Minecraft:NetherNet - Revision history

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Sync: updated from Minecraft

← Older revision		Revision as of 11:15, 4 October 2026
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	=== Capability check ===		=== Capability check ===

	The client sends ~~<code>~~GET /v1/join~~</code>~~. A successful response has a 2xx status, an ~~<code>~~application/json~~</code>~~ content type, and a JSON object with server information. A non-2xx response indicates that NetherNet is unavailable, and the client does not continue with connection setup.		The client sends {{cd\|GET /v1/join}}. A successful response has a 2xx status, an {{cd\|application/json}} content type, and a JSON object with server information. A non-2xx response indicates that NetherNet is unavailable, and the client does not continue with connection setup.

	{\| class="wikitable"		{\| class="wikitable"
	! Field !! Type !! Description		! Field !! Type !! Description
	\|-		\|-
	\| ~~<code>~~name~~</code>~~ \|\| String \|\| Server name.		\| {{cd\|name}} \|\| String \|\| Server name.
	\|-		\|-
	\| ~~<code>~~protocol~~</code>~~ \|\| Number \|\| Bedrock protocol version supported by the server.		\| {{cd\|protocol}} \|\| Number \|\| Bedrock protocol version supported by the server.
	\|-		\|-
	\| ~~<code>~~version~~</code>~~ \|\| String \|\| Bedrock game version.		\| {{cd\|version}} \|\| String \|\| Bedrock game version.
	\|-		\|-
	\| ~~<code>~~level~~</code>~~ \|\| String \|\| Name of the loaded world.		\| {{cd\|level}} \|\| String \|\| Name of the loaded world.
	\|-		\|-
	\| ~~<code>~~players~~</code>~~ \|\| Number \|\| Current player count.		\| {{cd\|players}} \|\| Number \|\| Current player count.
	\|-		\|-
	\| ~~<code>~~maxPlayers~~</code>~~ \|\| Number \|\| Maximum player count.		\| {{cd\|maxPlayers}} \|\| Number \|\| Maximum player count.
	\|-		\|-
	\| ~~<code>~~gameType~~</code>~~ \|\| Number \|\| Default game mode: 0 for Survival, 1 for Creative, or 2 for Adventure.		\| {{cd\|gameType}} \|\| Number \|\| Default game mode: 0 for Survival, 1 for Creative, or 2 for Adventure.
	\|}		\|}

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	! Direction !! Method and path !! Content type !! Body		! Direction !! Method and path !! Content type !! Body
	\|-		\|-
	\| Client to server \|\| ~~<code>~~POST /v1/join/{networkId}~~</code>~~ \|\| ~~<code>~~application/sdp~~</code>~~ \|\| The complete SDP offer, including ICE candidates.		\| Client to server \|\| {{cd\|POST /v1/join/{networkId}}} \|\| {{cd\|application/sdp}} \|\| The complete SDP offer, including ICE candidates.
	\|-		\|-
	\| Server to client \|\| HTTP 2xx response \|\| ~~<code>~~application/sdp~~</code>~~ \|\| The complete SDP answer, including ICE candidates.		\| Server to client \|\| HTTP 2xx response \|\| {{cd\|application/sdp}} \|\| The complete SDP answer, including ICE candidates.
	\|}		\|}

	The ~~<code>~~{networkId}~~</code>~~ path value identifies the client to the signaling service. Treat it as an opaque string. A non-2xx response ends the attempt; the client does not retry automatically. NetherNet uses full [[Minecraft:wikipedia:Interactive_Connectivity_Establishment\|ICE]], so candidate gathering completes before the offer or answer is sent. The signaling service routes the offer to the host and returns its answer. It is not involved in the game-data connection after setup.<ref name="nethernet-guide" />		The {{cd\|{networkId}}} path value identifies the client to the signaling service. Treat it as an opaque string. A non-2xx response ends the attempt; the client does not retry automatically. NetherNet uses full [[Minecraft:wikipedia:Interactive_Connectivity_Establishment\|ICE]], so candidate gathering completes before the offer or answer is sent. The signaling service routes the offer to the host and returns its answer. It is not involved in the game-data connection after setup.<ref name="nethernet-guide" />

