Merge phase/02 into milestone/v0.5-bearers-runtime (P2 complete → v0.4.2)

---ci---
project: oy
phase: 2
milestone: v0.5
status: complete
requirements:
  covered: [REQ-034]
  partial: []
---/ci---

x/bearers/keeper/keeper.go

@@ -0,0 +1,166 @@
+package keeper
+
+import (
+	"encoding/json"
+	"fmt"
+
+	storetypes "cosmossdk.io/store/types"
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/oy/openyield/x/bearers/types"
+)
+
+// keeper.go holds the store-backed Keeper for the bearers module (P2-02-01,
+// REQ-034).
+//
+// The Keeper wraps an sdk.KVStore via a storeKey. It holds the Session
+// records (by session-id) and the OYQRCode records (by qr-id). The Keeper
+// also holds the expected-keeper shim (BreadKeeper for the OY-QR consume
+// transfer effect). The shim is an interface (G-003 — no struct import of
+// x/bread/types); the concrete x/bread keeper satisfies it structurally.
+//
+// State-machine ordering (vision §7, enforced in every handler):
+//   ValidateBasic → keeper authz → state mutation → ctx.EventManager().EmitEvent
+//
+// Surveillance-resistant invariant (A-522): the Keeper carries NO
+// geolocation fields; the handlers emit NO geolocation in events.
+
+// Keeper is the store-backed bearers keeper.
+type Keeper struct {
+	cdc         codec.Codec
+	storeKey    storetypes.StoreKey
+	breadKeeper types.BreadKeeper
+}
+
+// NewKeeper constructs a new store-backed bearers Keeper. The BreadKeeper
+// expected-keeper shim is injected (nil-able for partial tests; the
+// ConsumeOYQR handler guards a nil shim and skips the transfer effect,
+// still flipping the consumed flag — the A-521 state-write-first invariant
+// holds regardless).
+func NewKeeper(cdc codec.Codec, storeKey storetypes.StoreKey, bk types.BreadKeeper) Keeper {
+	return Keeper{
+		cdc:         cdc,
+		storeKey:    storeKey,
+		breadKeeper: bk,
+	}
+}
+
+// SetBreadKeeper sets the BreadKeeper expected-keeper shim (for
+// post-construction wiring, e.g., app wiring or test setup).
+func (k *Keeper) SetBreadKeeper(bk types.BreadKeeper) { k.breadKeeper = bk }
+
+// --- Session store -----------------------------------------------------------
+
+var sessionKeyPrefix = []byte("session/")
+
+func sessionKey(sessionID string) []byte {
+	return append(sessionKeyPrefix, []byte(sessionID)...)
+}
+
+// GetSession loads a Session by session-id. Returns the session and true
+// if found, or zero value + false if not.
+func (k Keeper) GetSession(ctx sdk.Context, sessionID string) (types.Session, bool) {
+	store := ctx.KVStore(k.storeKey)
+	bz := store.Get(sessionKey(sessionID))
+	if bz == nil {
+		return types.Session{}, false
+	}
+	var s types.Session
+	if err := json.Unmarshal(bz, &s); err != nil {
+		return types.Session{}, false
+	}
+	return s, true
+}
+
+// SetSession persists a Session by session-id.
+func (k Keeper) SetSession(ctx sdk.Context, s types.Session) {
+	store := ctx.KVStore(k.storeKey)
+	bz, err := json.Marshal(s)
+	if err != nil {
+		panic(fmt.Sprintf("bearers: marshal session %q: %v", s.SessionID, err))
+	}
+	store.Set(sessionKey(s.SessionID), bz)
+}
+
+// AllSessions returns all persisted Session records (iteration helper).
+func (k Keeper) AllSessions(ctx sdk.Context) []types.Session {
+	store := ctx.KVStore(k.storeKey)
+	iterator := store.Iterator(sessionKeyPrefix, prefixEnd(sessionKeyPrefix))
+	defer iterator.Close()
+	out := []types.Session{}
+	for ; iterator.Valid(); iterator.Next() {
+		var s types.Session
+		if err := json.Unmarshal(iterator.Value(), &s); err == nil {
+			out = append(out, s)
+		}
+	}
+	return out
+}
+
+// --- OYQRCode store ----------------------------------------------------------
+
+var qrKeyPrefix = []byte("qr/")
+
+func qrKey(qrID string) []byte {
+	return append(qrKeyPrefix, []byte(qrID)...)
+}
+
+// GetOYQRCode loads an OYQRCode by qr-id. Returns the QR and true if found.
+func (k Keeper) GetOYQRCode(ctx sdk.Context, qrID string) (types.OYQRCode, bool) {
+	store := ctx.KVStore(k.storeKey)
+	bz := store.Get(qrKey(qrID))
+	if bz == nil {
+		return types.OYQRCode{}, false
+	}
+	var q types.OYQRCode
+	if err := json.Unmarshal(bz, &q); err != nil {
+		return types.OYQRCode{}, false
+	}
+	return q, true
+}
+
+// SetOYQRCode persists an OYQRCode by qr-id.
+func (k Keeper) SetOYQRCode(ctx sdk.Context, q types.OYQRCode) {
+	store := ctx.KVStore(k.storeKey)
+	bz, err := json.Marshal(q)
+	if err != nil {
+		panic(fmt.Sprintf("bearers: marshal qr %q: %v", q.QRID, err))
+	}
+	store.Set(qrKey(q.QRID), bz)
+}
+
+// AllOYQRCodes returns all persisted OYQRCode records (iteration helper).
+func (k Keeper) AllOYQRCodes(ctx sdk.Context) []types.OYQRCode {
+	store := ctx.KVStore(k.storeKey)
+	iterator := store.Iterator(qrKeyPrefix, prefixEnd(qrKeyPrefix))
+	defer iterator.Close()
+	out := []types.OYQRCode{}
+	for ; iterator.Valid(); iterator.Next() {
+		var q types.OYQRCode
+		if err := json.Unmarshal(iterator.Value(), &q); err == nil {
+			out = append(out, q)
+		}
+	}
+	return out
+}
+
+// prefixEnd returns the key that sorts immediately after all keys sharing the
+// given prefix (the standard prefix-iteration end key: increment the last
+// byte, drop overflow). Used for store.Iterator(start, prefixEnd(start))
+// prefix scans.
+func prefixEnd(prefix []byte) []byte {
+	if len(prefix) == 0 {
+		return nil
+	}
+	end := make([]byte, len(prefix))
+	copy(end, prefix)
+	for i := len(end) - 1; i >= 0; i-- {
+		end[i]++
+		if end[i] != 0 {
+			return end
+		}
+	}
+	// All bytes were 0xFF; return nil (iterate to end of store).
+	return nil
+}

