diff --git a/rust/loki-rs/Cargo.toml b/rust/loki-rs/Cargo.toml
index 6b9fa01..95e5d7a 100644
--- a/rust/loki-rs/Cargo.toml
+++ b/rust/loki-rs/Cargo.toml
@@ -12,7 +12,7 @@ http-body-util = "0.1.5"
 hyper = { version = "1.12.0", features = ["http1", "server", "client"] }
 hyper-util = { version = "0.1.21", features = ["tokio", "server", "client-legacy", "http1"] }
 serde = { version = "1.0.229", features = ["derive"] }
-serde_json = "1.0.154"
+serde_json = { version = "1.0.154", features = ["raw_value"] }
 sha2 = "0.11.1"
 tokio = { version = "1.53.2", features = ["rt-multi-thread", "macros", "net", "io-util", "time", "signal", "process", "sync", "fs"] }
 
diff --git a/rust/loki-rs/src/lib.rs b/rust/loki-rs/src/lib.rs
index ef434cf..a73d88d 100644
--- a/rust/loki-rs/src/lib.rs
+++ b/rust/loki-rs/src/lib.rs
@@ -5,6 +5,7 @@
 //! - `engine` : supervision du moteur (`loki serve` et son arbre, lot 3) ;
 //! - `ui` : UI web statique embarquée (lot 2) ;
 //! - `auth` : authentification de l'API de pilotage (lot 2) ;
+//! - `oai` : surface compatible OpenAI `/v1` relayée au moteur (lot 5) ;
 //! - `update` : mise à jour des binaires au démarrage du conteneur.
 
 pub mod api;
@@ -13,6 +14,7 @@ pub mod child;
 pub mod engine;
 pub mod engstatus;
 pub mod gguf;
+pub mod oai;
 pub mod paths;
 pub mod presets;
 pub mod proxy;
diff --git a/rust/loki-rs/src/oai.rs b/rust/loki-rs/src/oai.rs
new file mode 100644
index 0000000..dd2f06c
--- /dev/null
+++ b/rust/loki-rs/src/oai.rs
@@ -0,0 +1,330 @@
+//! Surface compatible OpenAI (`/v1/*`), relayée par la façade directement au
+//! moteur (lot 5) — port de `mountOAI`, `requireCompletionKey` et
+//! `oaiHandler` (`llm_oai.go`, `web_auth.go`).
+//!
+//! Les DÉCISIONS restent au Go (`web_internal_oai.go`), qui tient l'état de
+//! la conversation : il dit où router (`route`), compte la requête « en vol »
+//! et refuse pendant un benchmark ou une optimisation (`begin`), puis apprend
+//! sa fin (`end`) — à la fin du flux ou quand le client part.
+//!
+//! Comme le Go : on NE touche PAS à `Authorization` (llama-server revérifie
+//! la clé, `--api-key`), on ne bufferise rien (les jetons arrivent un par
+//! un), et les `X-Forwarded-*` entrants ne passent pas au moteur.
+
+use bytes::Bytes;
+use http_body_util::{BodyExt, Full, combinators::BoxBody};
+use hyper::body::{Frame, Incoming, SizeHint};
+use hyper::header::{self, HeaderValue};
+use hyper::{Method, Request, Response, StatusCode, Uri};
+use hyper_util::client::legacy::{Client, connect::HttpConnector};
+use serde_json::{Value, json, value::RawValue};
+use std::collections::BTreeMap;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+use crate::api::Ctx;
+use crate::auth;
+use crate::proxy::{Body, strip_hop_by_hop};
+use crate::store::Store;
+
+pub type OutBody = BoxBody<Bytes, hyper::Error>;
+pub type EngineClient = Client<HttpConnector, OutBody>;
+
+/// Réponse d'erreur au format OpenAI (`sendOAIError`) : les SDK lisent
+/// `body.error.message`.
