feat: add trait-based tool declaration#677

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DaleSeo merged 6 commits into from
Feb 25, 2026
Merged

feat: add trait-based tool declaration #677

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eacd729
feat: add trait-based tool declaration
Evian-Zhang Feb 21, 2026
099a994
fix: typo
Evian-Zhang Feb 21, 2026
c89e1c2
fix: add docs, make more idomatic patterns, allow for empty parameter…
Evian-Zhang Feb 25, 2026
388c706
fix: format code
Evian-Zhang Feb 25, 2026
820ce05
fix: add default trait
Evian-Zhang Feb 25, 2026
8403ea0
fix: docs typo
Evian-Zhang Feb 25, 2026
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5 changes: 1 addition & 4 deletions crates/rmcp-macros/src/tool.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -238,10 +238,7 @@ pub fn tool(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream> {
// if not found, use a default empty JSON schema object
// TODO: should be updated according to the new specifications
syn::parse2::<Expr>(quote! {
std::sync::Arc::new(serde_json::json!({
"type": "object",
"properties": {}
}).as_object().unwrap().clone())
rmcp::handler::server::common::schema_for_empty_input()
})?
}
};
Expand Down
2 changes: 1 addition & 1 deletion crates/rmcp/README.md
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Original file line numberDiff line numberDiff line change
Expand Up@@ -130,7 +130,7 @@ async fn calculate(&self, params: Parameters<CalculationRequest>) -> Result<Json
# }
```

The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type.
The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type. See the [documentation of `tool` module](crate::handler::server::router::tool) for more instructions.

## Tasks

Expand Down
14 changes: 14 additions & 0 deletions crates/rmcp/src/handler/server/common.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,20 @@ pub fn schema_for_type<T: JsonSchema + std::any::Any>() -> Arc<JsonObject> {
})
}

// TODO: should be updated according to the new specifications
/// Schema used when input is empty.
pub fn schema_for_empty_input() -> Arc<JsonObject> {
std::sync::Arc::new(
serde_json::json!({
"type": "object",
"properties": {}
})
.as_object()
.unwrap()
.clone(),
)
}

/// Generate and validate a JSON schema for outputSchema (must have root type "object").
pub fn schema_for_output<T: JsonSchema + std::any::Any>() -> Result<Arc<JsonObject>, String> {
thread_local! {
Expand Down
161 changes: 161 additions & 0 deletions crates/rmcp/src/handler/server/router/tool.rs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,132 @@
//! Tools for MCP servers.
//!
//! It's straightforward to define tools using [`tool_router`][crate::tool_router] and
//! [`tool`][crate::tool] macro.
//!
//! ```rust
//! # use rmcp::{
//! # tool_router, tool,
//! # handler::server::{wrapper::{Parameters, Json}, tool::ToolRouter},
//! # schemars
//! # };
//! # use serde::{Serialize, Deserialize};
//! struct Server {
//! tool_router: ToolRouter<Self>,
//! }
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! struct AddParameter {
//! left: usize,
//! right: usize
//! }
//! #[derive(Serialize, schemars::JsonSchema)]
//! struct AddOutput {
//! sum: usize
//! }
//! #[tool_router]
//! impl Server {
//! #[tool(name = "adder", description = "Modular add two integers")]
//! fn add(
//! &self,
//! Parameters(AddParameter { left, right }): Parameters<AddParameter>
//! ) -> Json<AddOutput> {
//! Json(AddOutput { sum: left.wrapping_add(right) })
//! }
//! }
//! ```
//!
//! Using the macro-based code pattern above is suitable for small MCP servers with simple interfaces.
//! When the business logic become larger, it is recommended that each tool should reside
//! in individual file, combined into MCP server using [`SyncTool`] and [`AsyncTool`] traits.
//!
//! ```rust
//! # use rmcp::{
//! # handler::server::{
//! # tool::ToolRouter,
//! # router::tool::{SyncTool, AsyncTool, ToolBase},
//! # },
//! # schemars, ErrorData
//! # };
//! # pub struct MyCustomError;
//! # impl From<MyCustomError> for ErrorData {
//! # fn from(err: MyCustomError) -> ErrorData { unimplemented!() }
//! # }
//! # use serde::{Serialize, Deserialize};
//! # use std::borrow::Cow;
//! // In tool1.rs
//! pub struct ComplexTool1;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool1Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool1Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool1 {
//! type Parameter = ComplexTool1Input;
//! type Output = ComplexTool1Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool1".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl SyncTool<MyToolServer> for ComplexTool1 {
//! fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//! // In tool2.rs
//! pub struct ComplexTool2;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool2Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool2Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool2 {
//! type Parameter = ComplexTool2Input;
//! type Output = ComplexTool2Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool2".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl AsyncTool<MyToolServer> for ComplexTool2 {
//! async fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//!
//! // In tool_router.rs
//! struct MyToolServer {
//! tool_router: ToolRouter<Self>,
//! }
//! impl MyToolServer {
//! pub fn tool_router() -> ToolRouter<Self> {
//! ToolRouter::new()
//! .with_sync_tool::<ComplexTool1>()
//! .with_async_tool::<ComplexTool2>()
//! }
//! }
//! ```
//!
//! It's also possible to use macro-based and trait-based tool definition together: Since
//! [`ToolRouter`] implements [`Add`][std::ops::Add], you can add two tool routers into final
//! router as showed in [the documentation of `tool_router`][crate::tool_router].

mod tool_traits;

use std::{borrow::Cow, sync::Arc};

use futures::{FutureExt, future::BoxFuture};
use schemars::JsonSchema;
pub use tool_traits::{AsyncTool, SyncTool, ToolBase};

use crate::{
handler::server::{
Expand DownExpand Up@@ -219,6 +344,42 @@ where
self
}

/// Add a tool that implements [`SyncTool`]
pub fn with_sync_tool<T>(self) -> Self
where
T: SyncTool<S> + 'static,
{
if T::input_schema().is_some() {
self.with_route((
tool_traits::tool_attribute::<T>(),
tool_traits::sync_tool_wrapper::<S, T>,
))
} else {
self.with_route((
tool_traits::tool_attribute::<T>(),
tool_traits::sync_tool_wrapper_with_empty_params::<S, T>,
))
}
}

/// Add a tool that implements [`AsyncTool`]
pub fn with_async_tool<T>(self) -> Self
where
T: AsyncTool<S> + 'static,
{
if T::input_schema().is_some() {
self.with_route((
tool_traits::tool_attribute::<T>(),
tool_traits::async_tool_wrapper::<S, T>,
))
} else {
self.with_route((
tool_traits::tool_attribute::<T>(),
tool_traits::async_tool_wrapper_with_empty_params::<S, T>,
))
}
}

Comment thread
DaleSeo marked this conversation as resolved.
pub fn add_route(&mut self, item: ToolRoute<S>) {
let new_name = &item.attr.name;
validate_and_warn_tool_name(new_name);
Expand Down
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(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
var btn = document.createElement('button');
btn.textContent = 'Copy';
btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';
btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
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navigator.clipboard.writeText(codeBlock.textContent).then(function() {
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});
};
codeBlock.parentElement.style.position = 'relative';
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});
}
addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

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feat: add trait-based tool declaration#677

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 Merged

DaleSeo
merged 6 commits into

from

Feb 25, 2026
 Merged


feat: add trait-based tool declaration
#677
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eacd729

feat: add trait-based tool declaration


Evian-Zhang Feb 21, 2026
099a994

fix: typo


Evian-Zhang Feb 21, 2026
c89e1c2

fix: add docs, make more idomatic patterns, allow for empty parameter…


Evian-Zhang Feb 25, 2026
388c706

fix: format code


Evian-Zhang Feb 25, 2026
820ce05

fix: add default trait


Evian-Zhang Feb 25, 2026
8403ea0

fix: docs typo


Evian-Zhang Feb 25, 2026

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5 changes: 1 addition & 4 deletions
crates/rmcp-macros/src/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -238,10 +238,7 @@ pub fn tool(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream> {
 // if not found, use a default empty JSON schema object
 // TODO: should be updated according to the new specifications
 syn::parse2::<Expr>(quote! {
 std::sync::Arc::new(serde_json::json!({
 "type": "object",
 "properties": {}
 }).as_object().unwrap().clone())
 rmcp::handler::server::common::schema_for_empty_input()
 })?
 }
 };
Expand Down

2 changes: 1 addition & 1 deletion
crates/rmcp/README.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -130,7 +130,7 @@ async fn calculate(&self, params: Parameters<CalculationRequest>) -> Result<Json
# }
```

