play-faults fix: a fault's detail is fixed text by type; one timeout owner; pin the malformed-body and default-timeout legs

InferenceFault.detail is a &'static str, so no inference port (local,
connector, SDK) can put an endpoint, request or reply text into a fault. The
connector and SDK details that were built from error text are now fixed per
kind or reason. LocalBinding loses its public response_timeout field; the
short timeout the PlayTable canary needs comes from open_local_port_with_timeout,
which exists only under the ghostlight test-support feature (a dungeon
dev-dependency feature), so a release has one timeout, RESPONSE_TIMEOUT.
Canary tests on the malformed-body path (port and PlayTable), on the SDK and
connector ports, and on the default timeout at both resolving sites.

Not yet built or tested at this commit.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

crates/ghostlight-dungeon/Cargo.toml

@@ -42,5 +42,6 @@ uuid.workspace = true
 zeroize.workspace = true
 
 [dev-dependencies]
+ghostlight = { path = "../ghostlight", features = ["test-support"] }
 tempfile = "3"
 tower = { version = "0.5", features = ["util"] }

crates/ghostlight-dungeon/src/play.rs

@@ -1758,11 +1758,12 @@ impl PlayTable {
     async fn close_with_fault(&self, turn: &mut PlayTurn, detail: String) -> Result<(), PlayError> {
         turn.state = PlayTurnState::Closed;
         // R2: the one place a fault closes a turn, so the one place it is
-        // logged, whole. The local inference port builds its detail from the
+        // logged, whole. An `InferenceFault`'s detail is a `&'static str`, so
-        // fault kind and never from the transport error's text (tests pin
+        // no inference port (local, connector or SDK) can have put an
-        // that for each local failure class). The connector and SDK ports
+        // endpoint, request or reply text into it; the type guarantees that,
-        // build details from their own error text, which this line does not
+        // not this line. The details of the other failures that reach here
-        // scrub.
+        // (kernel, request build, snapshot) are their callers' own error
+        // text, and nothing here constrains them.
         tracing::warn!(turn_id = %turn.turn_id, detail = %detail, "play turn closed on a fault");
         turn.fault = Some(detail);
         // PA.f173: a fault can close a turn that was `AwaitingPlayer`, and
@@ -3303,7 +3304,7 @@ pub(crate) mod tests {
     /// exercise `world.play`'s own staleness comparison against a question
     /// that actually opened, rather than one hand-built.
     pub(crate) struct ScriptedPort {
-        queue: StdMutex<VecDeque<Result<InferenceOutput, String>>>,
+        queue: StdMutex<VecDeque<Result<InferenceOutput, &'static str>>>,
         seen: StdMutex<Vec<InferenceRequest>>,
     }
 
@@ -8226,18 +8227,15 @@ pub(crate) mod tests {
             "gpt-5.6-sol".into(),
         )
         .unwrap();
-        let inference = ghostlight::open_inference(
+        let binding = ghostlight::LocalBinding {
-            None,
+            endpoint,
-            None,
+            model_prefix: "local/".into(),
-            Some(ghostlight::LocalBinding {
+            caller_runtime_id: "play-test-runtime".into(),
-                endpoint,
+        };
-                model_prefix: "local/".into(),
+        let inference = match timeout {
-                caller_runtime_id: "play-test-runtime".into(),
+            Some(timeout) => ghostlight::open_local_port_with_timeout(binding, timeout).unwrap(),
-                response_timeout: timeout,
+            None => ghostlight::open_inference(None, None, Some(binding), &["local/play"]).unwrap(),
-            }),
+        };
-            &["local/play"],
-        )
-        .unwrap();
         let table = PlayTable::new(
             fixture.world.clone(),
             personas,
@@ -8262,6 +8260,7 @@ pub(crate) mod tests {
         account: &str,
         turn_number: u128,
         kind: &str,
+        reply_canaries: &[&str],
     ) {
         let (logs, _guard) = capture_logs();
         let directory = tempfile::tempdir().unwrap();
@@ -8277,7 +8276,10 @@ pub(crate) mod tests {
         let log = logs.text();
         let debug = format!("{view:?} {:?}", table.store.lock().await.current().unwrap());
         assert!(stored.contains(kind), "the error kind is kept: {stored}");
-        for canary in [endpoint.to_string(), endpoint.ip().to_string(), endpoint.port().to_string(), "chat/completions".to_owned()] {
+        let canaries = [endpoint.to_string(), endpoint.ip().to_string(), endpoint.port().to_string(), "chat/completions".to_owned()]
+            .into_iter()
+            .chain(reply_canaries.iter().map(|canary| (*canary).to_owned()));
+        for canary in canaries {
             for (where_, text) in [("stored fault", &stored), ("warn line", &log), ("card row", &row), ("debug", &debug)] {
                 assert!(!text.contains(&canary), "{canary} leaked into the {where_}: {text}");
             }
@@ -8291,7 +8293,7 @@ pub(crate) mod tests {
             let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
             listener.local_addr().unwrap()
         };
-        assert_faulted_turn_names_no_endpoint(endpoint, None, "player-fault-canary", 431, "refused the connection").await;
+        assert_faulted_turn_names_no_endpoint(endpoint, None, "player-fault-canary", 431, "refused the connection", &[]).await;
     }
 
