diff --git a/open-sse/providers/registry/opencode-go.js b/open-sse/providers/registry/opencode-go.js
index 0dad175f..06ae7ca1 100644
--- a/open-sse/providers/registry/opencode-go.js
+++ b/open-sse/providers/registry/opencode-go.js
@@ -21,6 +21,9 @@ export default {
   transport: {
     baseUrl: "https://opencode.ai/zen/go/v1/chat/completions",
     headers: {},
+    usage: {
+      url: "https://opencode.ai/zen/go/v1/usage",
+    },
   },
   // Multi-endpoint: pick the transport matching the client sourceFormat to skip
   // translation. Guarded per-model by `supportedFormats` (see chatCore) because
@@ -48,4 +51,8 @@ export default {
     { id: "qwen3.7-plus", name: "Qwen 3.7 Plus", supportedFormats: ["openai", "claude"] },
     { id: "qwen3.6-plus", name: "Qwen 3.6 Plus", supportedFormats: ["openai", "claude"] },
   ],
+  features: {
+    usage: true,
+    usageApikey: true,
+  },
 };
diff --git a/open-sse/services/usage.js b/open-sse/services/usage.js
index 51f00898..eeb46c3c 100644
--- a/open-sse/services/usage.js
+++ b/open-sse/services/usage.js
@@ -14,6 +14,7 @@ import { getCodeBuddyCnUsage, getCodeBuddyIntlUsage } from "./usage/codebuddy-cn
 import { getGrokCliUsage } from "./usage/grok-cli.js";
 import { getKimiUsage } from "./usage/kimi.js";
 import { getDeepseekUsage } from "./usage/deepseek.js";
+import { getOpenCodeGoUsage } from "./usage/opencode-go.js";
 import { getGroqUsage } from "./usage/groq.js";
 import { getZedUsage } from "./usage/zed.js";
 import { resolveQoderCredentials } from "./qoderModels.js";
@@ -55,6 +56,7 @@ const USAGE_HANDLERS = {
   "codebuddy-intl": (c) => getCodeBuddyIntlUsage(c.accessToken, c.apiKey, c.providerSpecificData, c.proxyOptions),
   "grok-cli": (c) => getGrokCliUsage(c.accessToken, c.providerSpecificData, c.proxyOptions),
   kimi: (c) => getKimiUsage(c.accessToken, c.apiKey, c.proxyOptions, c.providerSpecificData),
+  "opencode-go": (c) => getOpenCodeGoUsage(c.apiKey, c.proxyOptions),
   deepseek: (c) => getDeepseekUsage(c.apiKey, c.proxyOptions),
   groq: (c) => getGroqUsage(c.apiKey, c.proxyOptions),
   zed: (c) => getZedUsage(c.accessToken, c.providerSpecificData, c.proxyOptions),
diff --git a/open-sse/services/usage/opencode-go.js b/open-sse/services/usage/opencode-go.js
new file mode 100644
index 00000000..2d352498
--- /dev/null
+++ b/open-sse/services/usage/opencode-go.js
@@ -0,0 +1,107 @@
+/**
+ * OpenCode Go usage — GET https://opencode.ai/zen/go/v1/usage
+ * Auth: Bearer <apiKey>
+ */
+
+import { proxyAwareFetch } from "../../utils/proxyFetch.js";
+import { parseResetTime, toFiniteNumber, U } from "./shared.js";
+
+const USAGE_URL = U("opencode-go").url;
+const QUOTA_NAMES = {
+  rolling: "Rolling",
+  weekly: "Weekly",
+  monthly: "Monthly",
+};
+
+function parsePercent(value) {
+  if (typeof value === "number" && Number.isFinite(value)) return value;
+  if (typeof value === "string" && value.trim()) {
+    const parsed = Number(value);
+    if (Number.isFinite(parsed)) return parsed;
+  }
+  return null;
+}
+
+export async function getOpenCodeGoUsage(apiKey = null, proxyOptions = null) {
+  if (!apiKey || typeof apiKey !== "string" || !apiKey.trim()) {
+    return {
+      message: "OpenCode Go API key not available. Add a key to view usage.",
+    };
+  }
+
+  try {
+    const response = await proxyAwareFetch(
+      USAGE_URL,
+      {
+        method: "GET",
+        headers: {
+          Authorization: `Bearer ${apiKey.trim()}`,
+          Accept: "application/json",
+        },
+      },
+      proxyOptions,
+    );
+
+    if (response.status === 401) {
+      return {
+        plan: "OpenCode Go",
+        message: "OpenCode Go authentication failed. Check the API key.",
+      };
+    }
+
+    if (response.status === 403) {
+      const error = await response.json().catch(() => null);
+      const subscriptionRequired = error?.error?.type === "EntitlementError";
+      return {
+        plan: "OpenCode Go",
+        message: subscriptionRequired
+          ? "OpenCode Go subscription required for this API key."
