simple_agents_workflow/
client.rs

1//! [`WorkflowClient`] — wraps [`SimpleAgentsClient`] and adds workflow `run`, `stream`, `resume`.
2//!
3//! Because `simple-agents-core` cannot depend on `simple-agents-workflow` (that would create a
4//! circular dependency), the workflow methods live here instead of on `SimpleAgentsClient`.
5//!
6//! # Usage
7//!
8//! ```no_run
9//! use simple_agents_workflow::{WorkflowClient, WorkflowRunOptions, DefaultEventPrinter};
10//! use simple_agents_core::SimpleAgentsClient;
11//! use simple_agent_type::prelude::*;
12//! use async_trait::async_trait;
13//! use std::sync::Arc;
14//!
15//! struct MyProvider;
16//!
17//! #[async_trait]
18//! impl Provider for MyProvider {
19//!     fn name(&self) -> &str { "mock" }
20//!     fn transform_request(&self, _req: &CompletionRequest) -> Result<ProviderRequest> {
21//!         Ok(ProviderRequest::new("http://example.com"))
22//!     }
23//!     async fn execute(&self, _req: ProviderRequest) -> Result<ProviderResponse> {
24//!         Ok(ProviderResponse::new(200, serde_json::json!({})))
25//!     }
26//!     fn transform_response(&self, _resp: ProviderResponse) -> Result<CompletionResponse> {
27//!         unimplemented!()
28//!     }
29//! }
30//!
31//! # async fn example() -> std::result::Result<(), Box<dyn std::error::Error>> {
32//! let client = WorkflowClient::from_client(
33//!     SimpleAgentsClient::new(Arc::new(MyProvider)),
34//! );
35//!
36//! let messages = vec![Message::user("Hello")];
37//!
38//! // Run a workflow
39//! let output = client.run("workflow.yaml", messages.clone(), WorkflowRunOptions::default()).await?;
40//!
41//! // Stream a workflow
42//! let output = client.stream("workflow.yaml", messages, &DefaultEventPrinter, WorkflowRunOptions::default()).await?;
43//! # Ok(())
44//! # }
45//! ```
46
47use serde_json::Value;
48use simple_agent_type::message::Message;
49use simple_agents_core::{CompletionOptions, CompletionOutcome, SimpleAgentsClient};
50
51use crate::yaml_runner::{
52    workflow_execution, RunMetadata, StepTiming, WorkflowCheckpoint, WorkflowEventSink,
53    WorkflowRunOutput, YamlWorkflowEventSink, YamlWorkflowExecutionFlags,
54    YamlWorkflowExecutionRequest, YamlWorkflowExecutorBinding, YamlWorkflowRunOptions,
55    YamlWorkflowSource,
56};
57
58use simple_agent_type::prelude::SimpleAgentsError;
59
60/// Error type for workflow operations.
61#[derive(Debug)]
62pub enum WorkflowError {
63    /// Workflow-level run error.
64    Workflow(String),
65    /// Core LLM error.
66    Core(SimpleAgentsError),
67}
68
69impl std::fmt::Display for WorkflowError {
70    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
71        match self {
72            WorkflowError::Workflow(msg) => write!(f, "workflow error: {msg}"),
73            WorkflowError::Core(err) => write!(f, "core error: {err}"),
74        }
75    }
76}
77
78impl std::error::Error for WorkflowError {}
79
80impl From<SimpleAgentsError> for WorkflowError {
81    fn from(e: SimpleAgentsError) -> Self {
82        WorkflowError::Core(e)
83    }
84}
85
86/// Execution options for a workflow run.
87///
88/// Tools are passed via `tool_executor` — an optional callback that handles tool calls
89/// declared in the workflow YAML. This mirrors the OpenAI SDK pattern where tools are
90/// just another optional parameter on the same call.
91#[derive(Clone, Default)]
92pub struct RunOptions {
93    /// Override the `YamlWorkflowRunOptions` (telemetry, trace, model override).
94    pub workflow_options: YamlWorkflowRunOptions,
95    /// Override execution flags (streaming, healing, etc.).
96    pub execution_flags: YamlWorkflowExecutionFlags,
97}
98
99/// A client that wraps [`SimpleAgentsClient`] and exposes workflow operations.
100///
101/// The workflow methods (`run`, `stream`, `resume`) live here rather than on
102/// `SimpleAgentsClient` because `simple-agents-core` cannot depend on
103/// `simple-agents-workflow` without creating a circular crate dependency.
104pub struct WorkflowClient {
105    inner: SimpleAgentsClient,
106}
107
108impl WorkflowClient {
109    /// Create a `WorkflowClient` from an already-built `SimpleAgentsClient`.
110    pub fn from_client(client: SimpleAgentsClient) -> Self {
111        Self { inner: client }
112    }
113
114    /// Expose the underlying `SimpleAgentsClient` for direct LLM calls.