The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type.
The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type. See the [documentation of `tool` module](crate::handler::server::router::tool) for more instructions.

## Tasks

Expand Down

14 changes: 14 additions & 0 deletions
crates/rmcp/src/handler/server/common.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,20 @@ pub fn schema_for_type<T: JsonSchema + std::any::Any>() -> Arc<JsonObject> {
 })
}

// TODO: should be updated according to the new specifications
/// Schema used when input is empty.
pub fn schema_for_empty_input() -> Arc<JsonObject> {
 std::sync::Arc::new(
 serde_json::json!({
 "type": "object",
 "properties": {}
 })
 .as_object()
 .unwrap()
 .clone(),
 )
}

/// Generate and validate a JSON schema for outputSchema (must have root type "object").
pub fn schema_for_output<T: JsonSchema + std::any::Any>() -> Result<Arc<JsonObject>, String> {
 thread_local! {
Expand Down

161 changes: 161 additions & 0 deletions
crates/rmcp/src/handler/server/router/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,7 +1,132 @@
//! Tools for MCP servers.
//!
//! It's straightforward to define tools using [`tool_router`][crate::tool_router] and
//! [`tool`][crate::tool] macro.
//!
//! ```rust
//! # use rmcp::{
//! # tool_router, tool,
//! # handler::server::{wrapper::{Parameters, Json}, tool::ToolRouter},
//! # schemars
//! # };
//! # use serde::{Serialize, Deserialize};
//! struct Server {
//! tool_router: ToolRouter<Self>,
//! }
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! struct AddParameter {
//! left: usize,
//! right: usize
//! }
//! #[derive(Serialize, schemars::JsonSchema)]
//! struct AddOutput {
//! sum: usize
//! }
//! #[tool_router]
//! impl Server {
//! #[tool(name = "adder", description = "Modular add two integers")]
//! fn add(
//! &self,
//! Parameters(AddParameter { left, right }): Parameters<AddParameter>
//! ) -> Json<AddOutput> {
//! Json(AddOutput { sum: left.wrapping_add(right) })
//! }
//! }
//! ```
//!
//! Using the macro-based code pattern above is suitable for small MCP servers with simple interfaces.
//! When the business logic become larger, it is recommended that each tool should reside
//! in individual file, combined into MCP server using [`SyncTool`] and [`AsyncTool`] traits.
//!
//! ```rust
//! # use rmcp::{
//! # handler::server::{
//! # tool::ToolRouter,
//! # router::tool::{SyncTool, AsyncTool, ToolBase},
//! # },
//! # schemars, ErrorData
//! # };
//! # pub struct MyCustomError;
//! # impl From<MyCustomError> for ErrorData {
//! # fn from(err: MyCustomError) -> ErrorData { unimplemented!() }
//! # }
//! # use serde::{Serialize, Deserialize};
//! # use std::borrow::Cow;
//! // In tool1.rs
//! pub struct ComplexTool1;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool1Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool1Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool1 {
//! type Parameter = ComplexTool1Input;
//! type Output = ComplexTool1Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool1".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl SyncTool<MyToolServer> for ComplexTool1 {
//! fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//! // In tool2.rs
//! pub struct ComplexTool2;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool2Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool2Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool2 {
//! type Parameter = ComplexTool2Input;
//! type Output = ComplexTool2Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool2".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl AsyncTool<MyToolServer> for ComplexTool2 {
//! async fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//!
//! // In tool_router.rs
//! struct MyToolServer {
//! tool_router: ToolRouter<Self>,
//! }
//! impl MyToolServer {
//! pub fn tool_router() -> ToolRouter<Self> {
//! ToolRouter::new()
//! .with_sync_tool::<ComplexTool1>()
//! .with_async_tool::<ComplexTool2>()
//! }
//! }
//! ```
//!
//! It's also possible to use macro-based and trait-based tool definition together: Since
//! [`ToolRouter`] implements [`Add`][std::ops::Add], you can add two tool routers into final
//! router as showed in [the documentation of `tool_router`][crate::tool_router].

mod tool_traits;

use std::{borrow::Cow, sync::Arc};

use futures::{FutureExt, future::BoxFuture};
use schemars::JsonSchema;
pub use tool_traits::{AsyncTool, SyncTool, ToolBase};

use crate::{
 handler::server::{
Expand DownExpand Up@@ -219,6 +344,42 @@ where
 self
 }

