diff --git a/docs/tournament-openapi.yaml b/docs/tournament-openapi.yaml
new file mode 100644
index 0000000..4528e21
--- /dev/null
+++ b/docs/tournament-openapi.yaml
@@ -0,0 +1,623 @@
+openapi: 3.0.3
+info:
+  title: NowChess Tournament API
+  description: |
+    Swiss-system bot tournaments, modelled after the Lichess API style.
+
+    Game moves flow through the existing board and bot endpoints — this module
+    handles pairings, standings, and lifecycle only.
+
+    ## Streaming
+    Endpoints marked **NDJSON** return newline-delimited JSON objects
+    (`application/x-ndjson`). Each line is one complete JSON object. The
+    connection stays open until the tournament or round ends.
+
+    ## Bot flow
+    ```
+    POST /api/tournament                       # create
+    POST /api/tournament/{id}/join             # each bot joins
+    POST /api/tournament/{id}/start            # director starts
+
+    GET  /api/tournament/{id}/stream  (NDJSON) # open before start
+
+    -- per round --
+    receive gameStart { gameId, color }
+    GET  /bot/stream/game/{gameId}    (existing, NDJSON)
+    POST /bot/game/{gameId}/move/{uci}         (existing)
+    -- repeat --
+
+    GET  /api/tournament/{id}/results (NDJSON) # final standings
+    ```
+  version: 1.0.0
+
+servers:
+  - url: https://st.nowchess.janis-eccarius.de
+    description: Staging
+  - url: https://nowchess.janis-eccarius.de
+    description: Production
+  - url: http://localhost:8086
+    description: Local
+
+security:
+  - bearerAuth: []
+
+tags:
+  - name: Tournament
+    description: Tournament lifecycle
+  - name: Participation
+    description: Join and withdraw
+  - name: Results
+    description: Standings, pairings, and game export
+  - name: Stream
+    description: NDJSON event streams
+
+paths:
+
+  /api/tournament:
+    get:
+      tags: [Tournament]
+      summary: Get current tournaments
+      description: Returns tournaments grouped by status. No auth required.
+      security: []
+      responses:
+        "200":
+          description: Tournaments by status
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  created:
+                    type: array
+                    items:
+                      $ref: "#/components/schemas/TournamentInfo"
+                  started:
+                    type: array
+                    items:
+                      $ref: "#/components/schemas/TournamentInfo"
+                  finished:
+                    type: array
+                    items:
+                      $ref: "#/components/schemas/TournamentInfo"
+
+    post:
+      tags: [Tournament]
+      summary: Create a new tournament
+      description: The authenticated user becomes the tournament director.
+      requestBody:
+        required: true
+        content:
+          application/x-www-form-urlencoded:
+            schema:
+              $ref: "#/components/schemas/CreateTournamentForm"
+      responses:
+        "201":
+          description: Tournament created
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Tournament"
+        "400":
+          $ref: "#/components/responses/BadRequest"
+        "401":
+          $ref: "#/components/responses/Unauthorized"
+
+  /api/tournament/{id}:
+    parameters:
+      - $ref: "#/components/parameters/id"
+
+    get:
+      tags: [Tournament]
+      summary: Get a tournament
+      description: Includes the first page of standings in the `standing` field.
+      security: []
+      responses:
+        "200":
+          description: Tournament with embedded standings
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Tournament"
+        "404":
+          $ref: "#/components/responses/NotFound"
+
+    delete:
+      tags: [Tournament]
+      summary: Terminate a tournament
+      description: Only the director may terminate. Only allowed while status is `created`.
+      responses:
+        "204":
+          description: Terminated
+        "401":
+          $ref: "#/components/responses/Unauthorized"
+        "403":
+          $ref: "#/components/responses/Forbidden"
+        "404":
+          $ref: "#/components/responses/NotFound"
+        "409":
+          $ref: "#/components/responses/Conflict"
+
+  /api/tournament/{id}/start:
+    parameters:
+      - $ref: "#/components/parameters/id"
+
+    post:
+      tags: [Tournament]
+      summary: Start the tournament
+      description: |
+        Only the director may start. Requires at least 2 joined bots.
+        Computes round 1 pairings and creates games via `POST /api/board/game`.
+      responses:
+        "200":
+          description: Tournament started
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Tournament"
+        "401":
+          $ref: "#/components/responses/Unauthorized"
+        "403":
+          $ref: "#/components/responses/Forbidden"
+        "404":
+          $ref: "#/components/responses/NotFound"
+        "409":
+          $ref: "#/components/responses/Conflict"
+
+  /api/tournament/{id}/join:
+    parameters:
+      - $ref: "#/components/parameters/id"
+
+    post:
+      tags: [Participation]
+      summary: Join a tournament
+      description: |
+        Register the authenticated bot for the tournament. Only allowed while
+        status is `created`. The token subject must be a bot account.
+      responses:
+        "200":
+          description: Ok
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Ok"
+        "401":
+          $ref: "#/components/responses/Unauthorized"
+        "403":
+          $ref: "#/components/responses/Forbidden"
+        "404":
+          $ref: "#/components/responses/NotFound"
+        "409":
+          $ref: "#/components/responses/Conflict"
+
+  /api/tournament/{id}/withdraw:
+    parameters:
+      - $ref: "#/components/parameters/id"
+
+    post:
+      tags: [Participation]
+      summary: Withdraw from a tournament
+      description: Only allowed while status is `created`.
+      responses:
+        "200":
+          description: Ok
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Ok"
+        "401":
+          $ref: "#/components/responses/Unauthorized"
+        "403":
+          $ref: "#/components/responses/Forbidden"
+        "404":
+          $ref: "#/components/responses/NotFound"
+        "409":
+          $ref: "#/components/responses/Conflict"
+
+  /api/tournament/{id}/results:
+    parameters:
+      - $ref: "#/components/parameters/id"
+
+    get:
+      tags: [Results]
+      summary: Get results as NDJSON stream
+      description: |
+        Streams one `Result` object per line, sorted by rank ascending.
+        Available at any point during or after the tournament.
+      security: []
+      parameters:
+        - name: nb
+          in: query
+          description: Max number of results to stream (default all)
+          schema:
+            type: integer
+            minimum: 1
+      responses:
+        "200":
+          description: NDJSON stream of results
+          content:
+            application/x-ndjson:
+              schema:
+                $ref: "#/components/schemas/Result"
+        "404":
+          $ref: "#/components/responses/NotFound"
+
+  /api/tournament/{id}/round/{round}:
+    parameters:
+      - $ref: "#/components/parameters/id"
+      - name: round
+        in: path
+        required: true
+        schema:
+          type: integer
+          minimum: 1
+
+    get:
+      tags: [Results]
+      summary: Get pairings for a round
+      security: []
+      responses:
+        "200":
+          description: Pairings for the specified round
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  round:
+                    type: integer
+                    example: 2
+                  pairings:
+                    type: array
+                    items:
+                      $ref: "#/components/schemas/Pairing"
+        "404":
+          $ref: "#/components/responses/NotFound"
+
+  /api/tournament/{id}/export/games:
+    parameters:
+      - $ref: "#/components/parameters/id"
+
+    get:
+      tags: [Results]
+      summary: Export all games
+      description: |
+        Returns all games of the tournament. Accepts both PGN and NDJSON via
+        the `Accept` header.
+      security: []
+      parameters:
+        - name: Accept
+          in: header
+          schema:
+            type: string
+            enum:
+              - application/x-chess-pgn
+              - application/x-ndjson
+            default: application/x-chess-pgn
+      responses:
+        "200":
+          description: Games in the requested format
+          content:
+            application/x-chess-pgn:
+              schema:
+                type: string
+                description: Standard PGN, one game per block
+            application/x-ndjson:
+              schema:
+                $ref: "#/components/schemas/GameExport"
+        "404":
+          $ref: "#/components/responses/NotFound"
+
+  /api/tournament/{id}/stream:
+    parameters:
+      - $ref: "#/components/parameters/id"
+
+    get:
+      tags: [Stream]
+      summary: Stream tournament events
+      description: |
+        NDJSON stream scoped to one tournament. Keep this connection open for
+        the full tournament lifetime.
+
+        On `gameStart` the bot connects to the existing bot endpoints:
+        - `GET /bot/stream/game/{gameId}` — stream game state (existing)
+        - `POST /bot/game/{gameId}/move/{uci}` — submit moves (existing)
+      responses:
+        "200":
+          description: NDJSON event stream
+          content:
+            application/x-ndjson:
+              schema:
+                $ref: "#/components/schemas/TournamentEvent"
+        "401":
+          $ref: "#/components/responses/Unauthorized"
+        "404":
+          $ref: "#/components/responses/NotFound"
+
+components:
+
+  securitySchemes:
+    bearerAuth:
+      type: http
+      scheme: bearer
+      bearerFormat: JWT
+
+  parameters:
+    id:
+      name: id
+      in: path
+      required: true
+      schema:
+        type: string
+      example: t7kXq2
+
+  schemas:
+
+    Clock:
+      type: object
+      required: [limit, increment]
+      properties:
+        limit:
+          type: integer
+          description: Base time in seconds
+          example: 300
+        increment:
+          type: integer
+          description: Increment per move in seconds
+          example: 3
+
+    Variant:
+      type: object
+      properties:
+        key:
+          type: string
+          example: standard
+        name:
+          type: string
+          example: Standard
+
+    BotRef:
+      type: object
+      properties:
+        id:
+          type: string
+          example: bot_abc
+        name:
+          type: string
+          example: StockfishClone
+
+    Standing:
+      type: object
+      properties:
+        page:
+          type: integer
+          example: 1
+        players:
+          type: array
+          items:
+            $ref: "#/components/schemas/Result"
+
+    TournamentInfo:
+      description: Lightweight tournament summary used in list responses.