+          : "OpenCode Go access forbidden for this API key.",
+      };
+    }
+
+    if (!response.ok) {
+      return {
+        plan: "OpenCode Go",
+        message: `OpenCode Go usage API error (${response.status}).`,
+      };
+    }
+
+    const data = await response.json().catch(() => null);
+    if (!data?.usage || typeof data.usage !== "object") {
+      return {
+        plan: "OpenCode Go",
+        message: "OpenCode Go usage response did not contain quota data.",
+      };
+    }
+
+    const quotas = {};
+    for (const [period, name] of Object.entries(QUOTA_NAMES)) {
+      const quota = data.usage[period];
+      if (!quota || typeof quota !== "object") continue;
+      const percent = parsePercent(quota.percent);
+      if (percent === null) continue;
+      const used = Math.max(0, Math.min(100, toFiniteNumber(percent, 0)));
+      quotas[name] = {
+        used,
+        total: 100,
+        remaining: 100 - used,
+        remainingPercentage: 100 - used,
+        resetAt: parseResetTime(quota.resetsAt),
+        unlimited: false,
+      };
+    }
+
+
+    if (Object.keys(quotas).length === 0) {
+      return {
+        plan: "OpenCode Go",
+        message: "OpenCode Go usage response did not contain valid quota data.",
+      };
+    }
+
+    return { plan: "OpenCode Go", quotas };
+  } catch (error) {
+    return { message: `OpenCode Go error: ${error.message}` };
+  }
+}
diff --git a/tests/unit/opencode-go-usage.test.js b/tests/unit/opencode-go-usage.test.js
new file mode 100644
index 00000000..349554a4
--- /dev/null
+++ b/tests/unit/opencode-go-usage.test.js
@@ -0,0 +1,129 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("../../open-sse/utils/proxyFetch.js", () => ({
+  proxyAwareFetch: vi.fn(),
+}));
+
+import { proxyAwareFetch } from "../../open-sse/utils/proxyFetch.js";
+import { getUsageForProvider } from "../../open-sse/services/usage.js";
+import {
+  USAGE_APIKEY_PROVIDERS,
+  USAGE_SUPPORTED_PROVIDERS,
+} from "../../src/shared/constants/providers.js";
+
+const USAGE_URL = "https://opencode.ai/zen/go/v1/usage";
+
+function jsonResponse(body, status = 200) {
+  return new Response(JSON.stringify(body), {
+    status,
+    headers: { "Content-Type": "application/json" },
+  });
+}
+
+describe("OpenCode Go registry usage flags", () => {
+  it("is listed for the API key quota dashboard", () => {
+    expect(USAGE_SUPPORTED_PROVIDERS).toContain("opencode-go");
+    expect(USAGE_APIKEY_PROVIDERS).toContain("opencode-go");
+  });
+});
+
+describe("getUsageForProvider(opencode-go)", () => {
+  beforeEach(() => vi.clearAllMocks());
+
+  it("fetches and normalizes subscription usage", async () => {
+    proxyAwareFetch.mockResolvedValueOnce(
+      jsonResponse({
+        usage: {
+          rolling: { status: "ok", percent: 13, resetsAt: "2026-09-04T14:28:02.617Z" },
+          weekly: { status: "ok", percent: 5, resetsAt: "2026-09-07T00:00:00.617Z" },
+          monthly: { status: "ok", percent: 2, resetsAt: "2026-10-02T12:14:24.617Z" },
+        },
+      }),
+    );
+
+    const usage = await getUsageForProvider({
+      provider: "opencode-go",
+      apiKey: "sk-go-test",
+    });
+
