vectordotdev/vector · error

Source example has no sources section

Error message

Source example has no sources section

What it means

Vector's `vdev check component-examples` wraps each component example config to build a validation topology. `wrap_source` expects the example YAML for a source component to have a top-level `sources` section; if that key is absent it cannot identify the source key or wire up validation sinks, so it throws this error.

Solutions

1. Add a top-level `sources:` mapping containing the component key to the example YAML.
2. Verify the example file is registered/selected as a source example, not a transform or sink example.
3. Confirm YAML indentation places `sources:` at the document root, not nested under another key.

Example fix

// before (example YAML)
template: my_source
log:
  namespace: x

// after
sources:
  my_source:
    type: my_source
    log:
      namespace: x

const root = yaml.parse(exampleYaml);
if (typeof root !== 'object' || root === null || Array.isArray(root) || !('sources' in root) || typeof root.sources !== 'object' || root.sources === null) {
  throw new Error('source example must have a top-level `sources` mapping');
}

function hasSourcesSection(root) {
  return typeof root === 'object' && root !== null && !Array.isArray(root) && typeof root.sources === 'object' && root.sources !== null;
}

When it happens

Trigger: Running the component example check against an example file whose component YAML lacks a top-level `sources` mapping (e.g. it uses a different root key, nests the component under something else, or the file is not actually a source example).

Common situations: A new source was documented with an example YAML that follows a sink/transform template by mistake; the example was hand-edited and `sources:` was removed or renamed; a shared example file was reused for the wrong component type.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

• has no component identifier
• Sink example has no sinks section
• Sink is missing
• Source output has no name
• Transform example has no transforms section

AI-assisted analysis of vectordotdev/vector@bdb87aeaa4 (2026-09-16). Data as JSON: /api/errors/85df4582392d6feb. Report an issue: GitHub.

Appendix: source

Thrown at vdev/src/commands/check/component_examples.rs:170

fn wrap_config(
    kind: &str,
    component_yaml: YamlValue,
    component: &Value,
) -> Result<Option<YamlValue>> {
    match kind {
        "sources" => wrap_source(&component_yaml, component).map(Some),
        "transforms" => wrap_transform(&component_yaml, component),
        "sinks" => wrap_sink(&component_yaml, component),
        _ => Ok(Some(component_yaml)),
    }
}

fn wrap_source(component_yaml: &YamlValue, component: &Value) -> Result<YamlValue> {
    let mut root = yaml_mapping(component_yaml, "source example")?;
    let sources = yaml_mapping(
        mapping_value(&root, "sources")
            .ok_or_else(|| anyhow!("Source example has no sources section"))?,
        "source example sources",
    )?;
    let source_key = mapping_key(&sources, "source example")?;
    let mut sinks = Mapping::new();

    let outputs = component.get("outputs").and_then(Value::as_array);
    let has_named_outputs = outputs
        .and_then(|outputs| outputs.first())
        .and_then(|output| output.get("name"))
        .and_then(Value::as_str)
        .is_some_and(|name| name != "<component_id>");
    if has_named_outputs {
        for output in outputs.expect("Named outputs require an output list") {
            let name = output
                .get("name")
                .and_then(Value::as_str)
                .ok_or_else(|| anyhow!("Source output has no name"))?;
            sinks.insert(

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