+      type: object
+      properties:
+        id:
+          type: string
+          example: t7kXq2
+        fullName:
+          type: string
+          example: Friday Night Bots Swiss
+        clock:
+          $ref: "#/components/schemas/Clock"
+        variant:
+          $ref: "#/components/schemas/Variant"
+        rated:
+          type: boolean
+          example: true
+        nbPlayers:
+          type: integer
+          example: 8
+        nbRounds:
+          type: integer
+          example: 5
+        createdBy:
+          type: string
+          example: userId
+        startsAt:
+          type: string
+          format: date-time
+
+    Tournament:
+      allOf:
+        - $ref: "#/components/schemas/TournamentInfo"
+        - type: object
+          properties:
+            status:
+              type: string
+              enum: [created, started, finished]
+              example: started
+            round:
+              type: integer
+              description: Current round number
+              example: 2
+            standing:
+              $ref: "#/components/schemas/Standing"
+            winner:
+              description: Present only when status is `finished`
+              allOf:
+                - $ref: "#/components/schemas/BotRef"
+              nullable: true
+
+    CreateTournamentForm:
+      type: object
+      required: [name, nbRounds, clockLimit, clockIncrement]
+      properties:
+        name:
+          type: string
+          example: Friday Night Bots
+        nbRounds:
+          type: integer
+          minimum: 1
+          example: 5
+        clockLimit:
+          type: integer
+          description: Base time in seconds
+          example: 300
+        clockIncrement:
+          type: integer
+          description: Increment per move in seconds
+          example: 3
+        rated:
+          type: boolean
+          default: true
+
+    Result:
+      type: object
+      properties:
+        rank:
+          type: integer
+          example: 1
+        points:
+          type: number
+          format: double
+          example: 3.5
+        tieBreak:
+          type: number
+          format: double
+          description: Buchholz score (sum of opponents' points)
+          example: 9.0
+        bot:
+          $ref: "#/components/schemas/BotRef"
+        nbGames:
+          type: integer
+          example: 4
+        wins:
+          type: integer
+          example: 3
+        draws:
+          type: integer
+          example: 1
+        losses:
+          type: integer
+          example: 0
+
+    Pairing:
+      type: object
+      properties:
+        round:
+          type: integer
+          example: 2
+        white:
+          $ref: "#/components/schemas/BotRef"
+        black:
+          $ref: "#/components/schemas/BotRef"
+        gameId:
+          type: string
+          example: j0nPtcjl
+        winner:
+          type: string
+          enum: [white, black, draw]
+          nullable: true
+          description: Null while the game is ongoing
+
+    GameExport:
+      description: One game object per NDJSON line.
+      type: object
+      properties:
+        id:
+          type: string
+          example: j0nPtcjl
+        round:
+          type: integer
+          example: 2
+        white:
+          $ref: "#/components/schemas/BotRef"
+        black:
+          $ref: "#/components/schemas/BotRef"
+        winner:
+          type: string
+          enum: [white, black, draw]
+          nullable: true
+        moves:
+          type: string
+          description: Space-separated UCI moves
+          example: e2e4 e7e5 g1f3
+
+    TournamentEvent:
+      description: |
+        One JSON object per NDJSON line. Discriminate on `type`.
+
+        | type | extra fields |
+        |------|-------------|
+        | `tournamentStarted` | — |
+        | `roundStarted` | `round` |
+        | `gameStart` | `round`, `gameId`, `color` |
+        | `roundFinished` | `round` |
+        | `tournamentFinished` | `winner` |
+      type: object
+      required: [type]
+      properties:
+        type:
+          type: string
+          enum:
+            - tournamentStarted
+            - roundStarted
+            - gameStart
+            - roundFinished
+            - tournamentFinished
+        round:
+          type: integer
+          example: 2
+        gameId:
+          type: string
+          example: j0nPtcjl
+        color:
+          type: string
+          enum: [white, black]
+        winner:
+          $ref: "#/components/schemas/BotRef"
+
+    Ok:
+      type: object
+      properties:
+        ok:
+          type: boolean
+          example: true
+
+    Error:
+      type: object
+      properties:
+        error:
+          type: string
+          example: tournament already started
+
+  responses:
+    BadRequest:
+      description: Invalid request body or parameters
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Error"
+    Unauthorized:
+      description: Missing or invalid JWT
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Error"
+    Forbidden:
+      description: Action not permitted for this user or bot
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Error"
+    NotFound:
+      description: Tournament not found
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Error"
+    Conflict:
+      description: Conflicting state (e.g. already started, bot already joined)
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Error"
diff --git a/modules/tournament/build.gradle.kts b/modules/tournament/build.gradle.kts
new file mode 100644
index 0000000..c47f4a4
--- /dev/null
+++ b/modules/tournament/build.gradle.kts
@@ -0,0 +1,120 @@
+plugins {
+    id("scala")
+    id("org.scoverage") version "8.1"
+    id("io.quarkus")
+}
+
+group = "de.nowchess"
+version = "1.0-SNAPSHOT"
+
+@Suppress("UNCHECKED_CAST")
+val versions = rootProject.extra["VERSIONS"] as Map<String, String>
+
+repositories {
+    mavenCentral()
+}
+
+scala {
+    scalaVersion = versions["SCALA3"]!!
+}
+
+scoverage {
+    scoverageVersion.set(versions["SCOVERAGE"]!!)
+}
+
+tasks.withType<ScalaCompile> {
+    scalaCompileOptions.additionalParameters = listOf("-encoding", "UTF-8")
+}
+
+val quarkusPlatformGroupId: String by project
+val quarkusPlatformArtifactId: String by project
+val quarkusPlatformVersion: String by project
+
+dependencies {
+    implementation(project(":modules:api"))
+    implementation(project(":modules:security"))
+
+    runtimeOnly("io.quarkus:quarkus-jdbc-h2")
+
+    compileOnly("org.scala-lang:scala3-compiler_3") {
+        version {
+            strictly(versions["SCALA3"]!!)
+        }
+    }
+    implementation("org.scala-lang:scala3-library_3") {
+        version {
+            strictly(versions["SCALA3"]!!)
