diff --git a/node/node.go b/node/node.go
index 96fa8b967e..a1f37f7a1b 100644
--- a/node/node.go
+++ b/node/node.go
@@ -52,7 +52,8 @@ type Node struct {
 	DataExchange exchange.Interface
 	DAG          format.DAGService
 	// p2p protocols
-	PubSub     *pubsub.PubSub
+	PubSub *pubsub.PubSub
+	// services
 	ShareServ  share.Service   // not optional
 	HeaderServ *header.Service // not optional
 	StateServ  *state.Service  // not optional
diff --git a/service/state/core_access.go b/service/state/core_access.go
index 0796af7999..5320d17794 100644
--- a/service/state/core_access.go
+++ b/service/state/core_access.go
@@ -103,3 +103,14 @@ func (ca *CoreAccessor) SubmitTxWithBroadcastMode(
 	}
 	return txResp.TxResponse, nil
 }
+
+func (ca *CoreAccessor) KeyringSigner() *apptypes.KeyringSigner {
+	return ca.signer
+}
+
+func (ca *CoreAccessor) Conn() (*grpc.ClientConn, error) {
+	if ca.coreConn == nil {
+		return nil, fmt.Errorf("no running gRPC connection")
+	}
+	return ca.coreConn, nil
+}
diff --git a/service/state/endpoints.md b/service/state/endpoints.md
deleted file mode 100644
index d069fb9787..0000000000
--- a/service/state/endpoints.md
+++ /dev/null
@@ -1,37 +0,0 @@
-# Celestia-Node State API
-
-### `GET`   `/balance`
-
-Request
-```
-curl -X GET http://<ip>:26658/balance
-```
-
-Response
-```json
-{"denom":"uceles","amount":"999995000000000"}
-```
-
-### `POST`  `/balance/{address}`
-
-Request
-```
-curl -X GET http://<ip>:26658/balance/celes1vuw7pdcyap2u62x6dyqjdzznlg25jll6jj76d0
-```
-
-Response
-```json
-{"denom":"uceles","amount":"999995000000000"}
-```
-
-### `POST`  `/submit_tx/{tx}`
-
-Request
-```
-curl -X POST http://<ip>:26658/submit_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
-```
-
-Response
-```json
-{"txhash":"E4B98AF73852A2FC99E1708C3C5B7CE93449A0E9381387D022FAE759F76E1F0D","codespace":"sdk","code":19,"logs":null}
-```
\ No newline at end of file
diff --git a/service/state/interface.go b/service/state/interface.go
index 05de4b8b3b..4e03fc2d38 100644
--- a/service/state/interface.go
+++ b/service/state/interface.go
@@ -2,6 +2,10 @@ package state
 
 import (
 	"context"
+
+	"google.golang.org/grpc"
+
+	apptypes "github.com/celestiaorg/celestia-app/x/payment/types"
 )
 
 // Accessor represents the behaviors necessary for a user to
@@ -12,6 +16,13 @@ type Accessor interface {
 	Start(context.Context) error
 	// Stop stops the state Accessor.
 	Stop(context.Context) error
+
+	// KeyringSigner returns the KeyringSigner used by the Accessor.
+	KeyringSigner() *apptypes.KeyringSigner
+	// Conn returns a gRPC connection to node that serves state-related
+	// requests.
+	Conn() (*grpc.ClientConn, error)
+
 	// Balance retrieves the Celestia coin balance
 	// for the node's account/signer.
 	Balance(ctx context.Context) (*Balance, error)
diff --git a/service/state/pfd.go b/service/state/pfd.go
new file mode 100644
index 0000000000..ed736ec502
--- /dev/null
+++ b/service/state/pfd.go
@@ -0,0 +1,101 @@
+package state
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/cosmos/cosmos-sdk/x/auth/signing"
+
+	apptypes "github.com/celestiaorg/celestia-app/x/payment/types"
+	"github.com/celestiaorg/nmt/namespace"
+)
+
+var (
+	// shareSizes includes all the possible share sizes of the given data
+	// that the signer must sign over.
+	shareSizes = []uint64{16, 32, 64, 128}
+)
+
+// PayForData is an alias to the PayForMessage packet.
+type PayForData = apptypes.MsgWirePayForMessage
+
+// SubmitPayForData builds, signs and submits a PayForData message.
+func (s *Service) SubmitPayForData(
+	ctx context.Context,
+	nID namespace.ID,
+	data []byte,
+	gasLim uint64,
+	maxSize uint64,
+) (*TxResponse, error) {
+	pfd, err := s.BuildPayForData(ctx, nID, data, gasLim, maxSize)
+	if err != nil {
+		return nil, err
+	}
+
+	signed, err := s.SignPayForData(pfd, apptypes.SetGasLimit(gasLim))
+	if err != nil {
+		return nil, err
+	}
+
+	signer := s.accessor.KeyringSigner()
+	rawTx, err := signer.EncodeTx(signed)
+	if err != nil {
+		return nil, err
+	}
+
+	return s.accessor.SubmitTx(ctx, rawTx)
+}
+
+// BuildPayForData builds a PayForData message.
+func (s *Service) BuildPayForData(
+	ctx context.Context,
+	nID namespace.ID,
+	message []byte,
+	gasLim uint64,
+	maxSize uint64,
+) (*PayForData, error) {
+	// create the raw WirePayForMessage transaction
+	wpfmMsg, err := apptypes.NewWirePayForMessage(nID, message, shareSizes...)
+	if err != nil {
+		return nil, err
+	}
+	// TODO @renaynay: as a result of `padMessage`, the following is observed:
+	//  {wpfmMsg.MessageSize: 256,  len(message): 5}
+	if wpfmMsg.GetMessageSize() > maxSize {
+		return nil, fmt.Errorf("message size %d cannot exceed specified max size %d", wpfmMsg.GetMessageSize(), maxSize)
+	}
+
+	// get signer and conn info
+	signer := s.accessor.KeyringSigner()
+	conn, err := s.accessor.Conn()
+	if err != nil {
+		return nil, err
+	}
+
+	// query for account information necessary to sign a valid tx
+	err = signer.QueryAccountNumber(ctx, conn)
+	if err != nil {
+		return nil, err
+	}
+
+	// generate the signatures for each `MsgPayForMessage` using the `KeyringSigner`,
+	// then set the gas limit for the tx
+	gasLimOption := apptypes.SetGasLimit(gasLim)
+	err = wpfmMsg.SignShareCommitments(signer, gasLimOption)
+	if err != nil {
+		return nil, err
+	}
+
+	return wpfmMsg, nil
+}
+
+// SignPayForData signs the given PayForData message.
+func (s *Service) SignPayForData(pfd *PayForData, gasLimOption apptypes.TxBuilderOption) (signing.Tx, error) {
+	signer := s.accessor.KeyringSigner()
+	// Build and sign the final `WirePayForMessage` tx that now contains the signatures
+	// for potential `MsgPayForMessage`s
+	return signer.BuildSignedTx(
+		gasLimOption(signer.NewTxBuilder()),
+		pfd,
+	)
+}
diff --git a/service/state/rpc.go b/service/state/rpc.go
index 57eb69353c..70bb34c847 100644
--- a/service/state/rpc.go
+++ b/service/state/rpc.go
@@ -4,6 +4,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"net/http"
 
