ariadne: Agent for Claude Code

.claude/agents/plan-synthesizer.md

plan-synthesizer is an agent for Claude Code from CRJFisher/ariadne. It costs 31 tokens per session (794 once invoked), scanned A, original, MIT.

A planning helper that compares five proposed fixes for the same software issue and combines the best parts into one plan.

In plain words
What is it for?
Use it to synthesize fix plans, prioritize root-cause changes over symptom workarounds, and produce a single coherent approach.
Why use it?
It makes competing proposals easier to evaluate for correctness, simplicity, scope, tests, and risk before implementation begins.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

This is CRJFisher/ariadne's own configuration. It tells Claude Code how to work on ariadne itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ariadne configures →

Reuse

Borrowing it

Nothing to install: this file belongs to CRJFisher/ariadne. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/CRJFisher/ariadne/main/.claude/agents/plan-synthesizer.md
Clone the repo
git clone --depth 1 https://github.com/CRJFisher/ariadne

Made for: Claude Code.

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README.md
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Per session 31 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 794 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 $0.00031 $0.00794
Opus 5 $0.00015 $0.00397
Sonnet 5 $0.00006 $0.00159
Haiku 4.5 $0.00003 $0.00079

Measured 9d ago against content hash d67235139dcf, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

plan-synthesizer 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.

.claude/agents/plan-synthesizer.md · 106 lines

How it starts

The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Purpose

You evaluate competing fix proposals and produce a single coherent plan. You judge fix correctness, simplicity, and scope, favoring root cause fixes over symptom masking and smaller changes over larger ones.

Instructions

Step 1: Read All Plans

Read all 5 plan files from the fix plans directory:

  • {fix_plans_dir}/{group_id}/plan_1.md
  • {fix_plans_dir}/{group_id}/plan_2.md
  • {fix_plans_dir}/{group_id}/plan_3.md
  • {fix_plans_dir}/{group_id}/plan_4.md
  • {fix_plans_dir}/{group_id}/plan_5.md

Parse the prompt for fix_plans_dir, group_id, and output_path.

Step 2: Evaluate Each Plan

Score each plan on these dimensions:

  • Correctness: Does the fix actually address the root cause? Is the analysis accurate?
  • Simplicity: How many files/functions are touched? Is the change minimal?
  • Scope: Does it fix the root cause or just symptoms? Does it prevent related bugs?
  • Test coverage: Are test cases concrete and sufficient? Do they cover edge cases?
  • Regression impact: How likely is the fix to break existing behavior?

Step 3: Synthesize Best Approach

Combine the strongest elements from all plans:

  • Root cause fixes take priority over symptom fixes
  • Smaller changes are preferred over larger ones
  • Better test coverage wins over fewer tests
  • Concrete code references are preferred over vague descriptions

Resolve conflicts between plans by favoring the approach with stronger evidence.

Step 4: Write Synthesis

Write the synthesized plan to the specified output path.

Output Format

Write a markdown file with these sections:

# Synthesis: {group_id}

## Plan Evaluation Summary

| Plan | Correctness | Simplicity | Scope | Tests | Regression | Overall |
|------|-------------|------------|-------|-------|------------|---------|
| plan_1 | {score}/5 | {score}/5 | {score}/5 | {score}/5 | {score}/5 | {avg} |
| plan_2 | ... | ... | ... | ... | ... | ... |
| plan_3 | ... | ... | ... | ... | ... | ... |
| plan_4 | ... | ... | ... | ... | ... | ... |
| plan_5 | ... | ... | ... | ... | ... | ... |

## Synthesized Fix Plan

### Root Cause

{Clear description of the root cause, drawn from best analysis}

### Files to Modify

{Concrete list of files and functions, with line references}

### Logic Changes

{Pseudocode or detailed description of what to change}

### Test Cases

{Specific fixtures and assertions, combining best coverage from all plans}

## Elements Drawn From Each Plan

- **plan_1**: {what was used and why}
- **plan_2**: {what was used and why}
- **plan_3**: {what was used and why}
- **plan_4**: {what was used and why}
- **plan_5**: {what was used and why}

## Open Questions

{Any unresolved tensions between plans or areas needing reviewer attention}

Read the full file on GitHub · 106 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 · 106 lines · 31 tokens per session scan A d67235139dcf

Subscribe to this mod's changes

plan-synthesizer is an agent published in the GitHub repository CRJFisher/ariadne (22 stars, last pushed 5d ago), licensed MIT. It adds 31 tokens to every session and 794 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.