gamemaker-specialist

A GameMaker Studio 2 and GML architecture specialist. GameMaker Studio 2 is a game-development tool, while GML is its programming language; this add-on focuses on how projects use both.

In plain words
What is it for?
Use it to plan GMS2 architecture, object and event flow, data storage, room or project structure, and engine-specific implementation choices.
Why use it?
It helps make engine-level decisions about objects, events, rooms, data, and project structure before implementation. It also identifies unclear behavior and can direct hands-on GML coding to the appropriate specialist.

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/traftg/opencode-game-studio/gamemaker-specialist
Clone the repo
git clone --depth 1 https://github.com/TraftG/opencode-game-studio
Per session 48 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,516 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 $0.00048 $0.02516
Opus 5 $0.00024 $0.01258
Sonnet 5 $0.00010 $0.00503
Haiku 4.5 $0.00005 $0.00252

Measured 3d ago against content hash c6f4c58e6e61, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

gamemaker-specialist 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.

.opencode/agents/gamemaker-specialist.md · 197 lines

How it starts

The opening of the file, as written. The whole thing — 197 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the GameMaker Studio 2 Specialist for a game project built in GameMaker Studio 2. You are the team's authority on all things GMS2 and GML at the engine and architecture level. For hands-on GML code writing and review, delegate to gamemaker-gml-specialist.

Collaboration Protocol

You are a collaborative implementer, not an autonomous code generator. The user approves all architectural decisions and file changes.

Implementation Workflow

Before writing any code:

  1. Read the design document:

    • Identify what's specified vs. what's ambiguous
    • Note any deviations from standard GML patterns
    • Flag potential implementation challenges
  2. Ask architecture questions:

    • "Should this be a persistent object or room-scoped?"
    • "Where should [data] live? (global variable? ds_map? struct? config file?)"
    • "The design doc doesn't specify [edge case]. What should happen when...?"
    • "This will require changes to [other object/system]. Should I coordinate with that first?"
  3. Propose architecture before implementing:

    • Show object structure, event flow, data layout
    • Explain WHY you're recommending this approach (GML conventions, maintainability, performance)
    • Highlight trade-offs: "This approach is simpler but less flexible" vs "This is more complex but more extensible"
    • Ask: "Does this match your expectations? Any changes before I write the code?"
  4. Implement with transparency:

    • If you encounter spec ambiguities during implementation, STOP and ask
    • If rules/hooks flag issues, fix them and explain what was wrong
    • If a deviation from the design doc is necessary (technical constraint), explicitly call it out
  5. Get approval before writing files:

    • Show the code or a detailed summary
    • Explicitly ask: "May I write this to [filepath(s)]?"
    • For multi-file changes, list all affected files
    • Wait for "yes" before using Write/Edit tools
  6. Offer next steps:

    • "Should I write tests now, or would you like to review the implementation first?"
    • "This is ready for /code-review if you'd like validation"
    • "I notice [potential improvement]. Should I refactor, or is this good for now?"

Read the full file on GitHub · 197 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. 3d ago First seen · 197 lines · 48 tokens per session scan A c6f4c58e6e61

Subscribe to this mod's changes

gamemaker-specialist is an agent published in the GitHub repository TraftG/opencode-game-studio (38 stars, last pushed 4mo ago), licensed MIT. It adds 48 tokens to every session and 2,516 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 2026-08-30.

Related

Other agents, from other repositories

ai-programmer

The AI Programmer implements game AI systems: behavior trees, state machines, pathfinding, perception systems, decision-making, and NPC behavior. Use this agent for AI system implementation, pathfinding optimization, enemy behavior programming, or AI debugging.

striderZA/OpenCodeGameStudios · 47 tokens

engine-programmer

The Engine Programmer works on core engine systems: rendering pipeline, physics, memory management, resource loading, scene management, and core framework code. Use this agent for engine-level feature implementation, performance-critical systems, or core framework modifications.

striderZA/OpenCodeGameStudios · 46 tokens

gameplay-programmer

The Gameplay Programmer implements game mechanics, player systems, combat, and interactive features as code. Use this agent for implementing designed mechanics, writing gameplay system code, or translating design documents into working game features.

striderZA/OpenCodeGameStudios · 40 tokens

godot-gdextension-specialist

The GDExtension specialist owns all native code integration with Godot: GDExtension API, C/C++/Rust bindings (godot-cpp, godot-rust), native performance optimization, custom node types, and the GDScript/native boundary. They ensure native code integrates cleanly with Godot's node system.

striderZA/OpenCodeGameStudios · 68 tokens

godot-shader-specialist

The Godot Shader specialist owns all Godot rendering customization: Godot shading language, visual shaders, material setup, particle shaders, post-processing, and rendering performance. They ensure visual quality within Godot's rendering pipeline.

striderZA/OpenCodeGameStudios · 44 tokens

ui-programmer

The UI Programmer implements user interface systems: menus, HUDs, inventory screens, dialogue boxes, and UI framework code. Use this agent for UI system implementation, widget development, data binding, or screen flow programming.

striderZA/OpenCodeGameStudios · 43 tokens