feat(tracker-client): change default peer ID prefix from qB to RC

console/tracker-client/src/console/clients/udp/checker.rs

@@ -3,6 +3,7 @@ use std::num::NonZeroU16;
 use std::time::Duration;
 
 use bittorrent_primitives::info_hash::InfoHash as TorrustInfoHash;
+use bittorrent_tracker_client::peer_id::default_production_peer_id;
 use bittorrent_tracker_client::udp::client::UdpTrackerClient;
 use bittorrent_udp_tracker_protocol::common::InfoHash;
 use bittorrent_udp_tracker_protocol::{
@@ -129,7 +130,7 @@ impl Client {
             action_placeholder: AnnounceActionPlaceholder::default(),
             transaction_id,
             info_hash: InfoHash(info_hash.bytes()),
-            peer_id: params.peer_id.map_or(PeerId(*b"-qB00000000000000001"), PeerId),
+            peer_id: params.peer_id.map_or(default_production_peer_id(), PeerId),
             bytes_downloaded: NumberOfBytes::new(params.downloaded.unwrap_or(0)),
             bytes_uploaded: NumberOfBytes::new(params.uploaded.unwrap_or(0)),
             bytes_left: NumberOfBytes::new(params.left.unwrap_or(0)),

docs/adrs/20260512102000_define_tracker_client_peer_id_convention.md

@@ -0,0 +1,46 @@
+# Define Tracker-Client Peer ID Convention
+
+## Description
+
+Tracker-client defaults currently use a qBittorrent peer ID prefix (`-qB`), which
+misrepresents Torrust tracker-client traffic.
+
+Issue [#1564](https://github.com/torrust/torrust-tracker/issues/1564) requires
+adopting a Torrust-specific convention while keeping protocol fixtures explicit
+and package boundaries decoupled.
+
+## Agreement
+
+We adopt the following tracker-client peer ID convention:
+
+- Prefix: `RC` (Rust Client)
+- Version field: `3000` for the current `v3.0.0` line
+- Full layout: `-<CC><VVVV>-<12-digit-suffix>` (Azureus-style)
+
+Defaults are split by context:
+
+- Production defaults use `-RC3000-` plus a randomized 12-digit suffix.
+- The production default is generated once per process and reused.
+- Tests and fixtures use deterministic values such as
+  `-RC3000-000000000001`.
+
+Version source policy:
+
+- Version bytes are hard-coded per release for now.
+- The value is updated explicitly when the client versioning policy changes.
+
+Package coupling policy:
+
+- Protocol and server package fixtures do not import tracker-client constants.
+- They may define local deterministic constants that follow the same convention.
+
+## Date
+
+2026-05-12
+
+## References
+
+- <https://github.com/torrust/torrust-tracker/issues/1564>
+- <https://www.bittorrent.org/beps/bep_0020.html>
+- <https://wiki.theory.org/BitTorrentSpecification#peer_id>
+- [Issue Spec](../issues/open/1564-tracker-client-change-default-peer-id.md)

docs/adrs/index.md

@@ -5,3 +5,4 @@
 | [20240227164834](20240227164834_use_plural_for_modules_containing_collections.md)       | 2024-02-27 | Use plural for modules containing collections          | Module names should use plural when they contain multiple types with the same responsibility (e.g. `requests/`, `responses/`).                                                                                                             |
 | [20260420200013](20260420200013_adopt_custom_github_copilot_aligned_agent_framework.md) | 2026-04-20 | Adopt a custom, GitHub-Copilot-aligned agent framework | Use AGENTS.md, Agent Skills, and Custom Agent profiles instead of third-party agent frameworks.                                                                                                                                            |
 | [20260429000000](20260429000000_keep_database_as_aggregate_supertrait.md)               | 2026-04-29 | Keep `Database` as an aggregate supertrait             | Split the 18-method monolithic `Database` trait into four narrow context traits (`SchemaMigrator`, `TorrentMetricsStore`, `WhitelistStore`, `AuthKeyStore`) while keeping `Database` as an empty aggregate supertrait with a blanket impl. |
+| [20260512102000](20260512102000_define_tracker_client_peer_id_convention.md)            | 2026-05-12 | Define tracker-client peer ID convention               | Adopt `-RC3000-` Azureus-style defaults for tracker-client, use a once-per-process randomized production suffix, and keep deterministic `RC` test fixtures without cross-package constant coupling.                                        |

docs/issues/open/1564-tracker-client-change-default-peer-id.md

@@ -85,15 +85,15 @@ The literal `b"-qB00000000000000001"` appears in several places:
 