     /// The whole path with a timeout, the leg a Bonsai stall takes: the
@@ -8314,6 +8316,71 @@ pub(crate) mod tests {
             "player-fault-timeout",
             432,
             "timed out",
+            &[],
+        )
+        .await;
+    }
+
+    /// Reads one HTTP request (headers and the declared body) off `stream`.
+    fn read_http_request(stream: &mut std::net::TcpStream) {
+        use std::io::Read;
+        let mut buf = Vec::new();
+        let mut chunk = [0u8; 8192];
+        loop {
+            let Ok(read) = stream.read(&mut chunk) else { break };
+            if read == 0 {
+                break;
+            }
+            buf.extend_from_slice(&chunk[..read]);
+            let text = String::from_utf8_lossy(&buf).to_string();
+            if let Some(split) = text.find("\r\n\r\n") {
+                let len = text[..split]
+                    .to_ascii_lowercase()
+                    .lines()
+                    .find_map(|l| l.strip_prefix("content-length:").map(|v| v.trim().parse::<usize>().unwrap()))
+                    .unwrap_or(0);
+                if buf.len() >= split + 4 + len {
+                    break;
+                }
+            }
+        }
+    }
+
+    /// Loopback server that answers every request with a `200` whose whole
+    /// body is `body`.
+    fn replying_with(body: &'static str) -> std::net::SocketAddr {
+        use std::io::Write;
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+        let addr = listener.local_addr().unwrap();
+        std::thread::spawn(move || {
+            for stream in listener.incoming() {
+                let Ok(mut stream) = stream else { return };
+                read_http_request(&mut stream);
+                let _ = write!(
+                    stream,
+                    "HTTP/1.1 200 OK\r\ncontent-type: application/json\r\ncontent-length: {}\r\nconnection: close\r\n\r\n{}",
+                    body.len(),
+                    body
+                );
+            }
+        });
+        addr
+    }
+
+    /// The malformed-reply leg through the whole path: a whole body that is
+    /// not the declared shape closes the turn on a fault, and serde's text
+    /// for it, which echoes the reply's own value, reaches the stored fault,
+    /// the warn line, the card row and Debug nowhere.
+    #[tokio::test]
+    async fn a_malformed_local_reply_closes_the_turn_without_echoing_it() {
+        let endpoint = replying_with("\\"CANARY-reply-5d02c8\\"");
+        assert_faulted_turn_names_no_endpoint(
+            endpoint,
+            None,
+            "player-fault-malformed",
+            433,
+            "not the declared shape",
+            &["CANARY-reply-5d02c8"],
         )
         .await;
     }
@@ -8323,7 +8390,7 @@ pub(crate) mod tests {
     /// answers each later one with an `end_turn` tool call. Returns its
     /// address and the count of connections seen.
     fn closing_then_ending(drops: usize) -> (std::net::SocketAddr, Arc<std::sync::atomic::AtomicUsize>) {
-        use std::io::{Read, Write};
+        use std::io::Write;
         use std::sync::atomic::{AtomicUsize, Ordering};
         let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
         let addr = listener.local_addr().unwrap();
@@ -8337,26 +8404,7 @@ pub(crate) mod tests {
                     drop(stream);
                     continue;
                 }
-                let mut buf = Vec::new();
+                read_http_request(&mut stream);
-                let mut chunk = [0u8; 8192];
-                loop {
-                    let Ok(read) = stream.read(&mut chunk) else { break };
-                    if read == 0 {
-                        break;
-                    }
-                    buf.extend_from_slice(&chunk[..read]);
-                    let text = String::from_utf8_lossy(&buf).to_string();
-                    if let Some(split) = text.find("\r\n\r\n") {
-                        let len = text[..split]
-                            .to_ascii_lowercase()
-                            .lines()
-                            .find_map(|l| l.strip_prefix("content-length:").map(|v| v.trim().parse::<usize>().unwrap()))
-                            .unwrap_or(0);
-                        if buf.len() >= split + 4 + len {
-                            break;
-                        }
-                    }
-                }
                 let body = serde_json::json!({
                     "id": format!("resp-{n}"),
                     "choices": [{"message": {"role": "assistant", "content": null,

crates/ghostlight-dungeon/src/runtime.rs

@@ -576,7 +576,6 @@ fn open_controller(
             model_prefix: std::env::var("GHOSTLIGHT_LOCAL_MODEL_PREFIX")
                 .unwrap_or_else(|_| DEFAULT_LOCAL_MODEL_PREFIX.into()),
             caller_runtime_id: runtime_id.to_owned(),
-            response_timeout: None,
         }),
         Err(_) => None,
     };

crates/ghostlight/Cargo.toml

@@ -22,5 +22,10 @@ tracing.workspace = true
 uuid.workspace = true
 zeroize.workspace = true
 
