systemprompt_api/services/gateway/service/
mod.rs

1//! Gateway dispatch entry point: route resolution, policy and quota checks,
2//! upstream send, and response finalization.
3#![expect(
4    clippy::clone_on_ref_ptr,
5    reason = "Arc::clone usage is intentional and ergonomic in this gateway dispatch path"
6)]
7
8mod finalize;
9
10use std::sync::Arc;
11
12use anyhow::{Result, anyhow};
13use axum::body::Body;
14use axum::response::Response;
15use bytes::Bytes;
16use systemprompt_database::DbPool;
17use systemprompt_models::profile::{GatewayConfig, ProviderRegistry};
18
19use self::finalize::{FinalizeCtx, attach_request_id, finalize, run_request_safety_scan};
20use super::audit::{GatewayAudit, GatewayRequestContext};
21use super::policy::PolicyResolver;
22use super::protocol::canonical::CanonicalRequest;
23use super::protocol::inbound::InboundAdapter;
24use super::protocol::outbound::OutboundCtx;
25use super::quota;
26use super::registry::GatewayUpstreamRegistry;
27
28pub const REQUEST_ID_HEADER: &str = "x-systemprompt-request-id";
29
30#[derive(Debug, Clone, Copy)]
31pub struct GatewayService;
32
33#[derive(Debug)]
34pub struct DispatchInputs {
35    pub request: CanonicalRequest,
36    pub raw_body: Bytes,
37    pub ctx: GatewayRequestContext,
38    pub inbound: Arc<dyn InboundAdapter>,
39}
40
41#[derive(Debug, thiserror::Error)]
42#[error("{0}")]
43pub struct PolicyDenied(pub String);
44
45#[derive(Debug, thiserror::Error)]
46#[error("{message}")]
47pub struct QuotaExceeded {
48    pub message: String,
49    pub retry_after_seconds: i32,
50}
51
52impl GatewayService {
53    pub async fn dispatch(
54        config: &GatewayConfig,
55        registry: &ProviderRegistry,
56        db: &DbPool,
57        inputs: DispatchInputs,
58    ) -> Result<Response<Body>> {
59        let DispatchInputs {
60            request,
61            raw_body,
62            ctx,
63            inbound,
64        } = inputs;
65        if ctx.session_id.is_none() {
66            return Err(anyhow!(
67                "gateway dispatch missing conversation binding (session_id)"
68            ));
69        }
70
71        let ai_request_id = ctx.ai_request_id.clone();
72
73        if !config.is_model_exposed(registry, &request.model) {
74            tracing::warn!(
75                ai_request_id = %ai_request_id,
76                model = %request.model,
77                "Gateway denied: model not exposed by gateway policy or registry"
78            );
79            return Err(PolicyDenied(format!(
80                "model '{}' is not permitted by gateway policy",
81                request.model
82            ))
83            .into());
84        }
85
86        let route = config
87            .resolve_route(registry, &request.model)
88            .ok_or_else(|| anyhow!("No gateway route matches model '{}'", request.model))?;
89
90        let provider = route.resolve(registry).ok_or_else(|| {
91            anyhow!(
92                "Gateway route '{}' provider '{}' is not declared in profile.providers",
93                route.id.as_str(),
94                route.provider.as_str()
95            )
96        })?;
97
98        let secrets = systemprompt_config::SecretsBootstrap::get()
99            .map_err(|e| anyhow!("Secrets not available: {e}"))?;
100
101        let upstream_api_key = secrets
102            .get(provider.api_key_secret.as_str())
103            .ok_or_else(|| {
104                anyhow!(
105                    "Gateway API key secret '{}' not configured",
106                    provider.api_key_secret.as_str()
107                )
108            })?;
109
110        let upstream = GatewayUpstreamRegistry::global()
111            .get(provider.protocol.as_tag())
112            .ok_or_else(|| {
113                anyhow!(
114                    "Gateway has no outbound adapter for wire protocol '{}'",
115                    provider.protocol.as_tag()
116                )
117            })?;
118
119        let is_streaming = request.stream;
120
121        tracing::info!(
122            ai_request_id = %ai_request_id,
123            user_id = %ctx.user_id,
124            model = %request.model,
125            provider = %route.provider,
126            upstream = %provider.endpoint,
127            wire_protocol = %ctx.wire_protocol,
128            streaming = is_streaming,
129            "Gateway request dispatched"
130        );
131
132        let resolver = PolicyResolver::new(db)?;
133        let policy = resolver.resolve().await;
134
135        let audit = Arc::new(
136            GatewayAudit::new(db, ctx.clone()).map_err(|e| anyhow!("audit init failed: {e}"))?,
137        );
138
139        if let Err(e) = audit.open(&request, &raw_body).await {
140            tracing::error!(error = %e, "audit open failed — proceeding without audit row");
141        }
142
143        if let Some(decision) =
144            quota::precheck_and_reserve(db, &ctx.user_id, &policy.quota_windows).await?
145        {
146            if !decision.allow {
147                let msg = format!(
148                    "quota exceeded for window {}s (used {}/{:?})",
149                    decision.window_seconds, decision.state.requests, decision.limit_requests
150                );
151                if let Err(e) = audit.fail(&msg).await {
152                    tracing::warn!(error = %e, "quota audit fail failed");
153                }
154                return Err(QuotaExceeded {
155                    message: msg,
156                    retry_after_seconds: decision.window_seconds,
157                }
158                .into());
159            }
160        }
161
162        run_request_safety_scan(db, &ai_request_id, &request).await;
163
164        let upstream_model = route.effective_upstream_model(&request.model).to_owned();
165        let outbound_ctx = OutboundCtx {
166            route: route.as_ref(),
167            endpoint: &provider.endpoint,
168            api_key: upstream_api_key,
169            request: &request,
170            upstream_model: &upstream_model,
171        };
172
173        let outcome = match upstream.send(outbound_ctx).await {
174            Ok(o) => o,
175            Err(e) => {
176                if let Err(audit_err) = audit.fail(&e.to_string()).await {
177                    tracing::warn!(error = %audit_err, "upstream audit fail failed");
178                }
179                return Err(e);
180            },
181        };
182
183        let response = finalize(
184            outcome,
185            FinalizeCtx {
186                audit: Arc::clone(&audit),
187                db: db.clone(),
188                ai_request_id: ai_request_id.clone(),
189                policy,
190                inbound,
191                request_model: request.model.clone(),
192            },
193        )
194        .await;
195        Ok(attach_request_id(response, &ai_request_id))
196    }
197}
systemprompt_api/services/gateway/service/mod.rs

systemprompt_api/services/gateway/service/
mod.rs
