hasura/graphql-engine · error · DataConnectorError::InvalidHeaderValue

Invalid value specified for header {header_name}

Error message

Invalid value specified for header {header_name}

What it means

A header value configured on the data connector is not a valid HTTP header value (rejected by the header value parser), though the name was fine.

Source

Thrown at v3/crates/metadata-resolve/src/stages/data_connectors/error.rs:28

    }
}

#[derive(Debug, thiserror::Error)]
#[error("The data connector {data_connector_name} has an error: {error}")]
pub struct NamedDataConnectorError {
    pub data_connector_name: Qualified<DataConnectorName>,
    pub error: DataConnectorError,
}

#[derive(Debug, thiserror::Error)]
pub enum DataConnectorError {
    #[error("the data connector is defined more than once")]
    DuplicateDataConnectorDefinition,
    #[error("The url for the data connector is invalid: {error}")]
    InvalidDataConnectorUrl { error: url::ParseError },
    #[error("Invalid header name {header_name} specified")]
    InvalidHeaderName { header_name: String },
    #[error("Invalid value specified for header {header_name}")]
    InvalidHeaderValue { header_name: String },
    #[error("{0}")]
    NdcValidationError(NDCValidationError),
    #[error(
        "The version specified in the capabilities (\"{version}\") is an invalid version: {error}"
    )]
    InvalidNdcVersion {
        version: String,
        error: semver::Error,
    },
    #[error(
        "The version specified in the capabilities (\"{version}\") is not compatible with the schema version specified. The version requirement is {requirement}"
    )]
    IncompatibleNdcVersion {
        version: String,
        requirement: semver::VersionReq,
    },
}

View on GitHub (pinned to 724551b9ae)

Solutions

1. Verify the header value encoding
2. Ensure env-var interpolation produced the expected value
3. Rebuild metadata

http::HeaderValue::from_str(&value)?;

Catch InvalidHeaderValue and report which header failed.

When it happens

Trigger: Setting a header whose value contains invalid bytes/control characters, or non-UTF8 data; commonly a malformed auth token.

Common situations: Badly base64-encoded credentials, environment variables injecting newlines/control chars, or template syntax left in the value.

Related errors

• Invalid header name {header_name} specified
• Header '{0}', used in the auth config, is not a valid header
• Header value '{0}' is not a valid header value for header '{
• Error while preparing the response: {0}
• Invalid header name {0}

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/deb4c62e205867e7. Report an issue: GitHub.