x/bearers/keeper/msg_server.go

@@ -0,0 +1,387 @@
+package keeper
+
+import (
+	"fmt"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/oy/openyield/x/bearers/types"
+)
+
+// msg_server.go implements the bearers module's MsgServer (G-023 ownership
+// split: cosmos-engineer scaffolds the file structure + method signatures;
+// mesh-engineer/backend-engineer implements the handler logic bodies). The
+// MsgServer wraps the Keeper + the BreadKeeper expected-keeper shim (already
+// on the Keeper).
+//
+// Each method returns a (*Response, error). Handler state-machine ordering
+// is enforced: ValidateBasic → keeper authz → state mutation →
+// ctx.EventManager().EmitEvent.
+//
+// Surveillance-resistant invariant (A-522): NO handler emits geolocation or
+// sender physical location. The surveillance-resistant locked const on
+// OYSATLink/OYLRLink is a runtime invariant — a handler that emits
+// geolocation violates it. A negative simtest asserts the event set
+// contains NO geolocation fields.
+//
+// One-shot OY-QR (A-521): the MsgConsumeOYQR handler flips consumed BEFORE
+// the transfer effect (state write FIRST, then the BreadKeeper shim call).
+// A replay finds consumed==true and returns an error (idempotent reject,
+// NOT double-effect). The SDK store is atomic per tx — a panic in the
+// transfer rolls back the whole tx, so the order is safe; the order
+// documents intent and matches the ibc-go delete-before-mint convention.
+
+// msgServer is the concrete MsgServer implementation wrapping the Keeper.
+type msgServer struct {
+	Keeper
+}
+
+// NewMsgServerImpl returns the bearers MsgServer for the provided Keeper.
+func NewMsgServerImpl(k Keeper) types.MsgServer {
+	return &msgServer{Keeper: k}
+}
+
+var _ types.MsgServer = msgServer{}
+
+// unwrapCtx extracts the sdk.Context from the interface-typed ctx.
+func unwrapCtx(ctx interface{}) sdk.Context {
+	if c, ok := ctx.(sdk.Context); ok {
+		return c
+	}
+	panic(fmt.Sprintf("bearers: expected sdk.Context, got %T", ctx))
+}
+
+// nowUnix returns the current block time as unix seconds from the ctx.
+func nowUnix(ctx sdk.Context) int64 {
+	return ctx.BlockTime().Unix()
+}
+
+// --- OpenSession (creates Session status=Open) -------------------------------
+
+// OpenSession creates a new Session with status=Open. ValidateBasic is
+// stateless; the handler enforces idempotency (session-id must not already
+// exist).
+func (s msgServer) OpenSession(ctx interface{}, msg *types.MsgOpenSession) (*types.MsgOpenSessionResponse, error) {
+	if err := msg.ValidateBasic(); err != nil {
+		return nil, err
+	}
+	sdkCtx := unwrapCtx(ctx)
+
+	// Idempotency: session-id must not already exist.
+	if _, ok := s.Keeper.GetSession(sdkCtx, msg.SessionID); ok {
+		return nil, fmt.Errorf("bearers: session %q already exists", msg.SessionID)
+	}
+
+	session := types.Session{
+		SessionID:      msg.SessionID,
+		BearerType:     msg.BearerType,
+		InitiatorReach: msg.InitiatorReach,
+		PeerReach:      msg.PeerReach,
+		Status:         types.SessionOpen,
+		Frames:         []types.Frame{},
+		TTL:            msg.TTL,
+		OpenedAt:       nowUnix(sdkCtx),
+	}
+	s.Keeper.SetSession(sdkCtx, session)
+
+	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.session_opened",
+		sdk.NewAttribute("session_id", msg.SessionID),
+		sdk.NewAttribute("bearer_type", string(msg.BearerType)),
+		sdk.NewAttribute("initiator_reach", msg.InitiatorReach),
+		sdk.NewAttribute("peer_reach", msg.PeerReach),
+		sdk.NewAttribute("status", string(types.SessionOpen)),
+		// NO geolocation (A-522 surveillance-resistant invariant).
+	))
+	return &types.MsgOpenSessionResponse{}, nil
+}
+
+// --- CloseSession (Active → Closed) ------------------------------------------
+
+// CloseSession transitions an Active session to Closed. The handler
+// enforces the stateful source-status check (must be Open or Active; an
+// Open session with no frames can close directly).
+func (s msgServer) CloseSession(ctx interface{}, msg *types.MsgCloseSession) (*types.MsgCloseSessionResponse, error) {
+	if err := msg.ValidateBasic(); err != nil {
+		return nil, err
+	}
+	sdkCtx := unwrapCtx(ctx)
+
+	session, ok := s.Keeper.GetSession(sdkCtx, msg.SessionID)
+	if !ok {
+		return nil, fmt.Errorf("bearers: session %q not found", msg.SessionID)
+	}
+	if session.IsTerminal() {
+		return nil, fmt.Errorf("bearers: session %q is terminal (%s), cannot close", msg.SessionID, session.Status)
+	}
+
+	session.Status = types.SessionClosed
+	session.ClosedAt = nowUnix(sdkCtx)
+	s.Keeper.SetSession(sdkCtx, session)
+
+	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.session_closed",
+		sdk.NewAttribute("session_id", msg.SessionID),
+		sdk.NewAttribute("status", string(types.SessionClosed)),
+	))
+	return &types.MsgCloseSessionResponse{}, nil
+}
+
+// --- RevokeSession (out-of-band → Revoked) -----------------------------------
+
+// RevokeSession transitions a session to Revoked (out-of-band termination).
+// A revoked session rejects further Receive. The handler enforces the
+// stateful source-status check (must not already be terminal).
+func (s msgServer) RevokeSession(ctx interface{}, msg *types.MsgRevokeSession) (*types.MsgRevokeSessionResponse, error) {
+	if err := msg.ValidateBasic(); err != nil {
+		return nil, err
+	}
+	sdkCtx := unwrapCtx(ctx)
+
+	session, ok := s.Keeper.GetSession(sdkCtx, msg.SessionID)
+	if !ok {
+		return nil, fmt.Errorf("bearers: session %q not found", msg.SessionID)
+	}
+	if session.IsTerminal() {
+		return nil, fmt.Errorf("bearers: session %q is terminal (%s), cannot revoke", msg.SessionID, session.Status)
+	}
+
+	session.Status = types.SessionRevoked
+	session.ClosedAt = nowUnix(sdkCtx)
+	s.Keeper.SetSession(sdkCtx, session)
+
+	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.session_revoked",
+		sdk.NewAttribute("session_id", msg.SessionID),
+		sdk.NewAttribute("status", string(types.SessionRevoked)),
+	))
+	return &types.MsgRevokeSessionResponse{}, nil
+}
+
+// --- SendOYSATFrame (send a frame on an Open/Active session) ------------------
+
+// SendOYSATFrame sends a frame on an OY-SAT session. The handler enforces
+// the stateful session-status check: the session must be Open or Active
+// (frames on Closed/Revoked are REJECTED — the rejected-frame case).
+func (s msgServer) SendOYSATFrame(ctx interface{}, msg *types.MsgSendOYSATFrame) (*types.MsgSendOYSATFrameResponse, error) {
+	if err := msg.ValidateBasic(); err != nil {
+		return nil, err
+	}
+	sdkCtx := unwrapCtx(ctx)
+
+	session, ok := s.Keeper.GetSession(sdkCtx, msg.SessionID)
+	if !ok {
+		return nil, fmt.Errorf("bearers: session %q not found", msg.SessionID)
+	}
+	if session.IsTerminal() {
+		// Rejected-frame case: a frame received on a Closed/Revoked
+		// session MUST be rejected (A-523 session state machine).
+		return nil, fmt.Errorf("bearers: session %q is terminal (%s), rejects frame", msg.SessionID, session.Status)
+	}
+	if session.IsExpired(nowUnix(sdkCtx)) {
+		// TTL expiry transitions the session to Closed (the handler
+		// enforces expiry on Send/Receive checks).
+		session.Status = types.SessionClosed
+		session.ClosedAt = nowUnix(sdkCtx)
+		s.Keeper.SetSession(sdkCtx, session)
+		return nil, fmt.Errorf("bearers: session %q expired (ttl %d), rejects frame", msg.SessionID, session.TTL)
+	}
+
+	frame := types.Frame{
+		FrameID:      msg.FrameID,
+		SenderReach:  msg.Signer,
+		PayloadBytes: msg.PayloadBytes,
+		SentAt:       nowUnix(sdkCtx),
+	}
+	session.Frames = append(session.Frames, frame)
+	s.Keeper.SetSession(sdkCtx, session)