+        }
+    }
+
+    implementation(platform("${quarkusPlatformGroupId}:${quarkusPlatformArtifactId}:${quarkusPlatformVersion}"))
+    implementation("io.quarkus:quarkus-rest")
+    implementation("io.quarkus:quarkus-rest-jackson")
+    implementation("io.quarkus:quarkus-rest-client-jackson")
+    implementation("io.quarkus:quarkus-config-yaml")
+    implementation("io.quarkus:quarkus-arc")
+    implementation("io.quarkus:quarkus-hibernate-orm-panache")
+    implementation("io.quarkus:quarkus-jdbc-postgresql")
+    implementation("io.quarkus:quarkus-smallrye-jwt")
+    implementation("io.quarkus:quarkus-elytron-security-common")
+    implementation("io.quarkus:quarkus-smallrye-health")
+    implementation("io.quarkus:quarkus-logging-json")
+    implementation("io.quarkus:quarkus-micrometer")
+    implementation("io.quarkus:quarkus-micrometer-registry-prometheus")
+    implementation("io.quarkus:quarkus-opentelemetry")
+    implementation("io.quarkus:quarkus-smallrye-openapi")
+    implementation("com.fasterxml.jackson.module:jackson-module-scala_3:${versions["JACKSON_SCALA"]!!}")
+    implementation("io.quarkus:quarkus-redis-client")
+
+    testImplementation(platform("org.junit:junit-bom:5.13.4"))
+    testImplementation("org.junit.jupiter:junit-jupiter")
+    testImplementation("io.quarkus:quarkus-smallrye-jwt-build")
+    testImplementation("org.scalatest:scalatest_3:${versions["SCALATEST"]!!}")
+    testImplementation("co.helmethair:scalatest-junit-runner:${versions["SCALATEST_JUNIT"]!!}")
+    testImplementation("io.quarkus:quarkus-junit5")
+    testImplementation("io.quarkus:quarkus-junit5-mockito")
+    testImplementation("io.rest-assured:rest-assured")
+    testImplementation("io.quarkus:quarkus-jdbc-h2")
+    testImplementation("io.quarkus:quarkus-test-security")
+
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+}
+
+configurations.matching { !it.name.startsWith("scoverage") }.configureEach {
+    resolutionStrategy.force("org.scala-lang:scala-library:${versions["SCALA_LIBRARY"]!!}")
+}
+configurations.scoverage {
+    resolutionStrategy.eachDependency {
+        if (requested.group == "org.scoverage" && requested.name.startsWith("scalac-scoverage-plugin_")) {
+            useTarget("${requested.group}:scalac-scoverage-plugin_2.13.16:2.3.0")
+        }
+    }
+}
+
+tasks.withType<JavaCompile> {
+    options.encoding = "UTF-8"
+    options.compilerArgs.add("-parameters")
+}
+
+tasks.withType<Jar>().configureEach {
+    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+}
+
+tasks.test {
+    useJUnitPlatform {
+        includeEngines("scalatest", "junit-jupiter")
+        testLogging {
+            events("passed", "skipped", "failed")
+            showStandardStreams = true
+            exceptionFormat = org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
+        }
+    }
+    finalizedBy(tasks.reportScoverage)
+}
+tasks.reportScoverage {
+    dependsOn(tasks.test)
+}
+
+tasks.jar {
+    duplicatesStrategy = DuplicatesStrategy.INCLUDE
+}
diff --git a/modules/tournament/src/main/resources/application.yml b/modules/tournament/src/main/resources/application.yml
new file mode 100644
index 0000000..e7a0b36
--- /dev/null
+++ b/modules/tournament/src/main/resources/application.yml
@@ -0,0 +1,59 @@
+quarkus:
+  http:
+    port: 8088
+  application:
+    name: nowchess-tournament
+  redis:
+    hosts: redis://${REDIS_HOST:localhost}:${REDIS_PORT:6379}
+  rest-client:
+    core-service:
+      url: http://localhost:8080
+  datasource:
+    db-kind: h2
+    username: sa
+    password: ""
+    jdbc:
+      url: jdbc:h2:mem:nowchess-tournament;DB_CLOSE_DELAY=-1
+  hibernate-orm:
+    schema-management:
+      strategy: drop-and-create
+  smallrye-jwt:
+    enabled: true
+
+nowchess:
+  redis:
+    host: ${REDIS_HOST:localhost}
+    port: ${REDIS_PORT:6379}
+    prefix: ${REDIS_PREFIX:nowchess}
+  internal:
+    secret: ${INTERNAL_SECRET:123abc}
+
+mp:
+  jwt:
+    verify:
+      publickey:
+        location: keys/public.pem
+      issuer: nowchess
+
+"%deployed":
+  quarkus:
+    datasource:
+      db-kind: postgresql
+      username: ${DB_USER:nowchess}
+      password: ${DB_PASSWORD:nowchess}
+      jdbc:
+        url: ${DB_URL:jdbc:postgresql://localhost:5432/nowchess}
+    hibernate-orm:
+      schema-management:
+        strategy: update
+
+"%test":
+  quarkus:
+    datasource:
+      jdbc:
+        url: jdbc:h2:mem:nowchess-tournament;DB_CLOSE_DELAY=-1
+    hibernate-orm:
+      schema-management:
+        strategy: drop-and-create
+    arc:
+      exclude-types: de.nowchess.tournament.redis.GameResultStreamListener
diff --git a/modules/tournament/src/main/resources/keys/public.pem b/modules/tournament/src/main/resources/keys/public.pem
new file mode 100644
index 0000000..6b6b842
--- /dev/null
+++ b/modules/tournament/src/main/resources/keys/public.pem
@@ -0,0 +1,9 @@
+-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAxDsnsCAl0vQx7Vu9CLDZ
+g0SG05NgUzu9T+3DTEaHGq60T2uriO8BenwyvsF3BnDqTbKf4voohZ1DNfzdbT1J
+Fj8B62FrDmxcO+sp1/b5HUCJP6y2uSRCmzOHe5k7Pk1IEi72FgBpKXSRkFibRlVf
+634g7mgsPZAQ9PJEsv4Qvm05T9L6+Gmq6N3bMVLKRXs4RhDhaFbYH9GtUg1eI0yH
+YjGyRfqzW/nqVMstOLHt8CuPouq4p7eMzeDH3YHkxPm4GG5foCXMOd2DZrW0SCcr
+7dhFeNVWzQ2m53eOhBzNQX+v3pgjVStsePhBRt2LyGfwkNzmqDgqWsMzSHRMY+cn
+WQIDAQAB
+-----END PUBLIC KEY-----
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/client/CoreGameClient.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/client/CoreGameClient.scala
new file mode 100644
index 0000000..7c46eef
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/client/CoreGameClient.scala
@@ -0,0 +1,28 @@
+package de.nowchess.tournament.client
+
+import de.nowchess.security.{InternalClientHeadersFactory, InternalSecretClientFilter}
+import jakarta.ws.rs.*
+import jakarta.ws.rs.core.MediaType
+import org.eclipse.microprofile.rest.client.annotation.{RegisterClientHeaders, RegisterProvider}
+import org.eclipse.microprofile.rest.client.inject.RegisterRestClient
+
+case class CorePlayerInfo(id: String, displayName: String)
+case class CoreTimeControl(limitSeconds: Option[Int], incrementSeconds: Option[Int], daysPerMove: Option[Int])
+case class CoreCreateGameRequest(
+    white: Option[CorePlayerInfo],
+    black: Option[CorePlayerInfo],
+    timeControl: Option[CoreTimeControl],
+    mode: Option[String],
+)
+case class CoreGameResponse(gameId: String)
+
+@Path("/api/board/game")
+@RegisterRestClient(configKey = "core-service")
+@RegisterProvider(classOf[InternalSecretClientFilter])
+@RegisterClientHeaders(classOf[InternalClientHeadersFactory])
+trait CoreGameClient:
+
+  @POST
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def createGame(req: CoreCreateGameRequest): CoreGameResponse
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/config/JacksonConfig.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/config/JacksonConfig.scala
new file mode 100644
index 0000000..0498342
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/config/JacksonConfig.scala
@@ -0,0 +1,11 @@
+package de.nowchess.tournament.config
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import io.quarkus.jackson.ObjectMapperCustomizer
+import jakarta.inject.Singleton
+
+@Singleton
+class JacksonConfig extends ObjectMapperCustomizer:
+  def customize(objectMapper: ObjectMapper): Unit =
+    objectMapper.registerModule(DefaultScalaModule)
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/config/RedisConfig.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/config/RedisConfig.scala
new file mode 100644
index 0000000..1539695
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/config/RedisConfig.scala
@@ -0,0 +1,12 @@
+package de.nowchess.tournament.config
+
+import jakarta.enterprise.context.ApplicationScoped
+import org.eclipse.microprofile.config.inject.ConfigProperty
+import scala.compiletime.uninitialized
+
+@ApplicationScoped
+class RedisConfig:
+  // scalafix:off DisableSyntax.var
+  @ConfigProperty(name = "nowchess.redis.prefix", defaultValue = "nowchess")
+  var prefix: String = uninitialized
+  // scalafix:on DisableSyntax.var
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/domain/Tournament.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/domain/Tournament.scala
new file mode 100644
index 0000000..5198c8b
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/domain/Tournament.scala
@@ -0,0 +1,33 @@
+package de.nowchess.tournament.domain
+
+import jakarta.persistence.*
+import scala.compiletime.uninitialized
+import java.time.Instant
+
+@Entity
+@Table(name = "tournaments")
+class Tournament:
+  // scalafix:off DisableSyntax.var
+  @Id
+  var id: String = uninitialized
+
+  @Column(nullable = false)
+  var fullName: String = uninitialized
+
+  var nbRounds: Int = 0
+  var clockLimit: Int = 0
+  var clockIncrement: Int = 0
+  var rated: Boolean = true
+
+  @Column(nullable = false)
+  var status: String = "created"
+
+  var currentRound: Int = 0
+
+  @Column(nullable = false)
+  var createdBy: String = uninitialized