+pub fn oai_error(status: StatusCode, msg: &str, typ: &str, code: &str) -> Response<Body> {
+    auth::json(
+        status,
+        &json!({ "error": { "message": msg, "type": typ, "param": null, "code": code } }),
+    )
+}
+
+pub async fn serve(ctx: &Ctx, engine: &EngineClient, req: Request<Incoming>) -> Response<Body> {
+    let method = req.method().clone();
+    let path = req.uri().path().to_string();
+    let route = match ctx
+        .store
+        .internal_json(
+            Method::GET,
+            &format!(
+                "/internal/v1/oai/route?method={}&path={}",
+                crate::store::enc(method.as_str()),
+                crate::store::enc(&path)
+            ),
+            None,
+        )
+        .await
+    {
+        Ok(v) => v,
+        Err(e) => {
+            eprintln!("[loki-rs] /v1 : route illisible : {e}");
+            return oai_error(
+                StatusCode::SERVICE_UNAVAILABLE,
+                "configuration illisible — réessaie dans un instant",
+                "api_error",
+                "service_unavailable",
+            );
+        }
+    };
+
+    // requireCompletionKey : un préflight CORS ne porte jamais d'Authorization.
+    if method != Method::OPTIONS {
+        if route["key_ok"] != Value::Bool(true) {
+            return oai_error(
+                StatusCode::SERVICE_UNAVAILABLE,
+                "configuration illisible — réessaie dans un instant",
+                "api_error",
+                "service_unavailable",
+            );
+        }
+        let key = route["key"].as_str().unwrap_or("");
+        if !key.is_empty() && !auth::check_bearer(req.headers(), key) {
+            let mut r = oai_error(
+                StatusCode::UNAUTHORIZED,
+                "Clé API invalide ou absente — envoie l'en-tête Authorization: Bearer <clé>.",
+                "invalid_request_error",
+                "invalid_api_key",
+            );
+            r.headers_mut().insert(
+                header::WWW_AUTHENTICATE,
+                HeaderValue::from_static(r#"Bearer realm="loki""#),
+            );
+            return r;
+        }
+    }
+
+    let port = route["port"].as_u64().unwrap_or(8080);
+    let strata = route["strata"] == Value::Bool(true);
+    let side_live = route["side_live"] == Value::Bool(true);
+    let max_body = route["max_body"].as_u64().unwrap_or(0) as usize;
+
+    // SIDE_SLOT : la complétion d'un client passe par le second slot.
+    let (mut parts, body) = req.into_parts();
+    let post_v1 = method == Method::POST && path.starts_with("/v1/");
+    let (body, side): (OutBody, bool) = if post_v1 && side_live {
+        match side_slot_body(body, max_body).await {
+            Ok((b, side)) => {
+                parts
+                    .headers
+                    .insert(header::CONTENT_LENGTH, HeaderValue::from(b.len()));
+                parts.headers.remove(header::TRANSFER_ENCODING);
+                (Full::new(b).map_err(|n| match n {}).boxed(), side)
+            }
+            Err(r) => return *r,
+        }
+    } else {
+        (body.boxed(), false)
+    };
+
+    let read = method == Method::GET || method == Method::HEAD;
+    let begin = ctx
+        .store
+        .internal_json(
+            Method::POST,
+            "/internal/v1/oai/begin",
+            Some(&json!({ "read": read, "side": side, "post_v1": post_v1 })),
+        )
+        .await;
+    let ticket = match begin {
+        Ok(v) => {
+            if let Some(refus) = v.get("refuse").filter(|r| r.is_object()) {
+                let status = StatusCode::from_u16(refus["status"].as_u64().unwrap_or(503) as u16)
+                    .unwrap_or(StatusCode::SERVICE_UNAVAILABLE);
+                let mut r = oai_error(
+                    status,
+                    refus["message"].as_str().unwrap_or(""),
+                    refus["type"].as_str().unwrap_or("server_error"),
+                    refus["code"].as_str().unwrap_or(""),
+                );
+                if let Some(ra) = refus["retry_after"].as_str()
+                    && let Ok(v) = HeaderValue::from_str(ra)
+                {
+                    r.headers_mut().insert(header::RETRY_AFTER, v);
+                }
+                return r;
+            }
+            v["ticket"].as_u64()
+        }
+        Err(e) => {
+            // Sans ticket, le Go ne saurait pas qu'une requête occupe le moteur :
+            // il pourrait effacer le slot en plein calcul. On refuse.
