diff --git a/httpserver/src/main/kotlin/tbdex/sdk/httpserver/TbdexHttpServer.kt b/httpserver/src/main/kotlin/tbdex/sdk/httpserver/TbdexHttpServer.kt
index dc4dcccd..119dc811 100644
--- a/httpserver/src/main/kotlin/tbdex/sdk/httpserver/TbdexHttpServer.kt
+++ b/httpserver/src/main/kotlin/tbdex/sdk/httpserver/TbdexHttpServer.kt
@@ -24,7 +24,7 @@ import tbdex.sdk.httpserver.models.OfferingsApi
 import tbdex.sdk.httpserver.models.SubmitCallback
 import tbdex.sdk.protocol.models.MessageKind
 import tbdex.sdk.protocol.models.Offering
-import tbdex.server.tbdex.sdk.httpserver.handlers.submitRfq
+import tbdex.sdk.httpserver.handlers.submitRfq
 
 fun main() {
   val serverConfig = TbdexHttpServerConfig(
diff --git a/httpserver/src/main/kotlin/tbdex/sdk/httpserver/handlers/SubmitRfq.kt b/httpserver/src/main/kotlin/tbdex/sdk/httpserver/handlers/SubmitRfq.kt
index 11878963..ef525e3e 100644
--- a/httpserver/src/main/kotlin/tbdex/sdk/httpserver/handlers/SubmitRfq.kt
+++ b/httpserver/src/main/kotlin/tbdex/sdk/httpserver/handlers/SubmitRfq.kt
@@ -1,10 +1,11 @@
-package tbdex.server.tbdex.sdk.httpserver.handlers
+package tbdex.sdk.httpserver.handlers
 
 import io.ktor.http.HttpStatusCode
 import io.ktor.server.application.ApplicationCall
 import io.ktor.server.request.receiveText
 import io.ktor.server.response.respond
 import tbdex.sdk.httpclient.models.ErrorDetail
+import tbdex.sdk.httpserver.models.CallbackError
 import tbdex.sdk.httpserver.models.ExchangesApi
 import tbdex.sdk.httpserver.models.OfferingsApi
 import tbdex.sdk.httpserver.models.SubmitCallback
@@ -12,22 +13,64 @@ import tbdex.sdk.protocol.models.Message
 import tbdex.sdk.protocol.models.MessageKind
 import tbdex.sdk.protocol.models.Rfq
 
-// validate the message and then invoke submitCallback
+
+// todo: decide on the correct error response format
 suspend fun submitRfq(
   call: ApplicationCall,
   offeringsApi: OfferingsApi,
   exchangesApi: ExchangesApi,
   callback: SubmitCallback?
 ) {
+  val message: Rfq?
+
   try {
-    val message = Message.parse(call.receiveText()) as Rfq
-    val offering = offeringsApi.getOffering(message.data.offeringId.toString())
+    message = Message.parse(call.receiveText()) as Rfq
+  } catch (e: Exception) {
+    val errorResponse = ErrorDetail(detail = "Parsing of TBDex message failed: ${e.message}")
+    call.respond(HttpStatusCode.BadRequest, errorResponse)
+    return
+  }
 
-    callback?.invoke(call, MessageKind.rfq, offering)
-    call.respond(HttpStatusCode.Accepted)
+  val existingRfq = exchangesApi.getRfq(message.metadata.exchangeId.toString())
+  if (existingRfq != null) {
+    val errorResponse = ErrorDetail(detail = "RFQ already exists.")
+    call.respond(HttpStatusCode.Conflict, errorResponse)
+    return
+  }
+
+  val offering = offeringsApi.getOffering(message.data.offeringId.toString())
+  if (offering == null) {
+    val errorResponse = ErrorDetail(detail = "Offering with id ${message.data.offeringId} does not exist.")
+    call.respond(HttpStatusCode.BadRequest, errorResponse)
+    return
+  }
 
+  try {
+    message.verifyOfferingRequirements(offering)
   } catch (e: Exception) {
-    val errorResponse = ErrorDetail(detail = "Parsing of TBDex message failed: ${e.message}")
+    val errorResponse = ErrorDetail(detail = "Failed to verify offering requirements: ${e.message}")
     call.respond(HttpStatusCode.BadRequest, errorResponse)
+    return
+  }
+
+  if (callback == null) {
+    call.respond(HttpStatusCode.Accepted)
+    return
   }
+
+  try {
+    callback.invoke(call, MessageKind.rfq, offering)
+  } catch (e: Exception) {
+    if (e is CallbackError) {
+      // todo: e.details is a list of ErrorDetail. do we want to include all the errordetails?
+      call.respond(e.statusCode, e.details!!.first())
+      return
+    } else {
+      val errorResponse = ErrorDetail(detail = "umm idk")
+      call.respond(HttpStatusCode.InternalServerError, errorResponse)
+      return
+    }
+  }
+
+  call.respond(HttpStatusCode.Accepted)
 }
\ No newline at end of file
diff --git a/httpserver/src/main/kotlin/tbdex/sdk/httpserver/models/Callback.kt b/httpserver/src/main/kotlin/tbdex/sdk/httpserver/models/Callback.kt
index d87bd977..b1406151 100644
--- a/httpserver/src/main/kotlin/tbdex/sdk/httpserver/models/Callback.kt
+++ b/httpserver/src/main/kotlin/tbdex/sdk/httpserver/models/Callback.kt
@@ -6,9 +6,6 @@ import tbdex.sdk.httpclient.models.ErrorDetail
 import tbdex.sdk.protocol.models.MessageKind
 import tbdex.sdk.protocol.models.Offering
 
-//typealias GetCallback<T> = (RequestContext, Filters[T]) -> Any
-//typealias SubmitCallback<T, O> = (RequestContext, MessageKindClasses[T], SubmitCallbackOpts[O]) -> Unit
-
 typealias GetCallback = (ApplicationCall, Filter) -> Any
 typealias SubmitCallback = (ApplicationCall, MessageKind, Offering?) -> Unit
 
@@ -19,7 +16,8 @@ class GetOfferingsFilter(
 ) : Filter
 
 class GetExchangesFilter(
-  val exchangeIds: List<String>
+  val exchangeIds: List<String>,
+  val from: String
 ) : Filter
 
 sealed interface Filter
diff --git a/tbdex b/tbdex
index 1329531f..50bef4bb 160000
--- a/tbdex
+++ b/tbdex
@@ -1 +1 @@
-Subproject commit 1329531f24b7444fee5e493dacfc5413bbeeda3e
+Subproject commit 50bef4bbb955d8c9c0b3933a8e76818affec610c