hasura/graphql-engine · error · Error

Error parsing the request: {0}

Error message

Error parsing the request: {0}

What it means

The pre-response plugin failed to parse JSON while constructing or handling the hook request payload (serde_json::Error). It indicates the request-side schema does not match what the executor expects.

Source

Thrown at v3/crates/plugins/pre-response-plugin/src/execute/common.rs:23

    response::IntoResponse,
};

use hasura_authn_core::Session;
use lang_graphql::{ast::common as ast, http::RawRequest};
use open_dds::plugins::{LifecyclePluginUrl, LifecyclePreResponsePluginHookConfigRequest};
use reqwest::header::HeaderValue;
use serde::Serialize;
use tracing_util::{ErrorVisibility, TraceableError};

#[derive(Debug, thiserror::Error)]
pub enum Error {
    #[error("Error while making the HTTP request to the pre-parse plugin {0} - {1}")]
    ErrorWhileMakingHTTPRequestToTheHook(String, reqwest::Error),
    #[error("Error while building the request for the pre-parse plugin {0} - {1}")]
    BuildRequestError(String, String),
    #[error("Reqwest error: {0}")]
    ReqwestError(reqwest::Error),
    #[error("Error parsing the request: {0}")]
    PluginRequestParseError(serde_json::Error),
    #[error("Error parsing the engine response: {0}")]
    EngineResponseParseError(serde_json::Error),
    #[error("Unexpected status code: {0}")]
    UnexpectedStatusCode(u16),
    #[error("Error serializing the modified response: {0}")]
    ResponseSerializationError(serde_json::Error),
    #[error("Error while preparing the response: {0}")]
    ResponsePreparationError(axum::http::Error),
}

impl TraceableError for Error {
    fn visibility(&self) -> ErrorVisibility {
        ErrorVisibility::Internal
    }
}

impl Error {

View on GitHub (pinned to 724551b9ae)

Solutions

1. Use matching versions of the engine and pre-response plugin crates.
2. Capture the failing JSON payload in logs and diff it against the expected schema.
3. Fix the mock/hook implementation in tests to emit the contract-compliant shape.

// in tests, assert your mock emits the contract shape
serde_json::from_value::<PluginRequest>(mock_json).expect("mock must match contract");

When it happens

Trigger: The serialized request body for the hook does not deserialize into the expected request type — typically when the engine version and plugin version disagree on the request schema.

Common situations: Mixed engine/plugin versions after a partial upgrade; hand-rolled mock hook emitting an incompatible request shape in tests.

Related errors

• Error parsing the engine response: {0}
• Error serializing the modified response: {0}
• Serialization error: {0}
• Serialization error: {0}
• Error parsing the request: {0}

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/c7bb47a0f0a104e2. Report an issue: GitHub.