feat: scheduled pipelines + dependency cascade fix

CLAUDE.md

@@ -134,7 +134,7 @@ When adding task dependencies:
 
 ### MCP Tools
 
-All tools use PascalCase: `DelegateTask`, `TaskStatus`, `TaskLogs`, `CancelTask`, `ScheduleTask`, `ListSchedules`, `GetSchedule`, `CancelSchedule`, `PauseSchedule`, `ResumeSchedule`
+All tools use PascalCase: `DelegateTask`, `TaskStatus`, `TaskLogs`, `CancelTask`, `ScheduleTask`, `ListSchedules`, `GetSchedule`, `CancelSchedule`, `PauseSchedule`, `ResumeSchedule`, `CreatePipeline`, `SchedulePipeline`
 
 ## File Locations
 
@@ -154,6 +154,7 @@ Quick reference for common operations:
 | Schedule repository | `src/implementations/schedule-repository.ts` |
 | Schedule handler | `src/services/handlers/schedule-handler.ts` |
 | Schedule executor | `src/services/schedule-executor.ts` |
+| Schedule manager | `src/services/schedule-manager.ts` |
 | Cron utilities | `src/utils/cron.ts` |
 
 ## Documentation Structure

README.md

@@ -79,10 +79,12 @@ Once configured, use these tools in Claude Code:
 | **ScheduleTask** | Schedule recurring or one-time tasks | `ScheduleTask({ prompt: "...", scheduleType: "cron", cronExpression: "0 2 * * *" })` |
 | **ListSchedules** | List schedules with optional status filter | `ListSchedules({ status: "active" })` |
 | **GetSchedule** | Get schedule details and execution history | `GetSchedule({ scheduleId })` |
-| **CancelSchedule** | Cancel an active schedule | `CancelSchedule({ scheduleId, reason })` |
+| **CancelSchedule** | Cancel an active schedule (optionally cancel in-flight tasks) | `CancelSchedule({ scheduleId, reason, cancelTasks? })` |
 | **PauseSchedule** | Pause a schedule (resumable) | `PauseSchedule({ scheduleId })` |
 | **ResumeSchedule** | Resume a paused schedule | `ResumeSchedule({ scheduleId })` |
 | **ResumeTask** | Resume a failed/completed task with checkpoint context | `ResumeTask({ taskId, additionalContext? })` |
+| **CreatePipeline** | Create sequential task pipelines | `CreatePipeline({ steps: [...] })` |
+| **SchedulePipeline** | Create recurring/one-time scheduled pipelines | `SchedulePipeline({ steps: [...], cronExpression: "0 9 * * *" })` |
 
 ### CLI Commands
 
@@ -316,7 +318,8 @@ backbeat/
 - [x] v0.3.3 - Test infrastructure and memory management
 - [x] v0.4.0 - Task scheduling and task resumption
 - [x] v0.5.0 - Multi-agent support (Claude, Codex, Gemini)
-- [ ] v0.6.0 - Scheduled pipelines and loops
+- [x] v0.6.0 - Scheduled pipelines
+- [ ] v0.6.1 - Task/pipeline loops
 
 See **[ROADMAP.md](./docs/ROADMAP.md)** for detailed plans and timelines.
 

docs/FEATURES.md

@@ -202,6 +202,7 @@ Last Updated: March 2026
 - **PauseSchedule**: Pause an active schedule (can be resumed later)
 - **ResumeSchedule**: Resume a paused schedule
 - **CreatePipeline** (v0.4.1): Create sequential task pipelines with 2–20 steps, per-step delays, priority, and working directory overrides
+- **SchedulePipeline** (v0.6.0): Create recurring or one-time scheduled pipelines with 2–20 steps, each trigger creates a fresh pipeline instance with linear task dependencies
 
 ### Schedule Types
 - **CRON**: Standard 5-field cron expressions for recurring task execution
@@ -263,6 +264,29 @@ Last Updated: March 2026
 - **`agent` field on DelegateTask**: Specify agent per task (e.g., `{ agent: "codex" }`)
 - **Fallback**: Uses default agent when no agent specified
 
+## ✅ Scheduled Pipelines (v0.6.0)
+
+### Recurring & One-Time Pipelines
+- **SchedulePipeline MCP Tool**: Create a single schedule that triggers a full pipeline (2–20 steps) on each execution
+- **Cron + One-Time**: Supports both recurring cron expressions and single future execution
+- **Linear Dependencies**: Each trigger creates fresh tasks wired with linear dependencies (step N depends on step N-1)
+- **Per-Step Configuration**: Each step can have its own prompt, priority, working directory, and agent override (MCP only)
+- **Shared Defaults**: Schedule-level agent, priority, and working directory apply to all steps unless overridden
+
+### Pipeline Lifecycle
+- **Dependency Failure Cascade**: When a pipeline step fails, all downstream steps are automatically cancelled
+- **Cancel with Tasks**: `CancelSchedule` with `cancelTasks: true` cancels in-flight pipeline tasks from current execution
+- **Concurrency Tracking**: Pipeline completion tracked via tail task — prevents overlapping pipeline executions
+- **`afterScheduleId` Support**: Chain pipelines after other schedules (predecessor dependency injected on step 0)
+
+### CLI Support
+- `beat schedule create --pipeline --step "lint" --step "test" --cron "0 9 * * *"`: Create scheduled pipeline
+- `beat schedule cancel <id> --cancel-tasks`: Cancel schedule and in-flight tasks
+
+### Bug Fixes (v0.6.0)
+- **Dependency Failure Cascade**: Failed/cancelled upstream tasks now cascade cancellation to dependents (was incorrectly unblocking them)
+- **Queue Handler Race Condition**: Fast-path check prevents blocked tasks from being prematurely enqueued
+
 ## ❌ NOT Implemented (Despite Some Documentation Claims)
 - **Distributed Processing**: Single-server only
 - **Web UI**: No dashboard interface
@@ -274,6 +298,26 @@ Last Updated: March 2026
 