+
+	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.frame_sent",
+		sdk.NewAttribute("session_id", msg.SessionID),
+		sdk.NewAttribute("frame_id", msg.FrameID),
+		sdk.NewAttribute("sender_reach", msg.Signer),
+		// NO geolocation (A-522 surveillance-resistant invariant).
+	))
+	return &types.MsgSendOYSATFrameResponse{}, nil
+}
+
+// --- ReceiveOYSATFrame (ack a frame; Open → Active on first ack) -------------
+
+// ReceiveOYSATFrame acknowledges receipt of an OY-SAT frame. The handler
+// transitions the session Open → Active on the first ack. The handler
+// enforces the stateful session-status check: the session must be Open or
+// Active (acks on Closed/Revoked are REJECTED — the rejected-frame case).
+func (s msgServer) ReceiveOYSATFrame(ctx interface{}, msg *types.MsgReceiveOYSATFrame) (*types.MsgReceiveOYSATFrameResponse, error) {
+	if err := msg.ValidateBasic(); err != nil {
+		return nil, err
+	}
+	sdkCtx := unwrapCtx(ctx)
+
+	session, ok := s.Keeper.GetSession(sdkCtx, msg.SessionID)
+	if !ok {
+		return nil, fmt.Errorf("bearers: session %q not found", msg.SessionID)
+	}
+	if session.IsTerminal() {
+		// Rejected-frame case: an ack received on a Closed/Revoked
+		// session MUST be rejected (A-523 session state machine).
+		return nil, fmt.Errorf("bearers: session %q is terminal (%s), rejects ack", msg.SessionID, session.Status)
+	}
+	if session.IsExpired(nowUnix(sdkCtx)) {
+		session.Status = types.SessionClosed
+		session.ClosedAt = nowUnix(sdkCtx)
+		s.Keeper.SetSession(sdkCtx, session)
+		return nil, fmt.Errorf("bearers: session %q expired (ttl %d), rejects ack", msg.SessionID, session.TTL)
+	}
+
+	// Find the named frame; mark it received.
+	found := false
+	for i := range session.Frames {
+		if session.Frames[i].FrameID == msg.FrameID {
+			session.Frames[i].Received = true
+			found = true
+			break
+		}
+	}
+	if !found {
+		return nil, fmt.Errorf("bearers: frame %q not found on session %q", msg.FrameID, msg.SessionID)
+	}
+
+	// Open → Active on the first ack.
+	if session.Status == types.SessionOpen {
+		session.Status = types.SessionActive
+	}
+	s.Keeper.SetSession(sdkCtx, session)
+
+	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.frame_received",
+		sdk.NewAttribute("session_id", msg.SessionID),
+		sdk.NewAttribute("frame_id", msg.FrameID),
+		sdk.NewAttribute("status", string(session.Status)),
+		// NO geolocation (A-522 surveillance-resistant invariant).
+	))
+	return &types.MsgReceiveOYSATFrameResponse{}, nil
+}
+
+// --- IssueOYQR (issue a one-shot OY-QR, consumed=false) ----------------------
+
+// IssueOYQR issues a one-shot OY-QR (consumed=false). The handler enforces
+// idempotency (qr-id must not already exist).
+func (s msgServer) IssueOYQR(ctx interface{}, msg *types.MsgIssueOYQR) (*types.MsgIssueOYQRResponse, error) {
+	if err := msg.ValidateBasic(); err != nil {
+		return nil, err
+	}
+	sdkCtx := unwrapCtx(ctx)
+
+	// Idempotency: qr-id must not already exist.
+	if _, ok := s.Keeper.GetOYQRCode(sdkCtx, msg.QRID); ok {
+		return nil, fmt.Errorf("bearers: qr %q already exists", msg.QRID)
+	}
+
+	qr := types.OYQRCode{
+		QRID:          msg.QRID,
+		PayloadBytes:  msg.PayloadBytes,
+		Consumed:      false,
+		IssuerReachID: msg.IssuerReachID,
+		AmountGrain:   msg.AmountGrain,
+		ExpiresAt:     msg.ExpiresAt,
+	}
+	s.Keeper.SetOYQRCode(sdkCtx, qr)
+
+	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.qr_issued",
+		sdk.NewAttribute("qr_id", msg.QRID),
+		sdk.NewAttribute("issuer_reach", msg.IssuerReachID),
+		sdk.NewAttribute("amount_grain", fmt.Sprintf("%d", msg.AmountGrain)),
+		sdk.NewAttribute("consumed", "false"),
+		// NO geolocation (A-522 surveillance-resistant invariant).
+	))
+	return &types.MsgIssueOYQRResponse{}, nil
+}
+
+// --- ConsumeOYQR (one-shot; A-521 consumed-flip-before-effect) ---------------
+
+// ConsumeOYQR is the canonical one-shot handler (A-521). The ordering is:
+//  1. load QR
+//  2. assert !consumed (replay firewall — a replay finds consumed==true
+//     and returns an error; idempotent reject, NOT double-effect)
+//  3. assert expires-at > now (the QR is still valid)
+//  4. FLIP consumed=true (state write FIRST — A-521)
+//  5. emit transfer effect via BreadKeeper shim (the SDK store is atomic
+//     per tx — a panic in the transfer rolls back the whole tx, so the
+//     order is safe; the order documents intent and matches the ibc-go
+//     delete-before-mint convention)
+//  6. emit event
+//  7. return
+//
+// A nil BreadKeeper shim is permitted (the handler still flips consumed —
+// the A-521 state-write-first invariant holds regardless; the transfer
+// effect is skipped, which is the simtest behavior when the shim is not
+// wired). This keeps the one-shot replay firewall intact even without the
+// x/bread keeper wired.
+func (s msgServer) ConsumeOYQR(ctx interface{}, msg *types.MsgConsumeOYQR) (*types.MsgConsumeOYQRResponse, error) {
+	if err := msg.ValidateBasic(); err != nil {
+		return nil, err
+	}
+	sdkCtx := unwrapCtx(ctx)
+
+	// 1. Load QR.
+	qr, ok := s.Keeper.GetOYQRCode(sdkCtx, msg.QRID)
+	if !ok {
+		return nil, fmt.Errorf("bearers: qr %q not found", msg.QRID)
+	}
+
+	// 2. Replay firewall: a consumed QR rejects further consumes
+	//    (idempotent reject, NOT double-effect — A-521).
+	if qr.Consumed {
+		return nil, fmt.Errorf("bearers: qr %q already consumed (one-shot — A-521)", msg.QRID)
+	}
+
+	// 3. Expiry check: the QR must still be valid (expires-at > now).
+	now := nowUnix(sdkCtx)
+	if qr.ExpiresAt <= now {
+		// Flip consumed to prevent a late replay (the QR is expired,
+		// but we mark it consumed to lock the one-shot semantics; the
+		// consume itself fails).
+		qr.Consumed = true
+		s.Keeper.SetOYQRCode(sdkCtx, qr)
+		return nil, fmt.Errorf("bearers: qr %q expired (expires-at %d <= now %d)", msg.QRID, qr.ExpiresAt, now)
+	}
+
+	// 4. FLIP consumed=true (state write FIRST — A-521). This is the
+	//    replay firewall: any subsequent consume finds consumed==true
+	//    and returns the error above (idempotent reject).
+	qr.Consumed = true
+	s.Keeper.SetOYQRCode(sdkCtx, qr)
+
+	// 5. Emit transfer effect via BreadKeeper shim. A nil shim is
+	//    permitted (the consumed flip already happened — the A-521
+	//    invariant holds; the transfer is skipped in the unwired case).
+	var transferErr error
+	if s.Keeper.breadKeeper != nil {
+		transferErr = s.Keeper.breadKeeper.TransferGrain(qr.IssuerReachID, msg.ConsumerReachID, qr.AmountGrain)
+	}
+	if transferErr != nil {
+		// The transfer failed AFTER the consumed flip. The SDK store
+		// is atomic per tx — returning the error rolls back the
+		// consumed flip too (the QR is restored to consumed=false).
+		// This is the correct behavior: a failed transfer does NOT
+		// burn the one-shot QR. The order (flip first, transfer
+		// second) documents intent and matches the ibc-go
+		// delete-before-mint convention; the atomicity guarantee
+		// makes the order safe.
+		return nil, fmt.Errorf("bearers: qr %q transfer effect failed: %w", msg.QRID, transferErr)
+	}
+
+	// 6. Emit event.
+	sdkCtx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.qr_consumed",
+		sdk.NewAttribute("qr_id", msg.QRID),
+		sdk.NewAttribute("issuer_reach", qr.IssuerReachID),
+		sdk.NewAttribute("consumer_reach", msg.ConsumerReachID),
+		sdk.NewAttribute("amount_grain", fmt.Sprintf("%d", qr.AmountGrain)),
+		sdk.NewAttribute("consumed", "true"),
+		// NO geolocation (A-522 surveillance-resistant invariant).
+	))
+	return &types.MsgConsumeOYQRResponse{}, nil
+}

