feat(das-guardian): surface Gloas proposer preferences in scan modal

docs/docs.go

@@ -2840,6 +2840,32 @@ const docTemplate = `{
                 }
             }
         },
+        "api.APIDasGuardianProposerPreference": {
+            "type": "object",
+            "properties": {
+                "dependent_root": {
+                    "type": "string"
+                },
+                "fee_recipient": {
+                    "type": "string"
+                },
+                "from": {
+                    "type": "string"
+                },
+                "gas_limit": {
+                    "type": "integer"
+                },
+                "proposal_slot": {
+                    "type": "integer"
+                },
+                "received_at": {
+                    "type": "string"
+                },
+                "validator_index": {
+                    "type": "integer"
+                }
+            }
+        },
         "api.APIDasGuardianScanRequest": {
             "type": "object",
             "properties": {
@@ -2860,6 +2886,10 @@ const docTemplate = `{
                     "items": {
                         "type": "integer"
                     }
+                },
+                "wait_for_proposer_preferences_seconds": {
+                    "description": "WaitForProposerPreferencesSeconds, if \u003e 0, keeps the Gloas\n` + "`" + `proposer_preferences` + "`" + ` gossip subscription open for this many seconds\nafter the RPC exchange so the gossip mesh has time to deliver messages.\nCapped at 60s server-side. Ignored on pre-Gloas forks.",
+                    "type": "integer"
                 }
             }
         },
@@ -2893,6 +2923,13 @@ const docTemplate = `{
                     "type": "object",
                     "additionalProperties": true
                 },
+                "proposer_preferences": {
+                    "description": "Gloas SignedProposerPreferences sniffed off the peer's gossip during\nthe scan window. Empty pre-Gloas, or when no proposer published in time.",
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/api.APIDasGuardianProposerPreference"
+                    }
+                },
                 "remote_metadata": {
                     "description": "Metadata (from RemoteMetadata)",
                     "allOf": [

docs/swagger.json

@@ -2837,6 +2837,32 @@
                 }
             }
         },
+        "api.APIDasGuardianProposerPreference": {
+            "type": "object",
+            "properties": {
+                "dependent_root": {
+                    "type": "string"
+                },
+                "fee_recipient": {
+                    "type": "string"
+                },
+                "from": {
+                    "type": "string"
+                },
+                "gas_limit": {
+                    "type": "integer"
+                },
+                "proposal_slot": {
+                    "type": "integer"
+                },
+                "received_at": {
+                    "type": "string"
+                },
+                "validator_index": {
+                    "type": "integer"
+                }
+            }
+        },
         "api.APIDasGuardianScanRequest": {
             "type": "object",
             "properties": {
@@ -2857,6 +2883,10 @@
                     "items": {
                         "type": "integer"
                     }
+                },
+                "wait_for_proposer_preferences_seconds": {
+                    "description": "WaitForProposerPreferencesSeconds, if \u003e 0, keeps the Gloas\n`proposer_preferences` gossip subscription open for this many seconds\nafter the RPC exchange so the gossip mesh has time to deliver messages.\nCapped at 60s server-side. Ignored on pre-Gloas forks.",
+                    "type": "integer"
                 }
             }
         },
@@ -2890,6 +2920,13 @@
                     "type": "object",
                     "additionalProperties": true
                 },
+                "proposer_preferences": {
+                    "description": "Gloas SignedProposerPreferences sniffed off the peer's gossip during\nthe scan window. Empty pre-Gloas, or when no proposer published in time.",
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/api.APIDasGuardianProposerPreference"
+                    }
+                },
                 "remote_metadata": {
                     "description": "Metadata (from RemoteMetadata)",
                     "allOf": [