 /// Add a tool that implements [`SyncTool`]
 pub fn with_sync_tool<T>(self) -> Self
 where
 T: SyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

 /// Add a tool that implements [`AsyncTool`]
 pub fn with_async_tool<T>(self) -> Self
 where
 T: AsyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

Comment thread
DaleSeo marked this conversation as resolved.

 pub fn add_route(&mut self, item: ToolRoute<S>) {
 let new_name = &item.attr.name;
 validate_and_warn_tool_name(new_name);
Expand Down
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var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
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feat: add trait-based tool declaration#677

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 Merged

DaleSeo
merged 6 commits into

from

Feb 25, 2026
 Merged


feat: add trait-based tool declaration
#677
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eacd729

feat: add trait-based tool declaration


Evian-Zhang Feb 21, 2026
099a994

fix: typo


Evian-Zhang Feb 21, 2026
c89e1c2

fix: add docs, make more idomatic patterns, allow for empty parameter…


Evian-Zhang Feb 25, 2026
388c706

fix: format code


Evian-Zhang Feb 25, 2026
820ce05

fix: add default trait


Evian-Zhang Feb 25, 2026
8403ea0

fix: docs typo


Evian-Zhang Feb 25, 2026

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5 changes: 1 addition & 4 deletions
crates/rmcp-macros/src/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -238,10 +238,7 @@ pub fn tool(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream> {
 // if not found, use a default empty JSON schema object
 // TODO: should be updated according to the new specifications
 syn::parse2::<Expr>(quote! {
 std::sync::Arc::new(serde_json::json!({
 "type": "object",
 "properties": {}
 }).as_object().unwrap().clone())
 rmcp::handler::server::common::schema_for_empty_input()
 })?
 }
 };
Expand Down

2 changes: 1 addition & 1 deletion
crates/rmcp/README.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -130,7 +130,7 @@ async fn calculate(&self, params: Parameters<CalculationRequest>) -> Result<Json
# }
```

The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type.
The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type. See the [documentation of `tool` module](crate::handler::server::router::tool) for more instructions.

## Tasks

Expand Down

14 changes: 14 additions & 0 deletions
crates/rmcp/src/handler/server/common.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,20 @@ pub fn schema_for_type<T: JsonSchema + std::any::Any>() -> Arc<JsonObject> {
 })
}

// TODO: should be updated according to the new specifications
/// Schema used when input is empty.
pub fn schema_for_empty_input() -> Arc<JsonObject> {
 std::sync::Arc::new(
 serde_json::json!({
 "type": "object",
 "properties": {}
 })
 .as_object()
 .unwrap()
 .clone(),
 )
}

/// Generate and validate a JSON schema for outputSchema (must have root type "object").
pub fn schema_for_output<T: JsonSchema + std::any::Any>() -> Result<Arc<JsonObject>, String> {
 thread_local! {
Expand Down

161 changes: 161 additions & 0 deletions
crates/rmcp/src/handler/server/router/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,7 +1,132 @@
//! Tools for MCP servers.
//!
//! It's straightforward to define tools using [`tool_router`][crate::tool_router] and
//! [`tool`][crate::tool] macro.
//!
//! ```rust
//! # use rmcp::{
//! # tool_router, tool,
//! # handler::server::{wrapper::{Parameters, Json}, tool::ToolRouter},
//! # schemars
//! # };
//! # use serde::{Serialize, Deserialize};
//! struct Server {
//! tool_router: ToolRouter<Self>,
//! }
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! struct AddParameter {
//! left: usize,
//! right: usize
//! }
//! #[derive(Serialize, schemars::JsonSchema)]
//! struct AddOutput {
//! sum: usize
//! }
//! #[tool_router]
//! impl Server {
//! #[tool(name = "adder", description = "Modular add two integers")]
//! fn add(
//! &self,
//! Parameters(AddParameter { left, right }): Parameters<AddParameter>
//! ) -> Json<AddOutput> {
//! Json(AddOutput { sum: left.wrapping_add(right) })
//! }
//! }
//! ```
//!
//! Using the macro-based code pattern above is suitable for small MCP servers with simple interfaces.
//! When the business logic become larger, it is recommended that each tool should reside
//! in individual file, combined into MCP server using [`SyncTool`] and [`AsyncTool`] traits.
//!
//! ```rust
//! # use rmcp::{
//! # handler::server::{
//! # tool::ToolRouter,
//! # router::tool::{SyncTool, AsyncTool, ToolBase},
//! # },
//! # schemars, ErrorData
//! # };
//! # pub struct MyCustomError;
//! # impl From<MyCustomError> for ErrorData {
//! # fn from(err: MyCustomError) -> ErrorData { unimplemented!() }
//! # }
//! # use serde::{Serialize, Deserialize};
//! # use std::borrow::Cow;
//! // In tool1.rs
//! pub struct ComplexTool1;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool1Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool1Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool1 {
//! type Parameter = ComplexTool1Input;
//! type Output = ComplexTool1Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool1".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl SyncTool<MyToolServer> for ComplexTool1 {
//! fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//! // In tool2.rs
//! pub struct ComplexTool2;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool2Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool2Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool2 {
//! type Parameter = ComplexTool2Input;
//! type Output = ComplexTool2Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool2".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl AsyncTool<MyToolServer> for ComplexTool2 {
//! async fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//!
//! // In tool_router.rs
//! struct MyToolServer {
//! tool_router: ToolRouter<Self>,
//! }
//! impl MyToolServer {
//! pub fn tool_router() -> ToolRouter<Self> {
//! ToolRouter::new()
//! .with_sync_tool::<ComplexTool1>()
//! .with_async_tool::<ComplexTool2>()
//! }
//! }
//! ```
//!
//! It's also possible to use macro-based and trait-based tool definition together: Since
//! [`ToolRouter`] implements [`Add`][std::ops::Add], you can add two tool routers into final
//! router as showed in [the documentation of `tool_router`][crate::tool_router].

mod tool_traits;

use std::{borrow::Cow, sync::Arc};

use futures::{FutureExt, future::BoxFuture};
use schemars::JsonSchema;
pub use tool_traits::{AsyncTool, SyncTool, ToolBase};

use crate::{
 handler::server::{
Expand DownExpand Up@@ -219,6 +344,42 @@ where
 self
 }

 /// Add a tool that implements [`SyncTool`]
 pub fn with_sync_tool<T>(self) -> Self
 where
 T: SyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

 /// Add a tool that implements [`AsyncTool`]
 pub fn with_async_tool<T>(self) -> Self
 where
 T: AsyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

Comment thread
DaleSeo marked this conversation as resolved.

 pub fn add_route(&mut self, item: ToolRoute<S>) {
 let new_name = &item.attr.name;
 validate_and_warn_tool_name(new_name);
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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feat: add trait-based tool declaration#677

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DaleSeo
merged 6 commits into

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Feb 25, 2026
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feat: add trait-based tool declaration
#677
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eacd729

feat: add trait-based tool declaration


Evian-Zhang Feb 21, 2026
099a994

fix: typo


Evian-Zhang Feb 21, 2026
c89e1c2

fix: add docs, make more idomatic patterns, allow for empty parameter…


Evian-Zhang Feb 25, 2026
388c706

fix: format code


Evian-Zhang Feb 25, 2026
820ce05

fix: add default trait


Evian-Zhang Feb 25, 2026
8403ea0

fix: docs typo


Evian-Zhang Feb 25, 2026

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5 changes: 1 addition & 4 deletions
crates/rmcp-macros/src/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -238,10 +238,7 @@ pub fn tool(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream> {
 // if not found, use a default empty JSON schema object
 // TODO: should be updated according to the new specifications
 syn::parse2::<Expr>(quote! {
 std::sync::Arc::new(serde_json::json!({
 "type": "object",
 "properties": {}
 }).as_object().unwrap().clone())
 rmcp::handler::server::common::schema_for_empty_input()
 })?
 }
 };
Expand Down

2 changes: 1 addition & 1 deletion
crates/rmcp/README.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -130,7 +130,7 @@ async fn calculate(&self, params: Parameters<CalculationRequest>) -> Result<Json
# }
```