	== Connection sequence ==		== Connection sequence ==

	# The client checks support with ~~<code>~~GET /v1/join~~</code>~~.		# The client checks support with {{cd\|GET /v1/join}}.
	# The client creates a [[Minecraft:wikipedia:WebRTC\|WebRTC]] peer connection and the two data channels described below.		# The client creates a [[Minecraft:wikipedia:WebRTC\|WebRTC]] peer connection and the two data channels described below.
	# The client gathers ICE candidates and sends its SDP offer to ~~<code>~~POST /v1/join/{networkId}~~</code>~~.		# The client gathers ICE candidates and sends its SDP offer to {{cd\|POST /v1/join/{networkId}}}.
	# The signaling service forwards the offer to the host.		# The signaling service forwards the offer to the host.
	# The host creates an [[Minecraft:wikipedia:Session_Description_Protocol\|SDP]] answer, gathers its [[Minecraft:wikipedia:Interactive_Connectivity_Establishment\|ICE]] candidates, and returns the answer through the signaling service.		# The host creates an [[Minecraft:wikipedia:Session_Description_Protocol\|SDP]] answer, gathers its [[Minecraft:wikipedia:Interactive_Connectivity_Establishment\|ICE]] candidates, and returns the answer through the signaling service.
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	== Identity and trust ==		== Identity and trust ==

	Both the offer and answer include an <code>a=identity</code> attribute. The client's assertion identifies the authenticated player and is validated by the server. The server's answer must also contain an assertion for its operator identity; the client checks it before accepting the connection.<ref name="nethernet-guide" />		Both the offer and answer include an <code>a=identity</code><ref name="identity-rfc">[https://www.rfc-editor.org/info/rfc8827/#section-5\| RFC 8827: SDP Identity Attribute]</ref> attribute. The client's assertion identifies the authenticated player and is validated by the server. The server's answer must also contain an assertion for its operator identity; the client checks it before accepting the connection.<ref name="nethernet-guide" />

	The attribute contains a base64-encoded JSON object with an identity provider (~~<code>~~idp~~</code>~~) and an opaque ~~<code>~~assertion~~</code>~~. The assertion carries a signed token and a signature for the WebRTC certificate fingerprints. The client and server provide different identity assertions for their respective roles.<ref name="nethernet-guide" />		The attribute contains a base64-encoded JSON object with an identity provider ({{cd\|idp}}) and an opaque {{cd\|assertion}}. The assertion carries a signed token and a signature for the WebRTC certificate fingerprints. The client and server provide different identity assertions for their respective roles.<ref name="nethernet-guide" />

	With HTTPS signaling, the client relies on [[Minecraft:wikipedia:Transport_Layer_Security\|TLS]] to authenticate the server. With plaintext HTTP signaling, the client uses [[Minecraft:wikipedia:Trust_on_first_use\|TOFU]]: it prompts the player the first time it sees an operator key, then remembers that key for later connections. The <code>a=identity</code> attribute is required in the answer for both cases.<ref name="nethernet-guide" />		With HTTPS signaling, the client relies on [[Minecraft:wikipedia:Transport_Layer_Security\|TLS]] to authenticate the server. With plaintext HTTP signaling, the client uses [[Minecraft:wikipedia:Trust_on_first_use\|TOFU]]: it prompts the player the first time it sees an operator key, then remembers that key for later connections. The <code>a=identity</code><ref name="identity-rfc" /> attribute is required in the answer for both cases.<ref name="nethernet-guide" />

	== Data channels ==		== Data channels ==
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	! Channel !! Delivery !! Use		! Channel !! Delivery !! Use
	\|-		\|-
	\| ~~<code>~~ReliableDataChannel~~</code>~~ \|\| Reliable and ordered \|\| Data that must arrive in order. Supports fragmentation.		\| {{cd\|ReliableDataChannel}} \|\| Reliable and ordered \|\| Data that must arrive in order. Supports fragmentation.
	\|-		\|-
	\| ~~<code>~~UnreliableDataChannel~~</code>~~ \|\| Unreliable and unordered \|\| Latency-sensitive data that can tolerate loss. Does not support fragmentation.		\| {{cd\|UnreliableDataChannel}} \|\| Unreliable and unordered \|\| Latency-sensitive data that can tolerate loss. Does not support fragmentation.
	\|}		\|}

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	! Header value !! Meaning		! Header value !! Meaning
	\|-		\|-
	\| ~~<code>~~0~~</code>~~ \|\| Complete message, or the final fragment of a fragmented message.		\| {{cd\|0}} \|\| Complete message, or the final fragment of a fragmented message.
	\|-		\|-
	\| ~~<code>~~N~~</code>~~ where ~~<code>~~N > 0~~</code>~~ \|\| Fragment with ~~<code>~~N~~</code>~~ more fragments to follow.		\| {{cd\|N}} where {{cd\|N > 0}} \|\| Fragment with {{cd\|N}} more fragments to follow.
	\|}		\|}