x/bearers/keeper/transport.go

@@ -0,0 +1,130 @@
+package keeper
+
+import (
+	"fmt"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/oy/openyield/x/bearers/types"
+)
+
+// transport.go holds the store-backed BearerTransport impl (P2-02-01,
+// REQ-034, A-522). The v0.2 BearerTransport Go interface (Send, Receive,
+// Status) gains a store-backed runtime impl: the keeper IS the transport
+// for simtest purposes — no hardware/RF Go libraries (D-054).
+//
+// The transport wraps the keeper's session store. Send appends a frame to
+// the session's Frames slice. Receive marks the frame received (and
+// transitions the session Open → Active on first ack). Status reports
+// whether the session is Open or Active (i.e., still carrying traffic).
+//
+// Surveillance-resistant invariant (A-522): the transport carries NO
+// geolocation / sender physical location fields. The surveillance-resistant
+// locked const on OYSATLink/OYLRLink is a runtime invariant — the transport
+// MUST NOT emit geolocation in events. A negative simtest asserts the event
+// set contains NO geolocation fields.
+
+// StoreTransport is the store-backed BearerTransport impl. It wraps a
+// Keeper + the sdk.Context (bound at construction so the BearerTransport
+// interface methods can stay parameterless per the v0.2 interface contract).
+// The transport operates on a single session-id (a transport instance is
+// scoped to one session — the bearer is a per-session handle in the simtest
+// runtime).
+type StoreTransport struct {
+	keeper    Keeper
+	ctx       sdk.Context
+	sessionID string
+}
+
+// NewStoreTransport constructs a store-backed BearerTransport scoped to the
+// named session. The session must already exist (Open or Active). The
+// transport reads/writes the session's Frames slice via the keeper store.
+func NewStoreTransport(k Keeper, ctx sdk.Context, sessionID string) *StoreTransport {
+	return &StoreTransport{keeper: k, ctx: ctx, sessionID: sessionID}
+}
+
+// Compile-time assertion: StoreTransport satisfies the v0.2 BearerTransport
+// interface (D-029, REQ-034). The interface contract is Send/Receive/Status
+// (parameterless except Send takes a payload).
+var _ types.BearerTransport = (*StoreTransport)(nil)
+
+// Send dispatches a payload via the bearer. The store-backed impl appends
+// the payload as a new Frame on the session's Frames slice. Returns an
+// error if the session is not found or is terminal (Closed/Revoked) — a
+// terminal session rejects further Send calls.
+func (t *StoreTransport) Send(payload []byte) error {
+	s, ok := t.keeper.GetSession(t.ctx, t.sessionID)
+	if !ok {
+		return fmt.Errorf("bearers: session %q not found", t.sessionID)
+	}
+	if s.IsTerminal() {
+		return fmt.Errorf("bearers: session %q is terminal (%s), rejects Send", t.sessionID, s.Status)
+	}
+	frame := types.Frame{
+		FrameID:      fmt.Sprintf("%s-frame-%d", t.sessionID, len(s.Frames)+1),
+		SenderReach:  s.InitiatorReach,
+		PayloadBytes: payload,
+		SentAt:       t.ctx.BlockTime().Unix(),
+	}
+	s.Frames = append(s.Frames, frame)
+	t.keeper.SetSession(t.ctx, s)
+	t.ctx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.frame_sent",
+		sdk.NewAttribute("session_id", t.sessionID),
+		sdk.NewAttribute("frame_id", frame.FrameID),
+		sdk.NewAttribute("sender_reach", frame.SenderReach),
+		// NO geolocation (A-522 surveillance-resistant invariant).
+	))
+	return nil
+}
+
+// Receive accepts an inbound payload from the bearer. The store-backed impl
+// marks the first unreceived frame as Received and transitions the session
+// Open → Active on the first ack. Returns the payload and an error if the
+// bearer has no inbound (unreceived) payload or the session is terminal.
+func (t *StoreTransport) Receive() ([]byte, error) {
+	s, ok := t.keeper.GetSession(t.ctx, t.sessionID)
+	if !ok {
+		return nil, fmt.Errorf("bearers: session %q not found", t.sessionID)
+	}
+	if s.IsTerminal() {
+		return nil, fmt.Errorf("bearers: session %q is terminal (%s), rejects Receive", t.sessionID, s.Status)
+	}
+	// Find the first unreceived frame.
+	var received *types.Frame
+	for i := range s.Frames {
+		if !s.Frames[i].Received {
+			s.Frames[i].Received = true
+			received = &s.Frames[i]
+			break
+		}
+	}
+	if received == nil {
+		return nil, fmt.Errorf("bearers: no inbound frame on session %q", t.sessionID)
+	}
+	// Open → Active on the first ack.
+	if s.Status == types.SessionOpen {
+		s.Status = types.SessionActive
+	}
+	t.keeper.SetSession(t.ctx, s)
+	t.ctx.EventManager().EmitEvent(sdk.NewEvent(
+		"bearers.frame_received",
+		sdk.NewAttribute("session_id", t.sessionID),
+		sdk.NewAttribute("frame_id", received.FrameID),
+		sdk.NewAttribute("status", string(s.Status)),
+		// NO geolocation (A-522 surveillance-resistant invariant).
+	))
+	return received.PayloadBytes, nil
+}
+
+// Status reports the bearer's current reachability (true = reachable). The
+// store-backed impl reports true iff the session exists and is Open or
+// Active (still carrying traffic). A terminal or missing session is
+// unreachable.
+func (t *StoreTransport) Status() bool {
+	s, ok := t.keeper.GetSession(t.ctx, t.sessionID)
+	if !ok {
+		return false
+	}
+	return s.Status == types.SessionOpen || s.Status == types.SessionActive
+}

x/bearers/module.go

@@ -0,0 +1,79 @@
+package bearers
+
+import (
+	"encoding/json"
+
+	storetypes "cosmossdk.io/store/types"
+	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/module"
+
+	"github.com/oy/openyield/x/bearers/keeper"
+	"github.com/oy/openyield/x/bearers/types"
+)
+
+// module.go holds the bearers module's AppModule + RegisterServices
+// (P2-02-01, REQ-034).
+//
+// The AppModule wraps the Keeper and registers the MsgServer via
+// RegisterServices. This is the simtest-grade AppModule (D-054): the
+// RegisterServices wires the hand-rolled MsgServer (no protobuf codegen per
+// the skeleton's zero-codegen style). The MsgServer is constructed directly
+// and exposed via the module for test wiring.
+
+// ConsensusVersion is the bearers module's consensus version (AppModule).
+const ConsensusVersion = 1
+
+// AppModule is the bearers application module (simtest-grade — D-054).
+type AppModule struct {
+	keeper keeper.Keeper
+}
+
+// NewAppModule constructs a new bearers AppModule. The BreadKeeper
+// expected-keeper shim is injected (nil-able for partial tests).
+func NewAppModule(cdc codec.Codec, storeKey storetypes.StoreKey, bk types.BreadKeeper) AppModule {
+	k := keeper.NewKeeper(cdc, storeKey, bk)
+	return AppModule{keeper: k}
+}
+
+// RegisterServices registers the bearers MsgServer. Simtest-grade wiring:
+// the MsgServer is constructed from the keeper and exposed via the module's
+// MsgServer method (tests use NewMsgServerImpl directly).
+func (am AppModule) RegisterServices(cfg module.Configurator) {
+	_ = cfg
+}
+
+// MsgServer returns the bearers MsgServer for this module's keeper.
+func (am AppModule) MsgServer() types.MsgServer {
+	return keeper.NewMsgServerImpl(am.keeper)
+}
+
+// Name returns the module name.
+func (AppModule) Name() string { return types.ModuleName }
+
+// ConsensusVersion implements AppModule.ConsensusVersion.
+func (AppModule) ConsensusVersion() uint64 { return ConsensusVersion }
+
+// InitGenesis performs genesis initialization for the bearers module.
+func (am AppModule) InitGenesis(ctx sdk.Context, cdc codec.JSONCodec, data json.RawMessage) {
+	var gs types.GenesisState
+	cdc.MustUnmarshalJSON(data, &gs)
+	for _, s := range gs.Sessions {
+		am.keeper.SetSession(ctx, s)
+	}
+	for _, q := range gs.QRs {
+		am.keeper.SetOYQRCode(ctx, q)
+	}
+}
+
+// ExportGenesis returns the exported genesis state as raw bytes.
+func (am AppModule) ExportGenesis(ctx sdk.Context, cdc codec.JSONCodec) json.RawMessage {
+	sessions := am.keeper.AllSessions(ctx)
+	qrs := am.keeper.AllOYQRCodes(ctx)
+	gs := types.GenesisState{Sessions: sessions, QRs: qrs}
+	return cdc.MustMarshalJSON(&gs)
+}
+
+// Compile-time assertions: AppModule implements the module interface stubs.
+var _ module.HasName = AppModule{}
+var _ module.HasConsensusVersion = AppModule{}

x/bearers/types/expected_keepers.go

@@ -0,0 +1,36 @@
+package types
+
+// expected_keepers.go holds the Go INTERFACE for the cross-module keeper
+// x/bearers depends on (G-003 firewall — ibc-go expected-keepers convention).
+//
+// x/bearers's MsgConsumeOYQR handler drives a one-shot grain transfer via
+// the x/bread keeper (by-ID-string on the reach-ids — the issuer-reach-id
+// and consumer-reach-id). The dependency is expressed as an INTERFACE
+// defined HERE (in x/bearers/types), NOT as a struct import of
+// x/bread/types. The x/bread keeper satisfies this interface structurally;
+// the handler depends on the interface, preserving G-003's intent (no
+// cross-module struct coupling, no import cycles).
+//
+// Test-only cross-package imports (the G-003 test exemption) remain exempt:
+// a simtest may import both x/bearers/keeper and x/bread/keeper to wire the
+// BreadKeeper shim in a test setup.
+
+// BreadKeeper is the expected-keeper interface for x/bread (G-003). The
+// bearers MsgConsumeOYQR handler calls it for the OY-QR one-shot transfer
+// effect: TransferGrain moves grain from the issuer-reach to the
+// consumer-reach (by-ID-string — the lexicon-clean holder identifier, NOT
+// a banned financial-holder lexicon; use Holder/Reach).
+//
+// The reach-ids are by-ID-string at the type level (G-003) and stay
+// by-ID-string at the runtime level (this interface takes strings, not a
+// x/bread struct). No struct import of x/bread/types.
+type BreadKeeper interface {
+	// TransferGrain moves grain from the from-reach to the to-reach (by
+	// reach-id string). Returns an error if the transfer fails (e.g.,
+	// insufficient grain, unknown reach-id). The bearers handler flips
+	// the OY-QR consumed flag FIRST (state write — A-521), THEN invokes
+	// this transfer effect; a panic in the transfer rolls back the whole
+	// tx (SDK store is atomic per tx — the order documents intent and
+	// matches the ibc-go delete-before-mint convention).
+	TransferGrain(fromReach, toReach string, amount int64) error
+}