+[features]
+# Exposes `open_local_port_with_timeout` to a consumer's tests. Production
+# builds never enable it.
+test-support = []
+
 [dev-dependencies]
 tempfile = "3"

crates/ghostlight/src/controllers.rs

@@ -199,7 +199,12 @@ impl InferenceOutput {
 pub struct InferenceFault {
     disposition: InferenceFaultDisposition,
     class: InferenceFaultClass,
-    detail: String,
+    /// Fixed text chosen by the port that built the fault. It is a
+    /// `&'static str`, so no constructor can be handed text that was
+    /// computed from a request, a reply, an endpoint or an error's own
+    /// `Display`: a fault names what kind of trouble it is and never carries
+    /// an input value. The type enforces this for every port.
+    detail: &'static str,
 }
 
 /// What kind of trouble a fault is, as a typed value: the one place a reader
@@ -236,37 +241,37 @@ pub enum InferenceFaultDisposition {
 }
 
 impl InferenceFault {
-    pub(super) fn new(detail: impl Into<String>) -> Self {
+    pub(super) fn new(detail: &'static str) -> Self {
         Self {
             disposition: InferenceFaultDisposition::RecoveryRequired,
             class: InferenceFaultClass::Unclassified,
-            detail: detail.into(),
+            detail: detail,
         }
     }
 
     /// Transport trouble the owning flow may retry.
-    pub fn retryable(detail: impl Into<String>) -> Self {
+    pub fn retryable(detail: &'static str) -> Self {
         Self {
             disposition: InferenceFaultDisposition::Retryable,
             class: InferenceFaultClass::Unclassified,
-            detail: detail.into(),
+            detail: detail,
         }
     }
 
     /// The one disposition that makes `ControllerError::requires_quarantine`
     /// true for an `Inference` fault: the provider's answer cannot be trusted,
     /// so the tick driver stops rather than commits.
-    pub fn integrity_violation(detail: impl Into<String>) -> Self {
+    pub fn integrity_violation(detail: &'static str) -> Self {
         Self {
             disposition: InferenceFaultDisposition::IntegrityViolation,
             class: InferenceFaultClass::Unclassified,
-            detail: detail.into(),
+            detail: detail,
         }
     }
 
     /// The non-quarantining failure: this purpose cannot complete, but a
     /// sibling cell in the same tick is unaffected.
-    pub fn recovery_required(detail: impl Into<String>) -> Self {
+    pub fn recovery_required(detail: &'static str) -> Self {
         Self::new(detail)
     }
 
