe(false);
+				expect(compat?.supportsStrictMode).toBe(false);
+			}
+		});
+
+		test("compat schema accepts reasoningEffortMap and supportsStrictMode", () => {
+			writeRawModelsJson({
+				demo: {
+					baseUrl: "https://example.com/v1",
+					apiKey: "DEMO_KEY",
+					api: "openai-completions",
+					models: [
+						{
+							id: "demo-model",
+							reasoning: true,
+							input: ["text"],
+							cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+							contextWindow: 1000,
+							maxTokens: 100,
+							compat: {
+								reasoningEffortMap: {
+									minimal: "default",
+									high: "max",
+								},
+								supportsStrictMode: false,
+							},
+						},
+					],
+				},
+			});
+
+			const registry = new ModelRegistry(authStorage, modelsJsonPath);
+			const compat = registry.find("demo", "demo-model")?.compat as OpenAICompletionsCompat | undefined;
+
+			expect(registry.getError()).toBeUndefined();
+			expect(compat?.reasoningEffortMap).toEqual({ minimal: "default", high: "max" });
+			expect(compat?.supportsStrictMode).toBe(false);
+		});
+
 		test("model-level baseUrl overrides provider-level baseUrl for custom models", () => {
 			writeRawModelsJson({
 				"opencode-go": {