fix-diff

fix-diff is a command for coding agents from tinoimammp/vantage-security-agent. It costs 31 tokens per session (659 once invoked), scanned A, original, MIT.

A command that applies a code fix for one security finding from a scan of a commit, pull request, or merge request. A pull or merge request is a proposed change to a shared codebase.

In plain words
What is it for?
Use it when you have both the commit or request scan ID and the finding ID, then review the changed source before committing.
Why use it?
It connects the exact scan and finding to the fix, so a problem from a particular code change is not confused with another finding.

Command

Installs and runs on its own, but its text points at files inside its plugin — anything it tells you to read at a ${CLAUDE_PLUGIN_ROOT} path is only there once the plugin is installed. Installing the plugin gets both.

Part of the vantage plugin — 1 skill, 6 commands shipped together

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 commands/tinoimammp/vantage-security-agent/fix-diff
Clone the repo
git clone --depth 1 https://github.com/tinoimammp/vantage-security-agent

Or install vantage, the plugin that ships this one along with the rest of its 1 skill, 6 commands.

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 fix-diff

README.md
[![agentmods](https://agentmods.dev/badge/commands/tinoimammp/vantage-security-agent/fix-diff.svg)](https://agentmods.dev/commands/tinoimammp/vantage-security-agent/fix-diff)
Your own site
<a href="https://agentmods.dev/commands/tinoimammp/vantage-security-agent/fix-diff"><img src="https://agentmods.dev/badge/commands/tinoimammp/vantage-security-agent/fix-diff.svg" alt="Measured on agentmods" height="20"></a>
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 659 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 $0.00031 $0.00659
Opus 5 $0.00015 $0.00329
Sonnet 5 $0.00006 $0.00132
Haiku 4.5 $0.00003 $0.00066

Measured 3d ago against content hash 5cbf596de743, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fix-diff 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 3d 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.

commands/fix-diff.md · 46 lines

What it actually says

This command modifies source code in the current repository. Unlike every scan command, this is destructive by design — review the result with git diff before committing. This is /vantage:fix-issue's counterpart for findings from /vantage:scan-diff instead of a full pipeline run.

Fix finding $ARGUMENTS (expects two values: a commit-scan id — the commit hash, or pr-<number>/mr-<number> — then a finding id like F-001) against the current project.

  1. If either value is missing, stop and ask for both — do not guess which commit-scan or finding to fix. If the commit-scan id is unknown, list the existing ones by listing ./.vantage/artifacts/commit-scans/*/ directory names.
  2. Read ./.vantage/artifacts/commit-scans/<commit-scan-id>/validated-findings.json. Find the entry with this id.
    • File or entry not found → stop, report that it doesn't exist (check the commit-scan id and finding id, or re-run /vantage:scan-diff <commit-scan-id> first).
    • Found but validated: false → stop, report that only validated findings can be fixed.
    • ./.vantage/artifacts/commit-scans/<commit-scan-id>/fixes/<id>.md already exists → stop, report it's already been addressed — don't re-apply.
  3. Dispatch fix-agent via Task for this one finding (${CLAUDE_PLUGIN_ROOT}/agents/others/fix-agent.md), telling it explicitly to read the finding from artifacts/commit-scans/<commit-scan-id>/validated-findings.json (not the main pipeline's file) and, if present, artifacts/commit-scans/<commit-scan-id>/poc/<id>.md. It re-locates the vulnerable pattern in the current source (it may have moved), and applies the minimal targeted edit implementing the remediation — or marks it not_auto_fixable with a reason if a safe automated edit isn't possible.
  4. Confirm ./.vantage/artifacts/commit-scans/<commit-scan-id>/fixes/<id>.md was written, and append the result to ./.vantage/artifacts/run-log.md.

Report which file(s) changed (or why the fix was skipped), and remind the user that fix-agent never runs a build or test suite — they must review the diff and run their own tests before committing.

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. 3d ago First seen · 46 lines · 31 tokens per session scan A 5cbf596de743

Subscribe to this mod's changes

fix-diff is a command published in the GitHub repository tinoimammp/vantage-security-agent (4 stars, last pushed 1mo ago), licensed MIT. It adds 31 tokens to every session and 659 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 2026-08-31.