1use std::collections::BTreeMap;
2use std::sync::Arc;
3
4use serde_json::json;
5
6use crate::tools::{
7 ApprovalPolicy, ApprovalRequirement, CanUseToolPredicate, ToolContext, ToolExecutor,
8 ToolPolicy, ToolRunContext,
9};
10use crate::types::{Metadata, ToolCall, ToolDirective, ToolExecutionResult, ToolResultStatus};
11
12pub type BeforeToolDispatch = Arc<
13 dyn Fn(&ToolCall, &mut ToolContext) -> Result<(), crate::tools::ToolError>
14 + Send
15 + Sync
16 + 'static,
17>;
18
19#[derive(Clone, Default)]
20pub struct ToolRunOptions {
21 planned_tools: Option<Vec<String>>,
22 allowed_tools: Option<Vec<String>>,
23 disallowed_tools: Vec<String>,
24 can_use_tool: Option<CanUseToolPredicate>,
25 approval: ApprovalPolicy,
26 idempotency_key: Option<String>,
27 before_dispatch: Option<BeforeToolDispatch>,
28}
29
30impl ToolRunOptions {
31 pub fn from_policy(policy: &ToolPolicy) -> Self {
32 Self {
33 planned_tools: None,
34 allowed_tools: policy.allowed_tools.clone(),
35 disallowed_tools: policy.disallowed_tools.clone(),
36 can_use_tool: policy.can_use_tool.clone(),
37 approval: policy.approval,
38 idempotency_key: None,
39 before_dispatch: None,
40 }
41 }
42
43 pub fn planned_names(mut self, tools: impl IntoIterator<Item = impl Into<String>>) -> Self {
44 self.planned_tools = Some(tools.into_iter().map(Into::into).collect());
45 self
46 }
47
48 pub fn allow_only(mut self, tools: impl IntoIterator<Item = impl Into<String>>) -> Self {
49 self.allowed_tools = Some(tools.into_iter().map(Into::into).collect());
50 self
51 }
52
53 pub fn disallow(mut self, tool: impl Into<String>) -> Self {
54 self.disallowed_tools.push(tool.into());
55 self
56 }
57
58 pub fn can_use_tool<F>(mut self, predicate: F) -> Self
59 where
60 F: Fn(&str, &crate::types::ToolArguments) -> bool + Send + Sync + 'static,
61 {
62 self.can_use_tool = Some(Arc::new(predicate));
63 self
64 }
65
66 pub fn idempotency_key(mut self, idempotency_key: Option<String>) -> Self {
67 self.idempotency_key = idempotency_key;
68 self
69 }
70
71 pub fn before_dispatch(mut self, callback: BeforeToolDispatch) -> Self {
72 self.before_dispatch = Some(callback);
73 self
74 }
75}
76
77#[derive(Clone, Default)]
78pub struct ToolOrchestrator {
79 tools: BTreeMap<String, Arc<dyn ToolExecutor>>,
80}
81
82impl ToolOrchestrator {
83 pub fn from_tools(tools: Vec<Arc<dyn ToolExecutor>>) -> Self {
84 let tools = tools
85 .into_iter()
86 .map(|tool| (tool.name().to_string(), tool))
87 .collect();
88 Self { tools }
89 }
90
91 pub async fn run_one(
92 &self,
93 call: ToolCall,
94 context: &mut ToolContext,
95 options: ToolRunOptions,
96 ) -> Result<ToolExecutionResult, crate::tools::ToolError> {
97 self.run_one_with_approval(call, context, options, |_call, _requirement, _context| None)
98 .await
99 }
100
101 pub(crate) async fn run_one_with_approval<F>(
102 &self,
103 call: ToolCall,
104 context: &mut ToolContext,
105 options: ToolRunOptions,
106 approval: F,
107 ) -> Result<ToolExecutionResult, crate::tools::ToolError>
108 where
109 F: FnOnce(&ToolCall, ApprovalRequirement, &ToolContext) -> Option<ToolExecutionResult>,
110 {
111 self.run_one_with_approval_and_metadata(
112 call,
113 context,
114 options,
115 |call, requirement, context, _metadata| approval(call, requirement, context),
116 )
117 .await
118 }
119
120 pub(crate) async fn run_one_with_approval_and_metadata<F>(
121 &self,
122 call: ToolCall,
123 context: &mut ToolContext,
124 options: ToolRunOptions,
125 approval: F,
126 ) -> Result<ToolExecutionResult, crate::tools::ToolError>
127 where
128 F: FnOnce(
129 &ToolCall,
130 ApprovalRequirement,
131 &ToolContext,
132 &Metadata,
133 ) -> Option<ToolExecutionResult>,
134 {
135 if let Some(allowed) = options.allowed_tools.as_ref() {
136 if !allowed.iter().any(|tool| tool == &call.name) {
137 return Ok(policy_denial(&call, "allowed_tools"));
138 }
139 }
140 if options
141 .disallowed_tools
142 .iter()
143 .any(|tool| tool == &call.name)
144 {
145 return Ok(policy_denial(&call, "disallowed_tools"));
146 }
147 if options
148 .can_use_tool
149 .as_ref()
150 .is_some_and(|predicate| !predicate(&call.name, &call.arguments))
151 {
152 return Ok(policy_denial(&call, "can_use_tool"));
153 }
154 if options
155 .planned_tools
156 .as_ref()
