Audio direction skill for AI agents

audio-direction is a skill from the Summer skill library: a guide your AI agent reads when the task matches, so it builds the good version on the first try. Define the game’s sound (music style, SFX vocabulary, dynamic music) as .summer/audio-bible.md.


Status	Stable
Domains	Audio, Game design
Version	`1.0.7`
Engine version	`>=4.6`
Recommended set	Yes, installed by `--recommended`

When your agent uses it

Defining the sonic identity — music style, instruments, SFX vocabulary, dynamic music plan
Starting audio work with no audio bible, or soundtrack and SFX requests keep drifting in style
“what should my game sound like overall?” / “what is the audio vibe of this game?” — the whole-game sound question, before any single track or effect is made

Install

summer setup installs every skill for your agent. To add only this one:

npx -y summer-engine@latest skills install audio-direction --agent claude-code

Swap claude-code for your agent, such as codex or cursor. See Skills for every option.

The skill

Overview

Many indie games sound like one sound library used flat: the same generic “swoosh” for menu, jump, pickup and hit. This skill builds an audio bible that names the music style, the SFX vocabulary, the dynamic music plan, and the spatial / mix rules. Writes to .summer/audio-bible.md and configures the audio bus layout in the project so the rest of the work has a real foundation. Core principle: SFX needs a vocabulary, not a library. Eight named SFX classes with consistent character beat 80 random library hits.

Steps

1. Open with three references

Ask exactly this:

Three reference tracks, games, or films for the music. What instruments matter? And what’s the SFX vibe — chunky, clean, synthetic, or organic?

Three is the minimum. One or two collapses into a clone. If they freeze, offer four axes (not titles):

Pick the closest: a) orchestral + cinematic (Hollow Knight, Journey), b) lo-fi electronic + ambient (Disco Elysium, Outer Wilds), c) chiptune / synth (Hyper Light Drifter, Celeste), d) acoustic / folk (Sable, A Short Hike).

2. Read the brief and art bible if they exist

Read .summer/GameSoul.md
Read .summer/art-bible.md

Audio must rhyme with the visuals. Quote it back:

Art bible says “soft, hand-warmed, golden-hour, painterly”. That rhymes with acoustic / folk / lo-fi over orchestral or aggressive synth. Confirming.

If the brief says “horror”, that constrains the music style harder than the user’s references will. Name the constraint.

3. Pin the music style

Force one primary style. Sub-styles can blend, but a primary is required.

Style	Anchor instruments	Pairs with	Avoid
Orchestral cinematic	Strings, brass, choir	Story-led, fantasy	Casual / cozy
Acoustic / folk	Guitar, piano, hand percussion	Cozy, narrative	Action / horror
Lo-fi electronic	Vintage synth pad, tape sat, light beat	Atmospheric, indie	Combat-heavy
Chiptune / synthwave	8-bit / 16-bit chips, FM synth	Retro, platformer	Realism
Industrial / metal	Distorted bass, percussion-led	Horror, action	Cozy
Ambient drone	Pads, no drums, slow movement	Walking sim, horror	Action
Jazz / fusion	Live instruments, improv	Stylish, narrative	Generic action
Tracker / hyperpop	Glitchy, dense, modern	Esoteric, indie	Mass appeal

Ask:

One primary style. Which?

4. Define tempo + key range

Concrete numbers, not “varies”.

Tempo range: 80–110 BPM (slow side; combat would push 120+)
Key center: D minor (warm but melancholic)
Modulation rule: combat tracks shift to D dorian, calm tracks to D natural minor
Time signature: 4/4 default; 6/8 for emotional cues

5. Build the SFX vocabulary

Eight named classes. Each class has a character, not a single sound.

Class	Character	Examples in this game	DON’T
UI	Soft, woody, short (60-100ms)	Menu hover, button click, tab switch	No bell tones, no synth blips
Pickup positive	Warm, ascending interval (major third), 200-400ms	Coin, key, heal	No pure sine “ding”
Pickup neutral	Brief tactile, no melodic component	Note, breadcrumb, lore item	No ascending pitch (reads as reward)
Negative / damage	Punchy low-mid, slight detune	Player hit, enemy hit, fall damage	No long reverb tail
Movement / footstep	Material-aware (wood / stone / grass)	Walk, run, jump, land	No same sample for all surfaces
Attack / action	Front-loaded transient, short body	Swing, parry, dash	No layered orchestral hit
Ambient layer	Continuous, low presence	Wind, room tone, distant waves	No looping melody
Stinger / event	Distinctive, rare, melodic	Boss intro, level clear, story beat	No reuse for normal events

Ask:

Eight classes above. Adjust any character / examples / DON’Ts?

6. Define the dynamic music plan

Static music = one track loops forever in a level. Boring. Dynamic music = layers swell with player state. Pick a model.

