diff --git a/internal/engine/session.go b/internal/engine/session.go
index 2ef8e39cc..4520d01a7 100644
--- a/internal/engine/session.go
+++ b/internal/engine/session.go
@@ -67,6 +67,7 @@ type Session struct {
 	softwareName             string
 	softwareVersion          string
 	tempDir                  string
+	vpnConfig                map[string]model.OOAPIVPNProviderConfig
 
 	// closeOnce allows us to call Close just once.
 	closeOnce sync.Once
@@ -178,6 +179,7 @@ func NewSession(ctx context.Context, config SessionConfig) (*Session, error) {
 		torArgs:                 config.TorArgs,
 		torBinary:               config.TorBinary,
 		tunnelDir:               config.TunnelDir,
+		vpnConfig:               make(map[string]model.OOAPIVPNProviderConfig),
 	}
 	proxyURL := config.ProxyURL
 	if proxyURL != nil {
@@ -377,11 +379,21 @@ func (s *Session) FetchTorTargets(
 // FetchOpenVPNConfig fetches openvpn config from the API.
 func (s *Session) FetchOpenVPNConfig(
 	ctx context.Context, cc string) (map[string]model.OOAPIVPNProviderConfig, error) {
+	// TODO: need to cache only the requested provider, since it's different calls to the API.
+	if len(s.vpnConfig) > 0 {
+		return s.vpnConfig, nil
+	}
+
 	clnt, err := s.NewOrchestraClient(ctx)
 	if err != nil {
 		return nil, err
 	}
-	return clnt.FetchOpenVPNConfig(ctx, cc)
+	config, err := clnt.FetchOpenVPNConfig(ctx, cc)
+	if err != nil {
+		return nil, err
+	}
+	s.vpnConfig = config
+	return config, nil
 }
 
 // KeyValueStore returns the configured key-value store.
diff --git a/internal/experiment/openvpn/endpoint.go b/internal/experiment/openvpn/endpoint.go
index 836f07bc2..528ce0594 100644
--- a/internal/experiment/openvpn/endpoint.go
+++ b/internal/experiment/openvpn/endpoint.go
@@ -66,8 +66,8 @@ func newEndpointFromInputString(uri string) (*endpoint, error) {
 		return nil, fmt.Errorf("%w: expected provider as host: %s", ErrInvalidInput, parsedURL.Host)
 	}
 	if provider != "riseup" {
-		// because we are hardcoding at the moment. figure out a way to pass info for
-		// arbitrary providers as options instead
+		// I am hardcoding a single provider at the moment.
+		// I need to figure out a way to pass info for arbitrary providers as options instead.
 		return nil, fmt.Errorf("%w: unknown provider: %s", ErrInvalidInput, provider)
 	}
 
@@ -98,7 +98,8 @@ func newEndpointFromInputString(uri string) (*endpoint, error) {
 	return endpoint, nil
 }
 
-// String implements Stringer. This is a subset of the input URI scheme.
+// String implements Stringer. This is a compact representation of the endpoint,
+// which differs from the input URI scheme.
 func (e *endpoint) String() string {
 	var proto string
 	if e.Obfuscation == "obfs4" {
@@ -109,16 +110,23 @@ func (e *endpoint) String() string {
 	return fmt.Sprintf("%s://%s:%s/%s", proto, e.IPAddr, e.Port, e.Transport)
 }
 
-// AsInputURI is a string representation of this endpoint. It contains more information than the endpoint itself.
-// TODO: redo with latest format
-// openvpn://provider.corp/?address=1.1.1.1:1194&transport=tcp
+// AsInputURI is a string representation of this endpoint, as used in the experiment input URI format.
 func (e *endpoint) AsInputURI() string {
+	var proto string
+	if e.Obfuscation == "obfs4" {
+		proto = e.Protocol + "+obfs4"
+	} else {
+		proto = e.Protocol
+	}
+
 	provider := e.Provider
 	if provider == "" {
 		provider = "unknown"
 	}
-	i := fmt.Sprintf("%s/?provider=%s", e.String(), provider)
-	return i
+
+	return fmt.Sprintf(
+		"%s://%s.corp/?address=%s:%s&transport=%s",
+		proto, provider, e.IPAddr, e.Port, e.Transport)
 }
 
 // endpointList is a list of endpoints.
@@ -128,6 +136,7 @@ type endpointList []*endpoint
 // This is a hardcoded list for now, but the idea is that we can receive this from the check-in api in the future.
 // In any case, having hardcoded endpoints is good as a fallback for the cases in which we cannot contact
 // OONI's backend.
+// TODO: hardcoded, setup as backup if we cannot contact API.
 var allEndpoints = endpointList{
 	{
 		Provider:  "riseup",
diff --git a/internal/probeservices/openvpn.go b/internal/probeservices/openvpn.go
index 07a7f7801..0f5149bff 100644
--- a/internal/probeservices/openvpn.go
+++ b/internal/probeservices/openvpn.go
@@ -10,6 +10,7 @@ import (
 
 // FetchOpenVPNConfig returns valid configuration for the openvpn experiment.
 func (c Client) FetchOpenVPNConfig(ctx context.Context, cc string) (map[string]model.OOAPIVPNProviderConfig, error) {
+	fmt.Println("FETCHING OPENVPN CONFIG>>>>")
 	_, auth, err := c.GetCredsAndAuth()
 	if err != nil {
 		return nil, err