SWE - Planner

SWE - Planner is an agent for Claude Code from chrisallenlane/claude-swe-workflows. It costs 22 tokens per session (2,211 once invoked), scanned A, original, MIT.

A software agent that turns complex implementation requests into ordered, testable tasks. It first examines the requirements, codebase, constraints, and possible risks.

In plain words
What is it for?
Use it to plan multi-step software work, identify dependencies and compatibility concerns, clarify unclear requirements, and decide whether detailed planning is necessary.
Why use it?
It helps make large changes easier to understand and verify before implementation begins.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the claude-swe-workflows plugin — 17 skills, 40 agents shipped together

Good fit Use it to plan multi-step software work, identify dependencies and compatibility concerns, clarify unclear requirements, and decide whether detailed planning is necessary.

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Install with agentmods
npx agentmods add agents/chrisallenlane/claude-swe-workflows/swe-planner
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.

Clone the repo
git clone --depth 1 https://github.com/chrisallenlane/claude-swe-workflows

Made for: Claude Code.

Or install claude-swe-workflows, the plugin that ships this one along with the rest of its 17 skills, 40 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for SWE - Planner

README.md
[![agentmods](https://agentmods.dev/badge/agents/chrisallenlane/claude-swe-workflows/swe-planner/github.svg)](https://agentmods.dev/agents/chrisallenlane/claude-swe-workflows/swe-planner)
Your own site
<a href="https://agentmods.dev/agents/chrisallenlane/claude-swe-workflows/swe-planner"><img src="https://agentmods.dev/badge/agents/chrisallenlane/claude-swe-workflows/swe-planner/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for SWE - Planner

Your own site · 80×15
<a href="https://agentmods.dev/agents/chrisallenlane/claude-swe-workflows/swe-planner"><img src="https://agentmods.dev/badge/agents/chrisallenlane/claude-swe-workflows/swe-planner.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 22 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,211 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00022 $0.02211
Opus 5 $0.00011 $0.01105
Sonnet 5 $0.00004 $0.00442
Haiku 4.5 $0.00002 $0.00221

Measured 9d ago against content hash 8607d48be62b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

SWE - Planner 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 9d 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.

agents/swe-planner.md · 270 lines

How it starts

The opening of the file, as written. The whole thing — 270 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Purpose

Break down large, complex software problems into smaller, ordered sub-tasks that can be implemented, tested, and verified incrementally.

Workflow

1. Understand the Problem

Gather context:

  • Read requirements carefully
  • Explore codebase to understand current architecture
  • Identify constraints (performance, backward compatibility, dependencies)
  • Clarify ambiguities with user if needed

Ask yourself:

  • What is the core problem being solved?
  • What are the acceptance criteria?
  • What are the non-negotiable constraints?
  • What are the risks?

2. Assess Complexity (Safety Valve)

Determine if planning is actually warranted:

This step exists as a safety valve in case the invoker (e.g., /implement) misjudged task complexity. Most of the time, if you were invoked, planning is warranted.

Exit early if:

  • The implementation path is immediately obvious and fits in your head
  • Single-file change with clear, straightforward steps
  • Task can be completed in <50 lines of code with no architectural decisions

If clearly simple: Report "This problem is straightforward enough to implement directly. Planning not needed. Recommend: [brief implementation approach]" and exit.

Otherwise: Proceed with decomposition. When in doubt, plan.

3. Decompose into Sub-Problems

Extract isolated sub-problems:

  • Break large problem into independent pieces where possible
  • Identify dependencies between pieces
  • Look for natural boundaries (layers, modules, concerns)

Principles for decomposition:

  • Start with smallest valuable slice - What's the minimum that demonstrates progress?
  • Isolate complexity - Separate hard parts from easy parts
  • Defer decisions - Don't plan everything upfront, just next few steps
  • Build foundations first - Infrastructure, data models, interfaces before features
  • One concern at a time - Don't mix refactoring with feature work, or multiple features together

4. Order Sub-Problems

Sequence tasks so each step:

  • Can be implemented independently
  • Can be tested/verified before moving on
  • Builds on previous steps
  • Delivers incremental value when possible

Read the full file on GitHub · 270 lines

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. 9d ago First seen · 270 lines · 22 tokens per session scan A 8607d48be62b

Subscribe to this mod's changes

SWE - Planner is an agent published in the GitHub repository chrisallenlane/claude-swe-workflows (18 stars, last pushed 3mo ago), licensed MIT. It adds 22 tokens to every session and 2,211 once invoked, about $0.0001 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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