# Higgsfield AI Soul

Higgsfield AI Soul is a model that adds mood and aesthetic depth to images. It interprets scene or character descriptions through light, color, and texture to create natural or artistic visuals. The model adapts easily to different styles and works especially well with portraits, fashion looks, and atmospheric scenes. Even with simple prompts, it can produce results that balance realism with a subtle artistic touch.

## API Information

- **Model Slug:** higgsfield-ai-soul
- **Branded URL:** https://www.eachlabs.ai/higgsfield/higgsfield/higgsfield-ai-soul
- **Provider:** Higgsfield
- **Category:** Image to Image
- **Output Type:** image
- **Status:** active
- **Version:** 0.0.1
- **Base Cost:** 720p/default, batch 1/default: $0.09
- **Estimated Processing Time:** 20 seconds
- **Last Updated:** 2026-06-10
- **Interactive Demo:** https://www.eachlabs.ai/ai-models/higgsfield-ai-soul

## Pricing

- **Charge Type:** dynamic
- **Estimated Price (default example):** $0.0900
- **Pricing Details:** 720p/default, batch 1/default: $0.09

### Pricing Rules

| Condition | Pricing |
| --- | --- |
| quality eq_i "1080p" AND batch_size eq_i "4" | 1080p, batch 4: $0.31 |
| quality eq_i "1080p" | 1080p, batch 1/default: $0.19 |
| batch_size eq_i "4" | 720p/default, batch 4: $0.13 |
| Rule 4 | 720p/default, batch 1/default: $0.09 |

