Move autoblog to the current frontier models on both providers

.env.example

@@ -65,7 +65,10 @@ CRON_SECRET=change-me-to-a-long-random-string
 #   openai = prefer OPENAI_API_KEY, fall back to Anthropic if needed
 #   anthropic = prefer ANTHROPIC_API_KEY, fall back to OpenAI if needed
 BACKEND_AI_PROVIDER=openai
-BACKEND_AI_OPENAI_MODEL=gpt-5.5
+# Autoblog article models. Defaults are the frontier tier of each provider;
+# override to trade quality for price (e.g. gpt-5.6-terra, claude-sonnet-5).
+BACKEND_AI_OPENAI_MODEL=gpt-5.6-sol
+BACKEND_AI_ANTHROPIC_MODEL=claude-opus-5
 ANTHROPIC_API_KEY=
 OPENAI_API_KEY=
 GEMINI_API_KEY=

lib/ai/spend.ts

@@ -24,9 +24,16 @@ const RATES: Record<string, Rate> = {
   "claude-sonnet-4-6": { input: 3_000_000, output: 15_000_000 },
   "claude-opus-5": { input: 5_000_000, output: 25_000_000 },
   "claude-opus-4-8": { input: 5_000_000, output: 25_000_000 },
-  // OpenAI
+  // OpenAI. `gpt-5` is a prefix of every 5.x id, so each newer model needs
+  // its own row or rateFor() prices it at the 2025 gpt-5 rate.
   "gpt-5-mini": { input: 250_000, output: 2_000_000 },
   "gpt-5": { input: 1_250_000, output: 10_000_000 },
+  "gpt-5.5": { input: 5_000_000, output: 30_000_000 },
+  // gpt-5.6 Sol is $4/$20 under the promotional pricing published through
+  // 2026-11-21 (list was $5/$30). Revisit when the promotion ends.
+  "gpt-5.6-sol": { input: 4_000_000, output: 20_000_000 },
+  "gpt-5.6-terra": { input: 2_500_000, output: 15_000_000 },
+  "gpt-5.6-luna": { input: 1_000_000, output: 6_000_000 },
 };
 
 /**

lib/env.ts

@@ -69,8 +69,15 @@ export const env = {
   // so the only env var per provider is the API key.
   backendAiProvider:
     process.env.BACKEND_AI_PROVIDER ?? process.env.AI_TEXT_PROVIDER ?? "openai",
+  // Autoblog article text. Long-form, structured-output generation on the
+  // frontier tier of each provider; the model is env-overridable so a price
+  // cut or a new release is a variable change, not a deploy. Every dated
+  // Haiku/Sonnet callsite (keyword research, blog detection, pitches) keeps
+  // its own pin — those are short extraction prompts, not the article.
   backendAiOpenaiModel:
-    process.env.BACKEND_AI_OPENAI_MODEL ?? "gpt-5.5",
+    process.env.BACKEND_AI_OPENAI_MODEL ?? "gpt-5.6-sol",
+  backendAiAnthropicModel:
+    process.env.BACKEND_AI_ANTHROPIC_MODEL ?? "claude-opus-5",
   anthropicApiKey: process.env.ANTHROPIC_API_KEY ?? "",
   // Daily AI spend that triggers a warning. It warns only — nothing throttles
   // or pauses on it, because an alarm that turns the product off is worse

lib/lx/articleGen.ts

@@ -27,6 +27,7 @@ import {
   type ExchangeCandidate,
 } from "./exchangeMatcher";
 import { generateStructuredOutput } from "./backendAi";
+import { env } from "../env";
 import {
   MAX_PRIOR_BODIES,
   runQualityGate,
@@ -39,7 +40,7 @@ import {
 } from "../autopilot/entitlements";
 
 const EMBED_MODEL = "text-embedding-3-small";
-const CLAUDE_MODEL = "claude-opus-4-8";
+const CLAUDE_MODEL = env.backendAiAnthropicModel;
 const IMAGE_MODEL = "gpt-image-2";
 const IMAGE_SIZE = "1536x1024";
 // gpt-image-2 quality tier: low / medium / high / auto. We pay the premium
@@ -1296,8 +1297,10 @@ export async function generateArticle(
         openai,
         anthropicModel: CLAUDE_MODEL,
         // 3,200–4,500 words ≈ ~18k–25k output tokens. JSON escape overhead
-        // can push that another 30%. 48k gives meaningful headroom.
-        maxTokens: 48000,
+        // can push that another 30%, and on Opus 5 / gpt-5.6 the model's
+        // reasoning tokens come out of the same ceiling. 64k keeps headroom
+        // for both; the call streams, so the size costs no timeout risk.
+        maxTokens: 64000,
         anthropicCacheSystemPrompt: true,
       });
       candidate = normalizeArticleOutput(generated.output);

lib/lx/backendAi.ts

@@ -63,6 +63,25 @@ export function backendAiTextProviderLabel(): string {
   return pref === "auto" ? "Anthropic or OpenAI" : pref === "openai" ? "OpenAI" : "Anthropic";
 }
 