115    pub fn client(&self) -> &SimpleAgentsClient {
116        &self.inner
117    }
118
119    /// Run a YAML workflow file and return the full output.
120    ///
121    /// Tools are configured in the workflow YAML itself; runtime tool executors
122    /// (Python `custom_worker` / Node handler callbacks) are currently wired
123    /// through the binding layer.
124    pub async fn run(
125        &self,
126        workflow_path: &str,
127        messages: Vec<Message>,
128        options: RunOptions,
129    ) -> Result<WorkflowRunOutput, WorkflowError> {
130        let input = messages_to_value(messages);
131        let request = YamlWorkflowExecutionRequest {
132            source: YamlWorkflowSource::File(std::path::Path::new(workflow_path)),
133            workflow_input: &input,
134            executor: YamlWorkflowExecutorBinding::Client(&self.inner),
135            custom_worker: None,
136            options: &options.workflow_options,
137            flags: options.execution_flags,
138        };
139
140        let output = workflow_execution::run(request)
141            .await
142            .map_err(|e| WorkflowError::Workflow(e.to_string()))?;
143
144        // Map YamlWorkflowRunOutput to the clean WorkflowRunOutput
145        Ok(yaml_output_to_workflow_output(output))
146    }
147
148    /// Stream a YAML workflow file, emitting events to `sink`.
149    ///
150    /// Pass `&DefaultEventPrinter` to get tokens printed to stdout by default.
151    pub async fn stream(
152        &self,
153        workflow_path: &str,
154        messages: Vec<Message>,
155        sink: &dyn WorkflowEventSink,
156        options: RunOptions,
157    ) -> Result<WorkflowRunOutput, WorkflowError> {
158        let input = messages_to_value(messages);
159        let mut flags = options.execution_flags;
160        flags.workflow_streaming = true;
161
162        let request = YamlWorkflowExecutionRequest {
163            source: YamlWorkflowSource::File(std::path::Path::new(workflow_path)),
164            workflow_input: &input,
165            executor: YamlWorkflowExecutorBinding::Client(&self.inner),
166            custom_worker: None,
167            options: &options.workflow_options,
168            flags,
169        };
170
171        // Bridge the typed WorkflowEventSink to YamlWorkflowEventSink
172        let bridge = EventSinkBridge { inner: sink };
173        let output = workflow_execution::stream(request, &bridge)
174            .await
175            .map_err(|e| WorkflowError::Workflow(e.to_string()))?;
176
177        Ok(yaml_output_to_workflow_output(output))
178    }
179
180    /// Resume a workflow from a saved checkpoint.
181    pub async fn resume(
182        &self,
183        checkpoint: WorkflowCheckpoint,
184        options: RunOptions,
185    ) -> Result<WorkflowRunOutput, WorkflowError> {
186        // Reconstruct a messages-based input from the checkpoint
187        let messages = checkpoint.original_messages.clone();
188        self.run(&checkpoint.workflow_path, messages, options).await
189    }
190
191    /// Direct LLM completion (delegates to the inner client).
192    pub async fn complete(
193        &self,
194        request: &simple_agent_type::request::CompletionRequest,
195        options: CompletionOptions,
196    ) -> Result<CompletionOutcome, SimpleAgentsError> {
197        self.inner.complete(request, options).await
198    }
199}
200
201// ---------------------------------------------------------------------------
202// Internal helpers
203// ---------------------------------------------------------------------------
204
205/// Convert a list of messages into the `{"messages": [...]}` Value shape the
206/// YAML executor expects as workflow input.
207fn messages_to_value(messages: Vec<Message>) -> Value {
208    let msgs: Vec<Value> = messages
209        .into_iter()
210        .map(|m| serde_json::to_value(&m).unwrap_or(Value::Null))
211        .collect();
212    serde_json::json!({ "messages": msgs })
213}
214
215/// Bridge from the new typed [`WorkflowEventSink`] to the old
216/// [`YamlWorkflowEventSink`] that the executor uses internally.