+
+  var startsAt: Instant = uninitialized
+  var winnerId: String = uninitialized
+  var winnerName: String = uninitialized
+  // scalafix:on
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/domain/TournamentPairing.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/domain/TournamentPairing.scala
new file mode 100644
index 0000000..79a7d25
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/domain/TournamentPairing.scala
@@ -0,0 +1,31 @@
+package de.nowchess.tournament.domain
+
+import jakarta.persistence.*
+import scala.compiletime.uninitialized
+import java.util.UUID
+
+@Entity
+@Table(name = "tournament_pairings")
+class TournamentPairing:
+  // scalafix:off DisableSyntax.var
+  @Id
+  @GeneratedValue(strategy = GenerationType.UUID)
+  var id: UUID = uninitialized
+
+  @Column(nullable = false)
+  var tournamentId: String = uninitialized
+
+  var round: Int = 0
+  var whiteId: String = uninitialized
+  var whiteName: String = uninitialized
+
+  @Column(nullable = false)
+  var blackId: String = uninitialized
+
+  @Column(nullable = false)
+  var blackName: String = uninitialized
+
+  var gameId: String = uninitialized
+  var winner: String = uninitialized
+  var moveList: String = uninitialized
+  // scalafix:on
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/domain/TournamentParticipant.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/domain/TournamentParticipant.scala
new file mode 100644
index 0000000..3b5651a
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/domain/TournamentParticipant.scala
@@ -0,0 +1,31 @@
+package de.nowchess.tournament.domain
+
+import jakarta.persistence.*
+import scala.compiletime.uninitialized
+import java.util.UUID
+
+@Entity
+@Table(name = "tournament_participants")
+class TournamentParticipant:
+  // scalafix:off DisableSyntax.var
+  @Id
+  @GeneratedValue(strategy = GenerationType.UUID)
+  var id: UUID = uninitialized
+
+  @Column(nullable = false)
+  var tournamentId: String = uninitialized
+
+  @Column(nullable = false)
+  var botId: String = uninitialized
+
+  @Column(nullable = false)
+  var botName: String = uninitialized
+
+  var points: Double = 0.0
+  var tieBreak: Double = 0.0
+  var nbGames: Int = 0
+  var wins: Int = 0
+  var draws: Int = 0
+  var losses: Int = 0
+  var byeCount: Int = 0
+  // scalafix:on
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/dto/Dtos.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/dto/Dtos.scala
new file mode 100644
index 0000000..1ec6c7f
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/dto/Dtos.scala
@@ -0,0 +1,74 @@
+package de.nowchess.tournament.dto
+
+case class BotRef(id: String, name: String)
+
+case class Clock(limit: Int, increment: Int)
+
+case class Variant(key: String, name: String)
+
+case class CreateTournamentForm(
+    name: String,
+    nbRounds: Int,
+    clockLimit: Int,
+    clockIncrement: Int,
+    rated: Boolean = true,
+)
+
+case class ResultDto(
+    rank: Int,
+    points: Double,
+    tieBreak: Double,
+    bot: BotRef,
+    nbGames: Int,
+    wins: Int,
+    draws: Int,
+    losses: Int,
+)
+
+case class Standing(page: Int, players: List[ResultDto])
+
+case class TournamentDto(
+    id: String,
+    fullName: String,
+    clock: Clock,
+    variant: Variant,
+    rated: Boolean,
+    nbPlayers: Int,
+    nbRounds: Int,
+    createdBy: String,
+    startsAt: Option[String],
+    status: String,
+    round: Int,
+    standing: Standing,
+    winner: Option[BotRef],
+)
+
+case class TournamentListDto(
+    created: List[TournamentDto],
+    started: List[TournamentDto],
+    finished: List[TournamentDto],
+)
+
+case class PairingDto(
+    id: String,
+    round: Int,
+    white: Option[BotRef],
+    black: BotRef,
+    gameId: Option[String],
+    winner: Option[String],
+)
+
+case class GameExportDto(
+    id: String,
+    round: Int,
+    white: BotRef,
+    black: BotRef,
+    winner: Option[String],
+    moves: String,
+)
+
+case class RoundPairingsDto(round: Int, pairings: List[PairingDto])
+
+case class ErrorDto(error: String)
+
+case class OkDto(ok: Boolean = true)
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/error/TournamentError.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/error/TournamentError.scala
new file mode 100644
index 0000000..06c2734
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/error/TournamentError.scala
@@ -0,0 +1,10 @@
+package de.nowchess.tournament.error
+
+enum TournamentError(val message: String):
+  case NotFound(id: String)         extends TournamentError(s"Tournament $id not found")
+  case NotDirector                  extends TournamentError("Not the tournament director")
+  case WrongStatus(expected: String) extends TournamentError(s"Tournament must be in $expected status")
+  case AlreadyJoined                extends TournamentError("Already joined this tournament")
+  case NotJoined                    extends TournamentError("Not joined this tournament")
+  case NotEnoughParticipants        extends TournamentError("Need at least 2 participants to start")
+  case NotABot                      extends TournamentError("Only bot accounts can join tournaments")
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/redis/GameResultStreamListener.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/redis/GameResultStreamListener.scala
new file mode 100644
index 0000000..bd77bda
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/redis/GameResultStreamListener.scala
@@ -0,0 +1,82 @@
+package de.nowchess.tournament.redis
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import de.nowchess.api.dto.GameWritebackEventDto
+import de.nowchess.tournament.config.RedisConfig
+import de.nowchess.tournament.service.TournamentService
+import io.quarkus.redis.datasource.RedisDataSource
+import io.quarkus.redis.datasource.stream.{StreamMessage, XGroupCreateArgs, XReadGroupArgs}
+import io.quarkus.runtime.Startup
+import jakarta.annotation.PostConstruct
+import jakarta.enterprise.context.ApplicationScoped
+import jakarta.inject.Inject
+import org.eclipse.microprofile.context.ManagedExecutor
+import org.jboss.logging.Logger
+import scala.compiletime.uninitialized
+import scala.jdk.CollectionConverters.*
+import scala.util.{Failure, Success, Try}
+import java.util.UUID
+
+@Startup
+@ApplicationScoped
+class GameResultStreamListener:
+  // scalafix:off DisableSyntax.var
+  @Inject var redis: RedisDataSource                         = uninitialized
+  @Inject var objectMapper: ObjectMapper                     = uninitialized
+  @Inject var tournamentService: TournamentService           = uninitialized
+  @Inject var executor: ManagedExecutor                      = uninitialized
+  @Inject var redisConfig: RedisConfig                       = uninitialized
+  // scalafix:on
+
+  private val log        = Logger.getLogger(classOf[GameResultStreamListener])
+  private val groupName  = "tournament-result"
+  private val consumerId = UUID.randomUUID().toString
+
+  private def streamKey = s"${redisConfig.prefix}:game-writeback"
+
+  @PostConstruct
+  def startListening(): Unit =
+    createGroupIfAbsent()
+    executor.submit(new Runnable:
+      def run(): Unit = pollLoop()
+    )
+    log.infof("Tournament result listener started (consumer=%s)", consumerId)
+
+  private def createGroupIfAbsent(): Unit =
+    Try(redis.stream(classOf[String]).xgroupCreate(streamKey, groupName, "0", new XGroupCreateArgs().mkstream())) match
+      case Failure(ex) if Option(ex.getMessage).exists(_.contains("BUSYGROUP")) => ()
+      case Failure(ex) => log.warnf(ex, "Failed to create consumer group")
+      case Success(_)  => ()
+
+  private def pollLoop(): Unit =
+    while true do
+      Try {
+        val messages = redis.stream(classOf[String]).xreadgroup(
+          groupName,
+          consumerId,
+          streamKey,
+          ">",
+          new XReadGroupArgs().count(10).block(java.time.Duration.ofSeconds(2)),
+        )
+        if messages != null then messages.forEach(msg => handleMessage(msg))
+      } match
+        case Failure(ex) => log.warnf(ex, "Error in result poll loop")
+        case Success(_)  => ()
+
+  private def handleMessage(msg: StreamMessage[String, String, String]): Unit =
+    val json = msg.payload().get("data")
+    Try(objectMapper.readValue(json, classOf[GameWritebackEventDto])) match
+      case Failure(ex) =>
+        log.errorf(ex, "Unparseable game result event: %s", json)
+        ack(msg.id())
+      case Success(event) =>
+        if event.result.isDefined then
+          Try(tournamentService.handleGameResult(event.gameId, event.result.get, event.pgn)) match
+            case Failure(ex) => log.errorf(ex, "Failed to handle game result for %s", event.gameId)
+            case Success(_)  => ()
+        ack(msg.id())
+
+  private def ack(id: String): Unit =
+    Try(redis.stream(classOf[String]).xack(streamKey, groupName, id)) match
+      case Failure(ex) => log.warnf(ex, "Failed to ack message %s", id)
