fix(session): retry OpenAI overloaded stream errors

packages/opencode/src/provider/error.ts

@@ -144,9 +144,12 @@ export function parseStreamError(input: unknown): ParsedStreamError | undefined
 
   const responseBody = JSON.stringify(body)
   if (body.type !== "error") return
+  const errorCode = typeof body?.error?.code === "string" ? body.error.code : ""
+  const errorType = typeof body?.error?.type === "string" ? body.error.type : ""
 
-  switch (body?.error?.code) {
+  switch (errorCode) {
     case "server_error":
+    case "server_is_overloaded":
       return {
         type: "api_error",
         message: typeof body?.error?.message === "string" ? body.error.message : "OpenAI server error",
@@ -181,6 +184,14 @@ export function parseStreamError(input: unknown): ParsedStreamError | undefined
         responseBody,
       }
   }
+  if (errorType === "service_unavailable_error") {
+    return {
+      type: "api_error",
+      message: typeof body?.error?.message === "string" ? body.error.message : "OpenAI service unavailable",
+      isRetryable: true,
+      responseBody,
+    }
+  }
 }
 
 export type ParsedAPICallError =

packages/opencode/test/provider/error.test.ts

@@ -179,4 +179,24 @@ describe("provider stream error", () => {
       responseBody: JSON.stringify(input),
     })
   })
+
+  test("marks OpenAI overloaded service unavailable events as retryable", () => {
+    const input = {
+      type: "error",
+      sequence_number: 3,
+      error: {
+        type: "service_unavailable_error",
+        code: "server_is_overloaded",
+        message: "Our servers are currently overloaded. Please try again later.",
+        param: null,
+      },
+    }
+
+    expect(parseStreamError(input)).toStrictEqual({
+      type: "api_error",
+      message: input.error.message,
+      isRetryable: true,
+      responseBody: JSON.stringify(input),
+    })
+  })
 })

packages/opencode/test/session/retry.test.ts

@@ -148,6 +148,30 @@ describe("session.retry.retryable", () => {
     expect(SessionRetry.retryable(error)).toBe(input.error.message)
   })
 
+  test("retries OpenAI overloaded service unavailable stream events", () => {
+    const input = {
+      type: "error",
+      sequence_number: 3,
+      error: {
+        type: "service_unavailable_error",
+        code: "server_is_overloaded",
+        message: "Our servers are currently overloaded. Please try again later.",
+        param: null,
+      },
+    }
+    const error = MessageV2.fromError(input, { providerID })
+
+    expect(error).toStrictEqual({
+      name: "APIError",
+      data: {
+        message: input.error.message,
+        isRetryable: true,
+        responseBody: JSON.stringify(input),
+      },
+    })
+    expect(SessionRetry.retryable(error)).toBe(input.error.message)
+  })
+
   test("maps too_many_requests json messages", () => {
     const error = wrap(JSON.stringify({ type: "error", error: { type: "too_many_requests" } }))
     expect(SessionRetry.retryable(error)).toBe("Too Many Requests")