The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type.
The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type. See the [documentation of `tool` module](crate::handler::server::router::tool) for more instructions.

## Tasks

Expand Down

14 changes: 14 additions & 0 deletions
crates/rmcp/src/handler/server/common.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,20 @@ pub fn schema_for_type<T: JsonSchema + std::any::Any>() -> Arc<JsonObject> {
 })
}

// TODO: should be updated according to the new specifications
/// Schema used when input is empty.
pub fn schema_for_empty_input() -> Arc<JsonObject> {
 std::sync::Arc::new(
 serde_json::json!({
 "type": "object",
 "properties": {}
 })
 .as_object()
 .unwrap()
 .clone(),
 )
}

/// Generate and validate a JSON schema for outputSchema (must have root type "object").
pub fn schema_for_output<T: JsonSchema + std::any::Any>() -> Result<Arc<JsonObject>, String> {
 thread_local! {
Expand Down

161 changes: 161 additions & 0 deletions
crates/rmcp/src/handler/server/router/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,7 +1,132 @@
//! Tools for MCP servers.
//!
//! It's straightforward to define tools using [`tool_router`][crate::tool_router] and
//! [`tool`][crate::tool] macro.
//!
//! ```rust
//! # use rmcp::{
//! # tool_router, tool,
//! # handler::server::{wrapper::{Parameters, Json}, tool::ToolRouter},
//! # schemars
//! # };
//! # use serde::{Serialize, Deserialize};
//! struct Server {
//! tool_router: ToolRouter<Self>,
//! }
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! struct AddParameter {
//! left: usize,
//! right: usize
//! }
//! #[derive(Serialize, schemars::JsonSchema)]
//! struct AddOutput {
//! sum: usize
//! }
//! #[tool_router]
//! impl Server {
//! #[tool(name = "adder", description = "Modular add two integers")]
//! fn add(
//! &self,
//! Parameters(AddParameter { left, right }): Parameters<AddParameter>
//! ) -> Json<AddOutput> {
//! Json(AddOutput { sum: left.wrapping_add(right) })
//! }
//! }
//! ```
//!
//! Using the macro-based code pattern above is suitable for small MCP servers with simple interfaces.
//! When the business logic become larger, it is recommended that each tool should reside
//! in individual file, combined into MCP server using [`SyncTool`] and [`AsyncTool`] traits.
//!
//! ```rust
//! # use rmcp::{
//! # handler::server::{
//! # tool::ToolRouter,
//! # router::tool::{SyncTool, AsyncTool, ToolBase},
//! # },
//! # schemars, ErrorData
//! # };
//! # pub struct MyCustomError;
//! # impl From<MyCustomError> for ErrorData {
//! # fn from(err: MyCustomError) -> ErrorData { unimplemented!() }
//! # }
//! # use serde::{Serialize, Deserialize};
//! # use std::borrow::Cow;
//! // In tool1.rs
//! pub struct ComplexTool1;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool1Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool1Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool1 {
//! type Parameter = ComplexTool1Input;
//! type Output = ComplexTool1Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool1".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl SyncTool<MyToolServer> for ComplexTool1 {
//! fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//! // In tool2.rs
//! pub struct ComplexTool2;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool2Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool2Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool2 {
//! type Parameter = ComplexTool2Input;
//! type Output = ComplexTool2Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool2".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl AsyncTool<MyToolServer> for ComplexTool2 {
//! async fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//!
//! // In tool_router.rs
//! struct MyToolServer {
//! tool_router: ToolRouter<Self>,
//! }
//! impl MyToolServer {
//! pub fn tool_router() -> ToolRouter<Self> {
//! ToolRouter::new()
//! .with_sync_tool::<ComplexTool1>()
//! .with_async_tool::<ComplexTool2>()
//! }
//! }
//! ```
//!
//! It's also possible to use macro-based and trait-based tool definition together: Since
//! [`ToolRouter`] implements [`Add`][std::ops::Add], you can add two tool routers into final
//! router as showed in [the documentation of `tool_router`][crate::tool_router].

mod tool_traits;

use std::{borrow::Cow, sync::Arc};

use futures::{FutureExt, future::BoxFuture};
use schemars::JsonSchema;
pub use tool_traits::{AsyncTool, SyncTool, ToolBase};

use crate::{
 handler::server::{
Expand DownExpand Up@@ -219,6 +344,42 @@ where
 self
 }

 /// Add a tool that implements [`SyncTool`]
 pub fn with_sync_tool<T>(self) -> Self
 where
 T: SyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

 /// Add a tool that implements [`AsyncTool`]
 pub fn with_async_tool<T>(self) -> Self
 where
 T: AsyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

Comment thread
DaleSeo marked this conversation as resolved.

 pub fn add_route(&mut self, item: ToolRoute<S>) {
 let new_name = &item.attr.name;
 validate_and_warn_tool_name(new_name);
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

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feat: add trait-based tool declaration#677