 ## Goals
 
-- [ ] Replace all hard-coded `b"-qB00000000000000001"` peer IDs with a Torrust-specific prefix
-- [ ] Define tracker-client constants for deterministic test PeerId and production default generation
-- [ ] Update all affected test fixtures so protocol-level tests still pass
-- [ ] Add ADR documenting the PeerId convention for production and tests
-- [ ] Version bytes are hard-coded per release in tracker-client defaults
-- [ ] Production default PeerId suffix is generated once per process run
-- [ ] `linter all` exits with code `0`
-- [ ] `cargo machete` reports no unused dependencies
-- [ ] Existing tests pass
+- [x] Replace all hard-coded `b"-qB00000000000000001"` peer IDs with a Torrust-specific prefix
+- [x] Define tracker-client constants for deterministic test PeerId and production default generation
+- [x] Update all affected test fixtures so protocol-level tests still pass
+- [x] Add ADR documenting the PeerId convention for production and tests
+- [x] Version bytes are hard-coded per release in tracker-client defaults
+- [x] Production default PeerId suffix is generated once per process run
+- [x] `linter all` exits with code `0`
+- [x] `cargo machete` reports no unused dependencies
+- [x] Existing tests pass
 
 ## Implementation Plan
 
@@ -170,18 +170,18 @@ Create an ADR under `docs/adrs/` documenting:
 
 ### Acceptance Verification
 
-| AC ID | Status (`TODO`/`DONE`) | Evidence |
-| ----- | ---------------------- | -------- |
-| AC1   | TODO                   |          |
-| AC2   | TODO                   |          |
-| AC3   | TODO                   |          |
-| AC4   | TODO                   |          |
-| AC5   | TODO                   |          |
-| AC6   | TODO                   |          |
-| AC7   | TODO                   |          |
-| AC8   | TODO                   |          |
-| AC9   | TODO                   |          |
-| AC10  | TODO                   |          |
+| AC ID | Status (`TODO`/`DONE`) | Evidence                                                                                                                                     |
+| ----- | ---------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- |
+| AC1   | DONE                   | `rg -- '-qB00000000000000001' packages/tracker-client/src console/tracker-client/src` returns no matches                                     |
+| AC2   | DONE                   | `packages/tracker-client/src/peer_id.rs` defines deterministic test constants and production helper                                          |
+| AC3   | DONE                   | HTTP `QueryBuilder::with_default_values` and UDP checker default now call `default_production_peer_id()`                                     |
+| AC4   | DONE                   | Protocol fixtures/docs in `packages/http-protocol/src/v1/{requests/announce.rs,responses/announce.rs,query.rs}` use `-RC3000-...`            |
+| AC5   | DONE                   | Added `docs/adrs/20260512102000_define_tracker_client_peer_id_convention.md` and indexed in `docs/adrs/index.md`                             |
+| AC6   | DONE                   | Hard-coded `-RC3000-` prefix/version in `packages/tracker-client/src/peer_id.rs`                                                             |
+| AC7   | DONE                   | `OnceLock` caches process-wide default peer ID in `default_production_peer_id()`                                                             |
+| AC8   | DONE                   | `cargo test -p bittorrent-tracker-client`, `cargo test -p torrust-tracker-client`, and `cargo test -p bittorrent-http-tracker-protocol` pass |
+| AC9   | DONE                   | `linter all` passes                                                                                                                          |
+| AC10  | DONE                   | `cargo machete` reports no unused dependencies                                                                                               |
 
