fix(ai): correct Fireworks GLM prompt caching, closes #7676

packages/ai/CHANGELOG.md

@@ -91,6 +91,7 @@
 - Fixed newer provider refreshes being blocked by or overwritten by an older stalled generation, including persisted catalog publication.
 - Updated GPT-5.6 Terra and Luna pricing across OpenAI and passthrough model catalogs.
 - Fixed Fireworks Kimi K3 models to use the OpenAI-compatible API with native reasoning-effort levels and deferred tools ([#7199](https://github.com/earendil-works/pi/issues/7199), [#7230](https://github.com/earendil-works/pi/pull/7230) by [@XBeg9](https://github.com/XBeg9)).
+- Fixed Fireworks GLM 5.2 models sending the unsupported `prompt_cache_retention` field when long cache retention is enabled, and enabled session affinity for automatic prompt caching ([#7676](https://github.com/earendil-works/pi/issues/7676)).
 - Updated Groq's Qwen reasoning override for the replacement `qwen/qwen3.6-27b` model.
 - Fixed the OpenCode Go provider display name.
 - Fixed provider error normalization treating arrays and class instances as structured response bodies instead of preserving their original errors ([#7205](https://github.com/earendil-works/pi/pull/7205) by [@erikogenvik](https://github.com/erikogenvik)).

packages/ai/scripts/generate-models.ts

@@ -1187,6 +1187,84 @@ function processBasetenModels(provider: ModelsDevProvider | undefined): Model<Ap
 	return models;
 }
 
+function processFireworksModels(provider: ModelsDevProvider | undefined): Model<Api>[] {
+	if (!provider?.models) return [];
+
+	const anthropicCompat: AnthropicMessagesCompat = {
+		sendSessionAffinityHeaders: true,
+		supportsEagerToolInputStreaming: false,
+		supportsCacheControlOnTools: false,
+		supportsLongCacheRetention: false,
+	};
+	const openAICompat: OpenAICompletionsCompat = {
+		supportsStore: false,
+		supportsDeveloperRole: false,
+		sendSessionAffinityHeaders: true,
+		supportsLongCacheRetention: false,
+	};
+	const kimiK3Compat: OpenAICompletionsCompat = {
+		...openAICompat,
+		requiresReasoningContentOnAssistantMessages: true,
+		thinkingFormat: "openai",
+		deferredToolsMode: "kimi",
+	};
+	const models: Model<Api>[] = [];
+
+	for (const [modelId, model] of Object.entries(provider.models)) {
+		if (model.tool_call !== true) continue;
+
+		const input: ("text" | "image")[] = model.modalities?.input?.includes("image")
+			? ["text", "image"]
+			: ["text"];
+		const common = {
+			id: modelId,
+			name: model.name || modelId,
+			provider: "fireworks",
+			reasoning: model.reasoning === true,
+			input,
+			cost: {
+				input: model.cost?.input || 0,
+				output: model.cost?.output || 0,
+				cacheRead: model.cost?.cache_read || 0,
+				cacheWrite: model.cost?.cache_write || 0,
+			},
+			contextWindow: model.limit?.context || 4096,
+			maxTokens: model.limit?.output || 4096,
+		};
+
+		if (modelId.includes("glm-5p2")) {
+			models.push({
+				...common,
+				api: "openai-completions",
+				baseUrl: "https://api.fireworks.ai/inference/v1",
+				compat: openAICompat,
+			});
+		} else if (modelId.includes("kimi-k3")) {
+			models.push({
+				...common,
+				api: "openai-completions",
+				baseUrl: "https://api.fireworks.ai/inference/v1",
+				compat: kimiK3Compat,
+			});
+		} else {
+			models.push({
+				...common,
+				api: "anthropic-messages",
+				// Fireworks Anthropic-compatible API - SDK appends /v1/messages.
+				baseUrl: "https://api.fireworks.ai/inference",
+				// Fireworks prompt caching uses automatic prefix matching + session affinity.
+				// x-session-affinity routes requests to the same replica for cache hits.
+				// cache_control on tools and eager_input_streaming are not supported.
+				// See: https://docs.fireworks.ai/tools-sdks/anthropic-compatibility
+				compat: anthropicCompat,
+			});
+		}
+		recordModelsDevReasoningOptions("fireworks", modelId, model);
+	}
+
+	return models;
+}
+
 async function loadModelsDevData(): Promise<Model<any>[]> {
 	try {
 		console.log("Fetching models from models.dev API...");
@@ -1639,43 +1717,7 @@ async function loadModelsDevData(): Promise<Model<any>[]> {
 			}
 		}
 
