diff --git a/docs/flashbots-auction/advanced/bundle-cancellations.mdx b/docs/flashbots-auction/advanced/bundle-cancellations.mdx
index 2345706b..c5588963 100644
--- a/docs/flashbots-auction/advanced/bundle-cancellations.mdx
+++ b/docs/flashbots-auction/advanced/bundle-cancellations.mdx
@@ -2,6 +2,10 @@
 title: bundle cancellations
 ---
 
+:::info
+Bundles are built by [BuilderNet](https://buildernet.org/). The [BuilderNet `eth_sendBundle` docs](https://buildernet.org/docs/api#eth_sendbundle) are the reference for bundle fields, replacement and cancellation.
+:::
+
 Bundle cancellations are currently deployed to our mainnet staging environment: `https://relay-staging.flashbots.net`. You must send both bundles and cancellations to this endpoint for it to be successful.
 
 This staging environment is limited to sending and cancelling bundles, and
diff --git a/docs/flashbots-auction/advanced/rpc-endpoint.mdx b/docs/flashbots-auction/advanced/rpc-endpoint.mdx
index bd0259bf..138d6516 100644
--- a/docs/flashbots-auction/advanced/rpc-endpoint.mdx
+++ b/docs/flashbots-auction/advanced/rpc-endpoint.mdx
@@ -29,6 +29,10 @@ Each method is documented below.
 
 ### eth_sendBundle
 
+:::info
+Bundles are built by [BuilderNet](https://buildernet.org/). The [BuilderNet `eth_sendBundle` docs](https://buildernet.org/docs/api#eth_sendbundle) are the reference for bundle fields, replacement and cancellation.
+:::
+
 `eth_sendBundle` can be used to send your bundles to the Flashbots builder. The `eth_sendBundle` RPC has the following payload format:
 
 ```json
@@ -297,6 +301,10 @@ example response:
 
 ### eth_cancelBundle
 
+:::info
+Bundles are built by [BuilderNet](https://buildernet.org/). The [BuilderNet `eth_sendBundle` docs](https://buildernet.org/docs/api#eth_sendbundle) are the reference for bundle fields, replacement and cancellation.
+:::
+
 `eth_cancelBundle` is used to prevent a submitted bundle from being included on-chain. See [bundle cancellations](/flashbots-auction/advanced/bundle-cancellations) for more information.
 
 [`eth_cancelPrivateTransaction`](https://docs.alchemy.com/alchemy/apis/ethereum/eth_cancelPrivateTransaction/?a=fb) is also supported on [Alchemy](https://alchemy.com/?a=fb).