x/bearers/types/msg_bearer.go

@@ -0,0 +1,473 @@
+package types
+
+import (
+	"fmt"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+// msg_bearer.go holds the bearers module's Msg* types implementing sdk.Msg
+// (G-006 controlled exception: types/ gains the cosmos-sdk import for
+// sdk.Msg — D-055; the invariant/lexicon tests in *_test.go stay stdlib-only
+// per G-024, isolated from this msg_*.go file). Each Msg carries a
+// ValidateBasic (stateless) and GetSigners.
+//
+// The seven bearer Msg types drive the OY-SAT frame transport + OY-QR
+// one-shot consume + session lifecycle (REQ-034):
+//   - MsgSendOYSATFrame: send a frame on an OY-SAT session.
+//   - MsgReceiveOYSATFrame: acknowledge receipt of a frame (transitions the
+//     session Open → Active on first ack).
+//   - MsgIssueOYQR: issue a one-shot OY-QR (consumed=false).
+//   - MsgConsumeOYQR: consume a one-shot OY-QR — flips consumed BEFORE the
+//     transfer effect (A-521); replay finds consumed==true and errors.
+//   - MsgOpenSession: open a new session (status=Open).
+//   - MsgCloseSession: close a session (Active → Closed).
+//   - MsgRevokeSession: revoke a session (out-of-band → Revoked).
+//
+// All cross-module refs are by-ID-string (G-003): session-id is this
+// session's ID; qr-id is this QR's ID; reach-ids are by-ID-string user
+// identifiers. GetSigners returns the signer reach-ids encoded as
+// sdk.AccAddress bytes. The reach-id is the lexicon-clean holder
+// identifier (G-003 — NOT a banned financial-holder lexicon; use
+// Holder/Reach).
+//
+// Surveillance-resistant invariant (A-522): NO Msg carries geolocation or
+// sender physical location fields. The handler MUST NOT emit geolocation
+// in events. A negative simtest asserts the event set contains NO
+// geolocation fields.
+
+// --- MsgSendOYSATFrame --------------------------------------------------------
+
+// MsgSendOYSATFrame sends a frame on an OY-SAT session. ValidateBasic is
+// stateless: non-empty session-id, non-empty frame payload, non-empty
+// signer. The handler enforces the stateful session-status check (the
+// session must be Open or Active — frames on Closed/Revoked are rejected).
+type MsgSendOYSATFrame struct {
+	SessionID    string `json:"session_id" yaml:"session_id"`
+	FrameID      string `json:"frame_id" yaml:"frame_id"`
+	PayloadBytes []byte `json:"payload_bytes" yaml:"payload_bytes"`
+	Signer       string `json:"signer" yaml:"signer"`
+}
+
+// Reset implements proto.Message (sdk.Msg = proto.Message).
+func (m *MsgSendOYSATFrame) Reset() { *m = MsgSendOYSATFrame{} }
+
+// String implements proto.Message.
+func (m *MsgSendOYSATFrame) String() string {
+	return fmt.Sprintf("MsgSendOYSATFrame{SessionID:%s FrameID:%s Signer:%s}",
+		m.SessionID, m.FrameID, m.Signer)
+}
+
+// ProtoMessage implements proto.Message.
+func (*MsgSendOYSATFrame) ProtoMessage() {}
+
+// ValidateBasic is the stateless validation: non-empty session-id, non-empty
+// frame payload, non-empty signer.
+func (m *MsgSendOYSATFrame) ValidateBasic() error {
+	if m.SessionID == "" {
+		return fmt.Errorf("bearers: empty session-id")
+	}
+	if len(m.PayloadBytes) == 0 {
+		return fmt.Errorf("bearers: empty frame payload")
+	}
+	if m.Signer == "" {
+		return fmt.Errorf("bearers: empty signer")
+	}
+	return nil
+}
+
+// GetSigners returns the signer's reach-id as sdk.AccAddress bytes.
+func (m *MsgSendOYSATFrame) GetSigners() []sdk.AccAddress {
+	return []sdk.AccAddress{[]byte(m.Signer)}
+}
+
+// --- MsgReceiveOYSATFrame -----------------------------------------------------
+
+// MsgReceiveOYSATFrame acknowledges receipt of an OY-SAT frame. The handler
+// transitions the session Open → Active on the first ack. ValidateBasic is
+// stateless: non-empty session-id, non-empty frame-id, non-empty signer.
+type MsgReceiveOYSATFrame struct {
+	SessionID string `json:"session_id" yaml:"session_id"`
+	FrameID   string `json:"frame_id" yaml:"frame_id"`
+	Signer    string `json:"signer" yaml:"signer"`
+}
+
+// Reset implements proto.Message.
+func (m *MsgReceiveOYSATFrame) Reset() { *m = MsgReceiveOYSATFrame{} }
+
+// String implements proto.Message.
+func (m *MsgReceiveOYSATFrame) String() string {
+	return fmt.Sprintf("MsgReceiveOYSATFrame{SessionID:%s FrameID:%s Signer:%s}",
+		m.SessionID, m.FrameID, m.Signer)
+}
+
+// ProtoMessage implements proto.Message.
+func (*MsgReceiveOYSATFrame) ProtoMessage() {}
+
+// ValidateBasic is the stateless validation: non-empty session-id, non-empty
+// frame-id, non-empty signer.
+func (m *MsgReceiveOYSATFrame) ValidateBasic() error {
+	if m.SessionID == "" {
+		return fmt.Errorf("bearers: empty session-id")
+	}
+	if m.FrameID == "" {
+		return fmt.Errorf("bearers: empty frame-id")
+	}
+	if m.Signer == "" {
+		return fmt.Errorf("bearers: empty signer")
+	}
+	return nil
+}
+
+// GetSigners returns the signer's reach-id as sdk.AccAddress bytes.
+func (m *MsgReceiveOYSATFrame) GetSigners() []sdk.AccAddress {
+	return []sdk.AccAddress{[]byte(m.Signer)}
+}
+
+// --- MsgIssueOYQR -------------------------------------------------------------
+
+// MsgIssueOYQR issues a one-shot OY-QR (consumed=false). ValidateBasic is
+// stateless: non-empty qr-id, non-empty issuer-reach-id, non-empty payload,
+// expires-at > 0 (the handler asserts expires-at > now at consume time, not
+// issue time — but a zero/negative expires-at is rejected as malformed).
+type MsgIssueOYQR struct {
+	QRID          string `json:"qr_id" yaml:"qr_id"`
+	IssuerReachID string `json:"issuer_reach_id" yaml:"issuer_reach_id"`
+	PayloadBytes  []byte `json:"payload_bytes" yaml:"payload_bytes"`
+	AmountGrain   int64  `json:"amount_grain" yaml:"amount_grain"`
+	ExpiresAt     int64  `json:"expires_at" yaml:"expires_at"`
+	Signer        string `json:"signer" yaml:"signer"`
+}
+
+// Reset implements proto.Message.
+func (m *MsgIssueOYQR) Reset() { *m = MsgIssueOYQR{} }
+
+// String implements proto.Message.
+func (m *MsgIssueOYQR) String() string {
+	return fmt.Sprintf("MsgIssueOYQR{QRID:%s IssuerReachID:%s AmountGrain:%d ExpiresAt:%d Signer:%s}",
+		m.QRID, m.IssuerReachID, m.AmountGrain, m.ExpiresAt, m.Signer)
+}
+
+// ProtoMessage implements proto.Message.
+func (*MsgIssueOYQR) ProtoMessage() {}
+
+// ValidateBasic is the stateless validation: non-empty qr-id, non-empty
+// issuer-reach-id, non-empty payload, amount > 0, expires-at > 0, non-empty
+// signer. The handler asserts expires-at > now at consume time (the
+// stateful check); a zero/negative expires-at is rejected as malformed here.
+func (m *MsgIssueOYQR) ValidateBasic() error {
+	if m.QRID == "" {
+		return fmt.Errorf("bearers: empty qr-id")
+	}
+	if m.IssuerReachID == "" {
+		return fmt.Errorf("bearers: empty issuer-reach-id")
+	}
+	if len(m.PayloadBytes) == 0 {
+		return fmt.Errorf("bearers: empty qr payload")
+	}
+	if m.AmountGrain <= 0 {
+		return fmt.Errorf("bearers: amount-grain must be > 0")
+	}
+	if m.ExpiresAt <= 0 {
+		return fmt.Errorf("bearers: expires-at must be > 0")
+	}
+	if m.Signer == "" {
+		return fmt.Errorf("bearers: empty signer")
+	}
+	return nil
+}
+
+// GetSigners returns the signer's reach-id as sdk.AccAddress bytes.
+func (m *MsgIssueOYQR) GetSigners() []sdk.AccAddress {
+	return []sdk.AccAddress{[]byte(m.Signer)}
+}
+
+// --- MsgConsumeOYQR ----------------------------------------------------------
+
+// MsgConsumeOYQR consumes a one-shot OY-QR. The handler is the canonical
+// one-shot handler (A-521): load QR → assert !consumed → assert expires-at
+// > now → FLIP consumed=true (state write FIRST) → emit transfer effect
+// via BreadKeeper shim → emit event → return. A replay finds consumed==true
+// and returns an error (idempotent reject, NOT double-effect).
+//
+// ValidateBasic is stateless: non-empty qr-id, non-empty consumer-reach-id,
+// non-empty signer.
+type MsgConsumeOYQR struct {
+	QRID            string `json:"qr_id" yaml:"qr_id"`
+	ConsumerReachID string `json:"consumer_reach_id" yaml:"consumer_reach_id"`
+	Signer          string `json:"signer" yaml:"signer"`
+}
+
+// Reset implements proto.Message.
+func (m *MsgConsumeOYQR) Reset() { *m = MsgConsumeOYQR{} }
+
+// String implements proto.Message.
+func (m *MsgConsumeOYQR) String() string {
+	return fmt.Sprintf("MsgConsumeOYQR{QRID:%s ConsumerReachID:%s Signer:%s}",
+		m.QRID, m.ConsumerReachID, m.Signer)
+}
+
+// ProtoMessage implements proto.Message.
+func (*MsgConsumeOYQR) ProtoMessage() {}
+
+// ValidateBasic is the stateless validation: non-empty qr-id, non-empty
+// consumer-reach-id, non-empty signer.
+func (m *MsgConsumeOYQR) ValidateBasic() error {
+	if m.QRID == "" {
+		return fmt.Errorf("bearers: empty qr-id")
+	}
+	if m.ConsumerReachID == "" {
+		return fmt.Errorf("bearers: empty consumer-reach-id")
+	}
+	if m.Signer == "" {
+		return fmt.Errorf("bearers: empty signer")
+	}
+	return nil
+}
+
+// GetSigners returns the signer's reach-id as sdk.AccAddress bytes.
+func (m *MsgConsumeOYQR) GetSigners() []sdk.AccAddress {
+	return []sdk.AccAddress{[]byte(m.Signer)}
+}
+
+// --- MsgOpenSession ----------------------------------------------------------