+      case Success(_)  => ()
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/repository/PairingRepository.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/repository/PairingRepository.scala
new file mode 100644
index 0000000..31edcd6
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/repository/PairingRepository.scala
@@ -0,0 +1,47 @@
+package de.nowchess.tournament.repository
+
+import de.nowchess.tournament.domain.TournamentPairing
+import jakarta.enterprise.context.ApplicationScoped
+import jakarta.inject.Inject
+import jakarta.persistence.EntityManager
+import scala.compiletime.uninitialized
+import scala.jdk.CollectionConverters.*
+import java.util.UUID
+
+@ApplicationScoped
+class PairingRepository:
+
+  @Inject
+  // scalafix:off DisableSyntax.var
+  var em: EntityManager = uninitialized
+  // scalafix:on
+
+  def findByTournamentId(tournamentId: String): List[TournamentPairing] =
+    em.createQuery("FROM TournamentPairing WHERE tournamentId = :tid", classOf[TournamentPairing])
+      .setParameter("tid", tournamentId)
+      .getResultList
+      .asScala
+      .toList
+
+  def findByTournamentIdAndRound(tournamentId: String, round: Int): List[TournamentPairing] =
+    em.createQuery(
+      "FROM TournamentPairing WHERE tournamentId = :tid AND round = :round",
+      classOf[TournamentPairing],
+    ).setParameter("tid", tournamentId)
+      .setParameter("round", round)
+      .getResultList
+      .asScala
+      .toList
+
+  def findByGameId(gameId: String): Option[TournamentPairing] =
+    em.createQuery("FROM TournamentPairing WHERE gameId = :gid", classOf[TournamentPairing])
+      .setParameter("gid", gameId)
+      .getResultList
+      .asScala
+      .headOption
+
+  def persist(p: TournamentPairing): TournamentPairing =
+    if p.id == null then
+      em.persist(p)
+      p
+    else em.merge(p)
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/repository/ParticipantRepository.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/repository/ParticipantRepository.scala
new file mode 100644
index 0000000..d9b6ba6
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/repository/ParticipantRepository.scala
@@ -0,0 +1,43 @@
+package de.nowchess.tournament.repository
+
+import de.nowchess.tournament.domain.TournamentParticipant
+import jakarta.enterprise.context.ApplicationScoped
+import jakarta.inject.Inject
+import jakarta.persistence.EntityManager
+import scala.compiletime.uninitialized
+import scala.jdk.CollectionConverters.*
+import java.util.UUID
+
+@ApplicationScoped
+class ParticipantRepository:
+
+  @Inject
+  // scalafix:off DisableSyntax.var
+  var em: EntityManager = uninitialized
+  // scalafix:on
+
+  def findByTournamentId(tournamentId: String): List[TournamentParticipant] =
+    em.createQuery("FROM TournamentParticipant WHERE tournamentId = :tid", classOf[TournamentParticipant])
+      .setParameter("tid", tournamentId)
+      .getResultList
+      .asScala
+      .toList
+
+  def findByTournamentIdAndBotId(tournamentId: String, botId: String): Option[TournamentParticipant] =
+    em.createQuery(
+      "FROM TournamentParticipant WHERE tournamentId = :tid AND botId = :bid",
+      classOf[TournamentParticipant],
+    ).setParameter("tid", tournamentId)
+      .setParameter("bid", botId)
+      .getResultList
+      .asScala
+      .headOption
+
+  def persist(p: TournamentParticipant): TournamentParticipant =
+    if p.id == null then
+      em.persist(p)
+      p
+    else em.merge(p)
+
+  def delete(p: TournamentParticipant): Unit =
+    em.remove(if em.contains(p) then p else em.merge(p))
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/repository/TournamentRepository.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/repository/TournamentRepository.scala
new file mode 100644
index 0000000..bd22db7
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/repository/TournamentRepository.scala
@@ -0,0 +1,33 @@
+package de.nowchess.tournament.repository
+
+import de.nowchess.tournament.domain.Tournament
+import jakarta.enterprise.context.ApplicationScoped
+import jakarta.inject.Inject
+import jakarta.persistence.EntityManager
+import scala.compiletime.uninitialized
+import scala.jdk.CollectionConverters.*
+
+@ApplicationScoped
+class TournamentRepository:
+
+  @Inject
+  // scalafix:off DisableSyntax.var
+  var em: EntityManager = uninitialized
+  // scalafix:on
+
+  def findOptById(id: String): Option[Tournament] =
+    Option(em.find(classOf[Tournament], id))
+
+  def findByStatus(status: String): List[Tournament] =
+    em.createQuery("FROM Tournament WHERE status = :status", classOf[Tournament])
+      .setParameter("status", status)
+      .getResultList
+      .asScala
+      .toList
+
+  def persist(t: Tournament): Tournament =
+    if em.contains(t) then t else em.merge(t)
+
+  def delete(t: Tournament): Unit =
+    val managed = if em.contains(t) then t else em.merge(t)
+    em.remove(managed)
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/resource/TournamentResource.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/resource/TournamentResource.scala
new file mode 100644
index 0000000..a33165d
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/resource/TournamentResource.scala
@@ -0,0 +1,184 @@
+package de.nowchess.tournament.resource
+
+import de.nowchess.tournament.dto.*
+import de.nowchess.tournament.error.TournamentError
+import de.nowchess.tournament.service.{TournamentService, TournamentStreamManager}
+import io.smallrye.mutiny.Multi
+import jakarta.annotation.security.{PermitAll, RolesAllowed}
+import jakarta.enterprise.context.ApplicationScoped
+import jakarta.inject.Inject
+import jakarta.ws.rs.*
+import jakarta.ws.rs.core.{Context, HttpHeaders, MediaType, Response}
+import org.eclipse.microprofile.jwt.JsonWebToken
+import org.jboss.logging.Logger
+import scala.compiletime.uninitialized
+
+@Path("/api/tournament")
+@ApplicationScoped
+@Produces(Array(MediaType.APPLICATION_JSON))
+@Consumes(Array(MediaType.APPLICATION_JSON))
+class TournamentResource:
+
+  private val log = Logger.getLogger(classOf[TournamentResource])
+
+  // scalafix:off DisableSyntax.var
+  @Inject var tournamentService: TournamentService   = uninitialized
+  @Inject var streamManager: TournamentStreamManager = uninitialized
+  @Inject var jwt: JsonWebToken                      = uninitialized
+  // scalafix:on
+
+  @GET
+  @PermitAll
+  def list(): Response =
+    val (created, started, finished) = tournamentService.list()
+    val dto = TournamentListDto(
+      created = created.map(t => tournamentService.toDto(t)),
+      started = started.map(t => tournamentService.toDto(t)),
+      finished = finished.map(t => tournamentService.toDto(t)),
+    )
+    Response.ok(dto).build()
+
+  @POST
+  @RolesAllowed(Array("**"))
+  @Consumes(Array(MediaType.APPLICATION_FORM_URLENCODED))
+  def create(
+      @FormParam("name") name: String,
+      @FormParam("nbRounds") nbRounds: Int,
+      @FormParam("clockLimit") clockLimit: Int,
+      @FormParam("clockIncrement") clockIncrement: Int,
+      @FormParam("rated") @DefaultValue("true") rated: Boolean,
+  ): Response =
+    val userId = Option(jwt.getSubject).getOrElse("")
+    val form   = CreateTournamentForm(name, nbRounds, clockLimit, clockIncrement, rated)
+    val t      = tournamentService.create(userId, form)
+    Response.status(Response.Status.CREATED).entity(tournamentService.toDto(t)).build()
+
+  @GET
+  @Path("/{id}")
+  @PermitAll
+  def get(@PathParam("id") id: String): Response =
+    tournamentService.get(id) match
+      case None => Response.status(Response.Status.NOT_FOUND).entity(ErrorDto(s"Tournament $id not found")).build()
+      case Some(t) =>
+        val standings = tournamentService.getStandings(id)
+        Response.ok(tournamentService.toDto(t, standings)).build()
+
+  @DELETE
+  @Path("/{id}")
+  @RolesAllowed(Array("**"))
+  def terminate(@PathParam("id") id: String): Response =
+    val userId = Option(jwt.getSubject).getOrElse("")
+    tournamentService.terminate(id, userId) match
+      case Right(_)    => Response.noContent().build()
+      case Left(error) => errorResponse(error)
+
+  @POST
+  @Path("/{id}/start")
+  @RolesAllowed(Array("**"))
+  def start(@PathParam("id") id: String): Response =
+    val userId = Option(jwt.getSubject).getOrElse("")
+    tournamentService.start(id, userId) match
+      case Right(t)    => Response.ok(tournamentService.toDto(t)).build()
+      case Left(error) => errorResponse(error)
+
+  @POST
+  @Path("/{id}/join")
+  @RolesAllowed(Array("**"))
+  def join(@PathParam("id") id: String): Response =
+    val tokenType = Option(jwt.getClaim[AnyRef]("type")).map(_.toString).getOrElse("")
+    if tokenType != "bot" then
+      Response.status(Response.Status.FORBIDDEN).entity(ErrorDto("Only bots can join tournaments")).build()
+    else
+      val botId   = Option(jwt.getSubject).getOrElse("")
+      val botName = Option(jwt.getClaim[AnyRef]("name")).map(_.toString).getOrElse(botId)