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 Merged

DaleSeo
merged 6 commits into

from

Feb 25, 2026
 Merged


feat: add trait-based tool declaration
#677
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eacd729

feat: add trait-based tool declaration


Evian-Zhang Feb 21, 2026
099a994

fix: typo


Evian-Zhang Feb 21, 2026
c89e1c2

fix: add docs, make more idomatic patterns, allow for empty parameter…


Evian-Zhang Feb 25, 2026
388c706

fix: format code


Evian-Zhang Feb 25, 2026
820ce05

fix: add default trait


Evian-Zhang Feb 25, 2026
8403ea0

fix: docs typo


Evian-Zhang Feb 25, 2026

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5 changes: 1 addition & 4 deletions
crates/rmcp-macros/src/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -238,10 +238,7 @@ pub fn tool(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream> {
 // if not found, use a default empty JSON schema object
 // TODO: should be updated according to the new specifications
 syn::parse2::<Expr>(quote! {
 std::sync::Arc::new(serde_json::json!({
 "type": "object",
 "properties": {}
 }).as_object().unwrap().clone())
 rmcp::handler::server::common::schema_for_empty_input()
 })?
 }
 };
Expand Down

2 changes: 1 addition & 1 deletion
crates/rmcp/README.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -130,7 +130,7 @@ async fn calculate(&self, params: Parameters<CalculationRequest>) -> Result<Json
# }
```

The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type.
The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type. See the [documentation of `tool` module](crate::handler::server::router::tool) for more instructions.

## Tasks

Expand Down

14 changes: 14 additions & 0 deletions
crates/rmcp/src/handler/server/common.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,20 @@ pub fn schema_for_type<T: JsonSchema + std::any::Any>() -> Arc<JsonObject> {
 })
}

// TODO: should be updated according to the new specifications
/// Schema used when input is empty.
pub fn schema_for_empty_input() -> Arc<JsonObject> {
 std::sync::Arc::new(
 serde_json::json!({
 "type": "object",
 "properties": {}
 })
 .as_object()
 .unwrap()
 .clone(),
 )
}

/// Generate and validate a JSON schema for outputSchema (must have root type "object").
pub fn schema_for_output<T: JsonSchema + std::any::Any>() -> Result<Arc<JsonObject>, String> {
 thread_local! {
Expand Down

161 changes: 161 additions & 0 deletions
crates/rmcp/src/handler/server/router/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,7 +1,132 @@
//! Tools for MCP servers.
//!
//! It's straightforward to define tools using [`tool_router`][crate::tool_router] and
//! [`tool`][crate::tool] macro.
//!
//! ```rust
//! # use rmcp::{
//! # tool_router, tool,
//! # handler::server::{wrapper::{Parameters, Json}, tool::ToolRouter},
//! # schemars
//! # };
//! # use serde::{Serialize, Deserialize};
//! struct Server {
//! tool_router: ToolRouter<Self>,
//! }
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! struct AddParameter {
//! left: usize,
//! right: usize
//! }
//! #[derive(Serialize, schemars::JsonSchema)]
//! struct AddOutput {
//! sum: usize
//! }
//! #[tool_router]
//! impl Server {
//! #[tool(name = "adder", description = "Modular add two integers")]
//! fn add(
//! &self,
//! Parameters(AddParameter { left, right }): Parameters<AddParameter>
//! ) -> Json<AddOutput> {
//! Json(AddOutput { sum: left.wrapping_add(right) })
//! }
//! }
//! ```
//!
//! Using the macro-based code pattern above is suitable for small MCP servers with simple interfaces.
//! When the business logic become larger, it is recommended that each tool should reside
//! in individual file, combined into MCP server using [`SyncTool`] and [`AsyncTool`] traits.
//!
//! ```rust
//! # use rmcp::{
//! # handler::server::{
//! # tool::ToolRouter,
//! # router::tool::{SyncTool, AsyncTool, ToolBase},
//! # },
//! # schemars, ErrorData
//! # };
//! # pub struct MyCustomError;
//! # impl From<MyCustomError> for ErrorData {
//! # fn from(err: MyCustomError) -> ErrorData { unimplemented!() }
//! # }
//! # use serde::{Serialize, Deserialize};
//! # use std::borrow::Cow;
//! // In tool1.rs
//! pub struct ComplexTool1;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool1Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool1Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool1 {
//! type Parameter = ComplexTool1Input;
//! type Output = ComplexTool1Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool1".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl SyncTool<MyToolServer> for ComplexTool1 {
//! fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//! // In tool2.rs
//! pub struct ComplexTool2;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool2Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool2Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool2 {
//! type Parameter = ComplexTool2Input;
//! type Output = ComplexTool2Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool2".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl AsyncTool<MyToolServer> for ComplexTool2 {
//! async fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//!
//! // In tool_router.rs
//! struct MyToolServer {
//! tool_router: ToolRouter<Self>,
//! }
//! impl MyToolServer {
//! pub fn tool_router() -> ToolRouter<Self> {
//! ToolRouter::new()
//! .with_sync_tool::<ComplexTool1>()
//! .with_async_tool::<ComplexTool2>()
//! }
//! }
//! ```
//!
//! It's also possible to use macro-based and trait-based tool definition together: Since
//! [`ToolRouter`] implements [`Add`][std::ops::Add], you can add two tool routers into final
//! router as showed in [the documentation of `tool_router`][crate::tool_router].

mod tool_traits;

use std::{borrow::Cow, sync::Arc};

use futures::{FutureExt, future::BoxFuture};
use schemars::JsonSchema;
pub use tool_traits::{AsyncTool, SyncTool, ToolBase};

use crate::{
 handler::server::{
Expand DownExpand Up@@ -219,6 +344,42 @@ where
 self
 }

 /// Add a tool that implements [`SyncTool`]
 pub fn with_sync_tool<T>(self) -> Self
 where
 T: SyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

 /// Add a tool that implements [`AsyncTool`]
 pub fn with_async_tool<T>(self) -> Self
 where
 T: AsyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

Comment thread
DaleSeo marked this conversation as resolved.

 pub fn add_route(&mut self, item: ToolRoute<S>) {
 let new_name = &item.attr.name;
 validate_and_warn_tool_name(new_name);
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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DaleSeo
merged 6 commits into

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Feb 25, 2026
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feat: add trait-based tool declaration
#677
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eacd729

feat: add trait-based tool declaration


Evian-Zhang Feb 21, 2026
099a994

fix: typo


Evian-Zhang Feb 21, 2026
c89e1c2

fix: add docs, make more idomatic patterns, allow for empty parameter…


Evian-Zhang Feb 25, 2026
388c706

fix: format code


Evian-Zhang Feb 25, 2026
820ce05

fix: add default trait


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8403ea0

fix: docs typo


Evian-Zhang Feb 25, 2026

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5 changes: 1 addition & 4 deletions
crates/rmcp-macros/src/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -238,10 +238,7 @@ pub fn tool(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream> {
 // if not found, use a default empty JSON schema object
 // TODO: should be updated according to the new specifications
 syn::parse2::<Expr>(quote! {
 std::sync::Arc::new(serde_json::json!({
 "type": "object",
 "properties": {}
 }).as_object().unwrap().clone())
 rmcp::handler::server::common::schema_for_empty_input()
 })?
 }
 };
Expand Down

2 changes: 1 addition & 1 deletion
crates/rmcp/README.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -130,7 +130,7 @@ async fn calculate(&self, params: Parameters<CalculationRequest>) -> Result<Json
# }
```

