simple_agents_workflow/
client.rs

1//! [`WorkflowClient`] — wraps [`SimpleAgentsClient`] and adds workflow `run` and `stream`.
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, WorkflowEventSink, WorkflowRunOutput,
53    YamlWorkflowEventSink, YamlWorkflowExecutionFlags, YamlWorkflowExecutionRequest,
54    YamlWorkflowExecutorBinding, YamlWorkflowRunOptions, YamlWorkflowSource,
55};
56
57use simple_agent_type::prelude::SimpleAgentsError;
58
59/// Error type for workflow operations.
60#[derive(Debug)]
61pub enum WorkflowError {
62    /// Workflow-level run error.
63    Workflow(String),
64    /// Core LLM error.
65    Core(SimpleAgentsError),
66}
67
68impl std::fmt::Display for WorkflowError {
69    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
70        match self {
71            WorkflowError::Workflow(msg) => write!(f, "workflow error: {msg}"),
72            WorkflowError::Core(err) => write!(f, "core error: {err}"),
73        }
74    }
75}
76
77impl std::error::Error for WorkflowError {}
78
79impl From<SimpleAgentsError> for WorkflowError {
80    fn from(e: SimpleAgentsError) -> Self {
81        WorkflowError::Core(e)
82    }
83}
84
85/// Execution options for a workflow run.
86///
87/// Tools are passed via `tool_executor` — an optional callback that handles tool calls
88/// declared in the workflow YAML. This mirrors the OpenAI SDK pattern where tools are
89/// just another optional parameter on the same call.
90#[derive(Clone, Default)]
91pub struct RunOptions {
92    /// Override the `YamlWorkflowRunOptions` (telemetry, trace, model override).
93    pub workflow_options: YamlWorkflowRunOptions,
94    /// Override execution flags (streaming, healing, etc.).
95    pub execution_flags: YamlWorkflowExecutionFlags,
96}
97
98/// A client that wraps [`SimpleAgentsClient`] and exposes workflow operations.
99///
100/// The workflow methods (`run`, `stream`) live here rather than on
101/// `SimpleAgentsClient` because `simple-agents-core` cannot depend on
102/// `simple-agents-workflow` without creating a circular crate dependency.
103pub struct WorkflowClient {
104    inner: SimpleAgentsClient,
105}
106
107impl WorkflowClient {
108    /// Create a `WorkflowClient` from an already-built `SimpleAgentsClient`.
109    pub fn from_client(client: SimpleAgentsClient) -> Self {
110        Self { inner: client }
111    }
112
113    /// Expose the underlying `SimpleAgentsClient` for direct LLM calls.
114    pub fn client(&self) -> &SimpleAgentsClient {
115        &self.inner
116    }
117
118    /// Run a YAML workflow file and return the full output.
119    ///
120    /// Tools are configured in the workflow YAML itself; runtime tool executors
121    /// (Python `custom_worker` / Node handler callbacks) are currently wired
122    /// through the binding layer.
123    pub async fn run(
124        &self,
125        workflow_path: &str,
126        messages: Vec<Message>,
127        options: RunOptions,
128    ) -> Result<WorkflowRunOutput, WorkflowError> {
129        let input = messages_to_value(messages);
130        let request = YamlWorkflowExecutionRequest {
131            source: YamlWorkflowSource::File(std::path::Path::new(workflow_path)),
132            workflow_input: &input,
133            executor: YamlWorkflowExecutorBinding::Client(&self.inner),
134            custom_worker: None,
135            resume: None,
136            human_response: None,
137            options: &options.workflow_options,
138            flags: options.execution_flags,
139        };
140
141        let output = workflow_execution::run(request)
142            .await
143            .map_err(|e| WorkflowError::Workflow(e.to_string()))?;
144
145        // Map YamlWorkflowRunOutput to the clean WorkflowRunOutput
146        Ok(yaml_output_to_workflow_output(output))
147    }
148
149    /// Stream a YAML workflow file, emitting events to `sink`.
150    ///
151    /// Pass `&DefaultEventPrinter` to get tokens printed to stdout by default.
152    pub async fn stream(
153        &self,
154        workflow_path: &str,
155        messages: Vec<Message>,
156        sink: &dyn WorkflowEventSink,
157        options: RunOptions,
158    ) -> Result<WorkflowRunOutput, WorkflowError> {
159        let input = messages_to_value(messages);
160        let mut flags = options.execution_flags;
161        flags.workflow_streaming = true;
162
163        let request = YamlWorkflowExecutionRequest {
164            source: YamlWorkflowSource::File(std::path::Path::new(workflow_path)),
165            workflow_input: &input,
166            executor: YamlWorkflowExecutorBinding::Client(&self.inner),
167            custom_worker: None,
168            resume: None,
169            human_response: None,
170            options: &options.workflow_options,
171            flags,
172        };
173
174        // Bridge the typed WorkflowEventSink to YamlWorkflowEventSink
175        let bridge = EventSinkBridge { inner: sink };
176        let output = workflow_execution::stream(request, &bridge)
177            .await
178            .map_err(|e| WorkflowError::Workflow(e.to_string()))?;
179
180        Ok(yaml_output_to_workflow_output(output))
181    }
182
183    /// Direct LLM completion (delegates to the inner client).
184    pub async fn complete(
185        &self,
186        request: &simple_agent_type::request::CompletionRequest,
187        options: CompletionOptions,
188    ) -> Result<CompletionOutcome, SimpleAgentsError> {
189        self.inner.complete(request, options).await
190    }
191}
192
193// ---------------------------------------------------------------------------
194// Internal helpers
195// ---------------------------------------------------------------------------
196
197/// Convert a list of messages into the `{"messages": [...]}` Value shape the
198/// YAML executor expects as workflow input.