+      tournamentService.join(id, botId, botName) match
+        case Right(_)    => Response.ok(OkDto()).build()
+        case Left(error) => errorResponse(error)
+
+  @POST
+  @Path("/{id}/withdraw")
+  @RolesAllowed(Array("**"))
+  def withdraw(@PathParam("id") id: String): Response =
+    val tokenType = Option(jwt.getClaim[AnyRef]("type")).map(_.toString).getOrElse("")
+    if tokenType != "bot" then
+      Response.status(Response.Status.FORBIDDEN).entity(ErrorDto("Only bots can withdraw")).build()
+    else
+      val botId = Option(jwt.getSubject).getOrElse("")
+      tournamentService.withdraw(id, botId) match
+        case Right(_)    => Response.ok(OkDto()).build()
+        case Left(error) => errorResponse(error)
+
+  @GET
+  @Path("/{id}/results")
+  @Produces(Array("application/x-ndjson"))
+  @PermitAll
+  def results(
+      @PathParam("id") id: String,
+      @QueryParam("nb") @DefaultValue("100") nb: Int,
+  ): Response =
+    tournamentService.get(id) match
+      case None => Response.status(Response.Status.NOT_FOUND).entity("").build()
+      case Some(_) =>
+        val ndjson = tournamentService.getResults(id).take(nb).map { r =>
+          s"""{"rank":${r.rank},"points":${r.points},"tieBreak":${r.tieBreak},"bot":{"id":"${r.bot.id}","name":"${r.bot.name}"},"nbGames":${r.nbGames},"wins":${r.wins},"draws":${r.draws},"losses":${r.losses}}"""
+        }.mkString("\n")
+        Response.ok(ndjson).`type`("application/x-ndjson").build()
+
+  @GET
+  @Path("/{id}/round/{round}")
+  @PermitAll
+  def roundPairings(@PathParam("id") id: String, @PathParam("round") round: Int): Response =
+    tournamentService.get(id) match
+      case None => Response.status(Response.Status.NOT_FOUND).entity(ErrorDto(s"Tournament $id not found")).build()
+      case Some(_) =>
+        val pairings = tournamentService.getPairings(id, round)
+        Response.ok(RoundPairingsDto(round, pairings)).build()
+
+  @GET
+  @Path("/{id}/export/games")
+  @PermitAll
+  @Produces(Array(MediaType.APPLICATION_JSON, MediaType.WILDCARD, "application/x-ndjson", "application/x-chess-pgn"))
+  def exportGames(@PathParam("id") id: String, @Context headers: HttpHeaders): Response =
+    tournamentService.get(id) match
+      case None => Response.status(Response.Status.NOT_FOUND).entity(ErrorDto(s"Tournament $id not found")).build()
+      case Some(_) =>
+        val acceptHeader = Option(headers.getHeaderString("Accept")).getOrElse("")
+        val pairings     = tournamentService.getAllPairings(id)
+        if acceptHeader.contains("application/x-ndjson") then
+          val ndjson = pairings
+            .filter(p => Option(p.whiteId).isDefined && Option(p.gameId).isDefined)
+            .map { p =>
+              val winner = Option(p.winner).map(w => s""""$w"""").getOrElse("null")
+              val moves  = Option(p.moveList).getOrElse("")
+              s"""{"id":"${p.gameId}","round":${p.round},"white":{"id":"${p.whiteId}","name":"${p.whiteName}"},"black":{"id":"${p.blackId}","name":"${p.blackName}"},"winner":$winner,"moves":"$moves"}"""
+            }
+            .mkString("\n")
+          Response.ok(ndjson).`type`("application/x-ndjson").build()
+        else
+          val pgn = pairings.flatMap(p => Option(p.moveList)).mkString("\n\n")
+          Response.ok(pgn).`type`("application/x-chess-pgn").build()
+
+  @GET
+  @Path("/{id}/stream")
+  @RolesAllowed(Array("**"))
+  @Produces(Array("application/x-ndjson"))
+  def stream(@PathParam("id") id: String): Multi[String] =
+    tournamentService.get(id) match
+      case None => Multi.createFrom().failure(new NotFoundException(s"Tournament $id not found"))
+      case Some(_) =>
+        val botId = Option(jwt.getSubject).getOrElse("")
+        Multi.createFrom().emitter[String] { emitter =>
+          streamManager.register(id, botId, emitter)
+          emitter.onTermination(() => streamManager.unregister(id, botId, emitter))
+        }
+
+  private def errorResponse(error: TournamentError): Response =
+    val status = error match
+      case TournamentError.NotFound(_)           => Response.Status.NOT_FOUND
+      case TournamentError.NotDirector           => Response.Status.FORBIDDEN
+      case TournamentError.NotABot               => Response.Status.FORBIDDEN
+      case TournamentError.WrongStatus(_)        => Response.Status.CONFLICT
+      case TournamentError.AlreadyJoined         => Response.Status.CONFLICT
+      case TournamentError.NotJoined             => Response.Status.CONFLICT
+      case TournamentError.NotEnoughParticipants => Response.Status.CONFLICT
+    Response.status(status).entity(ErrorDto(error.message)).build()
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/service/SwissPairingService.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/service/SwissPairingService.scala
new file mode 100644
index 0000000..cf2fa01
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/service/SwissPairingService.scala
@@ -0,0 +1,68 @@
+package de.nowchess.tournament.service
+
+import de.nowchess.tournament.domain.{TournamentParticipant, TournamentPairing}
+import java.util.concurrent.ThreadLocalRandom
+
+object SwissPairingService:
+
+  def computePairings(
+      participants: List[TournamentParticipant],
+      pastPairings: List[TournamentPairing],
+  ): (List[(TournamentParticipant, TournamentParticipant)], Option[TournamentParticipant]) =
+    val sorted = sortParticipants(participants)
+    val (remaining, byeOpt) = extractByePlayer(sorted)
+    val pairs = buildPairs(remaining, pastPairings)
+    (pairs, byeOpt)
+
+  private def sortParticipants(participants: List[TournamentParticipant]): List[TournamentParticipant] =
+    participants.sortWith { (a, b) =>
+      if a.points != b.points then a.points > b.points
+      else if a.tieBreak != b.tieBreak then a.tieBreak > b.tieBreak
+      else a.botName < b.botName
+    }
+
+  private def extractByePlayer(
+      sorted: List[TournamentParticipant],
+  ): (List[TournamentParticipant], Option[TournamentParticipant]) =
+    if sorted.size % 2 == 0 then (sorted, None)
+    else
+      val minByes  = sorted.map(_.byeCount).min
+      val byeIndex = sorted.lastIndexWhere(_.byeCount == minByes)
+      val bye      = sorted(byeIndex)
+      (sorted.filterNot(_ eq bye), Some(bye))
+
+  private def buildPairs(
+      players: List[TournamentParticipant],
+      pastPairings: List[TournamentPairing],
+  ): List[(TournamentParticipant, TournamentParticipant)] =
+    val arr = players.toArray
+    resolveConflicts(arr, pastPairings)
+    arr.grouped(2).flatMap {
+      case Array(a, b) => Some(assignColors(a, b))
+      case _           => None
+    }.toList
+
+  private def resolveConflicts(arr: Array[TournamentParticipant], pastPairings: List[TournamentPairing]): Unit =
+    var i = 0
+    while i < arr.length - 1 do
+      if havePlayedBefore(arr(i), arr(i + 1), pastPairings) && i + 2 < arr.length then
+        val tmp    = arr(i + 1)
+        arr(i + 1) = arr(i + 2)
+        arr(i + 2) = tmp
+      i += 2
+
+  private def havePlayedBefore(
+      a: TournamentParticipant,
+      b: TournamentParticipant,
+      pastPairings: List[TournamentPairing],
+  ): Boolean =
+    pastPairings.exists(p =>
+      (p.whiteId == a.botId && p.blackId == b.botId) ||
+        (p.whiteId == b.botId && p.blackId == a.botId),
+    )
+
+  private def assignColors(
+      a: TournamentParticipant,
+      b: TournamentParticipant,
+  ): (TournamentParticipant, TournamentParticipant) =
+    if ThreadLocalRandom.current().nextBoolean() then (a, b) else (b, a)
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/service/TournamentService.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/service/TournamentService.scala
new file mode 100644
index 0000000..3112214
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/service/TournamentService.scala
@@ -0,0 +1,284 @@
+package de.nowchess.tournament.service
+
+import de.nowchess.tournament.client.{CoreCreateGameRequest, CoreGameClient, CorePlayerInfo, CoreTimeControl}
+import de.nowchess.tournament.domain.{Tournament, TournamentPairing, TournamentParticipant}
+import de.nowchess.tournament.dto.{BotRef, Clock, CreateTournamentForm, PairingDto, ResultDto, Standing, TournamentDto, Variant}
+import de.nowchess.tournament.error.TournamentError
+import de.nowchess.tournament.repository.{PairingRepository, ParticipantRepository, TournamentRepository}
+import jakarta.enterprise.context.ApplicationScoped
+import jakarta.inject.Inject
+import jakarta.transaction.Transactional
+import org.eclipse.microprofile.rest.client.inject.RestClient
+import org.jboss.logging.Logger
+import scala.compiletime.uninitialized
+import scala.util.{Failure, Success, Try}
+import java.time.Instant
+
+@ApplicationScoped
+class TournamentService:
+
+  private val log = Logger.getLogger(classOf[TournamentService])
+
+  // scalafix:off DisableSyntax.var
+  @Inject var tournamentRepository: TournamentRepository   = uninitialized