	Unfragmented messages have a header value of ~~<code>~~0~~</code>~~. On ~~<code>~~ReliableDataChannel~~</code>~~, oversized messages are split into fragments. Their header values count down to zero, and the receiver reassembles the payloads in order. On ~~<code>~~UnreliableDataChannel~~</code>~~, the header is always zero; messages too large for a single [[Minecraft:wikipedia:Stream_Control_Transmission_Protocol\|SCTP]] message are dropped rather than fragmented.<ref name="nethernet-guide" />		Unfragmented messages have a header value of {{cd\|0}}. On {{cd\|ReliableDataChannel}}, oversized messages are split into fragments. Their header values count down to zero, and the receiver reassembles the payloads in order. On {{cd\|UnreliableDataChannel}}, the header is always zero; messages too large for a single [[Minecraft:wikipedia:Stream_Control_Transmission_Protocol\|SCTP]] message are dropped rather than fragmented.<ref name="nethernet-guide" />

	== Game data ==		== Game data ==

SyncBot: Sync: new page from Minecraft

2026-10-03T11:20:10Z

Sync: new page from Minecraft

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{{DISPLAYTITLE:NetherNet}}
{{exclusive|bedrock}}
{{Work in progress}}

'''NetherNet''' is ''Minecraft''{{'}}s peer-to-peer networking transport, built on [[Minecraft:wikipedia:WebRTC|WebRTC]]. The client uses WebRTC data channels to exchange game data with a server. The connection is negotiated through HTTP signaling, then established directly between the client and server.<ref name="nethernet-guide">{{cite|url=https://mojang.github.io/bedrock-protocol-docs/guides/nether-net-onboarding-guide/|title=NetherNet HTTP Signaling — Partner Onboarding Guide|website=Minecraft Bedrock Protocol}}</ref>

== HTTP signaling ==

The client uses two HTTP endpoints. A successful capability check tells the client that the server supports NetherNet and provides server details. The client then uses the [[Minecraft:wikipedia:Session_Description_Protocol|SDP]] exchange endpoint to negotiate a WebRTC connection.<ref name="nethernet-guide" />

=== Capability check ===

The client sends <code>GET /v1/join</code>. A successful response has a 2xx status, an <code>application/json</code> content type, and a JSON object with server information. A non-2xx response indicates that NetherNet is unavailable, and the client does not continue with connection setup.

{| class="wikitable"
! Field !! Type !! Description
|-
| <code>name</code> || String || Server name.
|-
| <code>protocol</code> || Number || Bedrock protocol version supported by the server.
|-
| <code>version</code> || String || Bedrock game version.
|-
| <code>level</code> || String || Name of the loaded world.
|-
| <code>players</code> || Number || Current player count.
|-
| <code>maxPlayers</code> || Number || Maximum player count.
|-
| <code>gameType</code> || Number || Default game mode: 0 for Survival, 1 for Creative, or 2 for Adventure.
|}

=== SDP exchange ===

The client sends one HTTP request per connection attempt:

{| class="wikitable"
! Direction !! Method and path !! Content type !! Body
|-
| Client to server || <code>POST /v1/join/{networkId}</code> || <code>application/sdp</code> || The complete SDP offer, including ICE candidates.
|-
| Server to client || HTTP 2xx response || <code>application/sdp</code> || The complete SDP answer, including ICE candidates.
|}

The <code>{networkId}</code> path value identifies the client to the signaling service. Treat it as an opaque string. A non-2xx response ends the attempt; the client does not retry automatically. NetherNet uses full [[Minecraft:wikipedia:Interactive_Connectivity_Establishment|ICE]], so candidate gathering completes before the offer or answer is sent. The signaling service routes the offer to the host and returns its answer. It is not involved in the game-data connection after setup.<ref name="nethernet-guide" />

== Connection sequence ==

# The client checks support with <code>GET /v1/join</code>.
# The client creates a [[Minecraft:wikipedia:WebRTC|WebRTC]] peer connection and the two data channels described below.
# The client gathers ICE candidates and sends its SDP offer to <code>POST /v1/join/{networkId}</code>.
# The signaling service forwards the offer to the host.
# The host creates an [[Minecraft:wikipedia:Session_Description_Protocol|SDP]] answer, gathers its [[Minecraft:wikipedia:Interactive_Connectivity_Establishment|ICE]] candidates, and returns the answer through the signaling service.
# The client applies the answer. The client and host perform [[Minecraft:wikipedia:Interactive_Connectivity_Establishment|ICE]] connectivity checks, establish [[Minecraft:wikipedia:Datagram_Transport_Layer_Security|DTLS]] and [[Minecraft:wikipedia:Stream_Control_Transmission_Protocol|SCTP]], and open the data channels.
# Game data flows between the client and host over the [[Minecraft:wikipedia:WebRTC|WebRTC]] connection.<ref name="nethernet-guide" />

