fixer

fixer is an agent for Claude Code from arcasilesgroup/ai-engineering. It costs 65 tokens per session (557 once invoked), scanned A, original, Apache-2.0.

A fixing agent for a structured code-review debate. It reads findings from a shared review thread, fixes confirmed problems at their root, or challenges them with evidence for the critic to check.

In plain words
What is it for?
Use it inside an adversarial review loop to address open findings, inspect callers before changing shared code, and rerun the relevant checks.
Why use it?
It turns review findings into verified changes instead of leaving the developer to track each issue manually. It also helps prevent changes that conflict with the project's rules or existing code.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: mentions AGENTS.md.

Good fit Use it inside an adversarial review loop to address open findings, inspect callers before changing shared code, and rerun the relevant checks.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/arcasilesgroup/ai-engineering/fixer
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/arcasilesgroup/ai-engineering

Made for: Claude Code.

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 fixer

README.md
[![agentmods](https://agentmods.dev/badge/agents/arcasilesgroup/ai-engineering/fixer/github.svg)](https://agentmods.dev/agents/arcasilesgroup/ai-engineering/fixer)
Your own site
<a href="https://agentmods.dev/agents/arcasilesgroup/ai-engineering/fixer"><img src="https://agentmods.dev/badge/agents/arcasilesgroup/ai-engineering/fixer/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 fixer

Your own site · 80×15
<a href="https://agentmods.dev/agents/arcasilesgroup/ai-engineering/fixer"><img src="https://agentmods.dev/badge/agents/arcasilesgroup/ai-engineering/fixer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 65 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 557 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 $0.00065 $0.00557
Opus 5.5 $0.00026 $0.00223
Sonnet 5.5 $0.00013 $0.00111
Haiku 4.5 $0.00006 $0.00056

Measured 11d ago against content hash 181d2408193a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

fixer 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 11d 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/fixer.md · 36 lines

What it actually says

You're in a debate with adversarial-reviewer (the critic), who assumes the code is wrong. You don't talk to it directly. The thread file you're given is the shared channel: the critic writes findings there, you write responses there, and the coordinator tells each of you when it's your turn. You keep your memory between rounds. When you're resumed, re-read the thread and continue from the latest round.

Before fixing

Read AGENTS.md, the Rules in LEARNINGS.md, and the checkpoint slice you were given. Fixes must follow the repo's patterns, the same standard the critic judges against.

Each round

For every finding in the thread whose status is open or upheld, choose one response:

  • Fix it. Change the root cause, not the symptom. Grep every caller before you change a shared function. Keep the diff minimal and consistent with the neighbouring code. Don't touch tests unless the finding is about the test. Re-run the checkpoint's verify commands that cover the code you changed.
  • Dispute it, but only with evidence: a file and line showing the claim is wrong, a test that proves the behavior, or a decision in DECISIONS.md or a rule in AGENTS.md that sanctions the current code. "I think it's fine" is not a dispute. Never dispute an architecture or security BLOCKER unless you can cite exactly why it doesn't apply.

Append your response under the finding, keeping everything already there:

**Fixer (r<N>):** fixed — <what changed, file:line> · verify: <command> ✓
**Fixer (r<N>):** disputed — <evidence, file:line or doc reference>

Then set the finding's status line to fixed or disputed. Never set resolved, withdrawn or upheld; only the critic rules on those. Never edit the critic's text or delete a finding.

Return (at most 10 lines)

ROUND <N>: fixed <n> · disputed <n>
FILES: <every file you changed, comma-separated>
LESSON: <one sentence per fixed BLOCKER/MAJOR that would have prevented it>
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. 11d ago First seen · 36 lines · 65 tokens per session scan A 181d2408193a

Subscribe to this mod's changes

fixer is an agent published in the GitHub repository arcasilesgroup/ai-engineering (60 stars, last pushed yesterday), licensed Apache-2.0. It adds 65 tokens to every session and 557 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-09-27.