docs/swagger.yaml

@@ -292,6 +292,23 @@ definitions:
       syncnets:
         type: string
     type: object
+  api.APIDasGuardianProposerPreference:
+    properties:
+      dependent_root:
+        type: string
+      fee_recipient:
+        type: string
+      from:
+        type: string
+      gas_limit:
+        type: integer
+      proposal_slot:
+        type: integer
+      received_at:
+        type: string
+      validator_index:
+        type: integer
+    type: object
   api.APIDasGuardianScanRequest:
     properties:
       enr:
@@ -307,6 +324,13 @@ definitions:
         items:
           type: integer
         type: array
+      wait_for_proposer_preferences_seconds:
+        description: |-
+          WaitForProposerPreferencesSeconds, if > 0, keeps the Gloas
+          `proposer_preferences` gossip subscription open for this many seconds
+          after the RPC exchange so the gossip mesh has time to deliver messages.
+          Capped at 60s server-side. Ignored on pre-Gloas forks.
+        type: integer
     type: object
   api.APIDasGuardianScanResponse:
     properties:
@@ -327,6 +351,13 @@ definitions:
         additionalProperties: true
         description: P2P Information
         type: object
+      proposer_preferences:
+        description: |-
+          Gloas SignedProposerPreferences sniffed off the peer's gossip during
+          the scan window. Empty pre-Gloas, or when no proposer published in time.
+        items:
+          $ref: '#/definitions/api.APIDasGuardianProposerPreference'
+        type: array
       remote_metadata:
         allOf:
         - $ref: '#/definitions/api.APIDasGuardianMetadata'

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/allegro/bigcache/v3 v3.1.0
 	github.com/cockroachdb/pebble v1.1.5
 	github.com/ethereum/go-ethereum v1.17.2
-	github.com/ethpandaops/eth-das-guardian v0.1.1
+	github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522095023-d09ab17a2b35
 	github.com/ethpandaops/ethcore v0.0.0-20260320045412-9cdd5d70a29c
 	github.com/ethpandaops/ethwallclock v0.4.0
 	github.com/ethpandaops/go-eth2-client v0.1.2

go.sum

@@ -114,8 +114,16 @@ github.com/ethereum/go-bigmodexpfix v0.0.0-20250911101455-f9e208c548ab h1:rvv6MJ
 github.com/ethereum/go-bigmodexpfix v0.0.0-20250911101455-f9e208c548ab/go.mod h1:IuLm4IsPipXKF7CW5Lzf68PIbZ5yl7FFd74l/E0o9A8=
 github.com/ethereum/go-ethereum v1.17.2 h1:ag6geu0kn8Hv5FLKTpH+Hm2DHD+iuFtuqKxEuwUsDOI=
 github.com/ethereum/go-ethereum v1.17.2/go.mod h1:KHcRXfGOUfUmKg51IhQ0IowiqZ6PqZf08CMtk0g5K1o=
-github.com/ethpandaops/eth-das-guardian v0.1.1 h1:RN96h3HSAMyU4XUOCqkj/9+lB+UW7cVW4Wr4JzdjmZY=
-github.com/ethpandaops/eth-das-guardian v0.1.1/go.mod h1:7amdK4bN9N9Zp0b9Y9FcbDm1YrpeGBm8ix8qpiX0WuY=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522080519-13921e4ca7f1 h1:QbgdX6WLkOSGA6YFu3pg235nvNPgyHWzAORZhqf5WzE=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522080519-13921e4ca7f1/go.mod h1:nNlQGSz4cf8FPBuf0KIXHt1/lPfsuKXl1VfLipaUPeE=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522082151-67ee99d84f56 h1:UtfnQdPA8W5X6RiUOaeNisnjw/BZpcVFkeCdja08lFI=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522082151-67ee99d84f56/go.mod h1:nNlQGSz4cf8FPBuf0KIXHt1/lPfsuKXl1VfLipaUPeE=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522090705-b0aedc982964 h1:BRAxqF/Tor8PApcnFsevGzT7OfU933sNScThLI0TDw0=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522090705-b0aedc982964/go.mod h1:nNlQGSz4cf8FPBuf0KIXHt1/lPfsuKXl1VfLipaUPeE=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522091055-3f6edd4ccde3 h1:K8h1AX/mBg/s3EQTyrDH4yJsOx1/BfXo6DJDNH5zFtM=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522091055-3f6edd4ccde3/go.mod h1:nNlQGSz4cf8FPBuf0KIXHt1/lPfsuKXl1VfLipaUPeE=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522095023-d09ab17a2b35 h1:uJR6xuKYt8OMIsb+qng0XPE65VSXOn/Kn2dRQbVsm4U=
+github.com/ethpandaops/eth-das-guardian v0.1.2-0.20260522095023-d09ab17a2b35/go.mod h1:nNlQGSz4cf8FPBuf0KIXHt1/lPfsuKXl1VfLipaUPeE=
 github.com/ethpandaops/ethcore v0.0.0-20260320045412-9cdd5d70a29c h1:uBRIitwcuCJlRGioqm0jQRIojiH8DSyLRFSTCCBxN6o=
 github.com/ethpandaops/ethcore v0.0.0-20260320045412-9cdd5d70a29c/go.mod h1:QsmYTdesob+vQ6pW4KtRVvxLZUNop3cdtd/DgD30hJU=
 github.com/ethpandaops/ethwallclock v0.4.0 h1:+sgnhf4pk6hLPukP076VxkiLloE4L0Yk1yat+ZyHh1g=

