synapse/
error.rs

1//! Gateway error type → OpenAI-shaped JSON + HTTP status.
2
3#[cfg(feature = "server")]
4use axum::http::StatusCode;
5#[cfg(feature = "server")]
6use axum::response::{IntoResponse, Response};
7#[cfg(feature = "server")]
8use axum::Json;
9#[cfg(feature = "server")]
10use serde_json::json;
11use thiserror::Error;
12
13#[derive(Debug, Error)]
14pub enum GatewayError {
15    #[error("unknown model alias '{0}'")]
16    UnknownModel(String),
17    #[error("native feature '{feature}' is not available on route '{route}'")]
18    NativeFeatureUnsupported { feature: String, route: String },
19    #[error("invalid request: {0}")]
20    BadRequest(String),
21    #[error("all legs of route '{route}' failed")]
22    AllLegsFailed {
23        route: String,
24        failures: Vec<LegFailure>,
25    },
26    #[error("all providers for route '{0}' are unavailable")]
27    AllCircuitsOpen(String),
28    #[error("upstream timed out")]
29    UpstreamTimeout,
30    #[error("upstream error {status}: {body}")]
31    Upstream { status: u16, body: String },
32    #[error("request blocked by content policy '{policy}'")]
33    ContentBlocked {
34        policy: String,
35        scanners: Vec<String>,
36    },
37}
38
39#[derive(Debug, Clone, serde::Serialize)]
40pub struct LegFailure {
41    pub provider: String,
42    pub model: String,
43    pub message: String,
44}
45
46impl GatewayError {
47    #[cfg(feature = "server")]
48    pub fn status(&self) -> StatusCode {
49        match self {
50            GatewayError::UnknownModel(_) => StatusCode::NOT_FOUND,
51            GatewayError::NativeFeatureUnsupported { .. } | GatewayError::BadRequest(_) => {
52                StatusCode::BAD_REQUEST
53            }
54            GatewayError::AllLegsFailed { .. } | GatewayError::Upstream { .. } => {
55                StatusCode::BAD_GATEWAY
56            }
57            GatewayError::AllCircuitsOpen(_) => StatusCode::SERVICE_UNAVAILABLE,
58            GatewayError::UpstreamTimeout => StatusCode::GATEWAY_TIMEOUT,
59            GatewayError::ContentBlocked { .. } => StatusCode::BAD_REQUEST,
60        }
61    }
62
63    #[cfg(feature = "server")]
64    pub(crate) fn code(&self) -> &'static str {
65        match self {
66            GatewayError::UnknownModel(_) => "model_not_found",
67            GatewayError::NativeFeatureUnsupported { .. } => "native_feature_unsupported",
68            GatewayError::BadRequest(_) => "invalid_request_error",
69            GatewayError::AllLegsFailed { .. } => "all_legs_failed",
70            GatewayError::AllCircuitsOpen(_) => "circuit_open",
71            GatewayError::UpstreamTimeout => "upstream_timeout",
72            GatewayError::Upstream { .. } => "upstream_error",
73            GatewayError::ContentBlocked { .. } => "content_blocked",
74        }
75    }
76}
77
78#[cfg(feature = "server")]
79impl IntoResponse for GatewayError {
80    fn into_response(self) -> Response {
81        let mut error = json!({
82            "type": self.code(),
83            "message": self.to_string(),
84            "code": self.code(),
85        });
86        if let GatewayError::AllLegsFailed { failures, .. } = &self {
87            error["failures"] = json!(failures);
88        }
89        if let GatewayError::ContentBlocked { policy, scanners } = &self {
90            error["type"] = json!("content_policy_violation");
91            error["message"] = json!(format!(
92                "Request blocked by content policy '{policy}' (scanners: {})",
93                scanners.join(", ")
94            ));
95            error["scanners"] = json!(scanners);
96        }
97        (self.status(), Json(json!({ "error": error }))).into_response()
98    }
99}
100
101#[cfg(all(test, feature = "server"))]
102mod tests {
103    use super::*;
104    use axum::http::StatusCode;
105
106    #[test]
107    fn content_blocked_is_bad_request_with_named_scanners() {
108        let e = GatewayError::ContentBlocked {
109            policy: "strict".into(),
110            scanners: vec!["secrets".into(), "role_override".into()],
111        };
112        assert_eq!(e.status(), StatusCode::BAD_REQUEST);
113        assert_eq!(e.code(), "content_blocked");
114        let msg = e.to_string();
115        assert!(msg.contains("strict"), "message names the policy: {msg}");
116    }
117}
synapse/error.rs

synapse/
error.rs