@@ -457,7 +462,8 @@ impl PreparedInference {
         request: InferenceRequest,
     ) -> Result<PreparedInference, InferenceFault> {
         let request_bytes =
-            serde_json::to_vec(&request).map_err(|error| InferenceFault::new(error.to_string()))?;
+            serde_json::to_vec(&request)
+                .map_err(|_| InferenceFault::new("an inference request could not be serialized"))?;
         let purpose = request.purpose;
         let invocation = CodexTransportInvocation::new(
             caller_runtime_id,
@@ -465,7 +471,7 @@ impl PreparedInference {
             Sha256::digest(request_bytes).into(),
             request.provider,
         )
-        .map_err(|error| InferenceFault::new(error.to_string()))?;
+        .map_err(|_| InferenceFault::new("an inference invocation could not be built"))?;
         Ok(PreparedInference {
             purpose,
             invocation,
@@ -500,7 +506,7 @@ impl CodexConnectorInferencePort {
             MAX_CONNECTOR_FRAME_BYTES,
             Some(RESPONSE_TIMEOUT),
         )
-        .map_err(|error| InferenceFault::new(error.to_string()))?;
+        .map_err(|_| InferenceFault::new("the CodexConnector client could not be built"))?;
         Ok(Self {
             client,
             caller_runtime_id,
@@ -513,10 +519,11 @@ impl CodexConnectorInferencePort {
         caller_runtime_id: impl Into<String>,
     ) -> Result<Self, InferenceFault> {
         let bytes = Zeroizing::new(
-            std::fs::read(path.as_ref()).map_err(|error| InferenceFault::new(error.to_string()))?,
+            std::fs::read(path.as_ref())
+                .map_err(|_| InferenceFault::new("the CodexConnector key file could not be read"))?,
         );
         let raw = std::str::from_utf8(bytes.as_slice())
-            .map_err(|error| InferenceFault::new(error.to_string()))?;
+            .map_err(|_| InferenceFault::new("the CodexConnector key file is not UTF-8"))?;
         let key = raw.trim_end_matches(['\r', '\n']);
         if key.is_empty() || key.len() != raw.trim().len() {
             return Err(InferenceFault::new(
@@ -537,42 +544,51 @@ impl CodexConnectorInferencePort {
             .execute(&request.invocation)
             .map_err(|error| match error {
                 CodexConnectorClientError::Connection(_) => {
-                    InferenceFault::retryable(error.to_string())
+                    InferenceFault::retryable("the CodexConnector connection failed")
                 }
                 CodexConnectorClientError::InvalidConfig
                 | CodexConnectorClientError::FrameSize
                 | CodexConnectorClientError::Encoding
                 | CodexConnectorClientError::Transport(_) => {
-                    InferenceFault::integrity_violation(error.to_string())
+                    InferenceFault::integrity_violation("the CodexConnector transport failed")
                 }
             })?;
         let (events, receipt) = match result.disposition {
             CodexTransportDisposition::Refused(reason) => {
-                let detail = format!("CodexConnector refused request: {reason:?}");
                 return Err(match reason {
-                    CodexRefusal::InFlight | CodexRefusal::Capacity => {
+                    CodexRefusal::InFlight => {
-                        InferenceFault::retryable(detail)
+                        InferenceFault::retryable("CodexConnector refused request: in flight")
                     }
-                    CodexRefusal::Expired | CodexRefusal::Indeterminate => {
+                    CodexRefusal::Capacity => {
-                        InferenceFault::new(detail)
+                        InferenceFault::retryable("CodexConnector refused request: at capacity")
                     }
-                    CodexRefusal::IdentitySubstitution
+                    CodexRefusal::Expired => {
-                    | CodexRefusal::ProviderDigestSubstitution
+                        InferenceFault::new("CodexConnector refused request: expired")
-                    | CodexRefusal::Policy
+                    }
-                    | CodexRefusal::ReplayConflict
+                    CodexRefusal::Indeterminate => {
-                    | CodexRefusal::Malformed => InferenceFault::integrity_violation(detail),
+                        InferenceFault::new("CodexConnector refused request: indeterminate")
+                    }
+                    CodexRefusal::IdentitySubstitution => InferenceFault::integrity_violation(
+                        "CodexConnector refused request: identity substitution",
+                    ),
+                    CodexRefusal::ProviderDigestSubstitution => InferenceFault::integrity_violation(
+                        "CodexConnector refused request: provider digest substitution",
+                    ),
+                    CodexRefusal::Policy => {
+                        InferenceFault::integrity_violation("CodexConnector refused request: policy")
+                    }
+                    CodexRefusal::ReplayConflict => InferenceFault::integrity_violation(
+                        "CodexConnector refused request: replay conflict",
+                    ),
+                    CodexRefusal::Malformed => InferenceFault::integrity_violation(
+                        "CodexConnector refused request: malformed",
+                    ),
                 });
             }
             CodexTransportDisposition::Transported { events, receipt } => (events, receipt),
         };
-        if let CodexTransportOutcome::Failed {
+        if let CodexTransportOutcome::Failed { .. } = &receipt.outcome {
-            failure_kind,
+            return Err(InferenceFault::new("the Codex provider reported a failed outcome"));
-            message,
-        } = &receipt.outcome
-        {
-            return Err(InferenceFault::new(format!(
-                "Codex provider failed ({failure_kind}): {message}"
-            )));
         }
         let events = events
             .into_iter()
@@ -590,7 +606,7 @@ impl CodexConnectorInferencePort {
             })
             .collect();
         let receipt_bytes = rmp_serde::to_vec_named(&receipt)
-            .map_err(|error| InferenceFault::new(error.to_string()))?;
+            .map_err(|_| InferenceFault::new("the CodexConnector receipt could not be encoded"))?;
         Ok(InferenceOutput {
             events,
             receipt_digest: format!("sha256:{:x}", Sha256::digest(&receipt_bytes)),
@@ -612,14 +628,14 @@ impl InferencePort for CodexConnectorInferencePort {
         let port = self.clone();
         tokio::task::spawn_blocking(move || port.execute(request))
             .await
-            .map_err(|error| InferenceFault::new(error.to_string()))?
+            .map_err(|_| InferenceFault::new("the CodexConnector worker task failed"))?
     }
 }
 
 pub(super) fn unix_ms() -> Result<u64, InferenceFault> {
     let millis = SystemTime::now()
         .duration_since(UNIX_EPOCH)
-        .map_err(|error| InferenceFault::new(error.to_string()))?
+        .map_err(|_| InferenceFault::new("the system clock is before the Unix epoch"))?
         .as_millis();
     u64::try_from(millis).map_err(|_| InferenceFault::new("system time exceeds u64 milliseconds"))
 }
@@ -6833,6 +6849,34 @@ fn purpose_name(purpose: InferencePurpose) -> &'static str {
 #[cfg(test)]
 mod tests {
 
+    /// The connector port's share of the no-input-text rule: a key-file path
+    /// and a runtime identity each arrive as a canary, and the fault names
+    /// only what failed. (The legs that need a live connector, a refusal or a
+    /// failed provider outcome, are fixed text by the fault type.)
+    #[test]
+    fn a_connector_fault_carries_no_text_it_was_handed() {
+        const CANARY: &str = "CANARY-connector-2c4d7a";
+        let endpoint: SocketAddr = "127.0.0.1:9".parse().unwrap();
+        let directory = tempfile::tempdir().unwrap();
+        let not_utf8 = directory.path().join(CANARY);
+        std::fs::write(&not_utf8, [0xff_u8, 0xfe]).unwrap();
+        let faults = [
+            CodexConnectorInferencePort::from_secret_file(endpoint, directory.path().join("absent").join(CANARY), "runtime")
+                .err()
+                .expect("a missing key file opened"),
+            CodexConnectorInferencePort::from_secret_file(endpoint, &not_utf8, "runtime")
+                .err()
+                .expect("a key file that is not UTF-8 opened"),
+            CodexConnectorInferencePort::new(endpoint, "key".into(), format!(" {CANARY} "))
+                .err()
+                .expect("a runtime identity with whitespace opened"),
+        ];
+        for fault in faults {
+            let rendered = format!("{fault} | {fault:?}");
+            assert!(!rendered.contains(CANARY), "{CANARY} leaked into {rendered}");
+        }
+    }
+
     /// The decision lanes' tools go to the same provider under the same
     /// strict rules as the patch catalog; the interpreter's fixed tools and a
     /// granted catalog entry are checked offline here for the same reason.
@@ -11445,7 +11489,6 @@ mod tests {
                 endpoint: local_endpoint,
                 model_prefix: local_model_prefix,
                 caller_runtime_id: runtime_id,
-                response_timeout: None,
             }),
             &models.each(),
         )