+            eprintln!("[loki-rs] /v1 : begin : {e}");
+            return oai_error(
+                StatusCode::SERVICE_UNAVAILABLE,
+                "configuration illisible — réessaie dans un instant",
+                "api_error",
+                "service_unavailable",
+            );
+        }
+    };
+    let guard = TicketGuard {
+        store: ctx.store.clone(),
+        ticket,
+    };
+
+    // Vers le moteur : Host d'origine, sauf Strata qui refuse un Host inconnu.
+    let engine_host = format!("127.0.0.1:{port}");
+    let pq = parts
+        .uri
+        .path_and_query()
+        .map(|p| p.as_str())
+        .unwrap_or("/");
+    parts.uri = match format!("http://{engine_host}{pq}").parse::<Uri>() {
+        Ok(u) => u,
+        Err(_) => {
+            return oai_error(
+                StatusCode::BAD_REQUEST,
+                "URI invalide",
+                "invalid_request_error",
+                "bad_request",
+            );
+        }
+    };
+    strip_hop_by_hop(&mut parts.headers);
+    for h in [
+        "x-forwarded-for",
+        "x-forwarded-host",
+        "x-forwarded-proto",
+        "forwarded",
+    ] {
+        parts.headers.remove(h);
+    }
+    if strata && let Ok(v) = HeaderValue::from_str(&engine_host) {
+        parts.headers.insert(header::HOST, v);
+    }
+    let out = Request::from_parts(parts, body);
+    match engine.request(out).await {
+        Ok(resp) => {
+            let (mut rp, rb) = resp.into_parts();
+            strip_hop_by_hop(&mut rp.headers);
+            Response::from_parts(
+                rp,
+                Guarded {
+                    inner: rb,
+                    _guard: guard,
+                }
+                .boxed(),
+            )
+        }
+        Err(e) => {
+            drop(guard);
+            oai_error(
+                StatusCode::BAD_GATEWAY,
+                &format!("moteur injoignable : {e}"),
+                "api_error",
+                "upstream_unavailable",
+            )
+        }
+    }
+}
+
+/// `sideSlotProxyRewrite` : lit le corps (borné), pose `id_slot: 1` si c'est
+/// un objet JSON. Les valeurs sont gardées telles quelles (RawValue) ; les
+/// clés ressortent triées, comme `json.Marshal` d'une map Go.
+async fn side_slot_body(body: Incoming, max: usize) -> Result<(Bytes, bool), Box<Response<Body>>> {
+    let raw = match http_body_util::Limited::new(body, max + 1).collect().await {
+        Ok(c) => c.to_bytes(),
+        Err(e) => {
+            let too_big = e
+                .downcast_ref::<http_body_util::LengthLimitError>()
+                .is_some();
+            return Err(Box::new(if too_big {
+                oai_error(
+                    StatusCode::PAYLOAD_TOO_LARGE,
+                    "corps trop gros pour être routé vers le slot des clients",
+                    "invalid_request_error",
+                    "side_slot",
+                )
+            } else {
+                oai_error(
+                    StatusCode::BAD_REQUEST,
+                    &format!("corps illisible : {e}"),
+                    "invalid_request_error",
+                    "side_slot",
+                )
+            }));
+        }
+    };
+    Ok(match rewrite_id_slot(&raw) {
+        Some(b) => (Bytes::from(b), true),
+        None => (raw, false),
+    })
+}
+
+/// Corps avec `id_slot: 1`, ou `None` si ce n'est pas un objet JSON.
