Kuberwastaken/claurst · error

No screenshot data in response

Error message

No screenshot data in response

What it means

Thrown by the `screenshot` command when the CDP `Page.captureScreenshot` response has no string at `result.data`. CDP normally returns base64 PNG data there; a missing field means Chrome did not produce a screenshot payload (e.g. the target closed, page crashed, or an error result was returned instead).

Solutions

1. Re-run `/chrome screenshot` — transient races usually succeed on retry.
2. Reconnect with `/chrome connect` to get a fresh session bound to a live tab.
3. Ensure the target tab is open and responsive before screenshotting.
4. Check the CDP error in the response for a root cause (e.g. target crashed) and address it.

Example fix

// defensive caller
match chrome_screenshot() {
    Ok(path) => println!("saved {}", path),
    Err(e) if e.to_string().contains("No screenshot data") => {
        chrome_reconnect()?; // stale/failed target
        chrome_screenshot()?;
    }
    Err(e) => return Err(e),
}

// verify the session's tab is still open before capture
let alive: bool = cdp_call(ws, "Runtime.evaluate", json!({"expression": "!document.closed"})).await?.get("result").is_some();
if !alive { reconnect()?; }

fn extract_b64(resp: &Value) -> Option<&str> {
    resp["result"]["data"].as_str().filter(|s| !s.is_empty())
}

match screenshot().await {
    Ok(p) => Ok(p),
    Err(e) if e.to_string().contains("No screenshot data") => {
        reconnect()?;
        screenshot().await
    }
    Err(e) => Err(e),
}

When it happens

Trigger: Page.captureScreenshot returns a response lacking result.data — target tab closed mid-call, renderer crashed, or CDP returned an error object instead of a data payload.

Common situations: Screenshotting a tab the user just closed; capturing on a crashed/OOM page; Chrome under heavy load returning an error response; navigating during the capture so the target changed.

Related errors

• WebSocket closed unexpectedly
• WebSocket closed by Chrome
• CDP error
• No debuggable page found on port
• WebSocket connect to

AI-assisted analysis of Kuberwastaken/claurst@b0637c97ec (2026-09-10). Data as JSON: /api/errors/60321e78f03734cd. Report an issue: GitHub.

Appendix: source

Thrown at src-rust/crates/commands/src/chrome.rs:200

        }
        .await;
        store_session(s);
        result
    }

    /// Take a screenshot, write PNG to a temp file, return the path.
    pub async fn screenshot() -> anyhow::Result<String> {
        let mut s = take_session()?;
        let result = async {
            let resp = cdp_call(
                &mut s.ws,
                "Page.captureScreenshot",
                json!({ "format": "png", "captureBeyondViewport": false }),
            )
            .await?;
            let b64 = resp["result"]["data"]
                .as_str()
                .ok_or_else(|| anyhow::anyhow!("No screenshot data in response"))?;
            let bytes = base64::engine::general_purpose::STANDARD.decode(b64)?;

            let tmp = tempfile::Builder::new()
                .prefix("cc-chrome-")
                .suffix(".png")
                .tempfile()?;
            let path = tmp.path().to_path_buf();
            std::fs::write(&path, &bytes)?;
            // Persist file past the NamedTempFile drop.
            let _ = tmp.keep()?;
            Ok(format!("Screenshot saved to {}", path.display()))
        }
        .await;
        store_session(s);
        result
    }

    /// Click the first element matching a CSS selector.

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