## Input Schema

| Parameter | Type | Required | Default | Constraints | Description |
|-----------|------|----------|---------|-------------|-------------|
| prompt | string | Yes | - | - | - |
| aspect_ratio | string | Yes | - | 1152x2048,2048x1152,2048x1536,1536x2048,1344x2016,2016x1344,960x1696,1536x1536,1536x1152,1696x960,1152x1536,1088x1632,1632x1088 | - |
| style_id | string | No | - | {"b3c8075a-cb4c-42de-b8b3-7099dd2df672":{"title":"Creatures","image":"https://cdn.higgsfield.ai/soul-style/ce4416fd-37a7-42fe-af0d-10167d2cfa0a.webp"},"1fc861ed-5923-41a6-9963-b9f04681dddd":{"title":"Medieval","image":"https://cdn.higgsfield.ai/soul-style/6d384dd7-f756-41de-9628-06c6cb204423.jpg"},"40ff999c-f576-443c-b5b3-c7d1391a666e":{"title":"Spotlight","image":"https://cdn.higgsfield.ai/soul-style/47181b3d-429b-4f87-bb7c-2c5ca96da893.webp"},"a5f63c3b-70eb-4979-af5e-98c7ee1e18e8":{"title":"Giant People","image":"https://cdn.higgsfield.ai/soul-style/b6552305-c29f-4f41-9252-49c5470b2b73.webp"},"d2e8ba04-9935-4dee-8bc4-39ac789746fc":{"title":"Subway","image":"https://cdn.higgsfield.ai/soul-style/af958840-be6d-4444-b441-22b7e1891f5d.webp"},"6fb3e1f5-d721-4523-ac38-9902f2b2b850":{"title":"Library","image":"https://cdn.higgsfield.ai/soul-style/4d95d3b1-0db6-4125-a0d7-ba9ba770872f.webp"},"1cb4b936-77bf-4f9a-9039-f3d349a4cdbe":{"title":"Realistic","image":"https://cdn.higgsfield.ai/soul-style/acf8f24d-f567-4b7a-bede-aa63cb7c90dd.jpg"},"ca4e6ad3-3e93-4e03-81a0-d1722d2c128b":{"title":"DigitalCam","image":"https://cdn.higgsfield.ai/soul-style/0e82377e-e3dd-48a8-94fd-04a4ed038be4.webp"},"255f4045-d68b-42b1-9e4c-f49d3263a9d7":{"title":"Grillz Selfie","image":"https://cdn.higgsfield.ai/soul-style/f20194ec-4c8f-4ed5-9f23-152f7d09ecec.webp"},"cc099663-9621-422e-8626-c8ee68953a0c":{"title":"Bleached Brows","image":"https://cdn.higgsfield.ai/soul-style/aa99b83d-fe92-4542-8dab-b0c708d0cf30.jpg"},"7696fd45-6e67-47d7-b800-096ce21cd449":{"title":"Sitting on the Street","image":"https://cdn.higgsfield.ai/soul-style/e4cce90c-943a-45be-a324-0a92fe0fcb9d.jpg"},"d3e2b71d-b24b-462e-bd96-12f7a22b5142":{"title":"Crossing the street","image":"https://cdn.higgsfield.ai/soul-style/9ef39e1b-693e-4560-89e0-6dfb670f42ea.webp"},"4c24b43b-1984-407a-a0ae-c514f29b7e66":{"title":"Angel Wings","image":"https://cdn.higgsfield.ai/soul-style/2c8e708f-9fef-498c-bf66-bebfd8452705.webp"},"88126a43-86fb-4047-a2d6-c9146d6ca6ce":{"title":"Duplicate","image":"https://cdn.higgsfield.ai/soul-style/0f7a191d-93ea-40a5-ad16-ca2b85fdd753.jpg"},"ff1ad8a2-94e7-4e70-a12f-e992ca9a0d36":{"title":"Quiet luxury","image":"https://cdn.higgsfield.ai/soul-style/af2a00ab-3f9f-451b-8c0b-4abc81adb12a.webp"},"524be50a-4388-4ff5-a843-a73d2dd7ef87":{"title":"Elevator Mirror","image":"https://cdn.higgsfield.ai/soul-style/0139a8e4-eb76-474a-a13c-d764d38674d1.jpg"},"294bb3ee-eaef-4d2a-93e3-164268803db4":{"title":"360 