influxdata/influxdb · error · Error::NonUtf8ContentTypeHeader

invalid content-type header

Error message

invalid content-type header: {0}

What it means

`Error::NonUtf8ContentTypeHeader` is returned when the `Content-Type` header value cannot be read as a string (wrapping `hyper::header::ToStrError`). Like all HTTP headers, it must be visible ASCII for the server to parse the MIME type.

Solutions

1. Send a standard ASCII media type such as "application/json", "text/plain", or "application/vnd.influxdb.v3+csv"
2. Validate/sanitize any dynamic Content-Type value before inserting it into the request
3. Check the client or proxy producing the request for header corruption
4. Omit the header if the server can infer the type for the endpoint

Example fix

// before
headers.insert("Content-Type", HeaderValue::from_bytes(format!("text/{}", user_mime).as_bytes()).unwrap());
// after
headers.insert("Content-Type", HeaderValue::from_static("text/plain"));

const ALLOWED = new Set(['application/json','text/plain','application/vnd.influxdb.v3+csv']);
if (!ALLOWED.has(contentType)) throw new Error('bad content-type: ' + contentType);

When it happens

Trigger: Sending a request whose `Content-Type` header contains non-ASCII bytes — e.g. UTF-8 characters in the media type, control characters, or a client building the header from unvalidated input.

Common situations: Custom HTTP clients inserting user-supplied or localized strings into Content-Type, misbehaving proxies, or template-generated requests where the content type string was interpolated incorrectly.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• invalid content-encoding header
• invalid mime type ( )
• unacceptable content-type, expected
• arrow error
• Authorization header was malformed, the request was not in…

AI-assisted analysis of influxdata/influxdb@06200ef96b (2026-09-19). Data as JSON: /api/errors/529197e17da5de09. Report an issue: GitHub.

Appendix: source

Thrown at influxdb3_server/src/http.rs:208

    }
}

#[derive(Debug, Error)]
pub enum Error {
    /// The requested path has no registered handler.
    #[error("not found")]
    NoHandler,

    /// The request body content is not valid utf8.
    #[error("body content is not valid utf8: {0}")]
    NonUtf8Body(Utf8Error),

    /// The `Content-Encoding` header is invalid and cannot be read.
    #[error("invalid content-encoding header: {0}")]
    NonUtf8ContentEncodingHeader(hyper::header::ToStrError),

    /// The `Content-Type` header is invalid and cannot be read.
    #[error("invalid content-type header: {0}")]
    NonUtf8ContentTypeHeader(hyper::header::ToStrError),

    /// The specified `Content-Encoding` is not acceptable.
    #[error("unacceptable content-encoding: {0}")]
    InvalidContentEncoding(String),

    /// The specified `Content-Type` is not acceptable.
    #[error("unacceptable content-type, expected: {expected}")]
    InvalidContentType { expected: mime::Mime },

    /// The client disconnected.
    #[error("client disconnected")]
    ClientHangup(Box<dyn std::error::Error + Send + Sync>),

    /// The client sent a request body that exceeds the configured maximum.
    #[error("max request size ({0} bytes) exceeded")]
    RequestSizeExceeded(usize),

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