+  @Inject var participantRepository: ParticipantRepository = uninitialized
+  @Inject var pairingRepository: PairingRepository         = uninitialized
+  @Inject var streamManager: TournamentStreamManager       = uninitialized
+
+  @Inject
+  @RestClient
+  var coreGameClient: CoreGameClient = uninitialized
+  // scalafix:on
+
+  @Transactional
+  def create(createdBy: String, form: CreateTournamentForm): Tournament =
+    val t = new Tournament()
+    t.id = scala.util.Random.alphanumeric.take(6).mkString
+    t.fullName = form.name
+    t.nbRounds = form.nbRounds
+    t.clockLimit = form.clockLimit
+    t.clockIncrement = form.clockIncrement
+    t.rated = form.rated
+    t.status = "created"
+    t.currentRound = 0
+    t.createdBy = createdBy
+    tournamentRepository.persist(t)
+    t
+
+  def get(id: String): Option[Tournament] =
+    tournamentRepository.findOptById(id)
+
+  def list(): (List[Tournament], List[Tournament], List[Tournament]) =
+    (
+      tournamentRepository.findByStatus("created"),
+      tournamentRepository.findByStatus("started"),
+      tournamentRepository.findByStatus("finished"),
+    )
+
+  @Transactional
+  def terminate(id: String, userId: String): Either[TournamentError, Unit] =
+    for
+      t <- tournamentRepository.findOptById(id).toRight(TournamentError.NotFound(id))
+      _ <- Either.cond(t.createdBy == userId, (), TournamentError.NotDirector)
+      _ <- Either.cond(t.status == "created", (), TournamentError.WrongStatus("created"))
+    yield
+      tournamentRepository.delete(t)
+
+  @Transactional
+  def join(id: String, botId: String, botName: String): Either[TournamentError, Unit] =
+    for
+      t <- tournamentRepository.findOptById(id).toRight(TournamentError.NotFound(id))
+      _ <- Either.cond(t.status == "created", (), TournamentError.WrongStatus("created"))
+      _ <- Either.cond(
+        participantRepository.findByTournamentIdAndBotId(id, botId).isEmpty,
+        (),
+        TournamentError.AlreadyJoined,
+      )
+    yield
+      val p = new TournamentParticipant()
+      p.tournamentId = id
+      p.botId = botId
+      p.botName = botName
+      participantRepository.persist(p)
+
+  @Transactional
+  def withdraw(id: String, botId: String): Either[TournamentError, Unit] =
+    for
+      t <- tournamentRepository.findOptById(id).toRight(TournamentError.NotFound(id))
+      _ <- Either.cond(t.status == "created", (), TournamentError.WrongStatus("created"))
+      p <- participantRepository.findByTournamentIdAndBotId(id, botId).toRight(TournamentError.NotJoined)
+    yield participantRepository.delete(p)
+
+  @Transactional
+  def start(id: String, userId: String): Either[TournamentError, Tournament] =
+    for
+      t            <- tournamentRepository.findOptById(id).toRight(TournamentError.NotFound(id))
+      _            <- Either.cond(t.createdBy == userId, (), TournamentError.NotDirector)
+      _            <- Either.cond(t.status == "created", (), TournamentError.WrongStatus("created"))
+      participants <- validateMinParticipants(id)
+    yield
+      t.status = "started"
+      t.currentRound = 1
+      t.startsAt = Instant.now()
+      tournamentRepository.persist(t)
+      streamManager.publish(t.id, """{"type":"tournamentStarted"}""")
+      startRound(t, 1, participants)
+      t
+
+  private def validateMinParticipants(id: String): Either[TournamentError, List[TournamentParticipant]] =
+    val ps = participantRepository.findByTournamentId(id)
+    Either.cond(ps.size >= 2, ps, TournamentError.NotEnoughParticipants)
+
+  private def startRound(t: Tournament, round: Int, participants: List[TournamentParticipant]): Unit =
+    val pastPairings = pairingRepository.findByTournamentId(t.id)
+    val (pairs, byeOpt) = SwissPairingService.computePairings(participants, pastPairings)
+    byeOpt.foreach(bye => createByePairing(t.id, round, bye))
+    pairs.foreach { case (white, black) => createRealPairing(t.id, round, white, black, t) }
+    streamManager.publish(t.id, s"""{"type":"roundStarted","round":$round}""")
+
+  private def createByePairing(tournamentId: String, round: Int, bye: TournamentParticipant): Unit =
+    val pairing = new TournamentPairing()
+    pairing.tournamentId = tournamentId
+    pairing.round = round
+    pairing.blackId = bye.botId
+    pairing.blackName = bye.botName
+    pairing.winner = "bye"
+    pairingRepository.persist(pairing)
+    bye.points += 0.5
+    bye.byeCount += 1
+    participantRepository.persist(bye)
+
+  private def createRealPairing(
+      tournamentId: String,
+      round: Int,
+      white: TournamentParticipant,
+      black: TournamentParticipant,
+      t: Tournament,
+  ): Unit =
+    val tc = CoreTimeControl(Some(t.clockLimit), Some(t.clockIncrement), None)
+    val req = CoreCreateGameRequest(
+      Some(CorePlayerInfo(white.botId, white.botName)),
+      Some(CorePlayerInfo(black.botId, black.botName)),
+      Some(tc),
+      if t.rated then Some("Rated") else Some("Casual"),
+    )
+    Try(coreGameClient.createGame(req)) match
+      case Failure(ex) => log.errorf(ex, "Failed to create game for round %d in tournament %s", round, tournamentId)
+      case Success(resp) =>
+        val pairing = new TournamentPairing()
+        pairing.tournamentId = tournamentId
+        pairing.round = round
+        pairing.whiteId = white.botId
+        pairing.whiteName = white.botName
+        pairing.blackId = black.botId
+        pairing.blackName = black.botName
+        pairing.gameId = resp.gameId
+        pairingRepository.persist(pairing)
+        streamManager.publishToBot(tournamentId, white.botId, s"""{"type":"gameStart","round":$round,"gameId":"${resp.gameId}","color":"white"}""")
+        streamManager.publishToBot(tournamentId, black.botId, s"""{"type":"gameStart","round":$round,"gameId":"${resp.gameId}","color":"black"}""")
+
+  @Transactional
+  def handleGameResult(gameId: String, result: String, pgn: String): Unit =
+    pairingRepository.findByGameId(gameId).foreach { pairing =>
+      val (winnerStr, wPts, bPts) = parseResult(result)
+      pairing.winner = winnerStr
+      pairing.moveList = pgn
+      pairingRepository.persist(pairing)
+      updateParticipantStats(pairing, wPts, bPts)
+      checkRoundCompletion(pairing.tournamentId)
+    }
+
+  private def parseResult(result: String): (String, Double, Double) = result match
+    case "1-0"     => ("white", 1.0, 0.0)
+    case "0-1"     => ("black", 0.0, 1.0)
+    case "1/2-1/2" => ("draw", 0.5, 0.5)
+    case _         => ("draw", 0.5, 0.5)
+
+  private def updateParticipantStats(pairing: TournamentPairing, wPts: Double, bPts: Double): Unit =
+    Option(pairing.whiteId).foreach { wId =>
+      participantRepository.findByTournamentIdAndBotId(pairing.tournamentId, wId).foreach { p =>
+        p.points += wPts
+        p.nbGames += 1
+        if wPts == 1.0 then p.wins += 1 else if wPts == 0.5 then p.draws += 1 else p.losses += 1
+        participantRepository.persist(p)
+      }
+    }
+    participantRepository.findByTournamentIdAndBotId(pairing.tournamentId, pairing.blackId).foreach { p =>
+      p.points += bPts
+      p.nbGames += 1
+      if bPts == 1.0 then p.wins += 1 else if bPts == 0.5 then p.draws += 1 else p.losses += 1
+      participantRepository.persist(p)
+    }
+
+  private def checkRoundCompletion(tournamentId: String): Unit =
+    tournamentRepository.findOptById(tournamentId).foreach { t =>
+      val roundPairings = pairingRepository.findByTournamentIdAndRound(tournamentId, t.currentRound)
+      val allDone = roundPairings.nonEmpty && roundPairings.forall(p => Option(p.winner).isDefined)
+      if allDone then onRoundComplete(t)
+    }
+
+  private def onRoundComplete(t: Tournament): Unit =
+    streamManager.publish(t.id, s"""{"type":"roundFinished","round":${t.currentRound}}""")
+    recomputeBuchholz(t.id)
+    if t.currentRound >= t.nbRounds then finishTournament(t)
+    else
+      t.currentRound += 1
+      tournamentRepository.persist(t)
+      val participants = participantRepository.findByTournamentId(t.id)
+      startRound(t, t.currentRound, participants)
+
+  private def finishTournament(t: Tournament): Unit =
+    val participants = sortedStandings(participantRepository.findByTournamentId(t.id))
+    participants.headOption.foreach { winner =>
+      t.winnerId = winner.botId
+      t.winnerName = winner.botName
+    }
+    t.status = "finished"
+    tournamentRepository.persist(t)
+    val winnerInfo = participants.headOption
+      .map(w => s"""{"id":"${w.botId}","name":"${w.botName}"}""")
+      .getOrElse("null")
+    streamManager.publish(t.id, s"""{"type":"tournamentFinished","winner":$winnerInfo}""")
+
+  private def recomputeBuchholz(tournamentId: String): Unit =
+    val participants = participantRepository.findByTournamentId(tournamentId)
+    val pairings     = pairingRepository.findByTournamentId(tournamentId)
+    val pointsById   = participants.map(p => p.botId -> p.points).toMap