+    expect(proxyAwareFetch).toHaveBeenCalledWith(
+      USAGE_URL,
+      expect.objectContaining({
+        method: "GET",
+        headers: expect.objectContaining({ Authorization: "Bearer sk-go-test" }),
+      }),
+      null,
+    );
+    expect(usage).toEqual({
+      plan: "OpenCode Go",
+      quotas: {
+        Rolling: {
+          used: 13,
+          total: 100,
+          remaining: 87,
+          remainingPercentage: 87,
+          resetAt: "2026-09-04T14:28:02.617Z",
+          unlimited: false,
+        },
+        Weekly: expect.objectContaining({ used: 5, remainingPercentage: 95 }),
+        Monthly: expect.objectContaining({ used: 2, remainingPercentage: 98 }),
+      },
+    });
+  });
+
+  it("reports missing and rejected credentials", async () => {
+    const missing = await getUsageForProvider({ provider: "opencode-go" });
+    expect(missing.message).toMatch(/api key/i);
+    expect(proxyAwareFetch).not.toHaveBeenCalled();
+
+    proxyAwareFetch.mockResolvedValueOnce(jsonResponse({ error: "unauthorized" }, 401));
+    const rejected = await getUsageForProvider({
+      provider: "opencode-go",
+      apiKey: "bad",
+    });
+    expect(rejected.message).toMatch(/authentication failed/i);
+  });
+
+  it("distinguishes a missing subscription from invalid credentials", async () => {
+    proxyAwareFetch.mockResolvedValueOnce(
+      jsonResponse({ error: { type: "EntitlementError" } }, 403),
+    );
+
+    const usage = await getUsageForProvider({
+      provider: "opencode-go",
+      apiKey: "sk-without-go",
+    });
+
+    expect(usage.message).toMatch(/subscription required/i);
+  });
+
+  it("rejects responses without a valid quota percentage", async () => {
+    proxyAwareFetch.mockResolvedValueOnce(
+      jsonResponse({ usage: { rolling: { status: "ok" }, future: { percent: 10 } } }),
+    );
+
+    const usage = await getUsageForProvider({
+      provider: "opencode-go",
+      apiKey: "sk-go-test",
+    });
+
+    expect(usage.quotas).toBeUndefined();
+    expect(usage.message).toMatch(/valid quota data/i);
+  });
+
+  it("reports upstream and network failures", async () => {
+    proxyAwareFetch.mockResolvedValueOnce(jsonResponse({ error: "unavailable" }, 500));
+    const upstream = await getUsageForProvider({
+      provider: "opencode-go",
+      apiKey: "sk-go-test",
+    });
+    expect(upstream.message).toContain("500");
+
+    proxyAwareFetch.mockRejectedValueOnce(new Error("socket closed"));
+    const network = await getUsageForProvider({
+      provider: "opencode-go",
+      apiKey: "sk-go-test",
+    });
+    expect(network.message).toContain("socket closed");
+  });
+});
diff --git a/tests/unit/usage-dispatch.test.js b/tests/unit/usage-dispatch.test.js
index 5b86ee9e..84a5f469 100644
--- a/tests/unit/usage-dispatch.test.js
+++ b/tests/unit/usage-dispatch.test.js
@@ -16,7 +16,7 @@ const SUPPORTED = [
   "github", "gemini-cli", "antigravity", "claude", "codex", "kiro",
   "qoder", "iflow", "ollama", "glm", "glm-cn",
   "minimax", "minimax-cn", "vercel-ai-gateway", "grok-cli", "kimi",
-  "deepseek", "zed",
+  "deepseek", "opencode-go", "zed",
 ];
 
 describe("usage dispatch", () => {