217struct EventSinkBridge<'a> {
218    inner: &'a dyn WorkflowEventSink,
219}
220
221impl YamlWorkflowEventSink for EventSinkBridge<'_> {
222    fn emit(&self, event: &crate::yaml_runner::YamlWorkflowEvent) {
223        // Map YamlWorkflowEvent → WorkflowEvent
224        use crate::yaml_runner::{TokenKind, WorkflowEvent};
225        let mapped = match event.event_type.as_str() {
226            "workflow_started" => Some(WorkflowEvent::WorkflowStarted {
227                workflow_id: event.node_id.clone().unwrap_or_default(),
228            }),
229            "node_started" => Some(WorkflowEvent::NodeStarted {
230                node_id: event.node_id.clone().unwrap_or_default(),
231                node_type: node_type_from_kind(event.node_kind.as_deref()),
232            }),
233            "node_completed" => Some(WorkflowEvent::NodeCompleted {
234                node_id: event.node_id.clone().unwrap_or_default(),
235                output: event
236                    .snapshot
237                    .clone()
238                    .or_else(|| event.message.clone().map(Value::String))
239                    .unwrap_or(Value::Null),
240            }),
241            "node_tool_call_requested" => {
242                tool_name_from_event(event).map(|tool_name| WorkflowEvent::ToolCallRequested {
243                    node_id: event.node_id.clone().unwrap_or_default(),
244                    tool_name,
245                    arguments: event
246                        .metadata
247                        .as_ref()
248                        .and_then(|metadata| metadata.get("arguments"))
249                        .cloned()
250                        .unwrap_or(Value::Null),
251                })
252            }
253            "node_tool_call_completed" => {
254                tool_name_from_event(event).map(|tool_name| WorkflowEvent::ToolCallCompleted {
255                    node_id: event.node_id.clone().unwrap_or_default(),
256                    tool_name,
257                    output: event
258                        .metadata
259                        .as_ref()
260                        .and_then(|metadata| metadata.get("output"))
261                        .cloned()
262                        .unwrap_or(Value::Null),
263                })
264            }
265            "node_tool_call_failed" => Some(WorkflowEvent::NodeFailed {
266                node_id: event.node_id.clone().unwrap_or_default(),
267                error: event
268                    .message
269                    .clone()
270                    .unwrap_or_else(|| "tool call failed without an error message".to_string()),
271            }),
272            "node_stream_delta" | "node_stream_output_delta" => {
273                Some(WorkflowEvent::LlmTokenDelta {
274                    node_id: event.node_id.clone().unwrap_or_default(),
275                    token: event.delta.clone().unwrap_or_default(),
276                    token_kind: TokenKind::Output,
277                })
278            }
279            "node_stream_thinking_delta" => Some(WorkflowEvent::LlmTokenDelta {
280                node_id: event.node_id.clone().unwrap_or_default(),
281                token: event.delta.clone().unwrap_or_default(),
282                token_kind: TokenKind::Reasoning,
283            }),
284            "workflow_completed" => Some(WorkflowEvent::WorkflowCompleted {
285                output: event.snapshot.clone().unwrap_or(Value::Null),
286                metadata: event.metadata.clone(),
287            }),
288            _ => None,
289        };
290        if let Some(ev) = mapped {
291            self.inner.emit(&ev);
292        }
293    }
294}
295
296fn node_type_from_kind(kind: Option<&str>) -> crate::yaml_runner::NodeType {
297    use crate::yaml_runner::NodeType;
298
299    match kind {
300        Some("llm_call") => NodeType::LlmCall,
301        Some("switch") => NodeType::Switch,
302        Some("custom_worker") => NodeType::CustomWorker,
303        Some("end") => NodeType::End,
304        _ => NodeType::Unknown,
305    }
306}
307
308fn tool_name_from_event(event: &crate::yaml_runner::YamlWorkflowEvent) -> Option<String> {
309    event
310        .metadata
311        .as_ref()
312        .and_then(|metadata| metadata.get("tool_name"))
313        .and_then(Value::as_str)
314        .map(str::to_string)
315}
316
317/// Map the internal `YamlWorkflowRunOutput` to the cleaner public `WorkflowRunOutput`.
318fn yaml_output_to_workflow_output(
319    output: crate::yaml_runner::YamlWorkflowRunOutput,
320) -> WorkflowRunOutput {
321    let metadata = Some(RunMetadata {
322        total_elapsed_ms: output.total_elapsed_ms,
323        ttft_ms: output.ttft_ms,
324        total_input_tokens: output.total_input_tokens,
325        total_output_tokens: output.total_output_tokens,
326        total_tokens: output.total_tokens,
327        total_reasoning_tokens: output.total_reasoning_tokens,
328        tokens_per_second: output.tokens_per_second,
329        step_details: output
330            .step_timings
331            .iter()
332            .map(|step| StepTiming {
333                node_id: step.node_id.clone(),
334                node_type: step.node_kind.clone(),
335                model: step.model_name.clone(),
336                elapsed_ms: step.elapsed_ms,
337                input_tokens: step.prompt_tokens.map(u64::from),
338                output_tokens: step.completion_tokens.map(u64::from),
339                total_tokens: step.total_tokens.map(u64::from),
340                reasoning_tokens: step.reasoning_tokens.map(u64::from),
341                ttft_ms: None,
342            })
343            .collect(),
344        trace_id: output.trace_id.clone(),
345    });
346
347    WorkflowRunOutput {
348        workflow_id: output.workflow_id,
349        entry_node: output.entry_node,
350        trace: output.trace,
351        outputs: output.outputs,
352        terminal_node: output.terminal_node,
353        terminal_output: output.terminal_output,
354        metadata,
355        events: None,
356    }
357}
simple_agents_workflow/client.rs

simple_agents_workflow/
client.rs