+/**
+ * Thinking config for an Anthropic model.
+ *
+ * Claude 4.6 and later (Opus 5, Opus 4.8, Sonnet 5, Fable 5.1) run adaptive
+ * thinking: the model decides per request how much to reason, and `effort`
+ * bounds it. Sending `disabled` there is the wrong default — on Opus 5 it
+ * makes the model occasionally write its reasoning into the visible answer,
+ * and Fable 5.1 rejects it with a 400. Haiku 4.5 predates adaptive thinking
+ * (it only knows the budget_tokens form), so it stays off there; the Haiku
+ * callsites are short extraction prompts that pass `anthropicEffort: false`.
+ */
+export function anthropicThinkingFor(
+  model: string,
+): { type: "adaptive" } | { type: "disabled" } {
+  return /haiku-4-5|sonnet-4-5|opus-4-5|opus-4-1|claude-3/i.test(model)
+    ? { type: "disabled" }
+    : { type: "adaptive" };
+}
+
 export async function generateStructuredOutput<T>(
   args: StructuredOutputArgs<T>,
 ): Promise<{ provider: BackendAiProvider; output: T }> {
@@ -101,7 +120,7 @@ async function generateWithAnthropic<T>(
   const stream = args.anthropic.messages.stream({
     model: args.anthropicModel,
     max_tokens: args.maxTokens,
-    thinking: { type: "disabled" },
+    thinking: anthropicThinkingFor(args.anthropicModel),
     output_config: {
       ...(args.anthropicEffort === false
         ? {}

lib/lx/guestPostGen.ts

@@ -42,9 +42,10 @@ import {
   validateInternalLinks,
 } from "./articleGen";
 import { generateStructuredOutput } from "./backendAi";
+import { env } from "../env";
 import { SCAN_CREDITS } from "@/lib/credits";
 
-const CLAUDE_MODEL = "claude-opus-4-8";
+const CLAUDE_MODEL = env.backendAiAnthropicModel;
 
 type SiteCtx = {
   id: string;
@@ -183,7 +184,8 @@ export async function generateGuestPost(
       anthropic,
       openai,
       anthropicModel: CLAUDE_MODEL,
-      maxTokens: 48000,
+      // See articleGen: reasoning tokens share this ceiling on Opus 5.
+      maxTokens: 64000,
       anthropicCacheSystemPrompt: true,
     });
     article = normalizeArticleOutput(generated.output);

tests/ai-spend.test.ts

@@ -13,6 +13,15 @@ describe("rateFor", () => {
     expect(rateFor("claude-opus-5")?.output).toBe(25_000_000);
   });
 
+  it("prices each gpt-5.x release on its own row, not as gpt-5", () => {
+    // Every 5.x id starts with "gpt-5"; without an exact row the prefix
+    // match would bill Sol at the 2025 gpt-5 rate.
+    expect(rateFor("gpt-5.6-sol")?.output).toBe(20_000_000);
+    expect(rateFor("gpt-5.6-sol-2026-07-09")?.output).toBe(20_000_000);
+    expect(rateFor("gpt-5.5")?.output).toBe(30_000_000);
+    expect(rateFor("gpt-5")?.output).toBe(10_000_000);
+  });
+
   it("returns null for a model it does not know", () => {
     expect(rateFor("some-model-we-never-added")).toBeNull();
   });

tests/backend-ai-thinking.test.ts

@@ -0,0 +1,17 @@
+import { describe, it, expect } from "vitest";
+import { anthropicThinkingFor } from "@/lib/lx/backendAi";
+
+describe("anthropicThinkingFor", () => {
+  it("runs adaptive thinking on the current frontier models", () => {
+    // Fable 5.1 rejects `disabled` with a 400; Opus 5 accepts it but leaks
+    // reasoning into the visible answer. Adaptive is the documented default.
+    for (const m of ["claude-opus-5", "claude-opus-4-8", "claude-sonnet-5", "claude-fable-5-1"]) {
+      expect(anthropicThinkingFor(m)).toEqual({ type: "adaptive" });
+    }
+  });
+
+  it("keeps thinking off on Haiku 4.5, which predates adaptive", () => {
+    expect(anthropicThinkingFor("claude-haiku-4-5-20251001")).toEqual({ type: "disabled" });
+    expect(anthropicThinkingFor("claude-haiku-4-5")).toEqual({ type: "disabled" });
+  });
+});