vercel/ai · error · APICallError

SSE response body is empty

Error message

SSE response body is empty

What it means

Error "SSE response body is empty" thrown in vercel/ai.

Source

Thrown at packages/gateway/src/gateway-video-model.ts:82

        headers: combineHeaders(
          resolvedHeaders,
          headers ?? {},
          this.getModelConfigHeaders(),
          await resolve(this.config.o11yHeaders),
          { accept: 'text/event-stream' },
        ),
        body: this.buildRequestBody(options),
        successfulResponseHandler: async ({
          response,
          url,
          requestBodyValues,
        }: {
          url: string;
          requestBodyValues: unknown;
          response: Response;
        }) => {
          if (response.body == null) {
            throw new APICallError({
              message: 'SSE response body is empty',
              url,
              requestBodyValues,
              statusCode: response.status,
            });
          }

          const eventStream = parseJsonEventStream({
            stream: response.body,
            schema: gatewayVideoEventSchema,
          });

          const reader = eventStream.getReader();
          const { done, value: parseResult } = await reader.read();
          reader.releaseLock();

          if (done || !parseResult) {
            throw new APICallError({

View on GitHub (pinned to 69428b1f8b)

When it happens

Trigger: Thrown at packages/gateway/src/gateway-video-model.ts:82 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of vercel/ai@69428b1f8b (2026-08-30). Data as JSON: /api/errors/2c76eb000fc46e1e. Report an issue: GitHub.