 ---
 
+## 🆕 What's New in v0.6.0
+
+### Scheduled Pipelines
+- **`SchedulePipeline` MCP Tool**: Create cron or one-time schedules that trigger a full pipeline (2–20 steps) on each execution
+- **Linear Task Dependencies**: Each trigger creates fresh tasks with `task[i].dependsOn = [task[i-1].id]`
+- **Per-Step Agent Override**: MCP tool supports per-step `agent` field; CLI uses shared `--agent`
+- **`cancelTasks` on CancelSchedule**: Optional flag to also cancel in-flight pipeline tasks from current execution
+- **ListSchedules Enhancement**: Response includes `isPipeline` and `stepCount` indicators
+- **GetSchedule Enhancement**: Response includes full `pipelineSteps` when present
+- **CLI**: `--pipeline --step "..." --step "..."` flags for creating scheduled pipelines
+
+### Bug Fixes
+- **Dependency Failure Cascade**: When upstream task fails or is cancelled, dependent tasks are now cancelled instead of incorrectly unblocked (**breaking change**)
+- **Queue Handler Race Condition**: Fast-path `dependencyState` check prevents blocked tasks from being enqueued before dependency rows are written to DB
+
+### Database
+- **Migration 8**: `pipeline_steps` column on `schedules` table, `pipeline_task_ids` column on `schedule_executions` table
+
+---
+
 ## 🆕 What's New in v0.5.0
 
 ### Multi-Agent Support

docs/ROADMAP.md

@@ -42,7 +42,7 @@ Items originally planned for v0.3.1 that were completed across v0.3.1–v0.4.0:
 | Remove Cycle Detection from Repository Layer | Open | — |
 | Consolidate Graph Caching | Open | — |
 | JSDoc Coverage for dependency APIs | Open | — |
-| Failed/Cancelled Dependency Propagation Semantics | Open | Needs design decision |
+| Failed/Cancelled Dependency Propagation Semantics | ✅ Done | v0.6.0 (cascade cancellation) |
 
 Open items are low priority — they'll be addressed opportunistically or when performance demands it.
 
@@ -57,26 +57,19 @@ Agent registry with pluggable adapters (Claude, Codex, Gemini), per-task agent s
 
 ---
 
-### v0.6.0 - Scheduled Pipelines & Loops
-**Goal**: Time-triggered pipelines and condition-driven iteration
-**Priority**: High — completes the orchestration story
-**Issues**: [#78](https://github.com/dean0x/backbeat/issues/78), [#79](https://github.com/dean0x/backbeat/issues/79)
+### v0.6.0 - Scheduled Pipelines ✅
+**Status**: **RELEASED** (2026-03-18)
 
-#### Feature 1: Scheduled Pipelines (#78)
-Run a multi-step DAG on a cron or one-time schedule. Today `beat schedule create` only supports single tasks and `CreatePipeline` only runs immediately — this connects the two.
+Scheduled pipelines (`SchedulePipeline` MCP tool, `--pipeline --step` CLI), dependency failure cascade fix, queue handler race condition fix, `cancelTasks` on `CancelSchedule`. See [FEATURES.md](./FEATURES.md) for details.
 
-```bash
-beat schedule create --cron "0 9 * * *" --pipeline \
-  --step "lint the codebase" \
-  --step "run test suite" \
-  --step "deploy to staging"
-```
+---
 
-- Each trigger creates a fresh pipeline instance (new task IDs)
-- Steps inherit the schedule's agent unless overridden
-- Execution history tracks which schedule triggered which pipeline
+### v0.6.1 - Task/Pipeline Loops
+**Goal**: Condition-driven iteration
+**Priority**: High — completes the orchestration story
+**Issue**: [#79](https://github.com/dean0x/backbeat/issues/79)
 
-#### Feature 2: Task/Pipeline Loops (#79)
+#### Task/Pipeline Loops (#79)
 Repeat a task or pipeline until an exit condition is met — the [Ralph Wiggum Loop](https://ghuntley.com/loop/) pattern.
 
 ```bash
@@ -94,6 +87,7 @@ beat loop "implement next item from spec.md" \
 - v0.4.0 schedules (cron/one-time), checkpoints, `continueFrom`
 - v0.4.1 pipelines (`CreatePipeline`)
 - v0.5.0 multi-agent per-task selection
+- v0.6.0 scheduled pipelines
 
 ---
 
@@ -224,7 +218,8 @@ beat recipe create my-workflow  # interactive recipe builder
 | v0.3.1–3 | ✅ Released | Dependency optimizations + security |
 | v0.4.0 | ✅ Released | Scheduling, Resumption, Rename to Backbeat |
 | v0.5.0 | ✅ Released | Multi-Agent Support |
-| v0.6.0 | 🎯 Next | Scheduled Pipelines + Loops |
+| v0.6.0 | ✅ Released | Scheduled Pipelines |
+| v0.6.1 | 🎯 Next | Task/Pipeline Loops |
 | v0.7.0 | 📋 Planned | Agent Failover + Smart Routing |
 | v0.8.0 | 📋 Planned | Workflow Recipes & Templates |
 | v0.9.0 | 💭 Research | Monitoring + REST API + Dashboard |