feat: on-chain webhook subscription system with HMAC signing (Closes #508)

backend/alembic/versions/005_onchain_webhooks.py

@@ -0,0 +1,142 @@
+"""Add on-chain webhook subscriptions and delivery log tables.
+
+Revision ID: 005_onchain_webhooks
+Revises: 004_contributor_webhooks
+Create Date: 2026-03-23
+
+Implements bounty #508: on-chain event webhooks (escrow.locked,
+escrow.released, reputation.updated, stake.deposited, stake.withdrawn).
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+revision: str = "005_onchain_webhooks"
+down_revision: Union[str, None] = "004_contributor_webhooks"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Create onchain_webhook_subscriptions and onchain_webhook_delivery_logs tables."""
+
+    # ── subscriptions ──────────────────────────────────────────────────────────
+    op.create_table(
+        "onchain_webhook_subscriptions",
+        sa.Column(
+            "id",
+            postgresql.UUID(as_uuid=True),
+            primary_key=True,
+            server_default=sa.text("gen_random_uuid()"),
+        ),
+        sa.Column("user_id", postgresql.UUID(as_uuid=True), nullable=False),
+        sa.Column("url", sa.Text, nullable=False),
+        sa.Column("secret", sa.String(256), nullable=False),
+        # NULL = subscribe to all event types
+        sa.Column("event_filter", sa.Text, nullable=True),
+        sa.Column("active", sa.Boolean, nullable=False, server_default=sa.text("true")),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.text("now()"),
+        ),
+        sa.Column(
+            "updated_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.text("now()"),
+        ),
+        sa.Column("last_delivery_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("last_delivery_status", sa.String(20), nullable=True),
+        sa.Column(
+            "failure_count", sa.Integer, nullable=False, server_default=sa.text("0")
+        ),
+        sa.Column(
+            "total_deliveries",
+            sa.Integer,
+            nullable=False,
+            server_default=sa.text("0"),
+        ),
+        sa.Column(
+            "success_deliveries",
+            sa.Integer,
+            nullable=False,
+            server_default=sa.text("0"),
+        ),
+    )
+    op.create_index(
+        "ix_onchain_webhook_sub_user", "onchain_webhook_subscriptions", ["user_id"]
+    )
+    op.create_index(
+        "ix_onchain_webhook_sub_active", "onchain_webhook_subscriptions", ["active"]
+    )
+
+    # ── delivery logs ──────────────────────────────────────────────────────────
+    op.create_table(
+        "onchain_webhook_delivery_logs",
+        sa.Column(
+            "id",
+            postgresql.UUID(as_uuid=True),
+            primary_key=True,
+            server_default=sa.text("gen_random_uuid()"),
+        ),
+        sa.Column("subscription_id", postgresql.UUID(as_uuid=True), nullable=False),
+        sa.Column("batch_id", sa.String(36), nullable=False),
+        sa.Column("event_type", sa.String(50), nullable=False),
+        sa.Column("tx_signature", sa.String(100), nullable=False),
+        sa.Column("attempt", sa.Integer, nullable=False, server_default=sa.text("1")),
+        sa.Column("status_code", sa.Integer, nullable=True),
+        sa.Column(
+            "success", sa.Boolean, nullable=False, server_default=sa.text("false")
+        ),
+        sa.Column("error_message", sa.Text, nullable=True),
+        sa.Column(
+            "attempted_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.text("now()"),
+        ),
+        sa.Column("latency_ms", sa.Integer, nullable=True),
+    )
+    op.create_index(
+        "ix_onchain_delivery_sub_batch",
+        "onchain_webhook_delivery_logs",
+        ["subscription_id", "batch_id"],
+    )
+    op.create_index(
+        "ix_onchain_delivery_event",
+        "onchain_webhook_delivery_logs",
+        ["event_type"],
+    )
+    op.create_index(
+        "ix_onchain_delivery_attempted_at",
+        "onchain_webhook_delivery_logs",
+        ["attempted_at"],
+    )
+
+
+def downgrade() -> None:
+    """Drop on-chain webhook tables."""
+    op.drop_index(
+        "ix_onchain_delivery_attempted_at",
+        table_name="onchain_webhook_delivery_logs",
+    )
+    op.drop_index(
+        "ix_onchain_delivery_event", table_name="onchain_webhook_delivery_logs"
+    )
+    op.drop_index(
+        "ix_onchain_delivery_sub_batch", table_name="onchain_webhook_delivery_logs"
+    )
+    op.drop_table("onchain_webhook_delivery_logs")
+
+    op.drop_index(
+        "ix_onchain_webhook_sub_active", table_name="onchain_webhook_subscriptions"
+    )
+    op.drop_index(
+        "ix_onchain_webhook_sub_user", table_name="onchain_webhook_subscriptions"
+    )
+    op.drop_table("onchain_webhook_subscriptions")