 ## Risks and Trade-offs
 
@@ -197,21 +197,21 @@ Create an ADR under `docs/adrs/` documenting:
 | Field              | Value                                                            |
 | ------------------ | ---------------------------------------------------------------- |
 | Type               | Enhancement                                                      |
-| Status             | Planned                                                          |
+| Status             | Implemented (pending review)                                     |
 | Priority           | P3                                                               |
 | GitHub Issue       | [#1564](https://github.com/torrust/torrust-tracker/issues/1564)  |
 | Spec Path          | `docs/issues/open/1564-tracker-client-change-default-peer-id.md` |
-| Branch             | `1564-tracker-client-change-default-peer-id`                     |
+| Branch             | `1564-change-default-peer-id`                                    |
 | Related PR         | To be assigned                                                   |
-| Last Updated (UTC) | 2026-05-12 08:00                                                 |
+| Last Updated (UTC) | 2026-05-12 10:25                                                 |
 
 ## Progress Tracking
 
 ### Workflow Checkpoints
 
 - [ ] Spec drafted in `docs/issues/open/`
 - [ ] Spec reviewed and approved by user/maintainer
-- [ ] Implementation completed
+- [x] Implementation completed
 - [ ] Reviewer validated acceptance criteria and updated checkboxes
 - [ ] Committer verified spec progress is up to date before commit
 - [ ] Issue closed and spec moved from `docs/issues/open/` to `docs/issues/closed/`

packages/http-protocol/src/v1/query.rs

@@ -229,15 +229,15 @@ mod tests {
         #[test]
         fn should_parse_the_query_params_from_an_url_query_string() {
             let raw_query =
-                "info_hash=%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0&peer_id=-qB00000000000000001&port=17548";
+                "info_hash=%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0&peer_id=-RC3000-000000000001&port=17548";
 
             let query = raw_query.parse::<Query>().unwrap();
 
             assert_eq!(
                 query.get_param("info_hash").unwrap(),
                 "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"
             );
-            assert_eq!(query.get_param("peer_id").unwrap(), "-qB00000000000000001");
+            assert_eq!(query.get_param("peer_id").unwrap(), "-RC3000-000000000001");
             assert_eq!(query.get_param("port").unwrap(), "17548");
         }
 

packages/http-protocol/src/v1/requests/announce.rs

@@ -39,7 +39,7 @@ const NUMWANT: &str = "numwant";
 /// let request = Announce {
 ///     // Mandatory params
 ///     info_hash: "3b245504cf5f11bbdbe1201cea6a6bf45aee1bc0".parse::<InfoHash>().unwrap(),
-///     peer_id: PeerId(*b"-qB00000000000000001"),
+///     peer_id: PeerId(*b"-RC3000-000000000001"),
 ///     port: 17548,
 ///     // Optional params
 ///     downloaded: Some(NumberOfBytes::new(1)),
@@ -452,7 +452,7 @@ mod tests {
         fn should_be_instantiated_from_the_url_query_with_only_the_mandatory_params() {
             let raw_query = Query::from(vec![
                 (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                (PEER_ID, "-qB00000000000000001"),
+                (PEER_ID, "-RC3000-000000000001"),
                 (PORT, "17548"),
             ])
             .to_string();
@@ -465,7 +465,7 @@ mod tests {
                 announce_request,
                 Announce {
                     info_hash: "3b245504cf5f11bbdbe1201cea6a6bf45aee1bc0".parse::<InfoHash>().unwrap(), // DevSkim: ignore DS173237
-                    peer_id: PeerId(*b"-qB00000000000000001"),
+                    peer_id: PeerId(*b"-RC3000-000000000001"),
                     port: 17548,
                     downloaded: None,
                     uploaded: None,
@@ -481,7 +481,7 @@ mod tests {
         fn should_be_instantiated_from_the_url_query_params() {
             let raw_query = Query::from(vec![
                 (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                (PEER_ID, "-qB00000000000000001"),
+                (PEER_ID, "-RC3000-000000000001"),
                 (PORT, "17548"),
                 (DOWNLOADED, "1"),
                 (UPLOADED, "2"),
@@ -500,7 +500,7 @@ mod tests {
                 announce_request,
                 Announce {
                     info_hash: "3b245504cf5f11bbdbe1201cea6a6bf45aee1bc0".parse::<InfoHash>().unwrap(), // DevSkim: ignore DS173237
-                    peer_id: PeerId(*b"-qB00000000000000001"),
+                    peer_id: PeerId(*b"-RC3000-000000000001"),
                     port: 17548,
                     downloaded: Some(NumberOfBytes::new(1)),
                     uploaded: Some(NumberOfBytes::new(2)),
@@ -521,7 +521,7 @@ mod tests {
 
