1. The Programmatic Plumbing — OpenRTB 2.5 Everywhere
Every on-device exchange that’s live today speaks OpenRTB 2.5. The 2024-2025 spec refresh added ID-Provenance flags (source.idp) plus experimental switches for Privacy Sandbox testing, so bidders can see where any identifier originated and whether it’s a Protected-Audience cohort.
Pro tip for rookies: if your DSP already parses standard 2.5 JSON, you’re 90% integrated; most OEM quirks hide in ext objects that label placements like setup_wizard, push_alert, or lock_screen.
2. Who’s Really Ready for Real-Time?
| OEM | RTB Status | What You Need to Know |
| Xiaomi – Mi Ads | Full via Vungle Exchange (oRTB 2.5) | Bids in USD, full schain, MRAID-3 & OMID listed in api array. |
| OPPO – ColorOS Ads | Direct Real-Time API (JSON clone of ORTB) | Opened to third-party DSPs in Q1 2025, 2× request volume since launch; field names differ slightly (deviceId vs didsha1). |
| Transsion – Eagllwin | Private “oRTB-lite” Beta | Testing rewarded & interstitial formats; public rollout promised for H2 2025. |
If your bidder already handles vanilla 2.5, Xiaomi is plug-and-play. OPPO may need a thin field-mapper; Transsion is still invite-only.
3. Creative Specs You’ll Meet on-Device
- MRAID 3 for expandable, lock-screen, and setup-wizard units (declared as api=6). Xiaomi and OPPO both list it in bid requests.
- VAST 4.2 for splash video (Xiaomi) and feed video (OPPO).
- IAB Native object embedded under imp.native for installer cards inside system folders.
Beginner takeaway: If your tag can already serve MRAID 3, VAST 4.2 or IAB Native, you’re compliant with all three OEMs out of the gate.
4. Viewability & Brand-Safe Verification
The Open Measurement (OM) SDK 1.4 ships with Google Mobile Ads SDK 18.1+, which most system apps embed, so IAS, MOAT and DoubleVerify tags fire natively on Xiaomi and OPPO inventory.
In 2024 the IAB Tech Lab extended OM support to Samsung TV and LG TV platforms — proof the spec is spreading across hardware families.
Reality check: OM is fully certified for Xiaomi lock-screen and OPPO feed placements; Transsion’s beta feed has not yet completed certification.
5. Four-Step Starter Checklist
- Confirm endpoint flavour
Ask your DSP if they already ingest Xiaomi (via Vungle Exchange) or OPPO’s Real-Time API; if not, provide the endpoint URL and test keys. - Map custom fields
Besides standard 2.5 nodes, parse ext.scene (placement) plus the new ID-Provenance map — essential for compliant targeting under Privacy Sandbox. - Enable OM viewability
Add omid_partner_name in your creative tags; Xiaomi and OPPO auto-fire OM events if present. - Start cheap, ramp fast
Begin with test bids around $2 CPM — win rates on setup-screen impressions are high. Once CTR data rolls in, migrate to oCPC or tCPA inside the vendor console for efficient scaling.
Key Takeaways for 2025 UA Teams
- OpenRTB 2.5 is table stakes, but each OEM adds its own JSON seasoning.
- Xiaomi is turnkey today; OPPO is the next big wave; Transsion is warming up.
- Open Measurement SDK makes on-device viewability as auditable as traditional in-app inventory.
- Follow the checklist above and you can buy impressions that appear the moment a user powers on a new phone — no more CSV hand-offs or weeks of manual IOs.
Master these basics now and you’ll turn OEM programmatic into your quickest, lowest-friction user-acquisition channel for the rest of 2025 — and beyond.
