Face Recognition

LocalAI supports face recognition through the insightface backend: face verification (1:1), face identification (1:N) against a built-in vector store, face embedding, face detection, demographic analysis (age / gender), and antispoofing / liveness detection.

The backend ships two interchangeable engines under one image, each paired with a distinct gallery entry so users can pick by license and accuracy needs.

Licensing — read this first

The insightface Python library itself is MIT, but the pretrained model packs (buffalo_l, buffalo_s, antelopev2) are released by the upstream maintainers for non-commercial research use only. Pick the insightface-opencv entry for production / commercial deployments.

Quickstart

Pull the commercial-safe backend (recommended for copy-paste):

local-ai models install insightface-opencv

Verify that two images depict the same person:

curl -sX POST http://localhost:8080/v1/face/verify \
  -H "Content-Type: application/json" \
  -d '{
    "model": "insightface-opencv",
    "img1": "https://example.com/alice_1.jpg",
    "img2": "https://example.com/alice_2.jpg"
  }'

Response:

{
  "verified": true,
  "distance": 0.27,
  "threshold": 0.35,
  "confidence": 23.1,
  "model": "insightface-opencv",
  "img1_area": { "x": 120.4, "y": 82.1, "w": 198.3, "h": 260.5 },
  "img2_area": { "x": 110.8, "y": 95.0, "w": 205.6, "h": 268.2 },
  "processing_time_ms": 412.0
}

1:N identification workflow (register → identify → forget)

This is the primary “face recognition” flow. Under the hood it uses LocalAI’s built-in in-memory vector store — no external database to stand up.

1. Register known faces:

   curl -sX POST http://localhost:8080/v1/face/register \
     -H "Content-Type: application/json" \
     -d '{
       "model": "insightface-buffalo-l",
       "name": "Alice",
       "img": "https://example.com/alice.jpg"
     }'
   # → {"id": "8b7...", "name": "Alice", "registered_at": "2026-04-21T..."}

2. Identify an unknown probe:

   curl -sX POST http://localhost:8080/v1/face/identify \
     -H "Content-Type: application/json" \
     -d '{
       "model": "insightface-buffalo-l",
       "img": "https://example.com/unknown.jpg",
       "top_k": 5
     }'
   # → {"matches": [{"id":"8b7...","name":"Alice","distance":0.22,"match":true,...}]}

3. Remove a person by ID:

   curl -sX POST http://localhost:8080/v1/face/forget \
     -d '{"id": "8b7..."}'
   # → 204 No Content

API reference

POST /v1/face/verify (1:1)

Returns verified, distance, threshold, confidence, model, img1_area, img2_area, and processing_time_ms. When anti_spoofing is set, the response also carries per-image liveness fields: img1_is_real, img1_antispoof_score, img2_is_real, img2_antispoof_score. A failed liveness check on either image forces verified=false regardless of similarity.

POST /v1/face/analyze

Returns demographic attributes for every detected face:

Only insightface-buffalo-l / insightface-buffalo-s populate age and gender (genderage head). insightface-opencv returns face regions with empty attributes — SFace has no demographic classifier. Emotion and race are always empty in the current release.

POST /v1/face/register (1:N enrollment)

Returns {id, name, registered_at}. The id is an opaque UUID used by /v1/face/identify and /v1/face/forget.

POST /v1/face/identify (1:N recognition)

Returns a list of matches sorted by ascending distance, each with id, name, labels, distance, confidence, and match (distance ≤ threshold).

POST /v1/face/forget

Returns 204 No Content on success, 404 Not Found if the ID is unknown.

POST /v1/face/embed

Returns the L2-normalized face embedding vector for the detected face.

Returns {embedding: float[], dim: int, model: string}. Dimension is 512 for the insightface ArcFace/MBF recognizers and 128 for OpenCV’s SFace.

Note: the OpenAI-compatible /v1/embeddings endpoint is intentionally text-only by contract (input is a string or list of strings of TEXT to embed) — passing an image data-URI there does nothing useful. Use /v1/face/embed for image inputs.

Reused endpoint

• POST /v1/detection — returns face bounding boxes with class_name: "face"; works for both engines.

Antispoofing (liveness detection)

All gallery entries ship the Silent-Face-Anti-Spoofing MiniFASNetV2 + MiniFASNetV1SE ensemble (Apache 2.0, ~4 MB total, CPU-only) alongside the face recognition weights. Set anti_spoofing: true on /v1/face/verify or /v1/face/analyze to run liveness on each detected face. The two models look at different crop scales and their softmax outputs are averaged before argmax — the upstream-recommended setup.

/v1/face/verify with liveness gating:

curl -sX POST http://localhost:8080/v1/face/verify \
  -H "Content-Type: application/json" \
  -d '{
    "model": "insightface-opencv",
    "img1": "https://example.com/alice_selfie.jpg",
    "img2": "https://example.com/alice_id_scan.jpg",
    "anti_spoofing": true
  }'

Response (fields added when anti_spoofing is enabled):

{
  "verified": true,
  "distance": 0.27,
  "threshold": 0.5,
  "confidence": 46.0,
  "model": "insightface-opencv",
  "img1_area": { "x": 120, "y": 82, "w": 198, "h": 260 },
  "img2_area": { "x": 110, "y": 95, "w": 205, "h": 268 },
  "img1_is_real": true,
  "img1_antispoof_score": 0.82,
  "img2_is_real": true,
  "img2_antispoof_score": 0.74,
  "processing_time_ms": 431.0
}

If either image fails liveness (is_real=false), verified is forced to false — similarity alone is not enough.

/v1/face/analyze reports per-face is_real and antispoof_score when the flag is set.

Fail-loud semantics. If anti_spoofing: true is sent against a model installed without the MiniFASNet files (e.g. a custom entry that only listed the face recognition weights), the request returns a gRPC FAILED_PRECONDITION error — the endpoint will never silently return is_real=false. Re-install the gallery entry or point the backend at a model that bundles the MiniFASNet ONNX files.

Choosing an engine

The recommended default threshold for /v1/face/verify and /v1/face/identify depends on the recognizer:

Pass threshold explicitly when switching engines — the per-engine default only fires when the field is omitted.

Related features

• Object Detection — generic bounding-box detection; /v1/detection works with the insightface backend too.
• Embeddings — raw vector extraction; face embeddings live in the same endpoint under the hood.
• Stores — the generic vector store powering the 1:N recognition pipeline.