BoundaryML/baml · error

No assets in release metadata

Error message

No assets in release metadata

What it means

After parsing the release metadata, get_playground_dist accesses release["assets"].as_array(). If the JSON has no "assets" key or it is not an array (e.g. GitHub returned an error object or a message payload), this error is thrown. It is a structural guard ensuring release metadata looks like a normal GitHub release response.

Source

Thrown at engine/playground-server/src/server.rs:161

            .await
            .unwrap_or_else(|_| "Failed to read response body".to_string());
        return Err(anyhow::anyhow!(
            "GitHub API request failed with status {}: {}",
            status,
            body
        ));
    }

    tracing::info!("Parsing JSON response...");
    let release: serde_json::Value = resp
        .json()
        .await
        .map_err(|e| anyhow::anyhow!("Failed to parse JSON response: {e}"))?;

    // Find the main asset
    let assets = release["assets"]
        .as_array()
        .ok_or_else(|| anyhow::anyhow!("No assets in release metadata"))?;
    let asset = assets
        .iter()
        .find(|a| a["name"].as_str() == Some(&web_panel_asset_name))
        .ok_or_else(|| anyhow::anyhow!("No asset named '{}' in release", web_panel_asset_name))?;
    let download_url = asset["browser_download_url"]
        .as_str()
        .ok_or_else(|| anyhow::anyhow!("No download URL for asset"))?;

    // Find the checksum asset
    let checksum_asset = assets
        .iter()
        .find(|a| a["name"].as_str() == Some(&checksum_asset_name))
        .ok_or_else(|| {
            anyhow::anyhow!(
                "No checksum asset named '{}' in release",
                checksum_asset_name
            )
        })?;

View on GitHub (pinned to bd85ce9dee)

Solutions

1. Verify the GitHub release actually exists and is published (not draft) and has uploaded assets.
2. Check the API URL / release tag being requested points to the correct release.
3. Log the full release JSON to confirm the payload shape and update the parsing logic if GitHub changed the schema.

// preflight: confirm the release is published and has assets
let v: serde_json::Value = reqwest::get(&api_url).await?.json().await?;
if v["assets"].as_array().map_or(true, |a| a.is_empty()) {
    eprintln!("Release has no assets (draft or empty?) — abort early");
}

// check release payload shape
fn has_assets(release: &serde_json::Value) -> bool {
    release.get("assets").and_then(|a| a.as_array()).map_or(false, |a| !a.is_empty())
}

match get_playground_dist().await {
    Err(e) if e.to_string().contains("No assets in release metadata") => {
        eprintln!("Draft or asset-less release; pin a published release");
    }
    other => other?,
}

When it happens

Trigger: The parsed JSON lacks an assets array — e.g. GitHub returned {"message": "Not Found"} with a 200 from a cache, a draft release with no assets, or an unexpected API response shape.

Common situations: Querying a draft release (assets not visible via the public API); an unexpected API payload version; a release published without uploading the playground binaries.

Understand the failure class

Background: "invalid response format", "malformed payload", "missing data field": when an API returns 200 but the response shape is wrong — this error's family across 23 libraries.

Related errors

• No download URL for asset
• No download URL for checksum asset
• Failed to parse JSON response: {e}
• `{BAML_JSON_JSON}` is declared by the stdlib
• Failed to deserialize value: {e}

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/31b4fa6f4c5611a3. Report an issue: GitHub.