From d536e451fd1a194ded66194c40b97721dca9c2f1 Mon Sep 17 00:00:00 2001
From: Alex Promakh <alex@promakh.com>
Date: Mon, 19 Jan 2026 22:43:08 +0000
Subject: [PATCH] feat: for openrouter session uses cost from metadata

---
 packages/opencode/src/session/index.ts | 73 ++++++++++++++++++++------
 1 file changed, 58 insertions(+), 15 deletions(-)

diff --git a/packages/opencode/src/session/index.ts b/packages/opencode/src/session/index.ts
index 3fcdab5238c..275dd9682ef 100644
--- a/packages/opencode/src/session/index.ts
+++ b/packages/opencode/src/session/index.ts
@@ -20,6 +20,7 @@ import { Command } from "../command"
 import { Snapshot } from "@/snapshot"
 
 import type { Provider } from "@/provider/provider"
+import type { JSONObject } from "@ai-sdk/provider"
 import { PermissionNext } from "@/permission/next"
 import { Global } from "@/global"
 
@@ -409,6 +410,58 @@ export namespace Session {
     return part
   })
 
+  function extractProviderCost(metadata?: ProviderMetadata): number | null {
+    if (!metadata) return null
+
+    if (typeof metadata.openrouter?.usage == "object") {
+      const usage = metadata.openrouter?.usage as JSONObject;
+      if (typeof usage.cost == "number") {
+        return usage.cost;
+      }
+    }
+
+    return null
+  }
+
+  type UsageTokens = {
+      input: number;
+      output: number;
+      reasoning: number;
+      cache: {
+          write: number;
+          read: number;
+      };
+  }
+
+  const getCost = fn(z.object({
+    model: z.custom<Provider.Model>(),
+    tokens: z.custom<UsageTokens>(),
+    metadata: z.custom<ProviderMetadata>().optional(),
+  }), (input) => {
+    const {tokens, metadata} = input;
+    const providerCost = extractProviderCost(metadata);
+    if (providerCost) {
+      return providerCost;
+    }
+
+    // Approximated cost
+    const costInfo =
+        input.model.cost?.experimentalOver200K && tokens.input + tokens.cache.read > 200_000
+          ? input.model.cost.experimentalOver200K
+          : input.model.cost;
+    const appoximatedCost = new Decimal(0)
+        .add(new Decimal(tokens.input).mul(costInfo?.input ?? 0).div(1_000_000))
+        .add(new Decimal(tokens.output).mul(costInfo?.output ?? 0).div(1_000_000))
+        .add(new Decimal(tokens.cache.read).mul(costInfo?.cache?.read ?? 0).div(1_000_000))
+        .add(new Decimal(tokens.cache.write).mul(costInfo?.cache?.write ?? 0).div(1_000_000))
+        // TODO: update models.dev to have better pricing model, for now:
+        // charge reasoning tokens at the same rate as output tokens
+        .add(new Decimal(tokens.reasoning).mul(costInfo?.output ?? 0).div(1_000_000))
+        .toNumber();
+
+    return Number.isFinite(appoximatedCost) ? appoximatedCost : 0;
+  })
+
   export const getUsage = fn(
     z.object({
       model: z.custom<Provider.Model>(),
@@ -441,23 +494,13 @@ export namespace Session {
         },
       }
 
-      const costInfo =
-        input.model.cost?.experimentalOver200K && tokens.input + tokens.cache.read > 200_000
-          ? input.model.cost.experimentalOver200K
-          : input.model.cost
       return {
-        cost: safe(
-          new Decimal(0)
-            .add(new Decimal(tokens.input).mul(costInfo?.input ?? 0).div(1_000_000))
-            .add(new Decimal(tokens.output).mul(costInfo?.output ?? 0).div(1_000_000))
-            .add(new Decimal(tokens.cache.read).mul(costInfo?.cache?.read ?? 0).div(1_000_000))
-            .add(new Decimal(tokens.cache.write).mul(costInfo?.cache?.write ?? 0).div(1_000_000))
-            // TODO: update models.dev to have better pricing model, for now:
-            // charge reasoning tokens at the same rate as output tokens
-            .add(new Decimal(tokens.reasoning).mul(costInfo?.output ?? 0).div(1_000_000))
-            .toNumber(),
-        ),
         tokens,
+        cost: getCost({
+          model: input.model,
+          tokens: tokens,
+          metadata: input.metadata
+        }),
       }
     },
   )