+pub fn rewrite_id_slot(raw: &[u8]) -> Option<Vec<u8>> {
+    let mut obj: BTreeMap<String, Box<RawValue>> = serde_json::from_slice(raw).ok()?;
+    obj.insert("id_slot".into(), RawValue::from_string("1".into()).ok()?);
+    serde_json::to_vec(&obj).ok()
+}
+
+/// Rend le ticket au Go quand la réponse est finie ou abandonnée.
+struct TicketGuard {
+    store: Store,
+    ticket: Option<u64>,
+}
+
+impl Drop for TicketGuard {
+    fn drop(&mut self) {
+        let Some(ticket) = self.ticket.take() else {
+            return;
+        };
+        let store = self.store.clone();
+        if let Ok(rt) = tokio::runtime::Handle::try_current() {
+            rt.spawn(async move {
+                if let Err(e) = store
+                    .internal_json(
+                        Method::POST,
+                        "/internal/v1/oai/end",
+                        Some(&json!({ "ticket": ticket })),
+                    )
+                    .await
+                {
+                    eprintln!("[loki-rs] /v1 : end : {e}");
+                }
+            });
+        }
+    }
+}
+
+/// Corps de réponse du moteur, relayé trame par trame ; le ticket est rendu
+/// quand il est lâché (flux terminé ou client parti).
+struct Guarded {
+    inner: Incoming,
+    _guard: TicketGuard,
+}
+
+impl hyper::body::Body for Guarded {
+    type Data = Bytes;
+    type Error = hyper::Error;
+
+    fn poll_frame(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Option<Result<Frame<Bytes>, hyper::Error>>> {
+        Pin::new(&mut self.inner).poll_frame(cx)
+    }
+    fn is_end_stream(&self) -> bool {
+        self.inner.is_end_stream()
+    }
+    fn size_hint(&self) -> SizeHint {
+        self.inner.size_hint()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn id_slot_pose_cles_triees_valeurs_intactes() {
+        let raw = br#"{"stream":true,"model":"x","temperature":0.10000000000000001,"id_slot":0}"#;
+        let out = String::from_utf8(rewrite_id_slot(raw).unwrap()).unwrap();
+        assert_eq!(
+            out,
+            r#"{"id_slot":1,"model":"x","stream":true,"temperature":0.10000000000000001}"#
+        );
+        assert!(rewrite_id_slot(b"[1,2]").is_none());
+        assert!(rewrite_id_slot(b"pas du json").is_none());
+    }
+}
diff --git a/rust/loki-rs/src/proxy.rs b/rust/loki-rs/src/proxy.rs
index f2e1b05..6562228 100644
--- a/rust/loki-rs/src/proxy.rs
+++ b/rust/loki-rs/src/proxy.rs
@@ -30,6 +30,7 @@ use tokio::net::TcpListener;
 use crate::api;
 use crate::auth::{HostEnv, INTERNAL_HEADER, InternalClient};
 use crate::engine;
+use crate::oai;
 use crate::store::Store;
 use crate::ui;
 
@@ -62,6 +63,8 @@ pub struct Config {
 
 struct Proxy {
     client: Client<HttpConnector, Incoming>,
+    /// Vers le moteur (llama-server / Strata), pour `/v1`.
+    engine: oai::EngineClient,
     backend: SocketAddr,
     ctx: api::Ctx,
 }
@@ -75,6 +78,7 @@ pub async fn serve(
     let client = Client::builder(TokioExecutor::new()).build_http();
     let proxy = Arc::new(Proxy {
         client,
+        engine: Client::builder(TokioExecutor::new()).build_http(),
         backend: cfg.backend,
         ctx: api::Ctx {
             store: Store::new(cfg.backend, cfg.internal_token.clone()),
@@ -131,6 +135,10 @@ impl Proxy {
         if let Some(resp) = ui::serve(req.method(), path, req.headers()) {
             return resp;
         }
+        // Surface OpenAI : relayée au moteur, décisions demandées au Go.