cam","image":"https://cdn.higgsfield.ai/soul-style/a8951200-becf-4fa3-b41b-3a58e7ebcd72.jpg"},"62355e77-7096-45ae-9bea-e7c5b88c3b70":{"title":"Glitch","image":"https://cdn.higgsfield.ai/soul-style/bed53d7d-3061-4666-bcd6-2ad890387f97.webp"},"86fc814e-856a-4af0-98b0-d4da75d0030b":{"title":"FashionShow","image":"https://cdn.higgsfield.ai/soul-style/c056f71c-31c6-48f5-8d4c-b13bab458ede.jpg"},"34c50302-83ff-487d-b3a9-e35e501d80a7":{"title":"PixeletedFace","image":"https://cdn.higgsfield.ai/soul-style/a6bf56b4-eb67-49e5-aa26-e2dd45882100.webp"},"bc00b419-f8ca-4887-a990-e2760c3cb761":{"title":"Sunbathing","image":"https://cdn.higgsfield.ai/soul-style/97b9e378-ad9d-415e-b3f4-f4c8890dfb60.webp"},"7fa63380-64b7-48b1-b684-4c9ef37560a9":{"title":"Paper Face","image":"https://cdn.higgsfield.ai/soul-style/51362a07-60b0-4270-9125-03dea74ed03e.webp"},"f5c094c7-4671-4d86-90d2-369c8fdbd7a5":{"title":"90s Grain","image":"https://cdn.higgsfield.ai/soul-style/a5c20546-38eb-4d61-8eb2-5290908d55bc.jpg"},"372cc37b-9add-4952-a415-53db3998139f":{"title":"Geominimal","image":"https://cdn.higgsfield.ai/soul-style/670dae78-6481-4aab-b986-5060b1ae43ed.webp"},"0fe8ad66-ff61-411f-9186-b392e140b18c":{"title":"Foggy Morning","image":"https://cdn.higgsfield.ai/soul-style/3cbfe1d2-421e-421a-b7bd-dbee471a1d65.jpg"},"d8a35238-ba42-48a0-a76a-186a97734b9d":{"title":"Overexposed","image":"https://cdn.higgsfield.ai/soul-style/e668934b-9b36-4263-86e0-cdd58f7c267b.jpg"},"26241c54-ed78-4ea7-b1bf-d881737c9feb":{"title":"Sunset beach","image":"https://cdn.higgsfield.ai/soul-style/71d9f310-f966-41ec-a009-a87167bcbebe.webp"},"70fbb531-5ee2-492e-8c53-5dbd6923e8c2":{"title":"Giant Accessory","image":"https://cdn.higgsfield.ai/soul-style/f66daa40-480f-49f1-90ed-6b2af23a4554.jpg"},"9de8ed26-c8dd-413c-a5e3-47eec97bc243":{"title":"RingSelfie","image":"https://cdn.higgsfield.ai/soul-style/d5d6f14d-9ba1-4f29-96d9-792280f50782.jpg"},"a13917c7-02a4-450f-b007-e72d53151980":{"title":"Street view","image":"https://cdn.higgsfield.ai/soul-style/1c59f291-cf9d-45c1-92b0-53768f372d0e.webp"},"710f9073-f580-48dc-b5c3-9bbc7cbb7f37":{"title":"90's Editorial","image":"https://cdn.higgsfield.ai/soul-style/9cff0472-88b6-4ee2-a1e6-0976f79cdbe8.webp"},"181b3796-008a-403b-b31e-a9b760219f17":{"title":"2000s Cam","image":"https://cdn.higgsfield.ai/soul-style/acc02fcd-ce68-4019-b517-089025455ed6.jpg"},"07a85fb3-4407-4122-a4eb-42124e57734c":{"title":"CCTV","image":"https://cdn.higgsfield.ai/soul-style/ed84e65b-1c57-4ce2-bef0-8e98c9e6667f.webp"},"71fecd8c-6696-42df-b5eb-f69e4150ca01":{"title":"0.5 Outfit","image":"https://cdn.higgsfield.ai/soul-style/d014f6a2-792e-429b-b47a-33352ed95e2d.jpg"},"dab472a6-23f4-4cf8-98fe-f3e256f1b549":{"title":"Amalfi Summer","image":"https://cdn.higgsfield.ai/soul-style/61d13bb8-fbe2-4816-8d2b-231e5ef68930.webp"},"f96913e8-2fcf-4358-8545-75dd6c34c518":{"title":"Bimbocore","image":"https://cdn.higgsfield.ai/soul-style/fb283ea7-2fdb-4b50-acd3-f38d83d2c93e.jpg"},"8dd89de9-1cff-402e-88a8-580c29d91473":{"title":"0.5 Selfie","image":"https://cdn.higgsfield.ai/soul-style/add67dde-7dbf-4565-93e9-a9bb121e03b9.jpg"},"ba3d7634-447e-455c-98e3-63705d5403b8":{"title":"Sand","image":"https://cdn.higgsfield.ai/soul-style/665ca5a4-e1e7-4fed-8d53-01177ae0518d.jpg"},"83caff04-691c-468c-b4a0-fd6bbabe062b":{"title":"Vintage PhotoBooth","image":"https://cdn.higgsfield.ai/soul-style/e41faf36-e634-485d-be55-edcce8099043.jpg"},"b7c621b5-9d3c-46a3-8efb-4cdfbc592271":{"title":"Babydoll