 	"github.com/cosmos/cosmos-sdk/types"
@@ -13,17 +14,25 @@ import (
 	"github.com/celestiaorg/celestia-node/node/rpc"
 )
 
-var log = logging.Logger("state/rpc")
-
 var (
 	addrKey = "address"
 	txKey   = "tx"
+
+	log = logging.Logger("state/rpc")
 )
 
+type submitPFDRequest struct {
+	NamespaceID string `json:"namespace_id"`
+	Data        string `json:"data"`
+	GasLimit    uint64 `json:"gas_limit"`
+	MaxDataSize uint64 `json:"max_data_size"`
+}
+
 func (s *Service) RegisterEndpoints(rpc *rpc.Server) {
 	rpc.RegisterHandlerFunc("/balance", s.handleBalanceRequest, http.MethodGet)
 	rpc.RegisterHandlerFunc(fmt.Sprintf("/balance/{%s}", addrKey), s.handleBalanceForAddrRequest, http.MethodGet)
 	rpc.RegisterHandlerFunc(fmt.Sprintf("/submit_tx/{%s}", txKey), s.handleSubmitTx, http.MethodPost)
+	rpc.RegisterHandlerFunc("/submit_pfd", s.handleSubmitPFD, http.MethodPost)
 }
 
 func (s *Service) handleBalanceRequest(w http.ResponseWriter, r *http.Request) {
@@ -101,3 +110,51 @@ func (s *Service) handleSubmitTx(w http.ResponseWriter, r *http.Request) {
 		log.Errorw("writing /balance response", "err", err)
 	}
 }
+
+func (s *Service) handleSubmitPFD(w http.ResponseWriter, r *http.Request) {
+	// parse body from request
+	raw, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		log.Errorw("serving /submit_pfd request", "err", err)
+		return
+	}
+	// decode request
+	req := new(submitPFDRequest)
+	err = json.Unmarshal(raw, req)
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		log.Errorw("serving /submit_pfd request", "err", err)
+		return
+	}
+
+	nID, err := hex.DecodeString(req.NamespaceID)
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		log.Errorw("serving /submit_pfd request", "err", err)
+		return
+	}
+	data := []byte(req.Data)
+
+	// perform request
+	txResp, err := s.SubmitPayForData(r.Context(), nID, data, req.GasLimit, req.MaxDataSize)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		_, werr := w.Write([]byte(err.Error()))
+		if werr != nil {
+			log.Errorw("writing /submit_pfd response", "err", werr)
+		}
+		log.Errorw("serving /submit_pfd request", "err", err)
+		return
+	}
+	resp, err := json.Marshal(txResp)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		log.Errorw("serving /submit_pfd request", "err", err)
+		return
+	}
+	_, err = w.Write(resp)
+	if err != nil {
+		log.Errorw("writing /submit_pfd response", "err", err)
+	}
+}
diff --git a/service/state/state.go b/service/state/state.go
index 74e50ae99b..bd1b4d587f 100644
--- a/service/state/state.go
+++ b/service/state/state.go
@@ -8,7 +8,6 @@ import (
 // Balance is an alias to the Coin type from Cosmos-SDK.
 type Balance = sdk.Coin
 
-// Tx is an alias to the Tx type from celestia-core.
 type Tx = coretypes.Tx
 
 // TxResponse is an alias to the TxResponse type from Cosmos-SDK.