Workflow Run

Load a workflow template → bind variables → execute DAG → persist checkpoints → resume capable.

Architecture

Skill(skill="wf-player", args="<template> --context goal='...'")
  |
  +-- Phase 0: Entry Router
       |-- --list        -> list available templates, exit
       |-- --resume      -> load session, skip to Phase 3 (Execute)
       |-- --dry-run     -> load + show execution plan, no execution
       |-- default       -> Phase 1 (Load)
  |
  +-- Phase 1: Load & Bind
  |    Load template JSON, bind {variables} from --context, validate required vars
  |
  +-- Phase 2: Instantiate
  |    Init session state, topological sort, write WFR session file
  |
  +-- Phase 3: Execute Loop
  |    For each node in order:
  |      skill node   -> Skill(skill=...) [synchronous]
  |      cli node     -> ccw cli [background + stop, hook callback]
  |      command node -> Skill(skill="namespace:cmd") [synchronous]
  |      agent node   -> Agent(...) [run_in_background per node config]
  |      checkpoint   -> save state, optionally pause
  |
  +-- Phase 4: Complete
       Archive session, output summary

Shared Constants

Constant	Value
Session prefix	WFR
Session dir	.workflow/sessions/WFR-<slug>-<date>/
State file	session-state.json
Template dir	.workflow/templates/
Template index	.workflow/templates/index.json

Entry Router

Parse $ARGUMENTS:

Detection	Condition	Handler
List templates	--list in args	-> handleList
Resume session	--resume <session-id> in args	-> Phase 2 (resume)
Dry run	--dry-run in args	-> Phase 1 + 2, print plan, exit
Normal	Template slug/path provided	-> Phase 1
No args	Empty args	-> handleList + AskUserQuestion

handleList

Scan .workflow/templates/index.json. Display:

Available workflow templates:
  feature-tdd-review    [feature, complex]   3 work nodes, 2 checkpoints
  quick-bugfix          [bugfix, simple]     2 work nodes, 1 checkpoint
  ...

Run: Skill(skill="wf-player", args="<slug> --context goal='...'")

---

Phase 0 (Resume): Session Reconciliation

Trigger: --resume <session-id> or active WFR session found in .workflow/sessions/WFR-*/

1. Scan .workflow/sessions/WFR-*/session-state.json for status = "running" | "paused"
2. Multiple found → AskUserQuestion for selection
3. Load session-state.json
4. Identify last_checkpoint and node_states
5. Reset any running nodes back to pending (they were interrupted)
6. Determine next executable node from topological_order after last checkpoint
7. Resume at Phase 3 (Execute Loop) from that node

---

Phase 1: Load & Bind

Read phases/01-load.md and execute.

Objective: Load template, collect missing variables, bind all {variable} references.

Success: Template loaded, all required variables bound, bound_context{} ready.

---

Phase 2: Instantiate

Read phases/02-instantiate.md and execute.

Objective: Create WFR session directory, init state, compute execution plan.

Success: session-state.json written, topological_order ready.

---

Phase 3: Execute Loop

Read phases/03-execute.md and execute.

Objective: Execute each node in topological_order using appropriate mechanism.

CRITICAL — CLI node blocking:

• CLI nodes launch ccw cli in background and immediately STOP
• Wait for hook callback — DO NOT poll with TaskOutput
• Hook callback resumes execution at next node

Success: All nodes completed, all checkpoints saved.

---

Phase 4: Complete

Read phases/04-complete.md and execute.

Objective: Archive session, output execution summary and artifact paths.

---

Error Handling

Scenario	Resolution
Required variable missing	AskUserQuestion to collect it
Template not found	Show --list and suggest closest match
Node failed (on_fail=abort)	AskUserQuestion: Retry / Skip / Abort
Node failed (on_fail=skip)	Log warning, continue to next node
Node failed (on_fail=retry)	Retry once, then abort
Interrupted mid-execution	State saved at last checkpoint; resume with --resume <session-id>
Cycle in DAG	Error immediately, point to template for fix

Specs Reference

Spec	Purpose
specs/node-executor.md	Execution mechanism per node type
specs/state-schema.md	session-state.json schema