+        if path.starts_with("/v1/") {
+            return oai::serve(&self.ctx, &self.engine, req).await;
+        }
         if api::handles(req.method(), path) {
             return api::serve(&self.ctx, req).await;
         }
diff --git a/rust/loki-rs/src/store.rs b/rust/loki-rs/src/store.rs
index 055b09b..43749e4 100644
--- a/rust/loki-rs/src/store.rs
+++ b/rust/loki-rs/src/store.rs
@@ -62,6 +62,30 @@ impl Store {
             .map_err(|_| "store : délai dépassé".to_string())?
     }
 
+    /// Appel JSON à une autre route de l'API interne du Go (`/internal/v1/…`).
+    /// Code HTTP autre que 2xx → `Err`.
+    pub async fn internal_json(
+        &self,
+        method: Method,
+        path_and_query: &str,
+        body: Option<&serde_json::Value>,
+    ) -> Result<serde_json::Value, String> {
+        let body = body
+            .map(|b| serde_json::to_vec(b).unwrap_or_default())
+            .unwrap_or_default();
+        let (status, bytes) = self.call(method, path_and_query, body).await?;
+        if !status.is_success() {
+            return Err(format!(
+                "{path_and_query} : {status} {}",
+                String::from_utf8_lossy(&bytes)
+            ));
+        }
+        if bytes.is_empty() {
+            return Ok(serde_json::Value::Null);
+        }
+        serde_json::from_slice(&bytes).map_err(|e| e.to_string())
+    }
+
     /// Valeur brute ; `Ok(None)` = absente, `Err` = pas pu lire (à distinguer
     /// pour les secrets : comme `getBytesErr`).
     pub async fn get(&self, bucket: &str, key: &str) -> Result<Option<Vec<u8>>, String> {
diff --git a/rust/loki-rs/tests/common/fakego.rs b/rust/loki-rs/tests/common/fakego.rs
index bda6e0d..2923e88 100644
--- a/rust/loki-rs/tests/common/fakego.rs
+++ b/rust/loki-rs/tests/common/fakego.rs
@@ -24,6 +24,12 @@ pub struct FakeGo {
     pub broken: Mutex<bool>,
     /// Chemins relayés (hors API interne).
     pub relayed: Mutex<Vec<String>>,
+    /// /v1 : port du faux moteur, second slot en service, refus à renvoyer
+    /// par begin, journal des begin/end.
+    pub engine_port: Mutex<u16>,
+    pub side_live: Mutex<bool>,
+    pub refuse: Mutex<Option<serde_json::Value>>,
+    pub oai_log: Mutex<Vec<String>>,
 }
 
 impl FakeGo {
@@ -95,6 +101,39 @@ async fn handle(st: Arc<FakeGo>, req: Request<Incoming>) -> Response<Full<Bytes>
             let key = st.get("state", "web_key").unwrap_or_default();
             resp(200, format!(r#"{{"web_key":"{key}","version":"0.15.0"}}"#))
         }
+        "/internal/v1/oai/route" => {
+            let key = st.get("state", "api_key").unwrap_or_default();
+            let v = serde_json::json!({
+                "port": *st.engine_port.lock().unwrap(),
+                "strata": false,
+                "key": key,
+                "key_ok": true,
+                "max_body": 1024,
+                "side_live": *st.side_live.lock().unwrap(),
+            });
+            resp(200, v.to_string())
+        }
+        "/internal/v1/oai/begin" => {
+            let body = req.into_body().collect().await.unwrap().to_bytes();
+            let v: serde_json::Value = serde_json::from_slice(&body).unwrap();
+            st.oai_log.lock().unwrap().push(format!(
+                "begin read={} side={} post_v1={}",
+                v["read"], v["side"], v["post_v1"]
+            ));
+            if let Some(r) = st.refuse.lock().unwrap().clone() {
+                return resp(200, serde_json::json!({ "refuse": r }).to_string());
+            }
+            resp(200, r#"{"ticket":7}"#)
+        }
+        "/internal/v1/oai/end" => {
+            let body = req.into_body().collect().await.unwrap().to_bytes();
+            let v: serde_json::Value = serde_json::from_slice(&body).unwrap();
+            st.oai_log
+                .lock()
+                .unwrap()
+                .push(format!("end {}", v["ticket"]));
+            resp(204, "")
+        }
         "/internal/v1/store/all" => {
             let s = st.store.lock().unwrap();
             let m: BTreeMap<String, String> = s
diff --git a/rust/loki-rs/tests/lot5.rs b/rust/loki-rs/tests/lot5.rs
new file mode 100644
index 0000000..eddcb5f
--- /dev/null
+++ b/rust/loki-rs/tests/lot5.rs
@@ -0,0 +1,242 @@
+//! Lot 5 : /v1 relayé par la façade directement au moteur, décisions au Go.