The client configuration described in Mojang's guide uses [[Minecraft:wikipedia:User_Datagram_Protocol|UDP]] ICE candidates, disables trickle ICE,<ref>[https://datatracker.ietf.org/doc/html/rfc8838 RFC 8838: Trickle ICE]</ref> and bundles data channels over one transport. The offer and answer each carry all gathered ICE candidates.<ref name="nethernet-guide" />

== Identity and trust ==

Both the offer and answer include an <code>a=identity</code> attribute. The client's assertion identifies the authenticated player and is validated by the server. The server's answer must also contain an assertion for its operator identity; the client checks it before accepting the connection.<ref name="nethernet-guide" />

The attribute contains a base64-encoded JSON object with an identity provider (<code>idp</code>) and an opaque <code>assertion</code>. The assertion carries a signed token and a signature for the WebRTC certificate fingerprints. The client and server provide different identity assertions for their respective roles.<ref name="nethernet-guide" />

With HTTPS signaling, the client relies on [[Minecraft:wikipedia:Transport_Layer_Security|TLS]] to authenticate the server. With plaintext HTTP signaling, the client uses [[Minecraft:wikipedia:Trust_on_first_use|TOFU]]: it prompts the player the first time it sees an operator key, then remembers that key for later connections. The <code>a=identity</code> attribute is required in the answer for both cases.<ref name="nethernet-guide" />

== Data channels ==

The client opens two [[Minecraft:wikipedia:Stream_Control_Transmission_Protocol|SCTP]] data channels. The host accepts both channels and can send and receive on them.<ref name="nethernet-guide" />

{| class="wikitable"
! Channel !! Delivery !! Use
|-
| <code>ReliableDataChannel</code> || Reliable and ordered || Data that must arrive in order. Supports fragmentation.
|-
| <code>UnreliableDataChannel</code> || Unreliable and unordered || Latency-sensitive data that can tolerate loss. Does not support fragmentation.
|}

== Message framing ==

Each data-channel message begins with a one-byte header. The receiver removes this byte before processing the payload.<ref name="nethernet-guide" />

{| class="wikitable"
! Header value !! Meaning
|-
| <code>0</code> || Complete message, or the final fragment of a fragmented message.
|-
| <code>N</code> where <code>N > 0</code> || Fragment with <code>N</code> more fragments to follow.
|}

Unfragmented messages have a header value of <code>0</code>. On <code>ReliableDataChannel</code>, oversized messages are split into fragments. Their header values count down to zero, and the receiver reassembles the payloads in order. On <code>UnreliableDataChannel</code>, the header is always zero; messages too large for a single [[Minecraft:wikipedia:Stream_Control_Transmission_Protocol|SCTP]] message are dropped rather than fragmented.<ref name="nethernet-guide" />

== Game data ==

NetherNet carries [[Minecraft:Bedrock Edition]] game data in its data-channel messages. Game-packet formats are documented at [[Minecraft:Bedrock_Edition_protocol/Packets|Bedrock Edition protocol/Packets]].<ref name="nethernet-guide" />

== Use in ''Bedrock Edition'' ==

NetherNet became the default transport for Bedrock Dedicated Server in [[Minecraft:26.50]]. [[Minecraft:RakNet]] is deprecated in the [[Minecraft:26.60.22]] Preview.<ref>{{cite|url=https://feedback.minecraft.net/hc/en-us/articles/48940953884173-Minecraft-Beta-Preview-26-60-24|title=Minecraft Beta & Preview - 26.60.24|website=Minecraft Feedback|date=September 16, 2026}}</ref><ref>{{cite|url=https://feedback.minecraft.net/hc/en-us/articles/48740748263565-Minecraft-Beta-Preview-26-60-22-23|title=Minecraft Beta & Preview - 26.60.22/23|website=Minecraft Feedback|date=September 8, 2026}}</ref>

== References ==
{{reflist}}

== Navigation ==
{{Navbox Bedrock Edition}}

[[Category:Bedrock Edition]]