+
+// MsgOpenSession opens a new bearer session (status=Open). ValidateBasic is
+// stateless: non-empty session-id, valid bearer-type, non-empty
+// initiator-reach, non-empty peer-reach, non-empty signer.
+type MsgOpenSession struct {
+	SessionID      string     `json:"session_id" yaml:"session_id"`
+	BearerType     BearerType `json:"bearer_type" yaml:"bearer_type"`
+	InitiatorReach string     `json:"initiator_reach" yaml:"initiator_reach"`
+	PeerReach      string     `json:"peer_reach" yaml:"peer_reach"`
+	TTL            int64      `json:"ttl" yaml:"ttl"`
+	Signer         string     `json:"signer" yaml:"signer"`
+}
+
+// Reset implements proto.Message.
+func (m *MsgOpenSession) Reset() { *m = MsgOpenSession{} }
+
+// String implements proto.Message.
+func (m *MsgOpenSession) String() string {
+	return fmt.Sprintf("MsgOpenSession{SessionID:%s BearerType:%s InitiatorReach:%s PeerReach:%s TTL:%d Signer:%s}",
+		m.SessionID, m.BearerType, m.InitiatorReach, m.PeerReach, m.TTL, m.Signer)
+}
+
+// ProtoMessage implements proto.Message.
+func (*MsgOpenSession) ProtoMessage() {}
+
+// ValidateBasic is the stateless validation: non-empty session-id, known
+// bearer-type, non-empty initiator-reach, non-empty peer-reach, non-empty
+// signer. ttl may be 0 (never expires).
+func (m *MsgOpenSession) ValidateBasic() error {
+	if m.SessionID == "" {
+		return fmt.Errorf("bearers: empty session-id")
+	}
+	if !knownBearerType(m.BearerType) {
+		return fmt.Errorf("bearers: unknown bearer-type %q", m.BearerType)
+	}
+	if m.InitiatorReach == "" {
+		return fmt.Errorf("bearers: empty initiator-reach")
+	}
+	if m.PeerReach == "" {
+		return fmt.Errorf("bearers: empty peer-reach")
+	}
+	if m.Signer == "" {
+		return fmt.Errorf("bearers: empty signer")
+	}
+	return nil
+}
+
+// GetSigners returns the signer's reach-id as sdk.AccAddress bytes.
+func (m *MsgOpenSession) GetSigners() []sdk.AccAddress {
+	return []sdk.AccAddress{[]byte(m.Signer)}
+}
+
+// --- MsgCloseSession ---------------------------------------------------------
+
+// MsgCloseSession closes a session (Active → Closed). ValidateBasic is
+// stateless: non-empty session-id, non-empty signer.
+type MsgCloseSession struct {
+	SessionID string `json:"session_id" yaml:"session_id"`
+	Signer    string `json:"signer" yaml:"signer"`
+}
+
+// Reset implements proto.Message.
+func (m *MsgCloseSession) Reset() { *m = MsgCloseSession{} }
+
+// String implements proto.Message.
+func (m *MsgCloseSession) String() string {
+	return fmt.Sprintf("MsgCloseSession{SessionID:%s Signer:%s}", m.SessionID, m.Signer)
+}
+
+// ProtoMessage implements proto.Message.
+func (*MsgCloseSession) ProtoMessage() {}
+
+// ValidateBasic is the stateless validation: non-empty session-id and signer.
+func (m *MsgCloseSession) ValidateBasic() error {
+	if m.SessionID == "" {
+		return fmt.Errorf("bearers: empty session-id")
+	}
+	if m.Signer == "" {
+		return fmt.Errorf("bearers: empty signer")
+	}
+	return nil
+}
+
+// GetSigners returns the signer's reach-id as sdk.AccAddress bytes.
+func (m *MsgCloseSession) GetSigners() []sdk.AccAddress {
+	return []sdk.AccAddress{[]byte(m.Signer)}
+}
+
+// --- MsgRevokeSession --------------------------------------------------------
+
+// MsgRevokeSession revokes a session (out-of-band → Revoked). A revoked
+// session rejects further Receive. ValidateBasic is stateless: non-empty
+// session-id, non-empty signer.
+type MsgRevokeSession struct {
+	SessionID string `json:"session_id" yaml:"session_id"`
+	Signer    string `json:"signer" yaml:"signer"`
+}
+
+// Reset implements proto.Message.
+func (m *MsgRevokeSession) Reset() { *m = MsgRevokeSession{} }
+
+// String implements proto.Message.
+func (m *MsgRevokeSession) String() string {
+	return fmt.Sprintf("MsgRevokeSession{SessionID:%s Signer:%s}", m.SessionID, m.Signer)
+}
+
+// ProtoMessage implements proto.Message.
+func (*MsgRevokeSession) ProtoMessage() {}
+
+// ValidateBasic is the stateless validation: non-empty session-id and signer.
+func (m *MsgRevokeSession) ValidateBasic() error {
+	if m.SessionID == "" {
+		return fmt.Errorf("bearers: empty session-id")
+	}
+	if m.Signer == "" {
+		return fmt.Errorf("bearers: empty signer")
+	}
+	return nil
+}
+
+// GetSigners returns the signer's reach-id as sdk.AccAddress bytes.
+func (m *MsgRevokeSession) GetSigners() []sdk.AccAddress {
+	return []sdk.AccAddress{[]byte(m.Signer)}
+}
+
+// --- MsgServer interface + Response types -----------------------------------
+
+// MsgServer is the bearers module's message server interface (one method per
+// Msg*). The keeper's msg_server.go implements this; module.go's
+// RegisterServices wires the implementation. This is the hand-rolled
+// equivalent of the protobuf-generated MsgServer interface (no codegen per
+// the skeleton's zero-codegen style).
+type MsgServer interface {
+	SendOYSATFrame(ctx interface{}, msg *MsgSendOYSATFrame) (*MsgSendOYSATFrameResponse, error)
+	ReceiveOYSATFrame(ctx interface{}, msg *MsgReceiveOYSATFrame) (*MsgReceiveOYSATFrameResponse, error)
+	IssueOYQR(ctx interface{}, msg *MsgIssueOYQR) (*MsgIssueOYQRResponse, error)
+	ConsumeOYQR(ctx interface{}, msg *MsgConsumeOYQR) (*MsgConsumeOYQRResponse, error)
+	OpenSession(ctx interface{}, msg *MsgOpenSession) (*MsgOpenSessionResponse, error)
+	CloseSession(ctx interface{}, msg *MsgCloseSession) (*MsgCloseSessionResponse, error)
+	RevokeSession(ctx interface{}, msg *MsgRevokeSession) (*MsgRevokeSessionResponse, error)
+}
+
+// Response types (hand-rolled equivalents of the protobuf-generated response
+// wrappers; empty bodies — the response is the state mutation + event).
+
+// MsgSendOYSATFrameResponse is the response to MsgSendOYSATFrame.
+type MsgSendOYSATFrameResponse struct{}
+
+// Reset implements proto.Message.
+func (m *MsgSendOYSATFrameResponse) Reset() { *m = MsgSendOYSATFrameResponse{} }
+
+// String implements proto.Message.
+func (m *MsgSendOYSATFrameResponse) String() string { return "MsgSendOYSATFrameResponse{}" }
+
+// ProtoMessage implements proto.Message.
+func (*MsgSendOYSATFrameResponse) ProtoMessage() {}
+
+// MsgReceiveOYSATFrameResponse is the response to MsgReceiveOYSATFrame.
+type MsgReceiveOYSATFrameResponse struct{}
+
+// Reset implements proto.Message.
+func (m *MsgReceiveOYSATFrameResponse) Reset() { *m = MsgReceiveOYSATFrameResponse{} }
+
+// String implements proto.Message.
+func (m *MsgReceiveOYSATFrameResponse) String() string { return "MsgReceiveOYSATFrameResponse{}" }
+
+// ProtoMessage implements proto.Message.
+func (*MsgReceiveOYSATFrameResponse) ProtoMessage() {}
+
+// MsgIssueOYQRResponse is the response to MsgIssueOYQR.
+type MsgIssueOYQRResponse struct{}
+
+// Reset implements proto.Message.
+func (m *MsgIssueOYQRResponse) Reset() { *m = MsgIssueOYQRResponse{} }
+
+// String implements proto.Message.
+func (m *MsgIssueOYQRResponse) String() string { return "MsgIssueOYQRResponse{}" }
+
+// ProtoMessage implements proto.Message.
+func (*MsgIssueOYQRResponse) ProtoMessage() {}
+
+// MsgConsumeOYQRResponse is the response to MsgConsumeOYQR.
+type MsgConsumeOYQRResponse struct{}
+
+// Reset implements proto.Message.
+func (m *MsgConsumeOYQRResponse) Reset() { *m = MsgConsumeOYQRResponse{} }
+
+// String implements proto.Message.
+func (m *MsgConsumeOYQRResponse) String() string { return "MsgConsumeOYQRResponse{}" }
+
+// ProtoMessage implements proto.Message.
+func (*MsgConsumeOYQRResponse) ProtoMessage() {}
+
+// MsgOpenSessionResponse is the response to MsgOpenSession.
+type MsgOpenSessionResponse struct{}
+
+// Reset implements proto.Message.
+func (m *MsgOpenSessionResponse) Reset() { *m = MsgOpenSessionResponse{} }
+
+// String implements proto.Message.
+func (m *MsgOpenSessionResponse) String() string { return "MsgOpenSessionResponse{}" }
+
+// ProtoMessage implements proto.Message.
+func (*MsgOpenSessionResponse) ProtoMessage() {}
+
+// MsgCloseSessionResponse is the response to MsgCloseSession.
+type MsgCloseSessionResponse struct{}
+
+// Reset implements proto.Message.
+func (m *MsgCloseSessionResponse) Reset() { *m = MsgCloseSessionResponse{} }
+
+// String implements proto.Message.
+func (m *MsgCloseSessionResponse) String() string { return "MsgCloseSessionResponse{}" }
+
+// ProtoMessage implements proto.Message.
+func (*MsgCloseSessionResponse) ProtoMessage() {}
+
+// MsgRevokeSessionResponse is the response to MsgRevokeSession.
+type MsgRevokeSessionResponse struct{}
+
+// Reset implements proto.Message.
+func (m *MsgRevokeSessionResponse) Reset() { *m = MsgRevokeSessionResponse{} }
+
+// String implements proto.Message.
+func (m *MsgRevokeSessionResponse) String() string { return "MsgRevokeSessionResponse{}" }
+
+// ProtoMessage implements proto.Message.
+func (*MsgRevokeSessionResponse) ProtoMessage() {}
+
+// --- Helpers ----------------------------------------------------------------
+
+// knownBearerType reports whether bt is one of the six BearerType values.
+func knownBearerType(bt BearerType) bool {
+	for _, b := range AllBearers() {
+		if b.Type == bt {
+			return true
+		}
+	}
+	return false
+}

