Hi Vapi Support, I've found that warm transfers work on US infrastructure but fail on EU infrastructure with identical configuration. The Issue: EU deployment: Transfer executes as blind transfer (agent gets direct ring, no AI introduction) US deployment: Works correctly (AI speaks to agent first, then connects customer) Test Evidence: EU (failed): Call ID: 019c707d-10ac-7774-a90e-6bc737e58d5f Time: 2026-02-18 11:22 UTC Config: warm-transfer-say-summary, summaryPlan enabled Result: Agent received direct ring with no context US (success): Call ID: 019c7097-12ed-788b-9084-b6be1bfae644 Time: 2026-02-18 11:51 UTC Config: warm-transfer-experimental, summaryPlan enabled Result: AI spoke to agent first, gave summary, then connected customer Setup (identical for both): Twilio provider (AC39c92ac4437c9e6b82360b575d27bf6e) PSTN transport Destination: +447460233137 EU Org: 27aacff0-0a61-44be-8b4e-ec38aecf8511 US Org: 47944269-05c6-4837-b6fe-9ea5c06c2618 Already Tried: Multiple warm transfer modes Verified summaryPlan.enabled = true Tested with/without sipVerb Confirmed tool is properly configured Questions: Is warm transfer supported on api.eu.vapi.ai? If not, when will it be available? Can you review the call IDs to confirm the behavior difference? Why This Matters: We need EU infrastructure for GDPR compliance but also require warm transfers. Currently blocked from production. Can you help clarify if this is a known limitation? Thanks!

Hi, thanks for the detailed report, this looks like a regional limitation or bug on EU infrastructure. With identical configs working in the US but failing in EU, it suggests warm transfer with AI handoff isn’t fully supported on api.eu.vapi.ai yet. Can you confirm if this is a known limitation and when it will be fixed? Also, is there a GDPR-compliant workaround we can use in the meantime? @MoSan

Yes exactly! that's what I'm trying to confirm. From my testing: US infrastructure (api.vapi.ai): Warm transfer works perfectly EU infrastructure (api.eu.vapi.ai): Same config executes as blind transfer I need the Vapi team to confirm: Is warm transfer supported on EU infrastructure? If not, when will it be available? Any GDPR-compliant workaround in the meantime? This is blocking us from production on EU since we need both data residency and warm transfers. Call IDs for reference: EU (failed): 019c707d-10ac-7774-a90e-6bc737e58d5f US (worked): 019c7097-12ed-788b-9084-b6be1bfae644 @Vapi @James Christopher @User

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