feat: Workflow Control Plane support

CHANGELOG.md

@@ -5,6 +5,31 @@ All notable changes to the AxonFlow Python SDK will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.5.0] - 2026-01-17
+
+### Added
+
+- **Workflow Control Plane** (Issue #834): Governance gates for external orchestrators
+  - "LangChain runs the workflow. AxonFlow decides when it's allowed to move forward."
+  - `create_workflow()` - Register workflows from LangChain/LangGraph/CrewAI/external
+  - `step_gate()` - Check if step is allowed to proceed (allow/block/require_approval)
+  - `mark_step_completed()` - Mark a step as completed with optional output data
+  - `get_workflow()` - Get workflow status and step history
+  - `list_workflows()` - List workflows with filters (status, source, pagination)
+  - `complete_workflow()` - Mark workflow as completed
+  - `abort_workflow()` - Abort workflow with reason
+  - `resume_workflow()` - Resume after approval
+  - New types: `WorkflowStatus`, `WorkflowSource`, `GateDecision`, `StepType`, `ApprovalStatus`, `MarkStepCompletedRequest`
+  - Helper methods on `StepGateResponse`: `is_allowed()`, `is_blocked()`, `requires_approval()`
+  - Helper methods on `WorkflowStatus` and `WorkflowStatusResponse`: `is_terminal()`
+  - LangGraph adapter: `axonflow.adapters.langgraph.AxonFlowLangGraphAdapter`
+
+### Fixed
+
+- Datetime parsing now handles variable-length fractional seconds (e.g., 5 digits) for Python 3.9 compatibility
+
+---
+
 ## [1.4.0] - 2026-01-14
 
 ### Added

axonflow/__init__.py

@@ -127,6 +127,24 @@
     UsageRecordsResponse,
     UsageSummary,
 )
+from axonflow.workflow import (
+    AbortWorkflowRequest,
+    ApprovalStatus,
+    CreateWorkflowRequest,
+    CreateWorkflowResponse,
+    GateDecision,
+    ListWorkflowsOptions,
+    ListWorkflowsResponse,
+    MarkStepCompletedRequest,
+    PolicyMatch,
+    StepGateRequest,
+    StepGateResponse,
+    StepType,
+    WorkflowSource,
+    WorkflowStatus,
+    WorkflowStatusResponse,
+    WorkflowStepInfo,
+)
 
 __version__ = "1.2.0"
 __all__ = [
@@ -236,4 +254,21 @@
     "ModelPricing",
     "PricingInfo",
     "PricingListResponse",
+    # Workflow Control Plane types
+    "WorkflowStatus",
+    "WorkflowSource",
+    "GateDecision",
+    "ApprovalStatus",
+    "StepType",
+    "CreateWorkflowRequest",
+    "CreateWorkflowResponse",
+    "StepGateRequest",
+    "StepGateResponse",
+    "WorkflowStepInfo",
+    "WorkflowStatusResponse",
+    "ListWorkflowsOptions",
+    "ListWorkflowsResponse",
+    "MarkStepCompletedRequest",
+    "AbortWorkflowRequest",
+    "PolicyMatch",
 ]

axonflow/adapters/__init__.py

@@ -0,0 +1,8 @@
+"""AxonFlow adapters for external orchestrators."""
+
+from axonflow.adapters.langgraph import AxonFlowLangGraphAdapter, WorkflowBlockedError
+
+__all__ = [
+    "AxonFlowLangGraphAdapter",
+    "WorkflowBlockedError",
+]