MakeUp","image":"https://cdn.higgsfield.ai/soul-style/1d334a76-18b8-4d7e-9f77-1f3b5623d872.jpg"},"1900111a-4ce8-42a7-9394-7367f0e0385c":{"title":"Through The Glass","image":"https://cdn.higgsfield.ai/soul-style/c6ffc0df-5487-417b-82d9-2ec54d2aa122.jpg"},"36061eb7-4907-4cba-afb1-47afcf699873":{"title":"Gallery","image":"https://cdn.higgsfield.ai/soul-style/88d27015-a635-4c0f-bf47-19f7c280a659.webp"},"7df83cc9-1e13-4bd0-b6ff-1e6a456b9e5a":{"title":"Eating Food","image":"https://cdn.higgsfield.ai/soul-style/d58fc1ab-f332-4e9b-bdd3-257164e92930.jpg"},"5b6f467e-f509-4afe-a8db-4c07a6f3770d":{"title":"Swords Hill","image":"https://cdn.higgsfield.ai/soul-style/fe9aa7ca-01be-443f-be91-d55efb7691e7.jpg"},"e454956b-caf2-4913-a398-dbc03f1cbedf":{"title":"Office beach","image":"https://cdn.higgsfield.ai/soul-style/71391c5d-1171-4b32-9c74-6e97413ab33c.jpg"},"5ad23bca-4a4b-4316-8c59-b80d7709d8ee":{"title":"Help It's Too Big","image":"https://cdn.higgsfield.ai/soul-style/77e056f6-89db-4c06-833a-91f143ad4612.webp"},"0089e17c-d0f0-4d0c-b522-6d25c88a29fc":{"title":"Japandi","image":"https://cdn.higgsfield.ai/soul-style/c63129ae-e4db-4bdf-9617-f7201f4a4cd1.jpg"},"1b798b54-03da-446a-93bf-12fcba1050d7":{"title":"iPhone","image":"https://cdn.higgsfield.ai/soul-style/9627c330-e5e0-428d-8414-aeae83d57819.jpg"},"96758335-d1d1-42b7-9c21-5ac38c433485":{"title":"Gorpcore","image":"https://cdn.higgsfield.ai/soul-style/fbbfa936-7e5e-44f4-ac9c-774b38967130.jpg"},"5a72fec7-a12e-43db-8ef3-1d193b4f7ab4":{"title":"Indie sleaze","image":"https://cdn.higgsfield.ai/soul-style/3a5a91b6-330d-407e-8b55-c3900a95f0db.jpg"},"7f21e7bd-4df6-4cef-a9a9-9746bceaea1d":{"title":"Fairycore","image":"https://cdn.higgsfield.ai/soul-style/a9f12667-0dd4-452e-b704-4ac8f29a69d9.webp"},"0367d609-dfa1-4a81-a983-b2b19ecd6480":{"title":"Tumblr","image":"https://cdn.higgsfield.ai/soul-style/8d797478-cc70-47e1-9a35-242852667eb0.jpg"},"0c636e12-3411-4a65-8d86-67858caf2fa7":{"title":"Avant-garde","image":"https://cdn.higgsfield.ai/soul-style/62cfc3fb-bb46-4977-9fbb-cee0b68504d4.jpg"},"ea6f4dc0-d6dd-4bdf-a8cf-94ed1db91ab2":{"title":"HairClips","image":"https://cdn.higgsfield.ai/soul-style/35a6bbaa-4332-4537-8fce-28012da558be.jpg"},"cbefda85-0f76-49bd-82d7-9bcd65be00ca":{"title":"Y2K Posters","image":"https://cdn.higgsfield.ai/soul-style/a8d0899d-ec67-49a4-af7f-5fcf0a8f27be.webp"},"b7908955-2868-4e35-87a0-35e50cb92e5d":{"title":"Object Makeup","image":"https://cdn.higgsfield.ai/soul-style/bb5c5572-693a-4b21-ba6e-329dc7da2af3.webp"},"0b4dac9a-f73a-4e5b-a5a7-1a40ee40d6ac":{"title":"Graffiti","image":"https://cdn.higgsfield.ai/soul-style/65d773e0-b947-4edc-982e-493ce1f04dc3.webp"},"facaafeb-4ab5-4384-92a1-b4086180e9ac":{"title":"2000s Fashion","image":"https://cdn.higgsfield.ai/soul-style/12160548-47c0-4652-9e2e-3fc9fb413d47.webp"},"62ba1751-63af-4648-a11c-711ac64e216a":{"title":"Night Beach","image":"https://cdn.higgsfield.ai/soul-style/270b4eb1-e9b1-4909-9f5e-50ce99697cc6.jpg"},"811de7ab-7aaf-4a6b-b352-cdea6c34c8f1":{"title":"Movie","image":"https://cdn.higgsfield.ai/soul-style/a8417fb3-3801-4e00-b86f-57a55d59eacd.webp"},"12eda704-18e5-4783-aa0f-deba5296cc83":{"title":"Long