The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type.
The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type. See the [documentation of `tool` module](crate::handler::server::router::tool) for more instructions.

## Tasks

Expand Down

14 changes: 14 additions & 0 deletions
crates/rmcp/src/handler/server/common.rs

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,20 @@ pub fn schema_for_type<T: JsonSchema + std::any::Any>() -> Arc<JsonObject> {
 })
}

// TODO: should be updated according to the new specifications
/// Schema used when input is empty.
pub fn schema_for_empty_input() -> Arc<JsonObject> {
 std::sync::Arc::new(
 serde_json::json!({
 "type": "object",
 "properties": {}
 })
 .as_object()
 .unwrap()
 .clone(),
 )
}

/// Generate and validate a JSON schema for outputSchema (must have root type "object").
pub fn schema_for_output<T: JsonSchema + std::any::Any>() -> Result<Arc<JsonObject>, String> {
 thread_local! {
Expand Down

161 changes: 161 additions & 0 deletions
crates/rmcp/src/handler/server/router/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,7 +1,132 @@
//! Tools for MCP servers.
//!
//! It's straightforward to define tools using [`tool_router`][crate::tool_router] and
//! [`tool`][crate::tool] macro.
//!
//! ```rust
//! # use rmcp::{
//! # tool_router, tool,
//! # handler::server::{wrapper::{Parameters, Json}, tool::ToolRouter},
//! # schemars
//! # };
//! # use serde::{Serialize, Deserialize};
//! struct Server {
//! tool_router: ToolRouter<Self>,
//! }
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! struct AddParameter {
//! left: usize,
//! right: usize
//! }
//! #[derive(Serialize, schemars::JsonSchema)]
//! struct AddOutput {
//! sum: usize
//! }
//! #[tool_router]
//! impl Server {
//! #[tool(name = "adder", description = "Modular add two integers")]
//! fn add(
//! &self,
//! Parameters(AddParameter { left, right }): Parameters<AddParameter>
//! ) -> Json<AddOutput> {
//! Json(AddOutput { sum: left.wrapping_add(right) })
//! }
//! }
//! ```
//!
//! Using the macro-based code pattern above is suitable for small MCP servers with simple interfaces.
//! When the business logic become larger, it is recommended that each tool should reside
//! in individual file, combined into MCP server using [`SyncTool`] and [`AsyncTool`] traits.
//!
//! ```rust
//! # use rmcp::{
//! # handler::server::{
//! # tool::ToolRouter,
//! # router::tool::{SyncTool, AsyncTool, ToolBase},
//! # },
//! # schemars, ErrorData
//! # };
//! # pub struct MyCustomError;
//! # impl From<MyCustomError> for ErrorData {
//! # fn from(err: MyCustomError) -> ErrorData { unimplemented!() }
//! # }
//! # use serde::{Serialize, Deserialize};
//! # use std::borrow::Cow;
//! // In tool1.rs
//! pub struct ComplexTool1;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool1Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool1Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool1 {
//! type Parameter = ComplexTool1Input;
//! type Output = ComplexTool1Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool1".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl SyncTool<MyToolServer> for ComplexTool1 {
//! fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//! // In tool2.rs
//! pub struct ComplexTool2;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool2Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool2Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool2 {
//! type Parameter = ComplexTool2Input;
//! type Output = ComplexTool2Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool2".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl AsyncTool<MyToolServer> for ComplexTool2 {
//! async fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//!
//! // In tool_router.rs
//! struct MyToolServer {
//! tool_router: ToolRouter<Self>,
//! }
//! impl MyToolServer {
//! pub fn tool_router() -> ToolRouter<Self> {
//! ToolRouter::new()
//! .with_sync_tool::<ComplexTool1>()
//! .with_async_tool::<ComplexTool2>()
//! }
//! }
//! ```
//!
//! It's also possible to use macro-based and trait-based tool definition together: Since
//! [`ToolRouter`] implements [`Add`][std::ops::Add], you can add two tool routers into final
//! router as showed in [the documentation of `tool_router`][crate::tool_router].

mod tool_traits;

use std::{borrow::Cow, sync::Arc};

use futures::{FutureExt, future::BoxFuture};
use schemars::JsonSchema;
pub use tool_traits::{AsyncTool, SyncTool, ToolBase};

use crate::{
 handler::server::{
Expand DownExpand Up@@ -219,6 +344,42 @@ where
 self
 }

 /// Add a tool that implements [`SyncTool`]
 pub fn with_sync_tool<T>(self) -> Self
 where
 T: SyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

 /// Add a tool that implements [`AsyncTool`]
 pub fn with_async_tool<T>(self) -> Self
 where
 T: AsyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

Comment thread
DaleSeo marked this conversation as resolved.

 pub fn add_route(&mut self, item: ToolRoute<S>) {
 let new_name = &item.attr.name;
 validate_and_warn_tool_name(new_name);
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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feat: add trait-based tool declaration#677