199fn messages_to_value(messages: Vec<Message>) -> Value {
200    let msgs: Vec<Value> = messages
201        .into_iter()
202        .map(|m| serde_json::to_value(&m).unwrap_or(Value::Null))
203        .collect();
204    serde_json::json!({ "messages": msgs })
205}
206
207/// Bridge from the new typed [`WorkflowEventSink`] to the old
208/// [`YamlWorkflowEventSink`] that the executor uses internally.
209struct EventSinkBridge<'a> {
210    inner: &'a dyn WorkflowEventSink,
211}
212
213impl YamlWorkflowEventSink for EventSinkBridge<'_> {
214    fn emit(&self, event: &crate::yaml_runner::YamlWorkflowEvent) {
215        // Map YamlWorkflowEvent → WorkflowEvent
216        use crate::yaml_runner::{TokenKind, WorkflowEvent};
217        let mapped = match event.event_type.as_str() {
218            "workflow_started" => Some(WorkflowEvent::WorkflowStarted {
219                workflow_id: event.node_id.clone().unwrap_or_default(),
220            }),
221            "node_started" => Some(WorkflowEvent::NodeStarted {
222                node_id: event.node_id.clone().unwrap_or_default(),
223                node_type: node_type_from_kind(event.node_kind.as_deref()),
224            }),
225            "node_completed" => Some(WorkflowEvent::NodeCompleted {
226                node_id: event.node_id.clone().unwrap_or_default(),
227                output: event
228                    .snapshot
229                    .clone()
230                    .or_else(|| event.message.clone().map(Value::String))
231                    .unwrap_or(Value::Null),
232            }),
233            "node_tool_call_requested" => {
234                tool_name_from_event(event).map(|tool_name| WorkflowEvent::ToolCallRequested {
235                    node_id: event.node_id.clone().unwrap_or_default(),
236                    tool_name,
237                    arguments: event
238                        .metadata
239                        .as_ref()
240                        .and_then(|metadata| metadata.get("arguments"))
241                        .cloned()
242                        .unwrap_or(Value::Null),
243                })
244            }
245            "node_tool_call_completed" => {
246                tool_name_from_event(event).map(|tool_name| WorkflowEvent::ToolCallCompleted {
247                    node_id: event.node_id.clone().unwrap_or_default(),
248                    tool_name,
249                    output: event
250                        .metadata
251                        .as_ref()
252                        .and_then(|metadata| metadata.get("output"))
253                        .cloned()
254                        .unwrap_or(Value::Null),
255                })
256            }
257            "human_input_requested" => Some(WorkflowEvent::HumanInputRequested {
258                node_id: event.node_id.clone().unwrap_or_default(),
259                request: event.metadata.clone().unwrap_or(Value::Null),
260            }),
261            "human_input_received" => Some(WorkflowEvent::HumanInputReceived {
262                node_id: event.node_id.clone().unwrap_or_default(),
263                response: event.metadata.clone().unwrap_or(Value::Null),
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("human_input") => NodeType::HumanInput,
304        Some("end") => NodeType::End,
305        _ => NodeType::Unknown,
306    }
307}
308
309fn tool_name_from_event(event: &crate::yaml_runner::YamlWorkflowEvent) -> Option<String> {
310    event
311        .metadata
312        .as_ref()
313        .and_then(|metadata| metadata.get("tool_name"))
314        .and_then(Value::as_str)
315        .map(str::to_string)
316}
317
318/// Map the internal `YamlWorkflowRunOutput` to the cleaner public `WorkflowRunOutput`.
319fn yaml_output_to_workflow_output(
320    output: crate::yaml_runner::YamlWorkflowRunOutput,
321) -> WorkflowRunOutput {
322    let metadata = Some(RunMetadata {
323        total_elapsed_ms: output.total_elapsed_ms,
324        ttft_ms: output.ttft_ms,
325        total_input_tokens: output.total_input_tokens,
326        total_output_tokens: output.total_output_tokens,
327        total_tokens: output.total_tokens,
328        total_reasoning_tokens: output.total_reasoning_tokens,
329        tokens_per_second: output.tokens_per_second,
330        step_details: output
331            .step_timings
332            .iter()
333            .map(|step| StepTiming {
334                node_id: step.node_id.clone(),
335                node_type: step.node_kind.clone(),
336                model: step.model_name.clone(),
337                elapsed_ms: step.elapsed_ms,
338                input_tokens: step.prompt_tokens.map(u64::from),
339                output_tokens: step.completion_tokens.map(u64::from),
340                total_tokens: step.total_tokens.map(u64::from),
341                reasoning_tokens: step.reasoning_tokens.map(u64::from),
342                ttft_ms: None,
343            })
344            .collect(),
345        trace_id: output.trace_id.clone(),
346    });
347
348    WorkflowRunOutput {
349        workflow_id: output.workflow_id,
350        entry_node: output.entry_node,
351        trace: output.trace,
352        outputs: output.outputs,
353        globals: output.globals,
354        terminal_node: output.terminal_node,
355        terminal_output: output.terminal_output,
356        status: match output.status {
357            crate::yaml_runner::YamlWorkflowRunStatus::Completed => "completed".to_string(),
358            crate::yaml_runner::YamlWorkflowRunStatus::AwaitingHumanInput => {
359                "awaiting_human_input".to_string()
360            }
361        },
362        human_request: output
363            .human_request
364            .as_ref()
365            .and_then(|request| serde_json::to_value(request).ok()),
366        metadata,
367        events: None,
368    }
369}
simple_agents_workflow/client.rs

simple_agents_workflow/
client.rs