legs","image":"https://cdn.higgsfield.ai/soul-style/69a45320-c6ad-4242-8154-915121f42937.webp"},"5659c554-9367-4a27-8c66-333c072cbbc2":{"title":"7\\","image":"https://cdn.higgsfield.ai/soul-style/ebdf01bb-e964-4d7e-9d75-f0735492a5aa.webp"},"464ea177-8d40-4940-8d9d-b438bab269c7":{"title":"General","image":"https://cdn.higgsfield.ai/soul-style/671935ec-51a6-4f9d-9cb4-39661b9a9814.jpg"},"4b66c2db-8166-4293-b1aa-5269c9effb07":{"title":"Nail Check","image":"https://cdn.higgsfield.ai/soul-style/dc1274f0-b58d-4603-9f01-97337e512cac.jpg"},"bd78cfc6-9b92-4889-9347-f21dbf0a269c":{"title":"Coquette core","image":"https://cdn.higgsfield.ai/soul-style/9ce0b7cb-2252-4047-8c9a-291a90395e66.jpg"},"2fcf02e2-919a-4642-8b31-d58bde5e6bd9":{"title":"Mixed Media","image":"https://cdn.higgsfield.ai/soul-style/ca50ff8d-ed44-4043-b1ec-1c62247d4e44.webp"},"d24c016c-9fb1-47d0-9909-19f57a2830d4":{"title":"Selfcare","image":"https://cdn.higgsfield.ai/soul-style/6a5baf93-e0dc-4123-9f7b-868eab9b4e04.jpg"},"ad9de607-3941-4540-81ea-ba978ef1550b":{"title":"Grunge","image":"https://cdn.higgsfield.ai/soul-style/dc742858-f56d-4fcc-9736-e7c2a3005b84.jpg"},"673cf0d4-c193-4fa2-8ad3-b4db4611e3ae":{"title":"505room","image":"https://cdn.higgsfield.ai/soul-style/293ed3aa-0d8e-4073-839a-d1698eafdf85.jpg"},"3f90dc5b-f474-4259-95c4-d29fbd6be645":{"title":"Flight mode","image":"https://cdn.higgsfield.ai/soul-style/91490e65-80c2-42a0-bbec-971392a77462.webp"},"bab6e4bd-9093-4bb5-a371-01ef6cbd58ad":{"title":"Escalator","image":"https://cdn.higgsfield.ai/soul-style/c23eef21-0f45-4e93-8818-1da4a3061d01.webp"},"cc4e7248-dcfe-4c93-b264-2ab418a7556b":{"title":"Fisheye","image":"https://cdn.higgsfield.ai/soul-style/cacbe40f-8551-481a-a8f3-57692fc4ba4d.webp"},"30458874-d9c0-4d5a-b2b7-597e0eee2404":{"title":"Shoe Check","image":"https://cdn.higgsfield.ai/soul-style/55009845-16f0-43b0-a395-48c2bbe1f4d8.jpg"},"53bdadfa-8eb6-4eaa-8923-ebece4faa91c":{"title":"Rainy Day","image":"https://cdn.higgsfield.ai/soul-style/dfa98f2e-9b22-4272-a030-a5296b3b9b6a.jpg"},"de0118ba-7c27-49f7-9841-38abe2aae8e1":{"title":"Mt. Fuji","image":"https://cdn.higgsfield.ai/soul-style/7bc1844f-33b1-4578-b25c-2c8ab373e350.webp"},"82edba1e-b093-4484-a25e-9276e0454999":{"title":"Invertethereal","image":"https://cdn.higgsfield.ai/soul-style/5a70012c-02c4-45aa-934b-768587a2d0e4.jpg"},"6b9e6b4d-325a-4a78-a0fb-a00ddf612380":{"title":"Y2K","image":"https://cdn.higgsfield.ai/soul-style/75e73009-dd0c-4b9d-b0ef-93544b7e4491.jpg"},"99de6fc5-1177-49b9-b2e9-19e17d95bcaf":{"title":"Tokyo Streetstyle","image":"https://cdn.higgsfield.ai/soul-style/b8665543-a419-4fda-a8d0-b10f07b8c03d.jpg"},"b9e2d7dc-78e6-4f7d-95dd-b62690e7b200":{"title":"Artwork","image":"https://cdn.higgsfield.ai/soul-style/40243714-8b1c-44bc-87f2-ef3aacc2daf9.webp"},"a2a42ada-75cc-42a9-be12-cb16c1dec2a8":{"title":"Glazed doll skin makeup","image":"https://cdn.higgsfield.ai/soul-style/3c0eb808-90bf-4c84-b6fa-caae44265ef3.jpg"}} | - |
| style_strength | number | No | - | 0–1 | - |
| quality | string | No | 720p | 720p,1080p | - |
| seed | integer | No | - | - | - |
| custom_reference_id | string | No | - | - | - |
| image_url | string | No | - | - | - |
| custom_reference_strength | number | No | - | 0–1 | - |
| batch_size | integer | No | 1 | 1,4 | - |

