fix: stop guessing session model costs

src/agents/models-config.skips-writing-models-json-no-env-token.test.ts

@@ -83,10 +83,23 @@ describe("models-config", () => {
       const modelPath = path.join(resolveOpenClawAgentDir(), "models.json");
       const raw = await fs.readFile(modelPath, "utf8");
       const parsed = JSON.parse(raw) as {
-        providers: Record<string, { baseUrl?: string }>;
+        providers: Record<
+          string,
+          {
+            baseUrl?: string;
+            models?: Array<{
+              id?: string;
+              cost?: { input?: number; output?: number; cacheRead?: number; cacheWrite?: number };
+            }>;
+          }
+        >;
       };
 
       expect(parsed.providers["custom-proxy"]?.baseUrl).toBe("http://localhost:4000/v1");
+      expect(parsed.providers["custom-proxy"]?.models?.[0]).toMatchObject({
+        id: "llama-3.1-8b",
+        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+      });
     });
   });
 

src/agents/openclaw-tools.sessions.test.ts

@@ -123,6 +123,7 @@ describe("sessions tools", () => {
               status: "running",
               startedAt: 100,
               runtimeMs: 42,
+              estimatedCostUsd: 0.0042,
               childSessions: ["agent:main:subagent:worker"],
             },
             {
@@ -164,6 +165,7 @@ describe("sessions tools", () => {
         status?: string;
         startedAt?: number;
         runtimeMs?: number;
+        estimatedCostUsd?: number;
         childSessions?: string[];
         messages?: Array<{ role?: string }>;
       }>;
@@ -178,6 +180,7 @@ describe("sessions tools", () => {
     expect(group?.status).toBe("running");
     expect(group?.startedAt).toBe(100);
     expect(group?.runtimeMs).toBe(42);
+    expect(group?.estimatedCostUsd).toBe(0.0042);
     expect(group?.childSessions).toEqual(["agent:main:subagent:worker"]);
 
     const cronOnly = await tool.execute("call2", { kinds: ["cron"] });

src/agents/tools/sessions-helpers.ts

@@ -58,6 +58,7 @@ export type SessionListRow = {
   model?: string;
   contextTokens?: number | null;
   totalTokens?: number | null;
+  estimatedCostUsd?: number;
   status?: SessionRunStatus;
   startedAt?: number;
   endedAt?: number;

src/agents/tools/sessions-list-tool.ts

@@ -203,6 +203,8 @@ export function createSessionsListTool(opts?: {
           model: typeof entry.model === "string" ? entry.model : undefined,
           contextTokens: typeof entry.contextTokens === "number" ? entry.contextTokens : undefined,
           totalTokens: typeof entry.totalTokens === "number" ? entry.totalTokens : undefined,
+          estimatedCostUsd:
+            typeof entry.estimatedCostUsd === "number" ? entry.estimatedCostUsd : undefined,
           status: typeof entry.status === "string" ? entry.status : undefined,
           startedAt: typeof entry.startedAt === "number" ? entry.startedAt : undefined,
           endedAt: typeof entry.endedAt === "number" ? entry.endedAt : undefined,

src/utils/usage-format.test.ts

@@ -60,33 +60,23 @@ describe("usage-format", () => {
     expect(total).toBeCloseTo(0.003);
   });
 
-  it("falls back to built in pricing for common models", () => {
+  it("returns undefined when model pricing is not configured", () => {
     expect(
       resolveModelCostConfig({
         provider: "anthropic",
         model: "claude-sonnet-4-6",
       }),
-    ).toEqual({
-      input: 3,
-      output: 15,
-      cacheRead: 0.3,
-      cacheWrite: 3.75,
-    });
+    ).toBeUndefined();
 
     expect(
       resolveModelCostConfig({
         provider: "openai-codex",
         model: "gpt-5.4",
       }),
-    ).toEqual({
-      input: 2,
-      output: 8,
-      cacheRead: 0,
-      cacheWrite: 0,
-    });
+    ).toBeUndefined();
   });
 
-  it("prefers configured pricing over built in defaults", () => {
+  it("uses configured pricing when present", () => {
     const config = {
       models: {
         providers: {

src/utils/usage-format.ts

@@ -48,45 +48,6 @@ export function formatUsd(value?: number): string | undefined {
   return `$${value.toFixed(4)}`;
 }
 
-const BUILTIN_MODEL_COSTS: Record<string, ModelCostConfig> = {
-  "anthropic/claude-opus-4-6": {
-    input: 15,
-    output: 75,
-    cacheRead: 1.5,
-    cacheWrite: 18.75,
-  },
-  "anthropic/claude-sonnet-4-6": {
-    input: 3,
-    output: 15,
-    cacheRead: 0.3,
-    cacheWrite: 3.75,
-  },
-  "anthropic/claude-haiku-4-5": {
-    input: 0.8,
-    output: 4,
-    cacheRead: 0.08,
-    cacheWrite: 1,
-  },
-  "openai-codex/gpt-5.4": {
-    input: 2,
-    output: 8,
-    cacheRead: 0,
-    cacheWrite: 0,
-  },
-  "openai-codex/gpt-5.3-codex": {
-    input: 1,
-    output: 4,
-    cacheRead: 0,
-    cacheWrite: 0,
-  },
-  "openai-codex/gpt-5.3-codex-spark": {
-    input: 0.5,
-    output: 2,
-    cacheRead: 0,
-    cacheWrite: 0,
-  },
-};
-
 export function resolveModelCostConfig(params: {
   provider?: string;
   model?: string;
@@ -99,10 +60,7 @@ export function resolveModelCostConfig(params: {
   }
   const providers = params.config?.models?.providers ?? {};
   const entry = providers[provider]?.models?.find((item) => item.id === model);
-  if (entry?.cost) {
-    return entry.cost;
-  }
-  return BUILTIN_MODEL_COSTS[`${provider.toLowerCase()}/${model.toLowerCase()}`];
+  return entry?.cost;
 }
 
 const toNumber = (value: number | undefined): number =>