+
+mod common;
+
+use bytes::Bytes;
+use common::fakego;
+use http_body_util::{BodyExt, Full, StreamBody};
+use hyper::body::{Frame, Incoming};
+use hyper::{Request, Response, StatusCode, service::service_fn};
+use hyper_util::client::legacy::Client;
+use hyper_util::rt::{TokioExecutor, TokioIo};
+use std::convert::Infallible;
+use std::sync::{Arc, Mutex};
+use std::time::{Duration, Instant};
+use tokio::net::TcpListener;
+
+type B = http_body_util::combinators::BoxBody<Bytes, Infallible>;
+
+/// Faux moteur : /v1/models renvoie la requête vue (en-têtes + corps),
+/// /v1/chat/completions diffuse deux événements à 500 ms d'écart.
+async fn faux_moteur(vu: Arc<Mutex<Vec<String>>>) -> u16 {
+    let l = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let port = l.local_addr().unwrap().port();
+    tokio::spawn(async move {
+        while let Ok((s, _)) = l.accept().await {
+            let vu = vu.clone();
+            tokio::spawn(async move {
+                let svc = service_fn(move |req: Request<Incoming>| {
+                    let vu = vu.clone();
+                    async move {
+                        let path = req.uri().path().to_string();
+                        let mut lines: Vec<String> = req
+                            .headers()
+                            .iter()
+                            .map(|(k, v)| format!("{k}: {}", v.to_str().unwrap()))
+                            .collect();
+                        let body = req.into_body().collect().await.unwrap().to_bytes();
+                        lines.push(format!("body: {}", String::from_utf8_lossy(&body)));
+                        vu.lock().unwrap().push(lines.join("\n"));
+                        let r: Response<B> = if path == "/v1/chat/completions" {
+                            let (tx, rx) = tokio::sync::mpsc::channel::<Bytes>(2);
+                            tokio::spawn(async move {
+                                tx.send(Bytes::from_static(b"data: a\n\n")).await.unwrap();
+                                tokio::time::sleep(Duration::from_millis(500)).await;
+                                let _ = tx.send(Bytes::from_static(b"data: b\n\n")).await;
+                            });
+                            let s = futures_util::stream::unfold(rx, |mut rx| async move {
+                                rx.recv()
+                                    .await
+                                    .map(|b| (Ok::<_, Infallible>(Frame::data(b)), rx))
+                            });
+                            Response::new(BodyExt::boxed(StreamBody::new(s)))
+                        } else {
+                            Response::new(Full::new(Bytes::from_static(b"{\"data\":[]}")).boxed())
+                        };
+                        Ok::<_, Infallible>(r)
+                    }
+                });
+                let _ = hyper::server::conn::http1::Builder::new()
+                    .serve_connection(TokioIo::new(s), svc)
+                    .await;
+            });
+        }
+    });
+    port
+}
+
+async fn send(
+    facade: std::net::SocketAddr,
+    method: &str,
+    path: &str,
+    headers: &[(&str, &str)],
+    body: &str,
+) -> Response<Incoming> {
+    let mut req = Request::builder()
+        .method(method)
+        .uri(format!("http://{facade}{path}"));
+    for (k, v) in headers {
