Gravity Feed overview
What Gravity Feed is, the product family, the six workflows, status labels and the free 1 QPS plan.
Spatial9 Gravity Feed is a musical-intelligence feed for DAWs and plugins. Your DAW, plugin or agent sends a description of the session (tempo, sections, track roles and current positions, never audio), and Gravity Feed returns a placement and movement plan: where each instrument should sit, how it should move over the next bars, which effects could support that movement, and the exact automation points a supported plugin can write. The model chooses musical ideas; deterministic code computes every number.
This page is the overview. Use the quickstart to send a first request, the API reference for every route and error, and the DAW guides and plugin guides to connect your own tools.
Status at a glance
Every part of Gravity Feed carries one of these labels. A label is only raised after the matching test has been passed.
| Label | Meaning |
|---|---|
| Live | Running in production and covered by automated tests |
| Prototype | Code exists and can be downloaded, but has not been tested in the host yet |
| Documented route | The DAW or plugin vendor documents a control route; Spatial9 has not built or certified an adapter |
| Planned | Designed, not built |
| Legacy | The product is discontinued; no new work is planned |
| Reference | A neutral definition other profiles convert from |
| Part | Status |
|---|---|
REST API, MCP tool gravity_feed_plan, A2A skill gravity_feed_plan | Live |
| Website playground and console (keys, usage) | Live |
| REAPER + IEM StereoEncoder script | Prototype |
| Gravity Profiles for IEM StereoEncoder and ICST AmbiEncoder | Documented route, conversion not verified |
| Gravity Link (desktop bridge) and Gravity Capture (plugin) | Planned |
The product family
| Name | What it is | Status |
|---|---|---|
| Gravity Feed | The planning service and its API | Live |
| Gravity Connect | The three ways in: REST, MCP and A2A, sharing one limit | Live |
| Gravity Profiles | Machine-readable descriptions of a plugin's controls, ranges and OSC addresses | Two documented-route profiles |
| Gravity Link | A desktop bridge that relays plans to OSC plugins on your machine | Planned |
| Gravity Capture | A plugin that reads track context and writes plan automation in any VST3, AU or AAX host | Planned |
The six workflows
| Workflow | What you ask | What you get |
|---|---|---|
| Place | Where should these instruments sit? | A static position for each track |
| Move | How should this section move? | Motion curves with beat-accurate points |
| Shape | Which effects would support the movement? | Effect ideas, marked as suggestions |
| Explain | Why this plan? | A plain-language reason on every change |
| Compare | Show me options | Restrained, expressive and cinematic alternatives |
| Commit | Write it | Automation actions for profiles that support it, guarded by revision and expiry |
How a request flows
- Your adapter reads the session: tempo map, selection, sections, track roles, locks and current positions.
- It sends
POST /v1/planswithprivacy.audio_uploadedset tofalse. - Gravity Feed checks the request, admits it against your rate limit and asks the model for musical choices.
- Deterministic code applies locks, style bounds and plugin ranges, then computes positions, curves and actions.
- Your adapter shows the alternatives, and if the session revision still matches and the plan has not expired, writes the chosen one in a single undo step.
What it is not
- It does not listen to or upload audio.
audio_checksin every plan readsnot_evaluated. - It does not invent a quality score.
confidenceis alwaysnull. - It does not change effect parameters. Effect ideas have
executable: falseuntil an effect profile has been verified.
Limits and pricing
The free plan allows 1 query per second per account, with bursts of up to 5, shared across REST, MCP, A2A and the website. There is no monthly cap for now. One query is one plan request, which can cover up to 32 tracks and 128 beats. See limits and QPS. For more than 1 QPS, contact sales from the Gravity Feed page.
FAQ
Does Gravity Feed upload my audio?
No. Requests are metadata only and must declare audio_uploaded: false. Spatial9 stores a hash of the request, counts, timings and the returned plan.
Does the AI write the numbers?
No. The model picks musical actions such as slowly lifting the pad in the chorus. Deterministic code calculates every coordinate and curve point, so the same choice always gives the same numbers.
Which DAWs work today?
Anything that can make an HTTPS request can call the API. A REAPER script is available as a prototype. Other DAWs have documented routes described in the DAW guides, but no other adapter is certified.
What does 1 QPS mean?
One query per second: on average your account can request one new plan each second. Planning an eight-bar chorus for 12 tracks is one query, not 12.