crates/ghostlight/src/lib.rs

@@ -97,6 +97,8 @@ pub use elaboration::{
 };
 pub use lens::{Lens, LensWeights};
 pub use local_inference::{DEFAULT_LOCAL_MODEL_PREFIX, LocalBinding};
+#[cfg(feature = "test-support")]
+pub use local_inference::open_local_port_with_timeout;
 pub(crate) use mailbox::ElaborationPort;
 pub use mailbox::{ConsumerPort, ControllerPort, MailboxError, PlayPort, SeedPort, WorldMailbox};
 pub use patch::{

crates/ghostlight/src/local_inference.rs

@@ -31,10 +31,6 @@ pub struct LocalBinding {
     pub endpoint: SocketAddr,
     pub model_prefix: String,
     pub caller_runtime_id: String,
-    /// How long one request may take, reply body included. `None` is
-    /// `RESPONSE_TIMEOUT`; a consumer or test sets it to reach the timeout
-    /// path without waiting that out.
-    pub response_timeout: Option<std::time::Duration>,
 }
 
 const LOCAL_RECEIPT_SCHEMA: &str = "ghostlight.local_inference_receipt.v1";
@@ -135,6 +131,10 @@ pub(super) struct LocalInferencePort {
     endpoint: SocketAddr,
     prefix: String,
     caller_runtime_id: String,
+    /// Read only by the tests that pin which timeout a constructor resolves
+    /// to; the live timeout is the client's.
+    #[cfg(test)]
+    response_timeout: std::time::Duration,
 }
 
 impl LocalInferencePort {
@@ -154,8 +154,10 @@ impl LocalInferencePort {
         Self::with_timeout(endpoint, prefix, caller_runtime_id, RESPONSE_TIMEOUT)
     }
 
-    /// `new` with the response timeout named, so a test can reach the timeout
+    /// `new` with the response timeout named. `new` is the only production
-    /// path without waiting out `RESPONSE_TIMEOUT`.
+    /// caller and passes `RESPONSE_TIMEOUT`, so production has one timeout
+    /// owner; the other callers are tests that reach the timeout path without
+    /// waiting `RESPONSE_TIMEOUT` out.
     fn with_timeout(
         endpoint: SocketAddr,
         prefix: impl Into<String>,
@@ -175,6 +177,8 @@ impl LocalInferencePort {
             endpoint,
             prefix: prefix.into(),
             caller_runtime_id: caller_runtime_id.into(),
+            #[cfg(test)]
+            response_timeout: timeout,
         })
     }
 
@@ -188,7 +192,7 @@ impl LocalInferencePort {
             .map_err(send_fault)?;
         let status = response.status();
         if !status.is_success() {
-            let detail = format!("the local inference endpoint returned {status}");
+            let detail = "the local inference endpoint returned a non-success status";
             let class = InferenceFaultClass::Status(status.as_u16());
             return Err(if status.as_u16() == 429 || status.as_u16() == 503 {
                 InferenceFault::retryable(detail)
@@ -268,11 +272,8 @@ fn lower_request(prepared: &PreparedInference, prefix: &str) -> Result<Value, In
     }
     let mut tools = Vec::with_capacity(request.tools.len());
     for tool in &request.tools {
-        let parameters: Value = serde_json::from_str(&tool.parameters_json).map_err(|error| {
+        let parameters: Value = serde_json::from_str(&tool.parameters_json).map_err(|_| {
-            InferenceFault::integrity_violation(format!(
+            InferenceFault::integrity_violation("a tool's parameters are not valid JSON")
-                "tool `{}` parameters are not valid JSON: {error}",
-                tool.name
-            ))
         })?;
         tools.push(json!({
             "type": "function",
@@ -366,7 +367,7 @@ fn assemble_output(
             .unwrap_or_default(),
     };
     let receipt_bytes = rmp_serde::to_vec_named(&receipt)
-        .map_err(|error| InferenceFault::new(error.to_string()))?;
+        .map_err(|_| InferenceFault::new("the local inference receipt could not be encoded"))?;
     Ok(InferenceOutput::new(
         events,
         format!("sha256:{:x}", Sha256::digest(&receipt_bytes)),
@@ -405,15 +406,32 @@ impl InferencePort for LocalInferencePort {
 /// caller of this function, not only `open_inference`.
 pub(super) fn open_local_port(
     binding: LocalBinding,
+) -> Result<Arc<dyn InferencePort>, ControllerOpenError> {
+    Ok(Arc::new(local_port(binding)?))
+}
+
+/// The same port with a named response timeout, for a consumer's tests that
+/// reach the timeout path without waiting `RESPONSE_TIMEOUT` out. It exists
+/// only under the `test-support` feature, which production builds never
+/// enable, so `LocalBinding` carries no timeout and a release has exactly
+/// one: `RESPONSE_TIMEOUT`.
+#[cfg(feature = "test-support")]
+pub fn open_local_port_with_timeout(
+    binding: LocalBinding,
+    timeout: std::time::Duration,
 ) -> Result<Arc<dyn InferencePort>, ControllerOpenError> {
     Ok(Arc::new(LocalInferencePort::with_timeout(
         binding.endpoint,
         binding.model_prefix,
         binding.caller_runtime_id,
-        binding.response_timeout.unwrap_or(RESPONSE_TIMEOUT),
+        timeout,
     )?))
 }
 