+        req = req.header(*k, *v);
+    }
+    let client: Client<_, Full<Bytes>> = Client::builder(TokioExecutor::new()).build_http();
+    client
+        .request(req.body(Full::new(Bytes::from(body.to_string()))).unwrap())
+        .await
+        .unwrap()
+}
+
+async fn attendre_end(go: &fakego::FakeGo) {
+    for _ in 0..50 {
+        if go
+            .oai_log
+            .lock()
+            .unwrap()
+            .iter()
+            .any(|l| l.starts_with("end"))
+        {
+            return;
+        }
+        tokio::time::sleep(Duration::from_millis(20)).await;
+    }
+}
+
+#[tokio::test]
+async fn relais_et_ticket() {
+    let t = tempfile::tempdir().unwrap();
+    let (f, go, _stop) = fakego::start(t.path().into()).await;
+    let vu = Arc::new(Mutex::new(Vec::new()));
+    *go.engine_port.lock().unwrap() = faux_moteur(vu.clone()).await;
+    let r = send(
+        f,
+        "GET",
+        "/v1/models",
+        &[("host", "loki.exemple.fr"), ("x-forwarded-for", "6.6.6.6")],
+        "",
+    )
+    .await;
+    assert_eq!(r.status(), StatusCode::OK);
+    let body = r.into_body().collect().await.unwrap().to_bytes();
+    assert_eq!(&body[..], b"{\"data\":[]}");
+    attendre_end(&go).await;
+    assert_eq!(
+        *go.oai_log.lock().unwrap(),
+        vec!["begin read=true side=false post_v1=false", "end 7"]
+    );
+    let vu = vu.lock().unwrap()[0].clone();
+    assert!(vu.contains("host: loki.exemple.fr"), "{vu}");
+    assert!(!vu.contains("x-forwarded-for"), "{vu}");
+    assert!(go.relayed.lock().unwrap().is_empty(), "/v1 relayé au Go");
+}
+
+#[tokio::test]
+async fn flux_sans_tampon_ticket_rendu_a_la_fin() {
+    let t = tempfile::tempdir().unwrap();
+    let (f, go, _stop) = fakego::start(t.path().into()).await;
+    *go.engine_port.lock().unwrap() = faux_moteur(Arc::new(Mutex::new(Vec::new()))).await;
+    let t0 = Instant::now();
+    let r = send(f, "POST", "/v1/chat/completions", &[], r#"{"stream":true}"#).await;
+    let mut body = r.into_body();
+    let first = body.frame().await.unwrap().unwrap().into_data().unwrap();
+    assert_eq!(&first[..], b"data: a\n\n");
+    assert!(
+        t0.elapsed() < Duration::from_millis(300),
+        "{:?}",
+        t0.elapsed()
+    );
+    // Flux en cours : pas encore de end.
+    assert!(
+        !go.oai_log
+            .lock()
+            .unwrap()
+            .iter()
+            .any(|l| l.starts_with("end"))
+    );
+    while body.frame().await.is_some() {}
+    attendre_end(&go).await;
+    assert_eq!(
+        *go.oai_log.lock().unwrap(),
+        vec!["begin read=false side=false post_v1=true", "end 7"]
+    );
+}
+
+#[tokio::test]
+async fn second_slot_reecrit_le_corps() {
+    let t = tempfile::tempdir().unwrap();
+    let (f, go, _stop) = fakego::start(t.path().into()).await;
+    let vu = Arc::new(Mutex::new(Vec::new()));
+    *go.engine_port.lock().unwrap() = faux_moteur(vu.clone()).await;
+    *go.side_live.lock().unwrap() = true;
+    let r = send(f, "POST", "/v1/models", &[], r#"{"model":"m","id_slot":0}"#).await;
+    assert_eq!(r.status(), StatusCode::OK);
+    let vu = vu.lock().unwrap()[0].clone();
+    assert!(vu.contains(r#"body: {"id_slot":1,"model":"m"}"#), "{vu}");
+    assert!(go.oai_log.lock().unwrap()[0].contains("side=true"));
+    // Corps trop gros pour le second slot (max_body = 1024 dans le faux Go).