Model	How it works	Cost	Best for
Layered stems	One bar / multiple instrument layers; combat adds drum stem, calm removes it	Medium (need stems authored)	Most games
Vertical re-orchestration	Same melody, different instrumentation per state	High (composer-led)	Story-led / boss-heavy
Horizontal sequencing	Different tracks for different states, crossfade	Low (just author 3-5 full tracks)	Vertical slice scope
Procedural / generative	Generate from rules in real-time	High dev cost	Special-case

Pick one. State the state machine:

States:
  CALM        — exploration, low intensity
  TENSION     — enemies aware but not engaged
  COMBAT      — engaged
  VICTORY     — encounter cleared (4-second sting → return to CALM)

Transitions:
  CALM → TENSION   when an enemy detects the player (2s crossfade)
  TENSION → COMBAT when first damage exchanged (instant drum stem)
  COMBAT → VICTORY when last enemy dies (drum stem cuts, brass swell)
  VICTORY → CALM   after 4s

Rules:
  No state stays > 90s without variation (loop with bar-1 randomization)
  Volume ducking: dialogue active → music -6dB
  Boss music is its own track; ignores normal state machine

7. Define the spatial + mix rules

Rule	Value
3D attenuation curve	Inverse-square (default), max distance 25m
Reverb buses	1 small (interior), 1 large (cave / hall), 1 outdoor
HRTF for player	ON (headphone-friendly directional cues)
Master ceiling	-1 dBTP (true peak, no clipping on consoles)
Music vs SFX vs UI mix	-8 dB / 0 dB / -3 dB (SFX is loudest)
Footstep rolloff	Cuts at 4m for player; cuts at 10m for NPC (player needs them, distant NPCs are noise)
Compression	Light bus compression on master (2:1, slow attack, 100ms release)

8. Configure the audio bus layout

Real audio in Summer Engine needs a bus layout. A new project starts with only the Master bus, so configure the remaining buses now. Preferred (Summer MCP): Buses are typically in default_bus_layout.tres. Modify project setting:

summer_project_setting(key="audio/buses/default_bus_layout", value="res://audio/default_bus_layout.tres")

Ask the user:

May I create audio/default_bus_layout.tres with these buses: Master / Music / SFX / UI / Voice / Ambient / Reverb_Small / Reverb_Large / Reverb_Outdoor?

On yes, write the .tres directly via Write (it is the engine’s plain-text resource format):

Write audio/default_bus_layout.tres

Fallback (no MCP): Print the .tres for the user to paste, plus the project.godot line.

9. Save the audio bible

Always write the bible. Path: .summer/audio-bible.md.

# Audio Bible — <Game Name>

**References:** <3 specific tracks / games / films>
**Style:** <one of the 8 above>
**Tempo / key:** 80–110 BPM, D minor, 4/4

## SFX Vocabulary
| Class | Character | Examples | DON'T |
|---|---|---|---|
| UI | Soft, woody, 60-100ms | hover, click | bell tones |
| Pickup positive | Warm major-third, 200-400ms | coin, heal | pure sine |
| ... | ... | ... | ... |

## Dynamic Music Plan
**Model:** Layered stems
**States:** CALM / TENSION / COMBAT / VICTORY
**Transitions:** ...
**Rules:** ...

## Spatial + Mix
- 3D attenuation: inverse-square, 25m
- Reverb buses: small / large / outdoor
- HRTF: ON
- Master ceiling: -1 dBTP
- Mix bus: Music -8 dB, SFX 0 dB, UI -3 dB
- Footstep rolloff: 4m player / 10m NPC

## Bus Layout
Master → Music, SFX (→ Reverb_Small / Large / Outdoor), UI, Voice, Ambient

Ask:

May I create .summer/audio-bible.md with this bible?

10. Optional — generate first SFX seeds

If the user wants to start generating, propose 3-5 SFX seeds aligned with the vocabulary. These are starting points, not finals. Generate them with the sound-effect skill: the first sound effect in a chat starts with its question (three versions from three models, picked by ear in Summer Studio), and its prompt shape is the one that tested well.

assets.generate_audio({ capability: "sound_effects", text: "Foley one-shot: a fingertip taps a small wooden button, soft woody click, no tail, close-mic, dry, no reverb, no music, no voices.", durationSeconds: 0.5 })
assets.generate_audio({ capability: "sound_effects", text: "Foley one-shot: a small gold coin drops onto a wooden table, bright metallic ting with a short ring, close-mic, dry, no music, no voices.", durationSeconds: 0.5 })
assets.generate_audio({ capability: "sound_effects", text: "Foley one-shot: a fist hits a padded leather vest, low-mid thump, no tail, close-mic, dry, no reverb, no music, no voices.", durationSeconds: 0.5 })

capability is required; sound_effects reads from text (not prompt), and the length argument is durationSeconds (not duration) with a floor of 0.5 s (1 s for Stable Audio 3 SFX). Leave out modelId so the person’s approved default model runs. Ask for the character you want inside the text and let the player only use the front of the clip — you cannot request 80 ms. Ask first:

May I generate first-pass SFX seeds for UI, pickup, and damage classes? They’re starting points, not finals.