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 Merged

DaleSeo
merged 6 commits into

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Feb 25, 2026
 Merged


feat: add trait-based tool declaration
#677
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eacd729

feat: add trait-based tool declaration


Evian-Zhang Feb 21, 2026
099a994

fix: typo


Evian-Zhang Feb 21, 2026
c89e1c2

fix: add docs, make more idomatic patterns, allow for empty parameter…


Evian-Zhang Feb 25, 2026
388c706

fix: format code


Evian-Zhang Feb 25, 2026
820ce05

fix: add default trait


Evian-Zhang Feb 25, 2026
8403ea0

fix: docs typo


Evian-Zhang Feb 25, 2026

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5 changes: 1 addition & 4 deletions
crates/rmcp-macros/src/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -238,10 +238,7 @@ pub fn tool(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream> {
 // if not found, use a default empty JSON schema object
 // TODO: should be updated according to the new specifications
 syn::parse2::<Expr>(quote! {
 std::sync::Arc::new(serde_json::json!({
 "type": "object",
 "properties": {}
 }).as_object().unwrap().clone())
 rmcp::handler::server::common::schema_for_empty_input()
 })?
 }
 };
Expand Down

2 changes: 1 addition & 1 deletion
crates/rmcp/README.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -130,7 +130,7 @@ async fn calculate(&self, params: Parameters<CalculationRequest>) -> Result<Json
# }
```

The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type.
The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type. See the [documentation of `tool` module](crate::handler::server::router::tool) for more instructions.

## Tasks

Expand Down

14 changes: 14 additions & 0 deletions
crates/rmcp/src/handler/server/common.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,20 @@ pub fn schema_for_type<T: JsonSchema + std::any::Any>() -> Arc<JsonObject> {
 })
}

// TODO: should be updated according to the new specifications
/// Schema used when input is empty.
pub fn schema_for_empty_input() -> Arc<JsonObject> {
 std::sync::Arc::new(
 serde_json::json!({
 "type": "object",
 "properties": {}
 })
 .as_object()
 .unwrap()
 .clone(),
 )
}

/// Generate and validate a JSON schema for outputSchema (must have root type "object").
pub fn schema_for_output<T: JsonSchema + std::any::Any>() -> Result<Arc<JsonObject>, String> {
 thread_local! {
Expand Down

161 changes: 161 additions & 0 deletions
crates/rmcp/src/handler/server/router/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -1,7 +1,132 @@
//! Tools for MCP servers.
//!
//! It's straightforward to define tools using [`tool_router`][crate::tool_router] and
//! [`tool`][crate::tool] macro.
//!
//! ```rust
//! # use rmcp::{
//! # tool_router, tool,
//! # handler::server::{wrapper::{Parameters, Json}, tool::ToolRouter},
//! # schemars
//! # };
//! # use serde::{Serialize, Deserialize};
//! struct Server {
//! tool_router: ToolRouter<Self>,
//! }
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! struct AddParameter {
//! left: usize,
//! right: usize
//! }
//! #[derive(Serialize, schemars::JsonSchema)]
//! struct AddOutput {
//! sum: usize
//! }
//! #[tool_router]
//! impl Server {
//! #[tool(name = "adder", description = "Modular add two integers")]
//! fn add(
//! &self,
//! Parameters(AddParameter { left, right }): Parameters<AddParameter>
//! ) -> Json<AddOutput> {
//! Json(AddOutput { sum: left.wrapping_add(right) })
//! }
//! }
//! ```
//!
//! Using the macro-based code pattern above is suitable for small MCP servers with simple interfaces.
//! When the business logic become larger, it is recommended that each tool should reside
//! in individual file, combined into MCP server using [`SyncTool`] and [`AsyncTool`] traits.
//!
//! ```rust
//! # use rmcp::{
//! # handler::server::{
//! # tool::ToolRouter,
//! # router::tool::{SyncTool, AsyncTool, ToolBase},
//! # },
//! # schemars, ErrorData
//! # };
//! # pub struct MyCustomError;
//! # impl From<MyCustomError> for ErrorData {
//! # fn from(err: MyCustomError) -> ErrorData { unimplemented!() }
//! # }
//! # use serde::{Serialize, Deserialize};
//! # use std::borrow::Cow;
//! // In tool1.rs
//! pub struct ComplexTool1;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool1Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool1Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool1 {
//! type Parameter = ComplexTool1Input;
//! type Output = ComplexTool1Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool1".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl SyncTool<MyToolServer> for ComplexTool1 {
//! fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//! // In tool2.rs
//! pub struct ComplexTool2;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool2Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool2Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool2 {
//! type Parameter = ComplexTool2Input;
//! type Output = ComplexTool2Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool2".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl AsyncTool<MyToolServer> for ComplexTool2 {
//! async fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//!
//! // In tool_router.rs
//! struct MyToolServer {
//! tool_router: ToolRouter<Self>,
//! }
//! impl MyToolServer {
//! pub fn tool_router() -> ToolRouter<Self> {
//! ToolRouter::new()
//! .with_sync_tool::<ComplexTool1>()
//! .with_async_tool::<ComplexTool2>()
//! }
//! }
//! ```
//!
//! It's also possible to use macro-based and trait-based tool definition together: Since
//! [`ToolRouter`] implements [`Add`][std::ops::Add], you can add two tool routers into final
//! router as showed in [the documentation of `tool_router`][crate::tool_router].

mod tool_traits;

use std::{borrow::Cow, sync::Arc};

use futures::{FutureExt, future::BoxFuture};
use schemars::JsonSchema;
pub use tool_traits::{AsyncTool, SyncTool, ToolBase};

use crate::{
 handler::server::{
Expand DownExpand Up@@ -219,6 +344,42 @@ where
 self
 }

 /// Add a tool that implements [`SyncTool`]
 pub fn with_sync_tool<T>(self) -> Self
 where
 T: SyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

 /// Add a tool that implements [`AsyncTool`]
 pub fn with_async_tool<T>(self) -> Self
 where
 T: AsyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

Comment thread
DaleSeo marked this conversation as resolved.

 pub fn add_route(&mut self, item: ToolRoute<S>) {
 let new_name = &item.attr.name;
 validate_and_warn_tool_name(new_name);
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
// Apply on load
applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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feat: add trait-based tool declaration#677

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 Merged

DaleSeo
merged 6 commits into

from

Feb 25, 2026
 Merged


feat: add trait-based tool declaration
#677
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eacd729

feat: add trait-based tool declaration


Evian-Zhang Feb 21, 2026
099a994

fix: typo


Evian-Zhang Feb 21, 2026
c89e1c2

fix: add docs, make more idomatic patterns, allow for empty parameter…


Evian-Zhang Feb 25, 2026
388c706

fix: format code


Evian-Zhang Feb 25, 2026
820ce05

fix: add default trait


Evian-Zhang Feb 25, 2026
8403ea0

fix: docs typo


Evian-Zhang Feb 25, 2026

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5 changes: 1 addition & 4 deletions
crates/rmcp-macros/src/tool.rs

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -238,10 +238,7 @@ pub fn tool(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream> {
 // if not found, use a default empty JSON schema object
 // TODO: should be updated according to the new specifications
 syn::parse2::<Expr>(quote! {
 std::sync::Arc::new(serde_json::json!({
 "type": "object",
 "properties": {}
 }).as_object().unwrap().clone())
 rmcp::handler::server::common::schema_for_empty_input()
 })?
 }
 };
Expand Down

2 changes: 1 addition & 1 deletion
crates/rmcp/README.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -130,7 +130,7 @@ async fn calculate(&self, params: Parameters<CalculationRequest>) -> Result<Json
# }
```

The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type.
The `#[tool]` macro automatically generates an output schema from the `CalculationResult` type. See the [documentation of `tool` module](crate::handler::server::router::tool) for more instructions.