             #[test]
             fn it_should_fail_if_the_query_does_not_include_all_the_mandatory_params() {
-                let raw_query_without_info_hash = "peer_id=-qB00000000000000001&port=17548";
+                let raw_query_without_info_hash = "peer_id=-RC3000-000000000001&port=17548";
 
                 assert!(Announce::try_from(raw_query_without_info_hash.parse::<Query>().unwrap()).is_err());
 
@@ -530,7 +530,7 @@ mod tests {
                 assert!(Announce::try_from(raw_query_without_peer_id.parse::<Query>().unwrap()).is_err());
 
                 let raw_query_without_port =
-                    "info_hash=%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0&peer_id=-qB00000000000000001";
+                    "info_hash=%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0&peer_id=-RC3000-000000000001";
 
                 assert!(Announce::try_from(raw_query_without_port.parse::<Query>().unwrap()).is_err());
             }
@@ -539,7 +539,7 @@ mod tests {
             fn it_should_fail_if_the_info_hash_param_is_invalid() {
                 let raw_query = Query::from(vec![
                     (INFO_HASH, "INVALID_INFO_HASH_VALUE"),
-                    (PEER_ID, "-qB00000000000000001"),
+                    (PEER_ID, "-RC3000-000000000001"),
                     (PORT, "17548"),
                 ])
                 .to_string();
@@ -563,7 +563,7 @@ mod tests {
             fn it_should_fail_if_the_port_param_is_invalid() {
                 let raw_query = Query::from(vec![
                     (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                    (PEER_ID, "-qB00000000000000001"),
+                    (PEER_ID, "-RC3000-000000000001"),
                     (PORT, "INVALID_PORT_VALUE"),
                 ])
                 .to_string();
@@ -575,7 +575,7 @@ mod tests {
             fn it_should_fail_if_the_downloaded_param_is_invalid() {
                 let raw_query = Query::from(vec![
                     (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                    (PEER_ID, "-qB00000000000000001"),
+                    (PEER_ID, "-RC3000-000000000001"),
                     (PORT, "17548"),
                     (DOWNLOADED, "INVALID_DOWNLOADED_VALUE"),
                 ])
@@ -588,7 +588,7 @@ mod tests {
             fn it_should_fail_if_the_uploaded_param_is_invalid() {
                 let raw_query = Query::from(vec![
                     (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                    (PEER_ID, "-qB00000000000000001"),
+                    (PEER_ID, "-RC3000-000000000001"),
                     (PORT, "17548"),
                     (UPLOADED, "INVALID_UPLOADED_VALUE"),
                 ])
@@ -601,7 +601,7 @@ mod tests {
             fn it_should_fail_if_the_left_param_is_invalid() {
                 let raw_query = Query::from(vec![
                     (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                    (PEER_ID, "-qB00000000000000001"),
+                    (PEER_ID, "-RC3000-000000000001"),
                     (PORT, "17548"),
                     (LEFT, "INVALID_LEFT_VALUE"),
                 ])
@@ -614,7 +614,7 @@ mod tests {
             fn it_should_fail_if_the_event_param_is_invalid() {
                 let raw_query = Query::from(vec![
                     (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                    (PEER_ID, "-qB00000000000000001"),
+                    (PEER_ID, "-RC3000-000000000001"),
                     (PORT, "17548"),
                     (EVENT, "INVALID_EVENT_VALUE"),
                 ])
@@ -627,7 +627,7 @@ mod tests {
             fn it_should_fail_if_the_compact_param_is_invalid() {
                 let raw_query = Query::from(vec![
                     (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                    (PEER_ID, "-qB00000000000000001"),
+                    (PEER_ID, "-RC3000-000000000001"),
                     (PORT, "17548"),
                     (COMPACT, "INVALID_COMPACT_VALUE"),
                 ])
@@ -640,7 +640,7 @@ mod tests {
             fn it_should_fail_if_the_numwant_param_is_invalid() {
                 let raw_query = Query::from(vec![
                     (INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0"),
-                    (PEER_ID, "-qB00000000000000001"),
+                    (PEER_ID, "-RC3000-000000000001"),
                     (PORT, "17548"),
                     (NUMWANT, "-1"),
                 ])