11. Route to the next step

End with:

Bible saved. Next:

/design-mechanic to wire SFX cues into specific mechanics.

/game-feel if you haven’t paired audio with visual effect cues yet.

Author or generate the calm music track first; it’s the longest-running and sets the room tone.

Common mistakes

Mistake	Fix
Single reference for music	Three minimum. Listen for the common element across them.
”Library” instead of “vocabulary”	A bag of free SFX with no shared character feels random. Eight named classes with character notes.
Same SFX for all events	If pickup-coin and pickup-key sound identical, the player learns nothing from audio.
No dynamic music plan	Static loops bore in 90s. Pick a model (layered / vertical / horizontal / procedural).
Music louder than SFX	Players need SFX for gameplay; music is mood. Default mix is -8 dB music vs 0 dB SFX.
No reverb buses	”Send” architecture (rooms route to a small/large/outdoor reverb bus) is mandatory or your mix sounds dry-then-wet inconsistently.
Pure sine “ding” for pickup	Reads as cheap mobile game. Use a major-third interval with character.
Same footstep sample for all surfaces	Players hear footsteps constantly; material-aware steps carry much of the perceived audio quality.
No master ceiling / true peak	Audio clips on console builds without `-1 dBTP` ceiling. Always set it.
Assuming SetResourceProperty fails silently on inline sub_resources	It does not — inline targets work, and the structural failures (`node not found`, `property is not a resource`, `resource is null`) are explicit errors. What is silent on current engines is a bad value shape: a JSON object instead of an engine literal string, a misspelled `subProperty`, or a wrong-typed value returns `ok:true` yet no-ops or coerces destructively. Pass class names and literal strings, and confirm in the saved `.tres`/`.tscn`, never from `ok` alone. See `summer_docs_read` id `reference/mcp-tools-reference`.

Collaborative protocol

This skill writes one bible (.summer/audio-bible.md), creates a bus layout (audio/default_bus_layout.tres), modifies project.godot, and may generate audio (metered). Always ask before writing or generating. See summer_docs_read id reference/collaborative-protocol.

Want a working starter?

No template — this is a workflow that produces the bible the rest of the project obeys. After the bible exists, the bus layout is set up and any subsequent audio work (footstep system, dynamic music) reads from it.

From a shell

No Summer MCP tools in this session? Run each one as a command; when summer --version is missing or below 4.0, use npx -y summer-engine@latest in place of summer. Fields are flags in kebab-case (--scene-path res://main.tscn) or one --input '<json>', and summer ops describe <op> prints the exact input. The summer-cli skill has the rest.

In this skill	Command
`summer_assets_generate_audio`	`summer assets generate-audio`
`summer_docs_read`	`summer docs read`
`summer_add_node`	`summer engine add-node`
`summer_get_project_context`	`summer engine get-project-context`
`summer_get_scene_tree`	`summer engine get-scene-tree`
`summer_inspect_node`	`summer engine inspect-node`
`summer_project_setting`	`summer engine project-setting`

art-direction: Define the game’s visual style (palette, mood, lighting, post) as an art bible in .summer/art-bible.md.
brainstorm-game: Turn a vague game idea into a 1-page brief (genre, scope, core loop, mechanics) in .summer/GameSoul.md.
adaptive-music: Wire music stems to game state: combat, explore, boss and tension crossfades on a shared bus.
music-track: Generate a music track: game loops of 30s or more with a loop point, or linear cinematic cues.
sound-effect: Make sound effects (swings, hits, whooshes, reloads, UI): three versions to pick from, then wire them.

Source: library/skills/audio-direction/SKILL.md, rendered from summer-engine@4.3.0 on npm.

​When your agent uses it

​Install

​The skill

​Overview

​Steps

​1. Open with three references

​2. Read the brief and art bible if they exist

​3. Pin the music style

​4. Define tempo + key range

​5. Build the SFX vocabulary

​6. Define the dynamic music plan

​7. Define the spatial + mix rules

​8. Configure the audio bus layout

​9. Save the audio bible

​10. Optional — generate first SFX seeds

​11. Route to the next step

​Common mistakes

​Collaborative protocol

​Want a working starter?

​See also

​From a shell

​Related skills

When your agent uses it

Install

The skill

Overview

Steps

1. Open with three references

2. Read the brief and art bible if they exist

3. Pin the music style

4. Define tempo + key range

5. Build the SFX vocabulary

6. Define the dynamic music plan

7. Define the spatial + mix rules

8. Configure the audio bus layout

9. Save the audio bible

10. Optional — generate first SFX seeds

11. Route to the next step

Common mistakes

Collaborative protocol

Want a working starter?

See also

From a shell

Related skills