sdk, agent: review fixes (T18R)

- The serve loop ends the process after EOF or exit_after_response,
  also with background tasks or listeners.
- One schema generator per direction for the whole document, so types
  with the same name get distinct names.
- The agent gives the complete error (code, message, data) to the
  model, writes SKIP only after a successful request, caps tool output
  at 64 KiB, writes each history line in one write, and skips a damaged
  line.
- Endpoints skip blank and non-RPC lines. client_rs does not panic.
- #[must_use] on builders and the lock guard; #[schemars] attributes
  and duplicate hooks are compile errors; raw identifiers; -32000 for
  local SDK errors; x-sausage-params only for methods with params.

sdk/macros/src/lib.rs

@@ -2,8 +2,8 @@
 use proc_macro::TokenStream;
 use quote::quote;
 use syn::{
-    Attribute, Fields, FnArg, ImplItem, Item, ItemImpl, ReturnType, Type, parse_macro_input,
-    spanned::Spanned,
+    Attribute, Fields, FnArg, ImplItem, Item, ItemImpl, ReturnType, Type, ext::IdentExt,
+    parse_macro_input, spanned::Spanned,
 };
 fn docs(attrs: &[Attribute]) -> String {
     attrs
@@ -30,6 +30,12 @@ fn documented(attrs: &[Attribute], span: proc_macro2::Span) -> syn::Result<()> {
 }
 fn serde_subset(attrs: &[Attribute]) -> syn::Result<()> {
     for a in attrs {
+        if a.path().is_ident("schemars") {
+            return Err(syn::Error::new(
+                a.span(),
+                "schemars attributes are outside the schema subset",
+            ));
+        }
         if a.path().is_ident("serde") {
             a.parse_nested_meta(|m| {
                 if !["rename", "rename_all", "default", "skip_serializing_if"]
@@ -145,6 +151,8 @@ pub fn rpc(args: TokenStream, input: TokenStream) -> TokenStream {
         let mut arms = vec![];
         let mut entries = vec![];
         let mut stop = quote!();
+        let mut has_stop = false;
+        let mut has_retired = false;
         for member in &mut item.items {
             let ImplItem::Fn(f) = member else { continue };
             let retired = f.attrs.iter().any(|a| {
@@ -159,6 +167,18 @@ pub fn rpc(args: TokenStream, input: TokenStream) -> TokenStream {
                     .last()
                     .is_some_and(|s| s.ident == "on_stop")
             });
+            if stopping && std::mem::replace(&mut has_stop, true) {
+                return Err(syn::Error::new(
+                    f.span(),
+                    "only one on_stop method is allowed",
+                ));
+            }
+            if retired && std::mem::replace(&mut has_retired, true) {
+                return Err(syn::Error::new(
+                    f.span(),
+                    "only one on_retired method is allowed",
+                ));
+            }
             f.attrs.retain(|a| {
                 !a.path()
                     .segments
@@ -207,7 +227,7 @@ pub fn rpc(args: TokenStream, input: TokenStream) -> TokenStream {
             let wire = if retired {
                 "rpc.retired".to_string()
             } else {
-                name.to_string()
+                name.unraw().to_string()
             };
             let p = param
                 .map(|t| quote!(#t))
@@ -237,14 +257,18 @@ pub fn rpc(args: TokenStream, input: TokenStream) -> TokenStream {
                 entries.push(quote!(::sausage_plugin::method::<#p,#output>(&mut doc,#wire,#doc);));
             }
         }
-        let grace =
-            grace.map(|n| quote!(doc["x-sausage-grace"]=::sausage_plugin::serde_json::json!(#n);));
-        let names: Vec<_> = endpoints.iter().map(|(n, _)| n.to_string()).collect();
+        let grace = grace
+            .map(|n| quote!(doc.value["x-sausage-grace"]=::sausage_plugin::serde_json::json!(#n);));
+        let names: Vec<_> = endpoints
+            .iter()
+            .map(|(n, _)| n.unraw().to_string())
+            .collect();
         let types: Vec<_> = endpoints.iter().map(|(_, t)| t).collect();
         Ok(quote! {#item impl ::sausage_plugin::Interface for #ty {
             fn endpoint_types(&self)->Vec<(::std::any::TypeId,String)>{vec![#((::std::any::TypeId::of::<#types>(),#names.into())),*]}
-            fn methods_document()->::sausage_plugin::serde_json::Value {let mut doc=::sausage_plugin::document(env!("CARGO_PKG_NAME"),env!("CARGO_PKG_VERSION")); #(#entries)* #grace ::sausage_plugin::finish_document(doc)}
-            fn describe()->::sausage_plugin::serde_json::Value {let mut doc=<Self as ::sausage_plugin::Interface>::methods_document(); #(let endpoint=<#types as ::sausage_plugin::Interface>::methods_document();doc["x-sausage-endpoints"][#names]=::sausage_plugin::serde_json::json!({"methods":endpoint["methods"]});doc["components"]["schemas"].as_object_mut().unwrap().extend(endpoint["components"]["schemas"].as_object().unwrap().clone());)* doc}
+            fn add_methods(mut doc:&mut ::sausage_plugin::Discovery) {#(#entries)*}
+            fn methods_document()->::sausage_plugin::serde_json::Value {let mut doc=::sausage_plugin::document(env!("CARGO_PKG_NAME"),env!("CARGO_PKG_VERSION")); Self::add_methods(&mut doc); #grace ::sausage_plugin::finish_document(doc)}
+            fn describe()->::sausage_plugin::serde_json::Value {let mut doc=::sausage_plugin::document(env!("CARGO_PKG_NAME"),env!("CARGO_PKG_VERSION")); Self::add_methods(&mut doc); #grace #(doc.endpoint::<#types>(#names);)* ::sausage_plugin::finish_document(doc)}
             fn discover(&self)->::sausage_plugin::serde_json::Value {<Self as ::sausage_plugin::Interface>::describe()}
             fn dispatch<'a>(&'a self, method:&'a str, params: ::sausage_plugin::serde_json::Value,ctx:&'a ::sausage_plugin::Ctx)->::std::pin::Pin<Box<dyn ::std::future::Future<Output=::sausage_plugin::Result<::sausage_plugin::serde_json::Value>>+'a>> {Box::pin(async move {if !params.is_object() {return Err(::sausage_plugin::Error::new(-32602,"params must be an object"));} match method {#(#arms,)* _=>Err(::sausage_plugin::Error::new(-32601,"method not found"))}})}
             #stop