handlers/api/api_das_guardian.go

@@ -22,6 +22,11 @@ type APIDasGuardianScanRequest struct {
 	Slots       []uint64 `json:"slots,omitempty"`        // Optional slot numbers to scan
 	RandomMode  string   `json:"random_mode,omitempty"`  // Random slot selection mode: "non_missed", "with_blobs", "available"
 	RandomCount int32    `json:"random_count,omitempty"` // Number of random slots to select (default: 4)
+	// WaitForProposerPreferencesSeconds, if > 0, keeps the Gloas
+	// `proposer_preferences` gossip subscription open for this many seconds
+	// after the RPC exchange so the gossip mesh has time to deliver messages.
+	// Capped at 60s server-side. Ignored on pre-Gloas forks.
+	WaitForProposerPreferencesSeconds int32 `json:"wait_for_proposer_preferences_seconds,omitempty"`
 }
 
 // APIDasGuardianScanResponse represents the response from DAS Guardian scan
@@ -42,10 +47,26 @@ type APIDasGuardianScanResult struct {
 	// Metadata (from RemoteMetadata)
 	RemoteMetadata *APIDasGuardianMetadata `json:"remote_metadata,omitempty"`
 
+	// Gloas SignedProposerPreferences sniffed off the peer's gossip during
+	// the scan window. Empty pre-Gloas, or when no proposer published in time.
+	ProposerPreferences []*APIDasGuardianProposerPreference `json:"proposer_preferences,omitempty"`
+
 	// DAS Evaluation Result
 	EvalResult *APIDasGuardianEvalResult `json:"eval_result,omitempty"`
 }
 
+// APIDasGuardianProposerPreference is one SignedProposerPreferences gossip
+// message observed during the scan, attributed to the peer that delivered it.
+type APIDasGuardianProposerPreference struct {
+	ValidatorIndex uint64 `json:"validator_index"`
+	ProposalSlot   uint64 `json:"proposal_slot"`
+	FeeRecipient   string `json:"fee_recipient"`
+	GasLimit       uint64 `json:"gas_limit"`
+	DependentRoot  string `json:"dependent_root"`
+	ReceivedAt     string `json:"received_at"`
+	From           string `json:"from"`
+}
+
 // APIDasGuardianStatus represents the beacon node status
 type APIDasGuardianStatus struct {
 	ForkDigest     string `json:"fork_digest"`
@@ -110,11 +131,31 @@ func APIDasGuardianScan(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Honour an optional wait window so the Gloas proposer_preferences
+	// gossip subscription has time to deliver messages. Cap at 60s so a
+	// caller can't tie up a worker indefinitely.
+	waitSeconds := req.WaitForProposerPreferencesSeconds
+	if waitSeconds < 0 {
+		waitSeconds = 0
+	}
+	if waitSeconds > 60 {
+		waitSeconds = 60
+	}
+	scanTimeout := 30 * time.Second
+	if extra := time.Duration(waitSeconds) * time.Second; extra > 0 {
+		scanTimeout = 30*time.Second + extra
+	}
+
 	// Create temporary DAS Guardian instance
-	ctx, cancel := context.WithTimeout(r.Context(), 30*time.Second)
+	ctx, cancel := context.WithTimeout(r.Context(), scanTimeout)
 	defer cancel()
 