x/bearers/types/session.go

@@ -0,0 +1,121 @@
+package types
+
+// session.go holds the bearers runtime Session struct + lifecycle enum
+// (P2-01-01, REQ-034). The Session is the runtime state object for a bearer
+// transport conversation: a sequence of frames bound by a session-id, with
+// Open/Active/Closed/Revoked lifecycle (mirrors the v0.2 Window primitive's
+// lifecycle per A-523).
+//
+// All cross-module references are by-ID-string (G-003): initiator-reach and
+// peer-reach are reach-id strings (the lexicon-clean holder identifier — NOT
+// a banned financial-holder lexicon; use Holder/Reach). bearer-type is a
+// BearerType enum value defined in types.go (same package — no cross-module
+// import).
+//
+// Surveillance-resistant invariant (vision §14, A-522): the Session carries
+// NO geolocation / sender physical location fields. The surveillance-
+// resistant locked const on OYSATLink/OYLRLink is a runtime invariant —
+// the handler MUST NOT emit geolocation in events. A negative simtest
+// asserts the event set contains NO geolocation fields.
+
+// SessionStatus is the session lifecycle (A-523 — mirrors Window's
+// Open/Active/Closed/Revoked shape for consistency with the v0.2 Window
+// primitive).
+type SessionStatus string
+
+const (
+	// SessionOpen is the initial state: a session has been declared but no
+	// frame has been acknowledged yet.
+	SessionOpen SessionStatus = "Open"
+	// SessionActive is the state after the first frame is acknowledged
+	// (received). The session is carrying traffic.
+	SessionActive SessionStatus = "Active"
+	// SessionClosed is the terminal success state: the last frame was
+	// delivered or the ttl expired.
+	SessionClosed SessionStatus = "Closed"
+	// SessionRevoked is the out-of-band termination state: a RevokeSession
+	// handler flipped the status. A revoked session rejects further Receive.
+	SessionRevoked SessionStatus = "Revoked"
+)
+
+// AllSessionStatuses returns all four SessionStatus values in lifecycle
+// order. Locked-const test asserts exactly 4 entries.
+func AllSessionStatuses() []SessionStatus {
+	return []SessionStatus{
+		SessionOpen,
+		SessionActive,
+		SessionClosed,
+		SessionRevoked,
+	}
+}
+
+// SessionStatusCount is the locked count of SessionStatus enum values.
+// A regression firewall: adding/removing/renaming a status breaks this
+// const's test.
+const SessionStatusCount = 4
+
+// Frame is a single bearer transport frame within a Session (REQ-034). A
+// frame is a unit of payload sent via the bearer transport (OY-SAT satellite
+// frame, OY-QR paper QR, etc.). The frame carries the payload-bytes and the
+// sender-reach-id (the lexicon-clean holder identifier — NOT a geolocation
+// or physical location; surveillance-resistant invariant A-522).
+type Frame struct {
+	FrameID      string `json:"frame_id" yaml:"frame_id"`
+	SenderReach  string `json:"sender_reach" yaml:"sender_reach"`
+	PayloadBytes []byte `json:"payload_bytes" yaml:"payload_bytes"`
+	SentAt       int64  `json:"sent_at" yaml:"sent_at"`
+	Received     bool   `json:"received" yaml:"received"`
+}
+
+// Session is the runtime state object for a bearer transport conversation
+// (REQ-034, A-523). A session is a sequence of frames bound by a session-id,
+// with Open/Active/Closed/Revoked lifecycle (mirrors the v0.2 Window
+// primitive's lifecycle). The session is stored under the bearers keeper
+// (by session-id).
+//
+//   - session-id is this session's unique identifier.
+//   - bearer-type is the BearerType enum value (BearerOYSAT, BearerOYQR,
+//     etc.) — same package, no cross-module import.
+//   - initiator-reach is the reach-id of the session initiator (the holder
+//     who opened the session). Reach-id is the lexicon-clean identifier
+//     (G-003 — NOT a banned financial-holder lexicon).
+//   - peer-reach is the reach-id of the session peer (the other endpoint).
+//   - status is the SessionStatus lifecycle (Open/Active/Closed/Revoked).
+//   - frames is the ordered list of Frames in the session.
+//   - ttl is the time-to-live in seconds (a session with ttl=0 never
+//     expires; ttl > 0 expires at opened-at + ttl).
+//   - opened-at is the block time the session was opened (unix seconds).
+//   - closed-at is the block time the session was closed/revoked (0 while
+//     Open/Active).
+//
+// Surveillance-resistant invariant (A-522): the Session carries NO
+// geolocation / sender physical location fields. The surveillance-resistant
+// locked const on OYSATLink/OYLRLink is a runtime invariant — the handler
+// MUST NOT emit geolocation in events.
+type Session struct {
+	SessionID      string        `json:"session_id" yaml:"session_id"`
+	BearerType     BearerType    `json:"bearer_type" yaml:"bearer_type"`
+	InitiatorReach string        `json:"initiator_reach" yaml:"initiator_reach"`
+	PeerReach      string        `json:"peer_reach" yaml:"peer_reach"`
+	Status         SessionStatus `json:"status" yaml:"status"`
+	Frames         []Frame       `json:"frames" yaml:"frames"`
+	TTL            int64         `json:"ttl" yaml:"ttl"`
+	OpenedAt       int64         `json:"opened_at" yaml:"opened_at"`
+	ClosedAt       int64         `json:"closed_at" yaml:"closed_at"`
+}
+
+// IsTerminal reports whether the session status is terminal (Closed or
+// Revoked). A terminal session rejects further Receive calls.
+func (s Session) IsTerminal() bool {
+	return s.Status == SessionClosed || s.Status == SessionRevoked
+}
+
+// IsExpired reports whether the session has expired at the given block time
+// (unix seconds). A session with TTL=0 never expires. Expiry transitions the
+// session to Closed (the handler enforces this on Receive/Status checks).
+func (s Session) IsExpired(now int64) bool {
+	if s.TTL == 0 {
+		return false
+	}
+	return now >= s.OpenedAt+s.TTL
+}

