Sign API

Signs are individual biomarker signals detected from voice. Each sign represents a specific health dimension. Use GET /v2/signs to discover available signs, GET /v2/signs/{sign_name} to get details on one, and POST /v2/signs/{sign_name}/analyze to analyze a single sign against submitted audio.

For pre-built multi-sign bundles, use Model API.

GET /v2/signs

GET/v2/signs

Return the list of all signs available for individual analysis.

Response

Field	Type	Description
`signs`	array	List of sign objects.

Each object in signs:

Field	Type	Description
`name`	string	Sign identifier. Use as the `sign_name` path parameter on detail and analyze endpoints.
`label`	string	Human-readable sign name for display.

Example

curl -X GET "https://api.amplifierhealth.com/v2/signs" \
-H "X-Account-ID: your-account-id" \
-H "X-API-Key: your-api-key"

Example response

{
  "signs": [
    { "name": "airway-obstruction-pattern", "label": "Airway Obstruction Pattern" },
    { "name": "alcohol-use-pattern",        "label": "Alcohol Use Pattern" },
    { "name": "allergy",                    "label": "Allergy" },
    { "name": "anxiety",                    "label": "Anxiety" },
    { "name": "attention-dysregulation",    "label": "Attention Dysregulation" },
    { "name": "cognitive-impairment",       "label": "Cognitive Impairment" },
    { "name": "dehydration",                "label": "Dehydration" },
    { "name": "elevated-androgens",         "label": "Elevated Androgens" },
    { "name": "elevated-blood-pressure",    "label": "Elevated Blood Pressure" },
    { "name": "fatigue",                    "label": "Fatigue" },
    { "name": "head-impact",                "label": "Head Impact" },
    { "name": "hypervigilance",             "label": "Hypervigilance" },
    { "name": "iron-deficiency",            "label": "Iron Deficiency" },
    { "name": "metabolic-load",             "label": "Metabolic Load" },
    { "name": "mood-disruption",            "label": "Mood Disruption" },
    { "name": "stress",                     "label": "Stress" },
    { "name": "substance-use-pattern",      "label": "Substance Use Pattern" }
  ]
}

Errors

For authentication errors (401) and other codes, see Error Reference.

GET /v2/signs/{sign_name}

GET/v2/signs/{sign_name}

Return details for a single sign, including its display label and condition back-reference.

Path Parameters

Parameter	Type	Description
`sign_name`	string	The name of the sign to retrieve. See Valid sign names below.

Response

Field	Type	Description
`name`	string	Sign identifier.
`label`	string	Human-readable sign name.
`condition`	string or null	Back-reference to the corresponding legacy condition model ID (e.g. `"acute-stress"`). Populated when the sign has a mapped legacy identifier; null otherwise.

Example

curl -X GET "https://api.amplifierhealth.com/v2/signs/stress" \
-H "X-Account-ID: your-account-id" \
-H "X-API-Key: your-api-key"

Example response

{ "name": "stress", "label": "Stress", "condition": "acute-stress" }

Errors

HTTP	Code	Condition
404	`NOT_FOUND`	`sign_name` is not a recognized sign. Check the name against Valid sign names.

For other codes, see Error Reference.

POST /v2/signs/{sign_name}/analyze

POST/v2/signs/{sign_name}/analyze

Submit audio to analyze a single sign. Returns a job object immediately; poll GET /v2/jobs/{job_id} or use a webhook for the completed result.

Requests use Content-Type: multipart/form-data. The job object is returned immediately with status: "running" and result: null. When analysis completes, the result contains a singular signal object plus audio_quality.

Path Parameters

Parameter	Description
`sign_name`	The sign to analyze. Must be a sign available for standalone analysis — see Valid sign names.

Request Body

Requests use Content-Type: multipart/form-data.