157 .is_some_and(|planned| !planned.iter().any(|tool| tool == &call.name))
158 {
159 return Ok(policy_denial(&call, "planned_name"));
160 }
161
162 let Some(tool) = self.tools.get(&call.name) else {
163 return Ok(tool_error(
164 &call,
165 "tool_not_found",
166 format!("Unknown tool: {}", call.name),
167 None,
168 ));
169 };
170
171 context.begin_tool_call(&call);
172 context.idempotency_key = options.idempotency_key.clone();
173 let approval_requirement = match options.approval {
174 ApprovalPolicy::Never => ApprovalRequirement::NotRequired,
175 ApprovalPolicy::Always => ApprovalRequirement::Required,
176 ApprovalPolicy::Default | ApprovalPolicy::OnRequest => {
177 tool.approval_requirement(&call, &ToolRunContext::new(context))
178 }
179 };
180 let approval_result = approval(&call, approval_requirement, context, tool.metadata());
181 if let Some(mut result) = approval_result {
182 if result.tool_call_id.trim().is_empty() || result.tool_call_id == "pending" {
183 result.tool_call_id = call.id;
184 }
185 return Ok(result);
186 }
187
188 if let Some(callback) = options.before_dispatch.as_ref() {
189 callback(&call, context)?;
190 }
191
192 let future = tool.run(call.clone(), ToolRunContext::new(context));
193 let mut result = if let Some(timeout) = tool.timeout() {
194 match tokio::time::timeout(timeout, future).await {
195 Ok(result) => result?,
196 Err(_) => {
197 return Ok(crate::tools::ToolOutput::error(format!(
198 "Tool {} timed out after {} seconds.",
199 call.name,
200 timeout.as_secs_f64()
201 ))
202 .with_code("tool_timeout")
203 .retryable(true)
204 .to_result(&call.id));
205 }
206 }
207 } else {
208 future.await?
209 };
210 if result.tool_call_id.trim().is_empty() || result.tool_call_id == "pending" {
211 result.tool_call_id = call.id;
212 }
213 Ok(result)
214 }
215}
216
217fn policy_denial(call: &ToolCall, policy_source: &str) -> ToolExecutionResult {
218 tool_error(
219 call,
220 "tool_not_allowed",
221 format!("Tool {} is not allowed for these arguments.", call.name),
222 Some(policy_source),
223 )
224}
225
226fn tool_error(
227 call: &ToolCall,
228 error_code: &str,
229 message: impl Into<String>,
230 policy_source: Option<&str>,
231) -> ToolExecutionResult {
232 let error_code = error_code.to_string();
233 let message = message.into();
234 let mut metadata = BTreeMap::new();
235 if let Some(policy_source) = policy_source {
236 metadata.insert("mode".to_string(), json!("permission_denied"));
237 metadata.insert("policy_source".to_string(), json!(policy_source));
238 metadata.insert("tool_name".to_string(), json!(call.name));
239 metadata.insert("arguments".to_string(), json!(call.arguments));
240 metadata.insert("message".to_string(), json!(message));
241 }
242 ToolExecutionResult {
243 tool_call_id: call.id.clone(),
244 content: json!({
245 "ok": false,
246 "error": message,
247 "error_code": error_code,
248 "tool_name": call.name,
249 })
250 .to_string(),
251 status: ToolResultStatus::Error,
252 directive: ToolDirective::Continue,
253 error_code: Some(error_code),
254 metadata,
255 image_url: None,
256 image_path: None,
257 }
258}
259
260#[cfg(test)]
261mod tests {
262 use serde_json::{json, Value};
263
264 use super::*;
265 use crate::tools::{FunctionTool, ToolOutput};
266
267 #[tokio::test]
268 async fn metadata_aware_approval_callback_receives_effective_requirement() {
269 let tool = FunctionTool::builder("guarded")
270 .metadata("risk_level", json!("high"))
271 .needs_approval_if(|_context, _arguments| true)
272 .handler(|_context, _arguments: Value| async { Ok(ToolOutput::text("ran")) })
273 .build()
274 .expect("guarded tool");
275 let orchestrator = ToolOrchestrator::from_tools(vec![tool.to_executor()]);
276 let mut context = ToolContext::new("./workspace");
277
278 let result = orchestrator
279 .run_one_with_approval_and_metadata(
280 ToolCall::from_raw_arguments("guarded_call", "guarded", json!({})),
281 &mut context,
282 ToolRunOptions::default(),
283 |_call, requirement, _context, metadata| {
284 assert_eq!(requirement, ApprovalRequirement::Required);
285 assert_eq!(metadata["risk_level"], json!("high"));
286 None
287 },
288 )
289 .await
290 .expect("tool result");
291
292 assert_eq!(result.status, ToolResultStatus::Success);
293 }
294}