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.
npx agentmods add skills/danicat/skills/ebitengineernpx skills add danicat/skills --skill ebitengineergit clone --depth 1 https://github.com/danicat/skillsWrote 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.
[](https://agentmods.dev/skills/danicat/skills/ebitengineer)<a href="https://agentmods.dev/skills/danicat/skills/ebitengineer"><img src="https://agentmods.dev/badge/skills/danicat/skills/ebitengineer.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00091 | $0.02096 |
| Opus 5 | $0.00046 | $0.01048 |
| Sonnet 5 | $0.00018 | $0.00419 |
| Haiku 4.5 | $0.00009 | $0.00210 |
Grade A, and why
ebitengineer 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.
How it starts
The opening of the file, as written. The whole thing — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ebitengine 2D Game Development Guide (ebitengineer)
Comprehensive engineering guidelines for building modular, high-performance, cross-platform 2D games in Go using Ebitengine v2.
Trigger Conditions
Activate this skill whenever:
- Designing or implementing 2D game architecture, scene flow, or rendering in Go.
- Working with Ebitengine interfaces (
ebiten.Game), state machines, input management, audio, or custom typography. - Optimizing cycle timing, WASM audio synchronization, touch controls, server architecture, or writing unit tests for Go game components.
Core Architecture & Guidelines
1. Modular Architecture (internal/)
Organize the codebase into modular subsystems under internal/. Avoid monolithic single-file games.
- For complete directory tree and package responsibilities, see
references/project_structure.md.
Engine Reference Modules
For deep technical patterns, Go code implementations, and mathematical algorithms, consult these modular reference guides:
| Module | Reference File | Key Topics Covered |
|---|---|---|
| Project Structure | references/project_structure.md |
Package tree and internal/ subsystem responsibilities. |
| Server & Cloud Run | references/server_architecture.md |
WebAssembly build, Docker multi-stage, and Cloud Run REST API. |
| Physics & Collision | references/physics_and_collision.md |
AABB sweep tests, spatial hashing grid, and platformer slope math. |
| Tilemaps & Levels | references/tilemaps_and_levels.md |
Tiled/LDtk parsing, 16-pipe autotiling, and frustum tile culling. |
| UI & HUD System | references/ui_and_hud.md |
9-slice panel scaling, flex anchoring, progress bars, and widget FSM. |
| Input Action Mapping | references/input_action_mapping.md |
Rebindable action maps, analog deadzones, and input device abstraction. |
| Entity Management | references/entity_management.md |
Slice pools, deferred deletion buffers, and light component ECS. |
| Pathfinding & AI | references/pathfinding_and_ai.md |
A* grid pathfinding, steering behaviors (seek/arrive), and enemy FSM. |
What ships with it
8 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- references/entity_management.md 3.1 KB
- references/input_action_mapping.md 3.5 KB
- references/pathfinding_and_ai.md 4.6 KB
- references/physics_and_collision.md 3.8 KB
- references/project_structure.md 3.1 KB
- references/server_architecture.md 5.1 KB
- references/tilemaps_and_levels.md 3.6 KB
- references/ui_and_hud.md 4.8 KB
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.
- 3d ago First seen · 141 lines · 91 tokens per session scan A a46fac4ab155
ebitengineer is a skill published in the GitHub repository danicat/skills (16 stars, last pushed 4d ago), licensed Apache-2.0. It adds 91 tokens to every session and 2,096 once invoked, about $0.0005 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.
Other skills, from other repositories
printing-press-polish
Polish a generated CLI to pass verification and become publish-ready. Runs diagnostics (dogfood, verify, scorecard, go vet, gosec), automatically fixes all issues (verify failures, static-analysis findings, dead code, descriptions, README, MCP tool quality), reports the before/after delta, and offers to publish. Use…
layered-architecture-types
Enforce primitive-at-edges / strong-types-in-Business layering and the toBus/fromBusResponse/toDB converter pattern. Use when writing, editing, or auditing Go files under app/, business/domain/, or .../stores/db.
golang-testing
Production-ready Golang tests — table-driven tests, testify suites and mocks, parallel tests, fuzzing, fixtures, goroutine leak detection with goleak, snapshot testing, code coverage, integration tests, idiomatic test naming. Use when writing or reviewing Go tests, choosing a testing approach, setting up Go test CI…
golang-observability
Golang everyday observability — the always-on signals in production. Covers structured logging with slog, Prometheus metrics, OpenTelemetry distributed tracing, continuous profiling with pprof/Pyroscope, server-side RUM event tracking, alerting, and Grafana dashboards. Apply when instrumenting Go services for…
golang-data-structures
Golang data structures — slices (internals, capacity growth, preallocation, slices package), maps (internals, hash buckets, maps package), arrays, container/list/heap/ring, strings.Builder vs bytes.Buffer, generic collections, pointers (unsafe.Pointer, weak.Pointer), and copy semantics. Use when choosing or optimizing…
golang-dependency-management
Dependency management for Golang projects — go.mod and go.sum, go get install and upgrade flows, Minimal Version Selection, conflict resolution with replace/exclude/retract, govulncheck scanning of the module tree, outdated dependency and binary size auditing, vendoring, tool directives, and go.work workspaces. Use…