Hmbown/CodeWhale · error · anyhow::Error

Antigravity cloud-code SSE is not JSON

Error message

Antigravity cloud-code SSE is not JSON: {err}

What it means

Each cloud-code SSE data frame that is not the [DONE] sentinel is parsed with serde_json::from_str. If the frame is not valid JSON, the adapter yields 'Antigravity cloud-code SSE is not JSON' with the serde error and terminates the stream - it does not skip the frame or attempt recovery.

Solutions

  1. Replay the same request with curl -N to see the actual frame content.
  2. If it is an auth or HTML page, fix credentials or the endpoint URL before retrying.
  3. Remove proxy injections (block pages, banners) on the cloud-code route.
  4. If frames are genuinely JSON but interleaved with text, report upstream - the adapter fails closed on the first non-JSON frame.
Defensive patterns

Strategy: validation

Validate before calling

// Rust: probe that cloud-code data frames are JSON before wiring the consumer
let first = first_data_frame(&mut resp).await?; // "data: {...}"
let payload = extract_sse_data_value(&first).context("no data frame")?;
serde_json::from_str::<serde_json::Value>(payload)
    .context("cloud-code route returned non-JSON (auth page?)")?;

Try / catch

// deterministic - fix credentials/endpoint instead of retrying
Err(err) if err.to_string().contains("SSE is not JSON") => {
    return Err(err.context("verify cloud-code credentials and base URL"));
}

Prevention

When it happens

Trigger: The gateway answers the SSE route with an HTML login/error page or plain-text message; a proxy error or block page injected mid-stream; a data frame containing non-JSON text (banner, logging preamble); partial frame corruption.

Common situations: Expired or missing Antigravity credentials returning an HTML auth redirect; a wrong base URL; corporate proxies injecting block pages; environment banners prepended to streams.

Understand the failure class

Background: "Invalid JSON response" and "Failed to parse response" errors: when an API answers 200 but the body isn't the JSON your library expected — this error's family across 28 libraries.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@0c42157ee5 (2026-08-20). Data as JSON: /api/errors/ee0094e98cb63709. Report an issue: GitHub.

Appendix: source

Thrown at crates/tui/src/client/cloud_code.rs:218

                        Ok(None) => break,
                        Err(err) => {
                            yield Err(anyhow::anyhow!("{err}"));
                            return;
                        }
                    };
                    if line.is_empty() || line.starts_with(':') {
                        continue;
                    }
                    let Some(data) = super::extract_sse_data_value(&line) else {
                        continue;
                    };
                    if data == "[DONE]" {
                        break;
                    }
                    let value: Value = match serde_json::from_str(data) {
                        Ok(value) => value,
                        Err(err) => {
                            yield Err(anyhow::anyhow!(
                                "Antigravity cloud-code SSE is not JSON: {err}"
                            ));
                            return;
                        }
                    };
                    if let Some(error) = value.get("error") {
                        yield Ok(StreamEvent::Error {
                            error: error.clone(),
                        });
                        return;
                    }
                    let Some(text) = extract_cloud_code_text(&value) else {
                        if value.get("response").is_some() || value.get("candidates").is_some() {
                            continue;
                        }
                        yield Err(anyhow::anyhow!(
                            "Antigravity cloud-code SSE shape is unproven; failing closed"
                        ));

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