## Example Request

```bash
curl -X POST https://api.eachlabs.ai/v1/prediction/ \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "higgsfield-ai-soul",
  "input": {
    "aspect_ratio": "1152x2048",
    "prompt": "Golden midday light washes across pale stone, illuminating every detail with a soft but vibrant clarity. The East Asian model stands in a statuesque pose, weight shifted elegantly to one hip, one hand resting lightly against her frayed denim while the other lifts just enough to frame the cropped silk top. She faces the camera directly, her gaze piercing yet calm, lips gently parted, expression carrying a quiet strength. Her posture elongates her form with subtle curves, shoulders relaxed yet intentional, embodying effortless poise. The silk top gleams as it catches fragments of sunlight, while the distressed indigo denim contrasts with tactile depth—every loose thread sharp in focus. Balanced daylight ensures her face is crystal clear, no harsh shadows, only a luminous radiance across skin and fabric. The background of jagged stone fades softly at the edges, a gentle vignette guiding all attention to her confident stance and direct connection with the lens. The frame, shot at eye-level with a 50 mm focus, exudes high-fashion editorial energy—where elegance, strength, and natural textures converge in a hyperreal, cinematic still."
  }
}'
```

## Output Schema

Response returned by `GET /v1/prediction/{id}` when the job completes:

```json
{
  "status": "success",
  "predictionID": "string",
  "output": "string (URL of generated image)",
  "metrics": {
    "predict_time": "number (seconds)"
  }
}
```

## Polling

```bash
curl https://api.eachlabs.ai/v1/prediction/{PREDICTION_ID} \
  -H "Authorization: Bearer YOUR_API_KEY"
```

| Status | Meaning |
|--------|---------|
| `processing` | Still running — poll again |
| `success` | Done — read `output` |
| `error` | Failed — read `message` / `details` |

## Webhook (alternative to polling)

Pass `"webhook_url": "https://your.host/path"` in the create request. Eachlabs POSTs this payload when the job ends:

```json
{
  "exec_id": "prediction-uuid",
  "status": "succeeded",
  "output": "https://...",
  "error": ""
}
```

`status` is `"succeeded"` or `"failed"`. `exec_id` equals the `predictionID` from create. Return 2xx within 30 seconds.

## Errors

Error body: `{ "status": "error", "message": "...", "details": "..." }`

| Code | Meaning |
|------|---------|
| `400` | Invalid input |
| `401` | Missing / invalid `Authorization` bearer token |
| `404` | Unknown model or prediction id |
| `429` | Rate limit — 100 creates / min, 10 concurrent per key |
| `5xx` | Retry with backoff |

## Overview

**higgsfield-ai-soul — Image-to-Image AI Model**

Developed by Higgsfield as part of the higgsfield family, **higgsfield-ai-soul** is an advanced image-to-image AI model that infuses input images with mood, aesthetic depth, and artistic flair through precise control of light, color, and texture. Creators struggling to elevate static photos into emotionally resonant visuals find a powerful solution in higgsfield-ai-soul, which excels at transforming portraits, fashion shots, and atmospheric scenes into photorealistic or stylized masterpieces with subtle artistic touches. This **Higgsfield image-to-image** tool stands out for its exceptional rendering of fine details like helmet reflections, scratches, and skin textures, delivering outputs that balance realism and creativity even from simple prompts.

Ideal for users seeking an **image-to-image AI model** with cinematic quality, higgsfield-ai-soul powers community projects on Higgsfield's platform, enabling quick iterations without complex editing workflows.

## Usage Notes

- API Base URL: `https://api.eachlabs.ai/v1`
- Authentication: send `Authorization: Bearer YOUR_API_KEY`. Generate a key from the Eachlabs dashboard at https://www.eachlabs.ai/dashboard/api-keys.
- File-typed parameters (`*_url`, `image_url`, `video_url`, `audio_url`, etc.) accept publicly-reachable HTTPS URLs only. Upload your asset first (GCS / S3 / your CDN) and pass the resulting URL. Data-URIs and localhost URLs are rejected.
- For structured parameters (arrays / objects) send real JSON values, not stringified payloads.
- Monetary values are reported in USD; per-token / per-megapixel rates may be billed in micro-cents internally.
- Prefer `webhook_url` over polling for long-running predictions — see the Webhook Callback section.