+fn local_port(binding: LocalBinding) -> Result<LocalInferencePort, ControllerOpenError> {
+    LocalInferencePort::new(binding.endpoint, binding.model_prefix, binding.caller_runtime_id)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -805,7 +823,6 @@ mod tests {
                 endpoint: "93.184.216.34:443".parse().unwrap(),
                 model_prefix: DEFAULT_LOCAL_MODEL_PREFIX.into(),
                 caller_runtime_id: TEST_RUNTIME.into(),
-                response_timeout: None,
             }),
             &[TEST_MODEL],
         )
@@ -912,7 +929,6 @@ mod tests {
                 endpoint: "127.0.0.1:1".parse().unwrap(),
                 model_prefix: "claude".into(),
                 caller_runtime_id: TEST_RUNTIME.into(),
-                response_timeout: None,
             }),
             &["claude-opus-5"],
         )
@@ -1195,7 +1211,6 @@ mod tests {
                 endpoint: "127.0.0.1:1".parse().unwrap(),
                 model_prefix: String::new(),
                 caller_runtime_id: TEST_RUNTIME.into(),
-                response_timeout: None,
             }),
             &[TEST_MODEL],
         )
@@ -1659,6 +1674,48 @@ mod tests {
         assert_eq!(fault.disposition(), InferenceFaultDisposition::IntegrityViolation, "{fault:?}");
     }
 
+    /// The malformed-body leg of the no-input-text rule: serde's `Display`
+    /// for a type mismatch echoes the offending value, so a detail built from
+    /// it carries the reply's own text. The canary is a value inside a whole
+    /// body that fails to deserialize.
+    #[tokio::test]
+    async fn a_malformed_body_carries_neither_its_own_text_nor_the_endpoint() {
+        const CANARY: &str = "CANARY-reply-7f3e91";
+        let addr = ScriptedResponder::start(vec![(200, format!("\"{CANARY}\""))]).await.endpoint();
+        let fault = infer_once(&port(addr)).await.expect_err("a malformed body produced an output");
+        assert_eq!(fault.class(), InferenceFaultClass::BadReply, "{fault:?}");
+        let rendered = format!("{fault} | {fault:?}");
+        for canary in [CANARY.to_owned(), addr.to_string(), addr.ip().to_string()] {
+            assert!(!rendered.contains(&canary), "{canary} leaked into {rendered}");
+        }
+    }
+
+    /// The production default is `RESPONSE_TIMEOUT` (a cold model load lives
+    /// inside one request) at the constructor and at the port a binding
+    /// opens: a shorter default turns every cold start into a Timeout fault
+    /// that is never retried.
+    #[test]
+    fn the_production_default_timeout_is_response_timeout_at_both_resolving_sites() {
+        assert_eq!(RESPONSE_TIMEOUT, std::time::Duration::from_secs(900));
+        let endpoint: SocketAddr = "127.0.0.1:9".parse().unwrap();
+        let constructed = {
+            let _guard = client_build_lock().lock().expect("the client-build lock is never poisoned");
+            LocalInferencePort::new(endpoint, DEFAULT_LOCAL_MODEL_PREFIX, TEST_RUNTIME)
+                .expect("a loopback endpoint opens")
+        };
+        assert_eq!(constructed.response_timeout, RESPONSE_TIMEOUT);
+        let opened = {
+            let _guard = client_build_lock().lock().expect("the client-build lock is never poisoned");
+            local_port(LocalBinding {
+                endpoint,
+                model_prefix: DEFAULT_LOCAL_MODEL_PREFIX.into(),
+                caller_runtime_id: TEST_RUNTIME.into(),
+            })
+            .expect("a loopback binding opens")
+        };
+        assert_eq!(opened.response_timeout, RESPONSE_TIMEOUT);
+    }
+
     /// The timeout leg of the no-endpoint rule: reqwest's `Display` for a
     /// timeout ends with the request URL, so a detail built from it names the
     /// canary endpoint this test bound. Covers both a stalled send and a

