quickwit-oss/quickwit · error · UnsupportedMediaType

UnsupportedMediaType

Error message

UnsupportedMediaType

What it means

`UnsupportedMediaType` is a warp custom rejection raised in `extract_config_format` (quickwit/quickwit-serve/src/format.rs:105) when a REST handler that accepts an index/source/index-template config receives a `Content-Type` header whose MIME subtype is not `json`, `toml`, or `yaml`. Quickwit only knows how to deserialize the posted configuration body in those three formats, so any other content type is rejected with an HTTP 415 Unsupported Media Type response.

Source

Thrown at quickwit/quickwit-serve/src/format.rs:105

#[error(
    "request's content-type is not supported: supported media types are `application/json`, \
     `application/toml`, and `application/yaml`"
)]
pub(crate) struct UnsupportedMediaType;

impl warp::reject::Reject for UnsupportedMediaType {}

pub(crate) fn extract_config_format()
-> impl Filter<Extract = (ConfigFormat,), Error = Rejection> + Copy {
    warp::filters::header::optional::<mime_guess::Mime>(CONTENT_TYPE.as_str()).and_then(
        |mime_opt: Option<mime_guess::Mime>| {
            if let Some(mime) = mime_opt {
                let config_format = match mime.subtype().as_str() {
                    "json" => ConfigFormat::Json,
                    "toml" => ConfigFormat::Toml,
                    "yaml" => ConfigFormat::Yaml,
                    _ => {
                        return futures::future::err(warp::reject::custom(UnsupportedMediaType));
                    }
                };
                return futures::future::ok(config_format);
            }
            futures::future::ok(ConfigFormat::Json)
        },
    )
}

View on GitHub (pinned to a39730c5cd)

Solutions

1. Set the request `Content-Type` header to `application/json` (or `application/toml` / `application/yaml` to match the body encoding).
2. Ensure the body actually matches the declared Content-Type (JSON body with JSON header, TOML body with TOML header).
3. Avoid vendor MIME suffixes; use plain `application/json` rather than `application/vnd.api+json`, since only the bare subtype is matched.
4. If using a generated HTTP client, override the default content type for these config endpoints.

Example fix

// before
curl -X POST http://localhost:7280/indexes -H 'Content-Type: text/plain' --data-binary @index-config.yaml
// after
curl -X POST http://localhost:7280/indexes -H 'Content-Type: application/yaml' --data-binary @index-config.yaml

// Client-side check before sending
const ALLOWED = new Set(['application/json', 'application/toml', 'application/yaml']);
if (!ALLOWED.has(contentType)) {
  throw new Error(`Content-Type must be one of ${[...ALLOWED]}, got: ${contentType}`);
}

fn is_supported_config_content_type(content_type: &str) -> bool {
  matches!(
    content_type,
    "application/json" | "application/toml" | "application/yaml"
      | "text/yaml" | "text/x-yaml"
  )
}

// Client side: catch the 415 rejection and report the offending header
try {
  const res = await fetch(url, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body });
  if (!res.ok) throw new Error(`HTTP ${res.status}: ${await res.text()}`);
} catch (e) {
  if (String(e).includes('415') || String(e).includes('UnsupportedMediaType')) {
    console.error('Set Content-Type to application/json, application/toml, or application/yaml');
  }
  throw e;
}

When it happens

Trigger: Sending POST/PUT to /indexes, /indexes/{index}/sources, or index-template endpoints with a `Content-Type` such as `application/xml`, `text/plain`, `application/x-www-form-urlencoded`, or a vendor type whose subtype Quickwit does not map (e.g. `application/hal+json` resolves to subtype `hal+json`, not `json`).

Common situations: curl or HTTP client defaulting to no/incorrect Content-Type; REST client tools posting form data; SDK-generated clients sending vendor MIME types like `application/vnd.api+json`; copy-pasted requests where the body is JSON but the header says `text/plain`.

Related errors

• Encountered unknown command: code {other}
• `index_id` in config file does not match index_id from query
• path based file sources are limited to a local usage, please
• `source_id` in config file does not match source_id from que
• Failed to fetch splits.

AI-assisted analysis of quickwit-oss/quickwit@a39730c5cd (2026-09-08). Data as JSON: /api/errors/b93c70e4040a8a80. Report an issue: GitHub.