executing-sequential-phase

A workflow for running dependent implementation tasks one at a time in the same worktree, a separate working copy of a Git repository.

In plain words
What is it for?
Use it for sequential phases of a plan where tasks must run in order and changes accumulate on stacked Git branches.
Why use it?
It lets each task build on the previous task without extra workspace creation or manual branch rearrangement.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/arittr/spectacular/executing-sequential-phase
Any agent
npx skills add arittr/spectacular --skill executing-sequential-phase
Clone the repo
git clone --depth 1 https://github.com/arittr/spectacular

Made for: Claude Code, Codex.

Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,703 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00049 $0.06703
Opus 5 $0.00024 $0.03351
Sonnet 5 $0.00010 $0.01341
Haiku 4.5 $0.00005 $0.00670

Measured 2d ago against content hash ed98a12b7ede, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

executing-sequential-phase scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/executing-sequential-phase/SKILL.md · 814 lines

How it starts

The opening of the file, as written. The whole thing — 814 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Executing Sequential Phase

Overview

Sequential phases use natural git-spice stacking in the main worktree.

Each task creates a branch with gs branch create, which automatically stacks on the current HEAD. No manual stacking operations needed.

Critical distinction: Sequential tasks BUILD ON each other. They need integration, not isolation.

When to Use

Use this skill when execute command encounters a phase marked "Sequential" in plan.md:

  • ✅ Tasks must run in order (dependencies)
  • ✅ Execute in existing {runid}-main worktree
  • ✅ Trust natural stacking (no manual gs upstack onto)
  • ✅ Stay on task branches (don't switch to base between tasks)

Sequential phases never use worktrees. They share one workspace where tasks build cumulatively.

Multi-Repo Support

Receiving Multi-Repo Context

The orchestrator passes:

  • WORKSPACE_MODE: "multi-repo" or "single-repo"
  • WORKSPACE_ROOT: Absolute path to workspace
  • Per-task TASK_REPO from plan

Sequential Execution Across Repos

In multi-repo mode, sequential tasks may span repos:

Phase 1 (sequential):
- Task 1.1: repo=shared-lib  # Shared types first
- Task 1.2: repo=backend     # Backend uses shared types
- Task 1.3: repo=frontend    # Frontend uses shared types

For each task, switch to that task's repo context.

Per-Repo Worktrees

In multi-repo sequential phases:

  • Each repo has its own main worktree: {repo}/.worktrees/{runId}-main/
  • Tasks execute in their repo's worktree
  • Switching tasks = switching repos (if different)

Per-Repo Setup Commands

Read setup commands from each task's repo:

# Multi-repo: Read from task's repo CLAUDE.md
INSTALL_CMD=$(grep -A1 "**install**:" ${TASK_REPO}/CLAUDE.md | tail -1)

Per-Repo Constitution

Pass correct constitution to subagents:

# Multi-repo
CONSTITUTION="@${TASK_REPO}/docs/constitutions/current/"

Per-Repo Stacking

Sequential tasks across repos create per-repo stacks:

Execution order:
1. Task 1.1 (shared-lib) → creates branch in shared-lib
2. Task 1.2 (backend) → creates branch in backend
3. Task 1.3 (backend) → stacks on 1.2 in backend
4. Task 1.4 (frontend) → creates branch in frontend

Result:
- shared-lib stack: task-1-1
- backend stack: task-1-2 → task-1-3
- frontend stack: task-1-4

Read the full file on GitHub · 814 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 814 lines · 49 tokens per session scan A ed98a12b7ede

Subscribe to this mod's changes

executing-sequential-phase is a skill published in the GitHub repository arittr/spectacular (20 stars, last pushed 7mo ago), licensed MIT. It adds 49 tokens to every session and 6,703 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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