API Parameters
Field	Type	Required	Description
audio	file	Required	Audio file (WAV, FLAC, MP3, or M4A). Max 32 MB per file. For longer recordings, MP3, M4A, or FLAC usually keep the file under the limit. See [Audio Requirements](/guides/audio-requirements#file-size).
diarize	boolean	Optional	Whether to apply speaker diarization. Default: false.
webhook_url	string	Optional	Per-request webhook URL. Overrides the account-level webhook for this job. The API sends an HTTP POST to this URL when analysis completes. Must be provided together with webhook_secret_key — omit both or include both.
webhook_secret_key	string	Optional	Required when webhook_url is provided. Used to sign the webhook payload (HMAC-SHA256) so your server can verify it came from Amplifier. Must be provided together with webhook_url — omit both or include both.

Valid sign names

The following signs are available for individual analysis via this endpoint:

Sign name	Label
`airway-obstruction-pattern`	Airway Obstruction Pattern
`alcohol-use-pattern`	Alcohol Use Pattern
`allergy`	Allergy
`anxiety`	Anxiety
`attention-dysregulation`	Attention Dysregulation
`cognitive-impairment`	Cognitive Impairment
`dehydration`	Dehydration
`elevated-androgens`	Elevated Androgens
`elevated-blood-pressure`	Elevated Blood Pressure
`fatigue`	Fatigue
`head-impact`	Head Impact
`hypervigilance`	Hypervigilance
`iron-deficiency`	Iron Deficiency
`metabolic-load`	Metabolic Load
`mood-disruption`	Mood Disruption
`stress`	Stress
`substance-use-pattern`	Substance Use Pattern

Code Examples

Submit

curl -X POST https://api.amplifierhealth.com/v2/signs/stress/analyze \
-H "X-Account-ID: your-account-id" \
-H "X-API-Key: your-api-key" \
-F "audio=@recording.wav;type=audio/wav"

Example response

The API returns immediately with the job object. status is running and result is null until processing completes:

{
  "job_id": "a2e4c7f1-3d9b-4e6a-b8c2-1f5d8e3a7b9c",
  "status": "running",
  "created_at": "2026-05-22T10:30:00Z",
  "completed_at": null,
  "result": null,
  "audio_content_type": "audio/wav",
  "audio_size_bytes": 876032,
  "audio_duration_seconds": 27.4,
  "audio_sample_rate": 16000,
  "job_type": "sign",
  "api_version": "v2",
  "sign_name": "stress"
}

Poll job

curl https://api.amplifierhealth.com/v2/jobs/a2e4c7f1-3d9b-4e6a-b8c2-1f5d8e3a7b9c \
-H "X-Account-ID: your-account-id" \
-H "X-API-Key: your-api-key"

See Jobs for the full job response schema. When status is done, the result contains a singular signal object plus audio_quality — see Response Schema — Sign Response.

Errors

HTTP	Code	Condition
404	`NOT_FOUND`	`sign_name` is not a recognized sign or is not available for standalone analysis. Check the name against Valid sign names.
400	`AUDIO_TOO_SHORT`	Recording is under 15 seconds.
400	`AUDIO_TOO_LONG`	Recording exceeds 20 minutes.
400	`UNSUPPORTED_FORMAT`	Audio format is not WAV, FLAC, MP3, or M4A.
422	`AUDIO_POOR_QUALITY`	Recording conditions below the threshold used for analysis.

If only one of webhook_url or webhook_secret_key is provided, the request returns 400 Bad Request. Provide both or omit both.

For other codes and retry guidance, see Error Reference.

Model-internal signs

Some signs appear in the signs list of named models returned by GET /v2/models/{model_name} but are not available for standalone analysis via this endpoint. These model-internal signs are not returned by GET /v2/signs and cannot be used as a sign_name here.

Examples of model-internal signs: cognitive-load, cardiovascular-strain, emotional-destabilization. If you need results for these signals, use the named model that includes them via POST /v2/models/{model_name}/analyze.