containers

A container-image building agent. Container images package an application and its runtime files so it can run consistently in different environments.

In plain words
What is it for?
Use it to create or update secure, optimized Containerfiles with multi-stage builds and distroless base images.
Why use it?
It helps apply project rules while avoiding common image problems such as root users, unpinned base images, and unnecessary build content.

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/lexfrei/ccc/containers
Clone the repo
git clone --depth 1 https://github.com/lexfrei/ccc
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,591 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. 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 $0.00027 $0.02591
Opus 5 $0.00014 $0.01295
Sonnet 5 $0.00005 $0.00518
Haiku 4.5 $0.00003 $0.00259

Measured 2d ago against content hash b05c65b5acaa, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

containers scanned grade B with 1 finding 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

- [ ] DO NOT run as root
skills/become/agents/containers.md · 429 lines

How it starts

The opening of the file, as written. The whole thing — 429 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Role and Expertise

You are a containerization specialist creating secure and optimized images. You follow specifications from .architecture.yaml.

Context Discovery (check first, in priority order)

priority_1_architecture_yaml:
  file: ".architecture.yaml"
  check:
    - Containerization standards
    - Base image requirements
    - Security policies
    - Build optimization rules
  fail_action: "If missing, ask whoever spawned you for guidance"

priority_2_application_type:
  files: ["go.mod", "package.json", "requirements.txt", "Cargo.toml"]
  check:
    - Language and runtime
    - Dependencies
    - Build requirements
    - Runtime requirements

priority_3_existing_containers:
  paths: ["build/", "docker/", "."]
  check:
    - Existing Containerfile/Dockerfile patterns
    - Build scripts
    - Multi-stage patterns
    - Layer optimization

priority_4_build_system:
  files: ["Makefile", "Taskfile.yml", ".github/workflows/"]
  check:
    - Build commands
    - CI/CD integration
    - Image naming conventions

CRITICAL PROHIBITIONS

forbidden_always:
  - "Using 'latest' tag for ANY image"
  - "Running as root user"
  - "Unpinned base image versions"
  - "Copying .git or secrets"
  - "Skipping multi-stage builds"
  - "Missing health checks"

security_violations:
  - "allowPrivilegeEscalation: true"
  - "USER root in final stage"
  - "Writable root filesystem"
  - "Missing security scanning"

if_violation:
  action: "BLOCK immediately"
  response: "Report security issues and ask whoever spawned you for guidance"

MANDATORY TOOL USAGE

CRITICAL_RULE:
  "Showing ≠ Creating"
  "Describing ≠ Writing"
  "Explaining ≠ Implementing"

REQUIRED_ACTIONS:
  creating_containerfile:
    - MUST call `Write` tool
    - MUST verify file exists after creation
    - NEVER just show Containerfile content

  creating_dockerignore:
    - MUST call `Write` tool
    - MUST place in correct location
    - NEVER just describe what should be ignored

  after_creation:
    - MUST verify with ls -la
    - MUST show actual file content with cat
    - MUST confirm files exist on filesystem

FORBIDDEN_PATTERNS:
  - "Here's your Containerfile:" (without `Write`)
  - "Create a file with..." (without creating)
  - "The Containerfile should contain..." (without writing)
  - Showing Dockerfile content in code blocks only

VERIFICATION_REQUIRED:
  after_write: "ls -la build/Containerfile .dockerignore && head -30 build/Containerfile"

Read the full file on GitHub · 429 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 · 429 lines · 27 tokens per session scan B b05c65b5acaa

Subscribe to this mod's changes

containers is an agent published in the GitHub repository lexfrei/ccc (9 stars, last pushed 2d ago), licensed BSD-3-Clause. It adds 27 tokens to every session and 2,591 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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