Experiments

An experiment is one instance-wide rollout the operator configures and Fluxer resolves against one account. The single route on this page resolves every experiment the server defines and returns them in one envelope, together with the polling cadence they share. voice_noise_suppression is the only experiment defined today, and Voice defines the placement protocol its assignment applies to.

Every assignment is advice. A client that ignores one behaves as it does with the rollout off, and no route and no Gateway event reports what a client actually ran.

Experiment assignments object

One resolution of every defined experiment against one account. Every field is present on every response.

Structure

Field	Type	Description
poll_interval_seconds	integer	Seconds to wait before revalidating, from 60 through 86400
poll_jitter_percent	integer	How far to spread the wait around the interval, from 0 through 50
assignments	assignment map object	One entry for each experiment the server defines

The two polling fields sit on the envelope rather than on any one experiment, because the cadence is a property of the route and not of a rollout. They are the operator’s experiment delivery configuration read back unchanged, so they hold the same values for every account and every experiment, whatever those experiments resolve to.

Assignment map object

One entry per experiment. The envelope reports this object even when it is empty.

Structure

Field	Type	Description
voice_noise_suppression?	noise suppression assignment object	The caller’s noise suppression assignment

Every key here is optional in the schema so that a peer running a different server version still validates the envelope. A client reading a server that has not defined an experiment it knows about, or that defines one it does not, drops the unknown key and treats the missing one as off rather than as an error.

This server version writes voice_noise_suppression on every response, including while the rollout is disabled. The disabled value is the first resolution outcome below, which reports enabled false and the stored config_version, so a client can tell an operator write from a no-op without a second request.

Noise suppression backends

Noise suppression runs in the client, on the microphone track, before that track is published. Fluxer processes no audio for it. The registry is closed, and a backend outside it is not a value this API produces or accepts.

Value	Description
none	No processing
standard	The browser or platform suppressor the client already has
gate	A noise gate keyed on input level
speex	The Speex preprocessor
rnnoise	The RNNoise recurrent model
gtcrn	The GTCRN model
deep_filter	The DeepFilterNet model

A client MUST treat a backend absent from enabled_backends as unavailable, including one named by backend or by a guild override.

Noise suppression assignment object

One resolution of the instance noise suppression rollout against one account. Every field is present whenever the key is written.

Structure

Field	Type	Description
enabled	boolean	Whether the rollout is running on this instance
config_version	integer	The revision of the instance configuration this assignment was resolved from
user_targeted	boolean	Whether the caller is inside the rollout
backend	?string	The backend the caller applies, and null where the caller is not targeted
source	?string	Which rule targeted the caller, one of user_rule or canary, and null where the caller is not targeted
guild_overrides	array[guild override object]	Per-guild backend replacements that apply to the caller
enabled_backends	array[string]	The backends the client MAY run
allow_user_override	boolean	Whether the account’s own stored choice replaces backend
stereo_enabled	boolean	Whether the client publishes a stereo microphone track
suppression_strength	integer	Suppression strength from 0 through 100, which only a backend that reads it applies

config_version counts operator writes, not assignment changes. It is raised by every Update instance configuration request that sets at least one noise suppression field, so it can advance while the caller’s assignment stays byte for byte the same.

Resolution outcomes

Three outcomes set user_targeted to false, and they differ in what else they report.

1. The rollout is off. enabled is false, enabled_backends and guild_overrides are empty, and allow_user_override and stereo_enabled are false.
2. The operator has excluded the caller. enabled is true, and every other field is as in the first outcome.
3. The caller was not drawn. enabled is true, and enabled_backends, guild_overrides, allow_user_override, and stereo_enabled all hold their configured values.

A caller is drawn either by the operator’s allowlist, which sets source to user_rule, or by the sampled share of the account population, which sets source to canary. A caller that is drawn while backend is absent from enabled_backends is reported as not drawn, with user_targeted false and both backend and source null.

A client branches on user_targeted rather than on enabled_backends, because the third outcome keeps the array populated. A guild_overrides entry applies in its guild whether or not the caller was drawn.

config_version reports the stored revision in all three outcomes, the rollout being off included.

Noise suppression guild override object

One backend replacement scoped to one guild. A guild named here replaces backend while the caller is connected to a voice channel of that guild.

Structure

Field	Type	Description
guild_id	snowflake	The guild the replacement applies in
backend	string	The backend to run in that guild

An override naming a backend that is absent from enabled_backends is dropped before the response is written, so every entry is runnable.

Get experiment assignments

GET/v1/experimentsBot

Resolves every defined experiment for the caller and returns an experiment assignments object. The response is derived per account, so it is never shared between accounts.

Response body

Experiment assignments object.

Response

Status	Body	Condition
200	response body	The envelope was resolved
304	empty	The request sent a matching If-None-Match

Request headers

Field	Type	Description
If-None-Match?	string	An ETag from an earlier response to this route

A client sends the ETag it last received. Fluxer compares it against the tag of the envelope it just resolved and answers 304 with no body on a match. * matches any current tag. A weak comparison is used, so a W/ prefix on either side does not defeat the match.

Response headers

Field	Type	Description
ETag	string	A strong tag over the envelope body, sent on 200 and on 304
Cache-Control	string	The literal value private, no-cache
Vary	string	The literal value Authorization, replaced by Origin where the cross-origin policy echoed an allowed origin

The tag is a hash of the body alone, so two accounts resolving to the same envelope receive the same tag. It changes whenever any field changes, the polling fields and config_version included.

ETag is listed in Access-Control-Expose-Headers and If-None-Match in Access-Control-Allow-Headers, so a cross-origin client reads the tag and revalidates with it.

Polling

A client reads this route once per session and then again every poll_interval_seconds, offset by a random amount up to poll_jitter_percent of that interval in either direction. It sends the last ETag on every request after the first. A client MUST NOT poll faster than the lower end of that jitter range.

Raising poll_interval_seconds sheds request volume. Raising poll_jitter_percent spreads a fleet that has synchronised on one interval. A client that has never reached this route holds the built-in defaults of 300 seconds and 15 percent, so neither value reaches a client that cannot read it.

Rate limit

60 requests per 10 seconds for each authenticated user, on the default bucket.