feat(zoo-gateway): cache model catalog per session with ETag revalida…

knip.json

@@ -16,6 +16,7 @@
 	"ignoreDependencies": ["lint-staged"],
 	"ignoreBinaries": ["dotenvx"],
 	"ignoreExportsUsedInFile": true,
+	"tags": ["-@knipignore"],
 	"playwright": false,
 	"playwright-ct": false,
 	"workspaces": {

src/api/providers/__tests__/model-catalog-adapters.spec.ts

@@ -267,6 +267,7 @@ describe("model catalog adapters", () => {
 			fetcher.mockReset()
 			fetcher.mockResolvedValue(CATALOG)
 		}
+		fetchers.getZooGatewayModels.mockResolvedValue({ kind: "ok", models: CATALOG })
 	})
 
 	describe.each(cases)("$name", ({ create, fetcher, scope, expectedArgs, forwardsSignal }) => {

src/api/providers/__tests__/zoo-gateway.spec.ts

@@ -456,6 +456,83 @@ describe("ZooGatewayHandler", () => {
 			])
 		})
 
+		it("yields reasoning chunks from delta.reasoning and delta.reasoning_content before text", async () => {
+			mockCreate.mockImplementation(async () =>
+				asyncStreamFrom([
+					{
+						choices: [{ delta: { reasoning: "Let me think" }, index: 0 }],
+					},
+					{
+						choices: [{ delta: { reasoning_content: " carefully", content: "answer" }, index: 0 }],
+					},
+				]),
+			)
+
+			const handler = new ZooGatewayHandler(mockOptions)
+			const chunks = await collectStream(handler.createMessage("prompt", [{ role: "user", content: "Hi" }]))
+
+			expect(chunks).toEqual([
+				{ type: "reasoning", text: "Let me think" },
+				{ type: "reasoning", text: " carefully" },
+				{ type: "text", text: "answer" },
+			])
+		})
+
+		it("preserves reasoning on follow-up requests for non-Anthropic models", () => {
+			const handler = new ZooGatewayHandler({ ...mockOptions, zooGatewayModelId: "reflection/beam-free" })
+
+			expect(handler.getModel().info.preserveReasoning).toBe(true)
+		})
+
+		it("leaves Anthropic models on their existing thinking path", () => {
+			const handler = new ZooGatewayHandler(mockOptions)
+
+			expect(handler.getModel().info.preserveReasoning).toBeUndefined()
+		})
+
+		it("sends reasoning_content on the follow-up request when history has a reasoning block", async () => {
+			mockCreate.mockImplementation(async () => asyncStreamFrom([]))
+			const handler = new ZooGatewayHandler({ ...mockOptions, zooGatewayModelId: "reflection/beam-free" })
+			const history = [
+				{
+					role: "assistant" as const,
+					content: [
+						{ type: "reasoning" as const, text: "I need to read a file.", summary: [] },
+						{ type: "tool_use" as const, id: "call_abc", name: "read_file", input: { path: "foo.txt" } },
+					],
+				},
+				{
+					role: "user" as const,
+					content: [{ type: "tool_result" as const, tool_use_id: "call_abc", content: "file contents" }],
+				},
+			] as unknown as Parameters<ZooGatewayHandler["createMessage"]>[1]
+
+			await handler.createMessage("prompt", history).next()
+
+			const assistant = mockCreate.mock.calls[0][0].messages.find(
+				(message: { role?: string }) => message.role === "assistant",
+			)
+			expect(assistant.reasoning_content).toBe("I need to read a file.")
+			expect(assistant.tool_calls[0].id).toBe("call_abc")
+			expect(assistant.tool_calls[0].function.name).toBe("read_file")
+		})
+
+		it("does not yield a reasoning chunk when the delta has no reasoning text", async () => {
+			mockCreate.mockImplementation(async () =>
+				asyncStreamFrom([
+					{
+						choices: [{ delta: { content: "just text" }, index: 0 }],
+					},
+				]),
+			)
+
+			const handler = new ZooGatewayHandler(mockOptions)
+			const chunks = await collectStream(handler.createMessage("prompt", [{ role: "user", content: "Hi" }]))
+
+			expect(chunks).toEqual([{ type: "text", text: "just text" }])
+			expect(chunks.some((chunk) => chunk.type === "reasoning")).toBe(false)
+		})
+
 		it("throws the upstream reason when the gateway sends an in-stream error chunk", async () => {
 			mockCreate.mockImplementation(async () =>
 				asyncStreamFrom([