Creative Specs

Praevis accepts video (VAST), banner, and native ad formats. All creatives must be served over HTTPS and comply with the quality requirements below.

Multiple Creatives per Campaign

Upload multiple creatives per campaign with weighted rotation for A/B/C testing. Test different creative variants within a single campaign without managing separate campaigns.

Campaign Setup

Campaigns support both single creative and multiple creative configurations. Use the Campaign API to configure creative rotation:

Single Creative

{
  "campaign_id": "summer-promo-2026",
  "campaign_name": "Summer Promo",
  "targeting": {
    "countries": ["ARE", "SAU"],
    "devices": ["ctv"]
  },
  "bidding": {
    "base_cpm": 2.50,
    "max_cpm": 5.00
  },
  "budget": {
    "daily_cents": 50000,
    "total_cents": 1500000
  },
  "creative": {
    "vast_url": "https://cdn.example.com/hero.xml",
    "impression_trackers": ["https://tracker.example.com/imp?creative=hero"],
    "creative_id": "hero-1"
  }
}

Multiple Creatives with Weighted Rotation

{
  "campaign_id": "summer-promo-abc-test",
  "campaign_name": "Summer Promo - A/B/C Test",
  "targeting": {
    "countries": ["ARE", "SAU"],
    "devices": ["ctv"]
  },
  "bidding": {
    "base_cpm": 2.50,
    "max_cpm": 5.00
  },
  "budget": {
    "daily_cents": 50000,
    "total_cents": 1500000
  },
  "creatives": [
    {
      "creative_id": "hero-variant",
      "vast_url": "https://cdn.example.com/hero.xml",
      "impression_trackers": ["https://tracker.example.com/imp?creative=hero"],
      "weight": 50
    },
    {
      "creative_id": "family-variant",
      "vast_url": "https://cdn.example.com/family.xml",
      "impression_trackers": ["https://tracker.example.com/imp?creative=family"],
      "weight": 30
    },
    {
      "creative_id": "adventure-variant",
      "vast_url": "https://cdn.example.com/adventure.xml",
      "impression_trackers": ["https://tracker.example.com/imp?creative=adventure"],
      "weight": 20
    }
  ],
  "rotation_strategy": "weighted"
}

Rotation Strategies

Weight Distribution

• Weights are relative values (don’t need to sum to 100)
• If no weights provided, creatives are distributed equally
• Weights are auto-normalized internally

Examples:

// 50%, 30%, 20% distribution
"weights": [50, 30, 20]
 
// Same as above - auto-normalized
"weights": [5, 3, 2]
 
// Equal distribution - weights ignored
"rotation_strategy": "round_robin"

Validation Rules

// ❌ INVALID - Both fields provided
{
  "creative": {...},
  "creatives": [...]
}
 
// ❌ INVALID - Neither field provided
{
  "targeting": {...}
}
 
// ✅ VALID - Single creative
{
  "creative": {...}
}
 
// ✅ VALID - Multiple creatives
{
  "creatives": [...]
}

Testing Your Creatives

Use impression_trackers to monitor which creative variant is served:

{
  "creative_id": "hero-variant",
  "impression_trackers": [
    "https://tracker.example.com/imp?campaign=summer&creative=hero"
  ]
}

Praevis fires impression trackers when the creative is served, allowing you to track performance per variant.

Creative Performance

Track creative rotation distribution via your impression trackers. Compare:

• Win rate per creative_id
• Click-through rate per creative_id
• Conversion rate per creative_id

Adjust weights based on performance data to optimize campaign results.

Video / VAST

VAST versions

Video specs

These specs are recommendations for best compatibility across publishers. Praevis does not hard-reject creatives outside these ranges — but publishers’ video players may. MP4 container and H.264 codec are strongly recommended. Other resolutions and durations will work but may have lower fill rates.

CTV-specific requirements

• Min bitrate: 2,000 kbps (< 2,000 kbps may be rejected by CTV players)
• Skip: Praevis publishers control skip settings — respect imp.video.skip in the bid request
• MRAID: Not applicable on CTV
• VPAID: Not supported — use VAST 4.x with <Verification> for viewability instead

Wrapper depth

Maximum VAST wrapper depth: 3 levels. Deeper chains may time out or be rejected by players.

Banner

Supported sizes

Banner specs

Native (OpenRTB Native 1.2)

Required assets

Optional assets

• Rating (1–5 stars)
• Price
• Downloads count

MRAID

MRAID 3.0 is supported for mobile interstitials and rich media. Use only in imp.banner context where imp.banner.api includes 5 (MRAID 3.0).

Not applicable on CTV.

Blocked ad categories

The following categories are not accepted on the Praevis network:

Publishers may also have category block lists — these are applied per publisher before the auction.

Audio

Audio specs

Audio companion

Audio campaigns can include a companion banner (300x250 recommended) displayed alongside the audio player.

Automated Creative Validation

Praevis automatically validates all creatives when you create or update a campaign. Validation is non-blocking — warnings are returned in the API response but creatives still serve.

What we check

Example API response with warnings

{
  "id": "campaign-123",
  "status": "active",
  "creative_warnings": [
    { "creative_id": "hero-1", "warning": "no_audio_track" },
    { "creative_id": "banner-1", "warning": "non_standard_size:300x251" }
  ]
}

Creative CDN

All creatives are automatically cached to the Praevis CDN (courier.praevis.com) at 330+ edge locations. DSP origin URLs are never exposed to SSAI platforms or publishers.

• VAST wrappers are unwrapped and the underlying media file is cached
• Cached creatives serve from the nearest edge location
• CDN URLs are stable (content-addressed hashing)

Creative quality standards

Creatives must:

• Load within 1.5s on a standard connection
• Not redirect through more than 3 domains
• Not auto-play audio without user interaction (web)
• Not expand beyond declared dimensions
• Not trigger unexpected downloads
• Not use deceptive click patterns

Reporting creative performance

View creative-level stats via the API:

GET /api/demand/sources/{DSP_ID}/stats?period=7d&breakdown=creative

Returns win rate, impressions, and eCPM per creative ID (crid from your bid response).