-		// Process Fireworks models
-		if (data["fireworks-ai"]?.models) {
-			for (const [modelId, model] of Object.entries(data["fireworks-ai"].models)) {
-				const m = model as ModelsDevModel;
-				if (m.tool_call !== true) continue;
-
-				models.push({
-					id: modelId,
-					name: m.name || modelId,
-					api: "anthropic-messages",
-					provider: "fireworks",
-					// Fireworks Anthropic-compatible API - SDK appends /v1/messages
-					baseUrl: "https://api.fireworks.ai/inference",
-					reasoning: m.reasoning === true,
-					input: m.modalities?.input?.includes("image") ? ["text", "image"] : ["text"],
-					cost: {
-						input: m.cost?.input || 0,
-						output: m.cost?.output || 0,
-						cacheRead: m.cost?.cache_read || 0,
-						cacheWrite: m.cost?.cache_write || 0,
-					},
-					contextWindow: m.limit?.context || 4096,
-					maxTokens: m.limit?.output || 4096,
-					// Fireworks prompt caching uses automatic prefix matching + session affinity.
-					// x-session-affinity routes requests to the same replica for cache hits.
-					// cache_control on tools and eager_input_streaming are not supported.
-					// See: https://docs.fireworks.ai/tools-sdks/anthropic-compatibility
-					compat: {
-						sendSessionAffinityHeaders: true,
-						supportsEagerToolInputStreaming: false,
-						supportsCacheControlOnTools: false,
-						supportsLongCacheRetention: false,
-					},
-				});
-				recordModelsDevReasoningOptions("fireworks", modelId, m);
-			}
-		}
+		models.push(...processFireworksModels(data["fireworks-ai"]));
 
 		// Process NVIDIA NIM models
 		if (data.nvidia?.models) {
@@ -2269,24 +2311,6 @@ async function generateModels() {
 			candidate.cost.output = 1.9;
 			candidate.cost.cacheRead = 0.119;
 		}
-		if (candidate.provider === "fireworks" && candidate.id.includes("glm-5p2")) {
-			candidate.api = "openai-completions";
-			candidate.baseUrl = "https://api.fireworks.ai/inference/v1";
-			candidate.compat = { supportsStore: false, supportsDeveloperRole: false };
-		}
-		if (candidate.provider === "fireworks" && candidate.id.includes("kimi-k3")) {
-			candidate.api = "openai-completions";
-			candidate.baseUrl = "https://api.fireworks.ai/inference/v1";
-			candidate.compat = {
-				supportsStore: false,
-				supportsDeveloperRole: false,
-				requiresReasoningContentOnAssistantMessages: true,
-				thinkingFormat: "openai",
-				deferredToolsMode: "kimi",
-				sendSessionAffinityHeaders: true,
-				supportsLongCacheRetention: false,
-			};
-		}
 	}
 
 

packages/ai/test/fireworks-models.test.ts

@@ -58,6 +58,31 @@ describe("Fireworks models", () => {
 		expect(fast.thinkingLevelMap).toEqual(base.thinkingLevelMap);
 	});
 
+	it.each(["accounts/fireworks/models/glm-5p2", "accounts/fireworks/routers/glm-5p2-fast"] as const)(
+		"omits unsupported long cache retention for %s",
+		async (modelId) => {
+			const model = getModel("fireworks", modelId);
+			let payload: Record<string, unknown> | undefined;
+			const response = streamSimple(
+				model,
+				{ messages: [{ role: "user", content: "test", timestamp: 0 }] },
+				{
+					apiKey: "test-fireworks-key",
+					cacheRetention: "long",
+					sessionId: "test-fireworks-session",
+					onPayload: (value) => {
+						payload = value as Record<string, unknown>;
+						throw new Error("payload captured");
+					},
+				},
+			);
+			await response.result();
+
+			expect(payload).toBeDefined();
+			expect(payload?.prompt_cache_retention).toBeUndefined();
+		},
+	);
+
 	it("routes Kimi K3 through the OpenAI-compatible API with native effort controls", async () => {
 		const base = getModel("fireworks", "accounts/fireworks/models/kimi-k3");
 		const fast = getModel("fireworks", "accounts/fireworks/routers/kimi-k3-fast");

packages/ai/test/openai-completions-prompt-cache.test.ts

@@ -171,6 +171,16 @@ describe("openai-completions prompt caching", () => {
 		expect(headers["x-session-affinity"]).toBe("session-affinity");
 	});
 
+	it.each(["accounts/fireworks/models/glm-5p2", "accounts/fireworks/routers/glm-5p2-fast"] as const)(
+		"sends Fireworks session affinity for %s",
+		async (modelId) => {
+			const model = getModel("fireworks", modelId);
+			const { headers } = await captureRequest({ sessionId: "fireworks-session" }, model);
+
+			expect(headers["x-session-affinity"]).toBe("fireworks-session");
+		},
+	);
+
 	it("uses OpenAI no-session format when configured", async () => {
 		const model = createModel({
 			compat: { sendSessionAffinityHeaders: true, sessionAffinityFormat: "openai-nosession" },