crates/ghostlight/src/sdk_inference.rs

@@ -146,8 +146,27 @@ pub(super) enum SidecarFaultReason {
 }
 
 impl SidecarFaultReason {
-    fn into_fault(self, detail: String) -> InferenceFault {
+    /// The sidecar's own `detail` text is never carried: the reason names the
-        let detail = format!("SDK sidecar reported {self:?}: {detail}");
+    /// failure and the fault's text is fixed per reason.
+    fn into_fault(self) -> InferenceFault {
+        let detail = match self {
+            Self::RateLimited => "SDK sidecar reported rate limited",
+            Self::Overloaded => "SDK sidecar reported overloaded",
+            Self::ServerError => "SDK sidecar reported a server error",
+            Self::ApiTimeout => "SDK sidecar reported an API timeout",
+            Self::AuthenticationFailed => "SDK sidecar reported authentication failed",
+            Self::OrgNotAllowed => "SDK sidecar reported organization not allowed",
+            Self::BillingError => "SDK sidecar reported a billing error",
+            Self::InvalidRequest => "SDK sidecar reported an invalid request",
+            Self::ModelNotFound => "SDK sidecar reported model not found",
+            Self::MaxOutputTokens => "SDK sidecar reported max output tokens",
+            Self::MaxBudgetUsd => "SDK sidecar reported max budget",
+            Self::ExecutionError => "SDK sidecar reported an execution error",
+            Self::Unknown => "SDK sidecar reported an unknown failure",
+            Self::ProtocolViolation => "SDK sidecar reported a protocol violation",
+            Self::ToolRegistrationFailed => "SDK sidecar reported tool registration failed",
+            Self::TurnCapRefused => "SDK sidecar reported the turn cap refused",
+        };
         match self {
             Self::RateLimited | Self::Overloaded | Self::ServerError | Self::ApiTimeout => {
                 InferenceFault::retryable(detail)
@@ -468,7 +487,7 @@ impl SdkInferencePort {
                         }
                         Err(error) => {
                             let _ = self.link.restart().await;
-                            return Err(InferenceFault::new(error.to_string()));
+                            return Err(InferenceFault::new("the tool-result owner refused a tool call"));
                         }
                     }
                 }
@@ -482,10 +501,10 @@ impl SdkInferencePort {
                 SidecarFrame::Fault {
                     query_id: seen,
                     reason,
-                    detail,
+                    ..
                 } if seen == query_id => {
                     let _ = self.link.restart().await;
-                    return Err(reason.into_fault(detail));
+                    return Err(reason.into_fault());
                 }
                 _ => {
                     let _ = self.link.restart().await;
@@ -501,13 +520,11 @@ impl SdkInferencePort {
 fn link_fault(error: SidecarLinkError) -> InferenceFault {
     match error {
         SidecarLinkError::Closed => {
-            InferenceFault::new("the SDK sidecar exited during a query".to_string())
+            InferenceFault::new("the SDK sidecar exited during a query")
         }
-        SidecarLinkError::Spawn(detail) => {
+        SidecarLinkError::Spawn(_) => InferenceFault::new("the SDK sidecar could not start"),
-            InferenceFault::new(format!("the SDK sidecar could not start: {detail}"))
+        SidecarLinkError::Codec(_) => {
-        }
+            InferenceFault::integrity_violation("the SDK sidecar's framing was invalid")
-        SidecarLinkError::Codec(detail) => {
-            InferenceFault::integrity_violation(format!("SDK sidecar framing: {detail}"))
         }
     }
 }
@@ -526,9 +543,9 @@ pub(super) fn lower_query(
     if let Some(effort) = request.reasoning_effort.as_deref()
         && !SDK_EFFORT_LEVELS.contains(&effort)
     {
-        return Err(InferenceFault::integrity_violation(format!(
+        return Err(InferenceFault::integrity_violation(
-            "reasoning effort `{effort}` has no SDK counterpart"
+            "the requested reasoning effort has no SDK counterpart",
-        )));
+        ));
     }
     let mut items = request.input.iter();
     let Some(CodexInputItem::UserText { text: prompt }) = items.next() else {
@@ -641,7 +658,7 @@ fn assemble_output(
         total_cost_usd_estimate: material.total_cost_usd_estimate,
     };
     let receipt_bytes = rmp_serde::to_vec_named(&receipt)
-        .map_err(|error| InferenceFault::new(error.to_string()))?;
+        .map_err(|_| InferenceFault::new("the SDK receipt could not be encoded"))?;
     Ok(InferenceOutput {
         events: lowered,
         receipt_digest: format!("sha256:{:x}", Sha256::digest(&receipt_bytes)),
@@ -763,9 +780,9 @@ impl InferencePort for RoutedInferencePort {
         let model = request.provider_model().to_owned();
         match self.route(&model) {
             Some(port) => port.prepare(request),
-            None => Err(InferenceFault::integrity_violation(format!(
+            None => Err(InferenceFault::integrity_violation(
-                "no configured inference backend claims the model `{model}`"
+                "no configured inference backend claims the requested model",
-            ))),
+            )),
         }
     }
 
@@ -773,9 +790,9 @@ impl InferencePort for RoutedInferencePort {
         let model = request.invocation.request.model.clone();
         match self.route(&model) {
             Some(port) => port.infer(request).await,
-            None => Err(InferenceFault::integrity_violation(format!(
+            None => Err(InferenceFault::integrity_violation(
-                "no configured inference backend claims the model `{model}`"
+                "no configured inference backend claims the requested model",
-            ))),
+            )),
         }
     }
 