+    let gros = format!(r#"{{"x":"{}"}}"#, "a".repeat(2000));
+    let r = send(f, "POST", "/v1/models", &[], &gros).await;
+    assert_eq!(r.status(), StatusCode::PAYLOAD_TOO_LARGE);
+}
+
+#[tokio::test]
+async fn cle_des_completions() {
+    let t = tempfile::tempdir().unwrap();
+    let (f, go, _stop) = fakego::start(t.path().into()).await;
+    *go.engine_port.lock().unwrap() = faux_moteur(Arc::new(Mutex::new(Vec::new()))).await;
+    go.set("state", "api_key", "cle-oai");
+    let r = send(f, "GET", "/v1/models", &[], "").await;
+    assert_eq!(r.status(), StatusCode::UNAUTHORIZED);
+    assert_eq!(r.headers()["www-authenticate"], r#"Bearer realm="loki""#);
+    let body = r.into_body().collect().await.unwrap().to_bytes();
+    let v: serde_json::Value = serde_json::from_slice(&body).unwrap();
+    assert_eq!(v["error"]["code"], "invalid_api_key");
+    assert!(
+        go.oai_log.lock().unwrap().is_empty(),
+        "begin sans authentification"
+    );
+    let r = send(
+        f,
+        "GET",
+        "/v1/models",
+        &[("authorization", "Bearer cle-oai")],
+        "",
+    )
+    .await;
+    assert_eq!(r.status(), StatusCode::OK);
+    // Préflight CORS : jamais d'Authorization, jamais refusé.
+    let r = send(f, "OPTIONS", "/v1/models", &[], "").await;
+    assert_eq!(r.status(), StatusCode::OK);
+}
+
+#[tokio::test]
+async fn refus_benchmark() {
+    let t = tempfile::tempdir().unwrap();
+    let (f, go, _stop) = fakego::start(t.path().into()).await;
+    *go.engine_port.lock().unwrap() = faux_moteur(Arc::new(Mutex::new(Vec::new()))).await;
+    *go.refuse.lock().unwrap() = Some(serde_json::json!({
+        "status": 503, "message": "benchmark en cours sur ce moteur — réessaie dans un moment",
+        "type": "server_error", "code": "benchmark_running", "retry_after": "30"
+    }));
+    let r = send(f, "POST", "/v1/chat/completions", &[], "{}").await;
+    assert_eq!(r.status(), StatusCode::SERVICE_UNAVAILABLE);
+    assert_eq!(r.headers()["retry-after"], "30");
+}
+
+#[tokio::test]
+async fn moteur_absent() {
+    let t = tempfile::tempdir().unwrap();
+    let (f, go, _stop) = fakego::start(t.path().into()).await;
+    let mort = TcpListener::bind("127.0.0.1:0")
+        .await
+        .unwrap()
+        .local_addr()
+        .unwrap()
+        .port();
+    *go.engine_port.lock().unwrap() = mort;
+    let r = send(f, "GET", "/v1/models", &[], "").await;
+    assert_eq!(r.status(), StatusCode::BAD_GATEWAY);
+    attendre_end(&go).await;
+    assert!(
+        go.oai_log.lock().unwrap().iter().any(|l| l == "end 7"),
+        "ticket non rendu"
+    );
+}