packages/http-protocol/src/v1/responses/announce.rs

@@ -134,7 +134,7 @@ impl Into<Vec<u8>> for Compact {
 /// use bittorrent_http_tracker_protocol::v1::responses::announce::{Normal, NormalPeer};
 ///
 /// let peer = NormalPeer {
-///     peer_id: *b"-qB00000000000000001",
+///     peer_id: *b"-RC3000-000000000001",
 ///     ip: IpAddr::V4(Ipv4Addr::new(0x69, 0x69, 0x69, 0x69)), // 105.105.105.105
 ///     port: 0x7070,                                          // 28784
 /// };
@@ -300,12 +300,12 @@ mod tests {
         let policy = AnnouncePolicy::new(111, 222);
 
         let peer_ipv4 = PeerBuilder::default()
-            .with_peer_id(&PeerId(*b"-qB00000000000000001"))
+            .with_peer_id(&PeerId(*b"-RC3000-000000000001"))
             .with_peer_addr(&SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0x69, 0x69, 0x69, 0x69)), 0x7070))
             .build();
 
         let peer_ipv6 = PeerBuilder::default()
-            .with_peer_id(&PeerId(*b"-qB00000000000000002"))
+            .with_peer_id(&PeerId(*b"-RC3000-000000000002"))
             .with_peer_addr(&SocketAddr::new(
                 IpAddr::V6(Ipv6Addr::new(0x6969, 0x6969, 0x6969, 0x6969, 0x6969, 0x6969, 0x6969, 0x6969)),
                 0x7070,
@@ -324,7 +324,7 @@ mod tests {
         let bytes = response.data.into();
 
         // cspell:disable-next-line
-        let expected_bytes = b"d8:completei333e10:incompletei444e8:intervali111e12:min intervali222e5:peersld2:ip15:105.105.105.1057:peer id20:-qB000000000000000014:porti28784eed2:ip39:6969:6969:6969:6969:6969:6969:6969:69697:peer id20:-qB000000000000000024:porti28784eeee";
+        let expected_bytes = b"d8:completei333e10:incompletei444e8:intervali111e12:min intervali222e5:peersld2:ip15:105.105.105.1057:peer id20:-RC3000-0000000000014:porti28784eed2:ip39:6969:6969:6969:6969:6969:6969:6969:69697:peer id20:-RC3000-0000000000024:porti28784eeee";
 
         assert_eq!(
             String::from_utf8(bytes).unwrap(),

packages/tracker-client/src/http/client/requests/announce.rs

@@ -7,6 +7,7 @@ use bittorrent_udp_tracker_protocol::PeerId;
 use serde_repr::Serialize_repr;
 
 use crate::http::{percent_encode_byte_array, ByteArray20};
+use crate::peer_id::default_production_peer_id;
 
 pub struct Query {
     pub info_hash: ByteArray20,
@@ -99,7 +100,7 @@ impl QueryBuilder {
             peer_addr: IpAddr::V4(Ipv4Addr::new(192, 168, 1, 88)),
             downloaded: 0,
             uploaded: 0,
-            peer_id: PeerId(*b"-qB00000000000000001").0,
+            peer_id: default_production_peer_id().0,
             port: 17548,
             left: 0,
             event: Some(Event::Started),

packages/tracker-client/src/lib.rs

@@ -1,2 +1,3 @@
 pub mod http;
+pub mod peer_id;
 pub mod udp;