What causes "Reqwest error: {0}" in hasura/graphql-engine?

Read the wrapped reqwest error for the category (body read, decode, redirect).

hasura/graphql-engine · error · Error

Reqwest error: {0}

Error message

Reqwest error: {0}

What it means

Generic reqwest::Error surface for the pre-response plugin executor, covering failures like response-body read errors that don't map to the specific build/send variants.

Source

Thrown at v3/crates/plugins/pre-response-plugin/src/execute/common.rs:21

use axum::{
    http::{HeaderMap, HeaderName, StatusCode},
    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
    }
}

View on GitHub (pinned to 724551b9ae)

Solutions

Read the wrapped reqwest error for the category (body read, decode, redirect).
Check plugin logs for panics or aborts at the same timestamp.
Tune proxy idle/read timeouts between engine and plugin.

Defensive patterns

Strategy: retry

Try / catch

Err(Error::ReqwestError(ref e)) if e.is_timeout() || e.is_body() => retry_with_backoff().await

Prevention

Tune LB/proxy idle timeouts above hook processing time.
Stream responses defensively; handle mid-body disconnects.
Track hook latency to preempt slow-read failures.

When it happens

Trigger: The hook connection drops while the engine reads the response body, or another reqwest operation fails outside the explicit send/build paths.

Common situations: Plugin aborting mid-response; aggressive proxy/LB idle timeouts cutting the stream.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

AI-assisted analysis of hasura/graphql-engine@724551b9ae (2026-08-28). Data as JSON: /api/errors/ca39b0ea5bf1a83b. Report an issue: GitHub.