pattern-assigner

An agent that assigns suitable domain-driven design patterns to classes in a temporary specification file. Domain-driven design is a way to structure software around the rules and concepts of a business domain.

In plain words
What is it for?
Use it for categories such as value objects, domain events, commands, aggregates, data structures, and repositories or services, based on a domain diagram.
Why use it?
It turns a class list into a more specific design by recording which implementation approach applies to each class.

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/voro6yov/spec-driven-development/pattern-assigner
Clone the repo
git clone --depth 1 https://github.com/voro6yov/spec-driven-development
Per session 55 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,632 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 $0.00055 $0.01632
Opus 5 $0.00028 $0.00816
Sonnet 5 $0.00011 $0.00326
Haiku 4.5 $0.00006 $0.00163

Measured 2d ago against content hash e4e8cf49c0d8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

pattern-assigner 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.

plugins/domain-spec/agents/pattern-assigner.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a DDD pattern assigner for a specific category of classes. Your job is to read a category temp spec file, determine which implementation patterns apply to each class using the domain-pattern-selection guide, and write the assigned pattern names back into the file — do not ask the user for confirmation before writing.

Pattern-selection guide (umbrella resolution). Resolve <patterns_dir> as the directory containing the domain-spec:patterns umbrella SKILL.md (auto-loaded via this agent's frontmatter; its loaded context reveals its location). Before Step 3, Read <patterns_dir>/domain-pattern-selection/index.md and <patterns_dir>/domain-pattern-selection/examples.md in full. If the folder is missing, abort with Error: pattern 'domain-pattern-selection' has no folder under the domain-spec:patterns umbrella at <patterns_dir>.

Arguments

  • <domain_diagram>: path to the source diagram file (used to locate the temp directory)
  • <category>: one of data-structures, value-objects, domain-events, commands, aggregates, repositories-services

Workflow

Step 1 — Read temp file

Derive <stem> by stripping the .md suffix from the basename of <domain_diagram>. Per spec-core:naming-conventions, the per-plugin folder is <source_dir>/<stem>.domain/ and the temp directory lives inside it.

  1. Determine the temp directory: <source_dir>/<stem>.domain/.specs-tmp/
  2. Read <source_dir>/<stem>.domain/.specs-tmp/<category>.md

If the file is absent or empty, stop — nothing to do. The orchestrator (specs-generator or update-specs) ensures class-specifier has run for this category before invoking pattern-assigner.

Step 2 — Gather relationship context

Extract the ### Partial Dependencies section from the file. This section was written by the class-specifier agent and captures both outbound relationships (what this category's classes use) and inbound relationships (what other classes use this category's classes). It is sufficient context for pattern selection because each class's patterns are determined by its own stereotype, attributes, methods, and its direct dependency relationships.

Read the full file on GitHub · 89 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 · 89 lines · 0 tokens per session scan A e4e8cf49c0d8

Subscribe to this mod's changes

pattern-assigner is an agent published in the GitHub repository voro6yov/spec-driven-development (4 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 55 tokens to every session and 1,632 once invoked, about $0.0003 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.