@@ -1482,7 +1499,7 @@ mod tests {
     fn soul_every_sidecar_reason_carries_its_named_disposition() {
         use SidecarFaultReason::*;
         for reason in [RateLimited, Overloaded, ServerError, ApiTimeout] {
-            let fault = reason.into_fault("detail".into());
+            let fault = reason.into_fault();
             assert!(
                 !fault.requires_recovery() && !fault.integrity_was_violated(),
                 "{reason:?} was not retryable"
@@ -1500,13 +1517,13 @@ mod tests {
             Unknown,
         ] {
             assert!(
-                reason.into_fault("detail".into()).requires_recovery(),
+                reason.into_fault().requires_recovery(),
                 "{reason:?} was not recovery-required"
             );
         }
         for reason in [ProtocolViolation, ToolRegistrationFailed, TurnCapRefused] {
             assert!(
-                reason.into_fault("detail".into()).integrity_was_violated(),
+                reason.into_fault().integrity_was_violated(),
                 "{reason:?} did not violate integrity"
             );
         }
@@ -1684,6 +1701,91 @@ mod tests {
         assert!(fault.integrity_was_violated(), "{fault:?}");
     }
 
+    fn assert_names_no(fault: &InferenceFault, canary: &str) {
+        let rendered = format!("{fault} | {fault:?}");
+        assert!(!rendered.contains(canary), "{canary} leaked into {rendered}");
+    }
+
+    /// The SDK port's share of the no-input-text rule: text the sidecar sent,
+    /// the link's own error text, a request's effort and a request's model
+    /// name each arrive as a canary, and none reaches the fault. The fault
+    /// type carries only fixed text, so this fails if a port ever routes a
+    /// computed string into it (through `Box::leak`, say).
+    #[tokio::test]
+    async fn an_sdk_fault_carries_no_text_it_was_handed() {
+        const CANARY: &str = "CANARY-sdk-91b6d0";
+
+        // The sidecar's own detail, for every reason it may name.
+        for reason in [
+            SidecarFaultReason::RateLimited,
+            SidecarFaultReason::Overloaded,
+            SidecarFaultReason::ServerError,
+            SidecarFaultReason::ApiTimeout,
+            SidecarFaultReason::AuthenticationFailed,
+            SidecarFaultReason::OrgNotAllowed,
+            SidecarFaultReason::BillingError,
+            SidecarFaultReason::InvalidRequest,
+            SidecarFaultReason::ModelNotFound,
+            SidecarFaultReason::MaxOutputTokens,
+            SidecarFaultReason::MaxBudgetUsd,
+            SidecarFaultReason::ExecutionError,
+            SidecarFaultReason::Unknown,
+            SidecarFaultReason::ProtocolViolation,
+            SidecarFaultReason::ToolRegistrationFailed,
+            SidecarFaultReason::TurnCapRefused,
+        ] {
+            let link = ScriptedLink::new(vec![SidecarFrame::Fault {
+                query_id: 1,
+                reason,
+                detail: CANARY.into(),
+            }]);
+            let port = SdkInferencePort::new(link, TEST_RUNTIME);
+            let prepared = prose_prepared(&port, "Say something true.");
+            let fault = port.infer(prepared).await.expect_err("a fault frame produced an output");
+            assert_names_no(&fault, CANARY);
+        }
+
+        // The link's own error text.
+        assert_names_no(&link_fault(SidecarLinkError::Spawn(CANARY.into())), CANARY);
+        assert_names_no(&link_fault(SidecarLinkError::Codec(CANARY.into())), CANARY);
+
+        // An effort the SDK has no counterpart for.
+        let port = SdkInferencePort::new(ScriptedLink::new(Vec::new()), TEST_RUNTIME);
+        let mut prepared = prose_prepared(&port, "Say something true.");
+        prepared.invocation.request.reasoning_effort = Some(CANARY.into());
+        let fault = lower_query(1, &prepared, 1).expect_err("an unmapped effort lowered");
+        assert_names_no(&fault, CANARY);
+
+        // A model no backend claims, prepared and inferred through the router.
+        let directory = tempfile::tempdir().unwrap();
+        let entry = directory.path().join("main.js");
+        std::fs::write(&entry, "// sidecar").unwrap();
+        let routed = open_inference(
+            None,
+            Some(SdkBinding {
+                sidecar_entry: entry,
+                caller_runtime_id: TEST_RUNTIME.into(),
+                model_prefix: DEFAULT_SDK_MODEL_PREFIX.into(),
+            }),
+            None,
+            &models(TEST_MODEL).each(),
+        )
+        .expect("the SDK model routes");
+        let request = tool_request(
+            CommandId::new(),
+            0,
+            InferencePurpose::Persona,
+            CANARY,
+            "Respond only in natural prose.",
+            vec![CodexInputItem::UserText { text: "Say something true.".into() }],
+            Vec::<CodexToolDefinition>::new(),
+            RequestShape { max_output_tokens: 1_200, parallel_tool_calls: false },
+        )
+        .expect("the request builds");
+        let fault = routed.prepare(request).err().expect("an unroutable model prepared");
+        assert_names_no(&fault, CANARY);
+    }
+
     /// Soul: the lowering's own gate table, every row.
     #[test]
     fn soul_lower_query_refuses_the_shapes_the_gate_table_names() {