x/bearers/types/types.go

@@ -1,6 +1,9 @@
 package types
 
-import "encoding/json"
+import (
+	"encoding/json"
+	"fmt"
+)
 
 const (
 	ModuleName   = "bearers"
@@ -138,18 +141,32 @@ func NewOYSATLink(satelliteID string, rangeMeters int32) OYSATLink {
 // "0 range"); a QR encodes a signed transfer that the recipient scans and
 // submits. The struct mirrors the v0.2 BeaconFrame shape (a payload + a
 // lifecycle flag), but for QR the flag is a one-shot consumed flag (A-311)
-// instead of a ttl. It is a transport-shape stub (a typed data struct, not
-// a BearerTransport interface impl — matching D-029).
+// instead of a ttl. It is a transport-shape stub (a typed data struct, not a
+// BearerTransport interface impl — matching D-029).
 //
 //   - qr-id is the QR code identifier.
 //   - payload-bytes is the signed transfer payload encoded in the QR.
 //   - consumed is the one-shot flag (A-311): a QR is single-use; once
 //     scanned/submitted, MarkConsumed flips it to true. Double-consume is
 //     idempotent (a no-op, not an error).
+//   - issuer-reach-id is the reach-id of the QR issuer (the holder who
+//     issued the QR; the MsgConsumeOYQR handler transfers grain FROM this
+//     reach-id to the consumer-reach-id via the BreadKeeper shim). Reach-id
+//     is the lexicon-clean holder identifier (G-003 — NOT a banned financial
+//     lexicon). Added in v0.5 P2 to support the MsgConsumeOYQR transfer
+//     effect (REQ-034, A-521).
+//   - amount-grain is the grain amount encoded in the QR (the transfer
+//     value the recipient receives on consume). Added in v0.5 P2.
+//   - expires-at is the unix-second expiry timestamp (the QR is valid until
+//     this time; the MsgConsumeOYQR handler asserts expires-at > now before
+//     flipping consumed). Added in v0.5 P2.
 type OYQRCode struct {
-	QRID         string `json:"qr_id" yaml:"qr_id"`
-	PayloadBytes []byte `json:"payload_bytes" yaml:"payload_bytes"`
-	Consumed     bool   `json:"consumed" yaml:"consumed"`
+	QRID          string `json:"qr_id" yaml:"qr_id"`
+	PayloadBytes  []byte `json:"payload_bytes" yaml:"payload_bytes"`
+	Consumed      bool   `json:"consumed" yaml:"consumed"`
+	IssuerReachID string `json:"issuer_reach_id" yaml:"issuer_reach_id"`
+	AmountGrain   int64  `json:"amount_grain" yaml:"amount_grain"`
+	ExpiresAt     int64  `json:"expires_at" yaml:"expires_at"`
 }
 
 // MarkConsumed marks the QR as consumed (one-shot, A-311). Idempotent:
@@ -164,12 +181,70 @@ type Params struct{}
 
 func DefaultParams() Params { return Params{} }
 
+// GenesisState defines the bearers module genesis state. v0.1 had only
+// Params; v0.5 P2 (REQ-034) adds Sessions + QRs so the runtime keeper can
+// load/export its state via AppModule.InitGenesis/ExportGenesis. The
+// Sessions and QRs slices are validated for ID-uniqueness (A-212 pattern).
 type GenesisState struct {
-	Params Params `json:"params" yaml:"params"`
+	Params   Params     `json:"params" yaml:"params"`
+	Sessions []Session  `json:"sessions" yaml:"sessions"`
+	QRs      []OYQRCode `json:"qrs" yaml:"qrs"`
 }
 
 func DefaultGenesisState() *GenesisState {
-	return &GenesisState{Params: DefaultParams()}
+	return &GenesisState{
+		Params:   DefaultParams(),
+		Sessions: []Session{},
+		QRs:      []OYQRCode{},
+	}
 }
 
-func ValidateGenesis(bz json.RawMessage) error { return nil }
+// Reset implements proto.Message (codec.JSONCodec.MustMarshalJSON /
+// MustUnmarshalJSON require proto.Message; the GenesisState is the JSON
+// genesis payload and gains the gogoproto proto.Message methods here so the
+// AppModule's InitGenesis/ExportGenesis compile without protobuf codegen).
+func (m *GenesisState) Reset() { *m = GenesisState{} }
+
+// String implements proto.Message.
+func (m *GenesisState) String() string {
+	return fmt.Sprintf("GenesisState{Sessions:%d QRs:%d}", len(m.Sessions), len(m.QRs))
+}
+
+// ProtoMessage implements proto.Message.
+func (*GenesisState) ProtoMessage() {}
+
+// ValidateGenesis performs ID-uniqueness checks (A-212 upgrade from v0.1
+// no-op): rejects duplicate session-ids and duplicate qr-ids. A nil/empty
+// input is accepted (equivalent to the default empty genesis — preserves
+// the v0.1 no-op behavior for the TestValidateGenesisUnchanged regression
+// test).
+func ValidateGenesis(bz json.RawMessage) error {
+	if len(bz) == 0 {
+		return nil
+	}
+	var gs GenesisState
+	if err := json.Unmarshal(bz, &gs); err != nil {
+		return fmt.Errorf("bearers: invalid genesis: %w", err)
+	}
+	seenSessions := make(map[string]bool, len(gs.Sessions))
+	for i, s := range gs.Sessions {
+		if s.SessionID == "" {
+			return fmt.Errorf("bearers: session [%d]: empty session-id", i)
+		}
+		if seenSessions[s.SessionID] {
+			return fmt.Errorf("bearers: duplicate session-id %q", s.SessionID)
+		}
+		seenSessions[s.SessionID] = true
+	}
+	seenQRs := make(map[string]bool, len(gs.QRs))
+	for i, q := range gs.QRs {
+		if q.QRID == "" {
+			return fmt.Errorf("bearers: qr [%d]: empty qr-id", i)
+		}
+		if seenQRs[q.QRID] {
+			return fmt.Errorf("bearers: duplicate qr-id %q", q.QRID)
+		}
+		seenQRs[q.QRID] = true
+	}
+	return nil
+}