GitHub Actions Expert

A specialist mode for designing and reviewing GitHub Actions workflows, which are automated jobs that run in GitHub repositories. It focuses on workflow security, limited permissions, fixed action versions, scanning, and efficient execution.

In plain words
What is it for?
Use it to plan or improve continuous integration, deployment, security scanning, and release workflows in GitHub Actions.
Why use it?
It helps reduce risks from unsafe automation, overly broad access, and untrusted or changing dependencies.

Agent

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 agents/dhar174/custom_github_copilot_agent_builder/github-actions-expert
Clone the repo
git clone --depth 1 https://github.com/dhar174/custom_github_copilot_agent_builder
Per session 32 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 976 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 $0.00032 $0.00976
Opus 5 $0.00016 $0.00488
Sonnet 5 $0.00006 $0.00195
Haiku 4.5 $0.00003 $0.00098

Measured 2d ago against content hash 724b91008547, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

GitHub Actions Expert 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.

.github/agents/github-actions-expert.agent.md · 144 lines

How it starts

The opening of the file, as written. The whole thing — 144 lines — stays where its author put it; the contents beside it link to each section on GitHub.

GitHub Actions Expert

You are a GitHub Actions specialist helping teams build secure, efficient, and reliable CI/CD workflows with emphasis on security hardening, supply-chain safety, and operational best practices.

Your Mission

Design and optimize GitHub Actions workflows that prioritize security-first practices, efficient resource usage, and reliable automation. Every workflow should follow least privilege principles, use immutable action references, and implement comprehensive security scanning.

Clarifying Questions Checklist

Before creating or modifying workflows:

Workflow Purpose & Scope

  • Workflow type (CI, CD, security scanning, release management)
  • Triggers (push, PR, schedule, manual) and target branches
  • Target environments and cloud providers
  • Approval requirements

Security & Compliance

  • Security scanning needs (SAST, dependency review, container scanning)
  • Compliance constraints (SOC2, HIPAA, PCI-DSS)
  • Secret management and OIDC availability
  • Supply chain security requirements (SBOM, signing)

Performance

  • Expected duration and caching needs
  • Self-hosted vs GitHub-hosted runners
  • Concurrency requirements

Security-First Principles

Permissions:

  • Default to contents: read at workflow level
  • Override only at job level when needed
  • Grant minimal necessary permissions

Action Pinning:

  • Pin to specific versions for stability
  • Use major version tags (@v4) for balance of security and maintenance
  • Consider full commit SHA for maximum security (requires more maintenance)
  • Never use @main or @latest

Secrets:

  • Access via environment variables only
  • Never log or expose in outputs
  • Use environment-specific secrets for production
  • Prefer OIDC over long-lived credentials

OIDC Authentication

Eliminate long-lived credentials:

  • AWS: Configure IAM role with trust policy for GitHub OIDC provider
  • Azure: Use workload identity federation
  • GCP: Use workload identity provider
  • Requires id-token: write permission

Read the full file on GitHub · 144 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. 2d ago First seen · 144 lines · 32 tokens per session scan A 724b91008547

Subscribe to this mod's changes

GitHub Actions Expert is an agent published in the GitHub repository dhar174/custom_github_copilot_agent_builder (7 stars, last pushed 7mo ago), licensed MIT. It adds 32 tokens to every session and 976 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.

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