-	dasGuardian, err := services.NewDasGuardian(ctx, logrus.WithField("component", "das-guardian-api"))
+	guardianOpts := make([]services.DasGuardianOption, 0, 1)
+	if waitSeconds > 0 {
+		guardianOpts = append(guardianOpts, services.WithProposerPreferencesWait(time.Duration(waitSeconds)*time.Second))
+	}
+
+	dasGuardian, err := services.NewDasGuardian(ctx, logrus.WithField("component", "das-guardian-api"), guardianOpts...)
 	if err != nil {
 		logrus.WithError(err).Error("failed to create DAS Guardian instance")
 		http.Error(w, `{"error": "failed to initialize DAS Guardian"}`, http.StatusInternalServerError)
@@ -199,6 +240,28 @@ func APIDasGuardianScan(w http.ResponseWriter, r *http.Request) {
 			}
 		}
 
+		// Map any Gloas SignedProposerPreferences messages that were observed
+		// off the wire during the scan window.
+		if len(scanResult.ProposerPreferences) > 0 {
+			prefs := make([]*APIDasGuardianProposerPreference, 0, len(scanResult.ProposerPreferences))
+			for _, obs := range scanResult.ProposerPreferences {
+				if obs == nil || obs.Message == nil || obs.Message.Message == nil {
+					continue
+				}
+				msg := obs.Message.Message
+				prefs = append(prefs, &APIDasGuardianProposerPreference{
+					ValidatorIndex: uint64(msg.ValidatorIndex),
+					ProposalSlot:   uint64(msg.ProposalSlot),
+					FeeRecipient:   fmt.Sprintf("0x%x", msg.FeeRecipient),
+					GasLimit:       msg.GasLimit,
+					DependentRoot:  fmt.Sprintf("0x%x", msg.DependentRoot),
+					ReceivedAt:     obs.ReceivedAt.Format(time.RFC3339),
+					From:           obs.From.String(),
+				})
+			}
+			result.ProposerPreferences = prefs
+		}
+
 		// Map evaluation result (always present since it's not a pointer)
 		// Extract data from RangeResult and RootResult arrays
 		var downloadedResult [][]string

services/dasguardian.go

@@ -19,7 +19,7 @@ type DasGuardian struct {
 	guardian *dasguardian.DasGuardian
 }
 
-func NewDasGuardian(ctx context.Context, logger logrus.FieldLogger) (*DasGuardian, error) {
+func NewDasGuardian(ctx context.Context, logger logrus.FieldLogger, options ...DasGuardianOption) (*DasGuardian, error) {
 	guardianApi := &dasGuardianAPI{}
 
 	// Convert FieldLogger to *logrus.Logger
@@ -39,6 +39,9 @@ func NewDasGuardian(ctx context.Context, logger logrus.FieldLogger) (*DasGuardia
 		ConnectionTimeout: 10 * time.Second,
 		InitTimeout:       1 * time.Second,
 	}
+	for _, opt := range options {
+		opt(opts)
+	}
 
 	guardian, err := dasguardian.NewDASGuardian(ctx, opts)
 	if err != nil {
@@ -50,6 +53,20 @@ func NewDasGuardian(ctx context.Context, logger logrus.FieldLogger) (*DasGuardia
 	}, nil
 }
 
+// DasGuardianOption customises the DasGuardianConfig used to construct the
+// underlying guardian. Used to enable Gloas-only paths like the proposer
+// preferences gossip wait without affecting the default scan.
+type DasGuardianOption func(*dasguardian.DasGuardianConfig)
+
+// WithProposerPreferencesWait configures the underlying scan to keep the
+// `proposer_preferences` gossip subscription open for the given duration so
+// the gossip mesh has time to deliver messages.
+func WithProposerPreferencesWait(d time.Duration) DasGuardianOption {
+	return func(cfg *dasguardian.DasGuardianConfig) {
+		cfg.ProposerPreferencesWaitDuration = d
+	}
+}
+
 func (d *DasGuardian) Close() error {
 	return d.guardian.Close()
 }