## Tasks

Expand Down

14 changes: 14 additions & 0 deletions
crates/rmcp/src/handler/server/common.rs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,20 @@ pub fn schema_for_type<T: JsonSchema + std::any::Any>() -> Arc<JsonObject> {
 })
}

// TODO: should be updated according to the new specifications
/// Schema used when input is empty.
pub fn schema_for_empty_input() -> Arc<JsonObject> {
 std::sync::Arc::new(
 serde_json::json!({
 "type": "object",
 "properties": {}
 })
 .as_object()
 .unwrap()
 .clone(),
 )
}

/// Generate and validate a JSON schema for outputSchema (must have root type "object").
pub fn schema_for_output<T: JsonSchema + std::any::Any>() -> Result<Arc<JsonObject>, String> {
 thread_local! {
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161 changes: 161 additions & 0 deletions
crates/rmcp/src/handler/server/router/tool.rs

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Original file line numberDiff line numberDiff line change
@@ -1,7 +1,132 @@
//! Tools for MCP servers.
//!
//! It's straightforward to define tools using [`tool_router`][crate::tool_router] and
//! [`tool`][crate::tool] macro.
//!
//! ```rust
//! # use rmcp::{
//! # tool_router, tool,
//! # handler::server::{wrapper::{Parameters, Json}, tool::ToolRouter},
//! # schemars
//! # };
//! # use serde::{Serialize, Deserialize};
//! struct Server {
//! tool_router: ToolRouter<Self>,
//! }
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! struct AddParameter {
//! left: usize,
//! right: usize
//! }
//! #[derive(Serialize, schemars::JsonSchema)]
//! struct AddOutput {
//! sum: usize
//! }
//! #[tool_router]
//! impl Server {
//! #[tool(name = "adder", description = "Modular add two integers")]
//! fn add(
//! &self,
//! Parameters(AddParameter { left, right }): Parameters<AddParameter>
//! ) -> Json<AddOutput> {
//! Json(AddOutput { sum: left.wrapping_add(right) })
//! }
//! }
//! ```
//!
//! Using the macro-based code pattern above is suitable for small MCP servers with simple interfaces.
//! When the business logic become larger, it is recommended that each tool should reside
//! in individual file, combined into MCP server using [`SyncTool`] and [`AsyncTool`] traits.
//!
//! ```rust
//! # use rmcp::{
//! # handler::server::{
//! # tool::ToolRouter,
//! # router::tool::{SyncTool, AsyncTool, ToolBase},
//! # },
//! # schemars, ErrorData
//! # };
//! # pub struct MyCustomError;
//! # impl From<MyCustomError> for ErrorData {
//! # fn from(err: MyCustomError) -> ErrorData { unimplemented!() }
//! # }
//! # use serde::{Serialize, Deserialize};
//! # use std::borrow::Cow;
//! // In tool1.rs
//! pub struct ComplexTool1;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool1Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool1Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool1 {
//! type Parameter = ComplexTool1Input;
//! type Output = ComplexTool1Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool1".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl SyncTool<MyToolServer> for ComplexTool1 {
//! fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//! // In tool2.rs
//! pub struct ComplexTool2;
//! #[derive(Deserialize, schemars::JsonSchema, Default)]
//! pub struct ComplexTool2Input { /* ... */ }
//! #[derive(Serialize, schemars::JsonSchema)]
//! pub struct ComplexTool2Output { /* ... */ }
//!
//! impl ToolBase for ComplexTool2 {
//! type Parameter = ComplexTool2Input;
//! type Output = ComplexTool2Output;
//! type Error = MyCustomError;
//! fn name() -> Cow<'static, str> {
//! "complex-tool2".into()
//! }
//!
//! fn description() -> Option<Cow<'static, str>> {
//! Some("...".into())
//! }
//! }
//! impl AsyncTool<MyToolServer> for ComplexTool2 {
//! async fn invoke(service: &MyToolServer, param: Self::Parameter) -> Result<Self::Output, Self::Error> {
//! // ...
//! # unimplemented!()
//! }
//! }
//!
//! // In tool_router.rs
//! struct MyToolServer {
//! tool_router: ToolRouter<Self>,
//! }
//! impl MyToolServer {
//! pub fn tool_router() -> ToolRouter<Self> {
//! ToolRouter::new()
//! .with_sync_tool::<ComplexTool1>()
//! .with_async_tool::<ComplexTool2>()
//! }
//! }
//! ```
//!
//! It's also possible to use macro-based and trait-based tool definition together: Since
//! [`ToolRouter`] implements [`Add`][std::ops::Add], you can add two tool routers into final
//! router as showed in [the documentation of `tool_router`][crate::tool_router].

mod tool_traits;

use std::{borrow::Cow, sync::Arc};

use futures::{FutureExt, future::BoxFuture};
use schemars::JsonSchema;
pub use tool_traits::{AsyncTool, SyncTool, ToolBase};

use crate::{
 handler::server::{
Expand DownExpand Up@@ -219,6 +344,42 @@ where
 self
 }

 /// Add a tool that implements [`SyncTool`]
 pub fn with_sync_tool<T>(self) -> Self
 where
 T: SyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::sync_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

 /// Add a tool that implements [`AsyncTool`]
 pub fn with_async_tool<T>(self) -> Self
 where
 T: AsyncTool<S> + 'static,
 {
 if T::input_schema().is_some() {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper::<S, T>,
 ))
 } else {
 self.with_route((
 tool_traits::tool_attribute::<T>(),
 tool_traits::async_tool_wrapper_with_empty_params::<S, T>,
 ))
 }
 }

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 pub fn add_route(&mut self, item: ToolRoute<S>) {
 let new_name = &item.attr.name;
 validate_and_warn_tool_name(new_name);
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