hasura/graphql-engine · error · PluginValidationError

Plugin {plugin_name} is defined more than once

Error message

Plugin {plugin_name} is defined more than once

What it means

Thrown when two lifecycle plugins in the metadata share the same qualified name. Plugin names form a namespace (per subgraph) and must be unique.

Source

Thrown at v3/crates/metadata-resolve/src/stages/plugins/error.rs:21

use open_dds::plugins::LifecyclePluginName;

#[derive(Debug, thiserror::Error)]
pub enum PluginValidationError {
    #[error("Plugin {plugin_name} references unknown data connector {data_connector_name}")]
    UnknownDataConnector {
        plugin_name: Qualified<LifecyclePluginName>,
        data_connector_name: Qualified<DataConnectorName>,
    },
    #[error(
        "Data connector {data_connector_name} is referenced by multiple {plugin_type} plugins: {plugin_name_a} and {plugin_name_b}"
    )]
    DuplicatePluginForDataConnector {
        plugin_type: String,
        data_connector_name: Qualified<DataConnectorName>,
        plugin_name_a: Qualified<LifecyclePluginName>,
        plugin_name_b: Qualified<LifecyclePluginName>,
    },
    #[error("Plugin {plugin_name} is defined more than once")]
    DuplicatePluginName {
        plugin_name: Qualified<LifecyclePluginName>,
    },
}

View on GitHub (pinned to 724551b9ae)

Solutions

1. Search all plugin definitions for the name in the error and remove or rename the duplicate
2. Check that no plugin metadata file is included twice in your build/export process
3. Adopt a naming convention (e.g. <connector>_<purpose>_plugin) to avoid collisions

Example fix

# before
plugins:
  - name: auditPlugin
    ...
  - name: auditPlugin   # duplicate
# after
plugins:
  - name: auditPlugin
    ...
  - name: auditPluginV2
    ...

const seen = new Set();
for (const p of plugins) {
  const key = `${p.subgraph}::${p.name}`;
  if (seen.has(key)) throw new Error(`duplicate plugin ${key}`);
  seen.add(key);
}

When it happens

Trigger: Declaring two lifecycle plugins with the same LifecyclePluginName (same subgraph + name), typically via duplicated definitions or overlapping metadata files; detected during the plugins validation stage.

Common situations: Copy-pasting a plugin block without renaming; including the same plugin file twice in the metadata build; merging subgraphs that both define a plugin with the same name.

Related errors

• Data connector {data_connector_name} is referenced by multip
• Cannot add query root field {0} as it already in use
• Cannot add mutation root field {0} as it already in use
• Cannot add subscription root field {0} as it already in use
• the boolean expression type with name {type_name} is defined

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/ca85685e4193df34. Report an issue: GitHub.