+    participants.foreach { p =>
+      val opponentIds = pairings.flatMap(pair =>
+        if pair.whiteId == p.botId then Some(pair.blackId)
+        else if pair.blackId == p.botId && Option(pair.whiteId).isDefined then Some(pair.whiteId)
+        else None,
+      )
+      p.tieBreak = opponentIds.flatMap(id => pointsById.get(id)).sum
+      participantRepository.persist(p)
+    }
+
+  def getStandings(tournamentId: String): List[ResultDto] =
+    val participants = sortedStandings(participantRepository.findByTournamentId(tournamentId))
+    participants.zipWithIndex.map { case (p, idx) =>
+      ResultDto(idx + 1, p.points, p.tieBreak, BotRef(p.botId, p.botName), p.nbGames, p.wins, p.draws, p.losses)
+    }
+
+  def getPairings(tournamentId: String, round: Int): List[PairingDto] =
+    pairingRepository.findByTournamentIdAndRound(tournamentId, round).map(toPairingDto)
+
+  def getAllPairings(tournamentId: String): List[TournamentPairing] =
+    pairingRepository.findByTournamentId(tournamentId)
+
+  def getResults(tournamentId: String): List[ResultDto] = getStandings(tournamentId)
+
+  def toDto(t: Tournament, standings: List[ResultDto] = Nil): TournamentDto =
+    val participants = participantRepository.findByTournamentId(t.id)
+    TournamentDto(
+      id = t.id,
+      fullName = t.fullName,
+      clock = Clock(t.clockLimit, t.clockIncrement),
+      variant = Variant("standard", "Standard"),
+      rated = t.rated,
+      nbPlayers = participants.size,
+      nbRounds = t.nbRounds,
+      createdBy = t.createdBy,
+      startsAt = Option(t.startsAt).map(_.toString),
+      status = t.status,
+      round = t.currentRound,
+      standing = Standing(1, standings),
+      winner = if t.winnerId != null then Some(BotRef(t.winnerId, t.winnerName)) else None,
+    )
+
+  private def toPairingDto(p: TournamentPairing): PairingDto =
+    PairingDto(
+      id = p.id.toString,
+      round = p.round,
+      white = Option(p.whiteId).map(id => BotRef(id, p.whiteName)),
+      black = BotRef(p.blackId, p.blackName),
+      gameId = Option(p.gameId),
+      winner = Option(p.winner),
+    )
+
+  private def sortedStandings(participants: List[TournamentParticipant]): List[TournamentParticipant] =
+    participants.sortWith { (a, b) =>
+      if a.points != b.points then a.points > b.points
+      else if a.tieBreak != b.tieBreak then a.tieBreak > b.tieBreak
+      else a.botName < b.botName
+    }
diff --git a/modules/tournament/src/main/scala/de/nowchess/tournament/service/TournamentStreamManager.scala b/modules/tournament/src/main/scala/de/nowchess/tournament/service/TournamentStreamManager.scala
new file mode 100644
index 0000000..8204d44
--- /dev/null
+++ b/modules/tournament/src/main/scala/de/nowchess/tournament/service/TournamentStreamManager.scala
@@ -0,0 +1,32 @@
+package de.nowchess.tournament.service
+
+import io.smallrye.mutiny.subscription.MultiEmitter
+import jakarta.enterprise.context.ApplicationScoped
+import java.util.concurrent.{ConcurrentHashMap, CopyOnWriteArrayList}
+import scala.jdk.CollectionConverters.*
+
+@ApplicationScoped
+class TournamentStreamManager:
+
+  private val tournamentEmitters = new ConcurrentHashMap[String, CopyOnWriteArrayList[MultiEmitter[? >: String]]]()
+  private val botEmitters        = new ConcurrentHashMap[String, CopyOnWriteArrayList[MultiEmitter[? >: String]]]()
+
+  private def botKey(tournamentId: String, botId: String): String = s"${tournamentId}:${botId}"
+
+  def register(tournamentId: String, botId: String, emitter: MultiEmitter[? >: String]): Unit =
+    tournamentEmitters.computeIfAbsent(tournamentId, _ => new CopyOnWriteArrayList[MultiEmitter[? >: String]]()).add(emitter)
+    botEmitters.computeIfAbsent(botKey(tournamentId, botId), _ => new CopyOnWriteArrayList[MultiEmitter[? >: String]]()).add(emitter)
+
+  def unregister(tournamentId: String, botId: String, emitter: MultiEmitter[? >: String]): Unit =
+    Option(tournamentEmitters.get(tournamentId)).foreach(_.remove(emitter))
+    Option(botEmitters.get(botKey(tournamentId, botId))).foreach(_.remove(emitter))
+
+  def publish(tournamentId: String, eventJson: String): Unit =
+    Option(tournamentEmitters.get(tournamentId)).foreach { list =>
+      list.asScala.foreach(e => scala.util.Try(e.emit(eventJson)))
+    }
+
+  def publishToBot(tournamentId: String, botId: String, eventJson: String): Unit =
+    Option(botEmitters.get(botKey(tournamentId, botId))).foreach { list =>
+      list.asScala.foreach(e => scala.util.Try(e.emit(eventJson)))
+    }
diff --git a/modules/tournament/src/test/resources/application.yml b/modules/tournament/src/test/resources/application.yml
new file mode 100644
index 0000000..64d5041
--- /dev/null
+++ b/modules/tournament/src/test/resources/application.yml
@@ -0,0 +1,32 @@
+quarkus:
+  http:
+    port: 8088
+  application:
+    name: nowchess-tournament
+  datasource:
+    db-kind: h2
+    username: sa
+    password: ""
+    jdbc:
+      url: "jdbc:h2:mem:nowchess-tournament;DB_CLOSE_DELAY=-1"
+  hibernate-orm:
+    schema-management:
+      strategy: drop-and-create
+  arc:
+    exclude-types: de.nowchess.tournament.redis.GameResultStreamListener
+mp:
+  jwt:
+    verify:
+      publickey:
+        location: keys/test-public.pem
+      issuer: nowchess
+smallrye:
+  jwt:
+    sign:
+      key:
+        location: keys/test-private.pem
+nowchess:
+  internal:
+    secret: test-secret
+    auth:
+      enabled: false
diff --git a/modules/tournament/src/test/resources/keys/test-private.pem b/modules/tournament/src/test/resources/keys/test-private.pem
new file mode 100644
index 0000000..ad772e8
--- /dev/null
+++ b/modules/tournament/src/test/resources/keys/test-private.pem
@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----
diff --git a/modules/tournament/src/test/resources/keys/test-public.pem b/modules/tournament/src/test/resources/keys/test-public.pem
new file mode 100644
index 0000000..a5b79c0
--- /dev/null
+++ b/modules/tournament/src/test/resources/keys/test-public.pem
@@ -0,0 +1,9 @@
+-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuMwR4ESzHs9m+sH3b70y
+VUfMcW6/5CVDIquKLdeCobU2hopBVvu+3s46KmmxVh+wjYw7wElgjNp+1z8S+H4V
+MM7024UWdlzTPNJSgfjiIz94aDS74HkjR20uAs7Tn5NiVbUBS0HWCf4LwaBT4AbW
+WDv0mVTC9vHeVPdia1kSAtXtR7daCsCiaDqrUya7P0bjpSkP3buJMGPJtIz8NOcB
+QNWETFAu/MSpJQlWArn2HsCFE3SsQEytGSlgaDwiZ8Q4PIMIKZ1dcB0KxxnG2b4X
+FYNxlqQ3GHZ6IFeK5bLMLOe/rgIRkckAZJpoVW/s0/i0+1lwzweOjJx5ChSGWsRJ
+BwIDAQAB
+-----END PUBLIC KEY-----
diff --git a/modules/tournament/src/test/scala/de/nowchess/tournament/resource/H2TestProfile.scala b/modules/tournament/src/test/scala/de/nowchess/tournament/resource/H2TestProfile.scala
new file mode 100644
index 0000000..951ea49
--- /dev/null
+++ b/modules/tournament/src/test/scala/de/nowchess/tournament/resource/H2TestProfile.scala
@@ -0,0 +1,15 @@
+package de.nowchess.tournament.resource
+
+import io.quarkus.test.junit.QuarkusTestProfile
+import java.util.Map as JMap
+
+class H2TestProfile extends QuarkusTestProfile:
+
+  override def getConfigOverrides(): JMap[String, String] =
+    JMap.of(
+      "quarkus.datasource.db-kind", "h2",
+      "quarkus.datasource.jdbc.url", "jdbc:h2:mem:nowchess-tournament;DB_CLOSE_DELAY=-1",
+      "quarkus.datasource.username", "sa",
+      "quarkus.datasource.password", "",
+      "quarkus.hibernate-orm.schema-management.strategy", "drop-and-create",
+    )
diff --git a/modules/tournament/src/test/scala/de/nowchess/tournament/resource/TournamentResourceTest.scala b/modules/tournament/src/test/scala/de/nowchess/tournament/resource/TournamentResourceTest.scala
new file mode 100644
index 0000000..de159db
--- /dev/null
+++ b/modules/tournament/src/test/scala/de/nowchess/tournament/resource/TournamentResourceTest.scala
@@ -0,0 +1,233 @@
+package de.nowchess.tournament.resource
+
+import de.nowchess.tournament.client.{CoreGameClient, CoreGameResponse}
+import io.quarkus.test.InjectMock
+import io.quarkus.test.junit.QuarkusTest
+import io.restassured.RestAssured
+import io.restassured.http.ContentType
+import io.restassured.response.ValidatableResponse
+import io.smallrye.jwt.build.Jwt
+import org.eclipse.microprofile.rest.client.inject.RestClient
+import org.hamcrest.Matchers.*
+import org.junit.jupiter.api.{BeforeEach, Test}
+import org.mockito.{ArgumentMatchers, Mockito}
+
+@QuarkusTest
+class TournamentResourceTest:
+
+  @InjectMock
+  @RestClient
+  // scalafix:off DisableSyntax.var
+  var coreGameClient: CoreGameClient = scala.compiletime.uninitialized
+  // scalafix:on
+
+  @BeforeEach
+  def setup(): Unit =
+    Mockito.when(coreGameClient.createGame(ArgumentMatchers.any())).thenReturn(CoreGameResponse("game-test-123"))
+
+  private def g() = RestAssured.`given`().contentType(ContentType.JSON)
+
+  private def directorToken(userId: String = "director-1"): String =
+    Jwt.issuer("nowchess").subject(userId).expiresIn(3600).sign()
+
+  private def botToken(botId: String, botName: String): String =
+    Jwt.issuer("nowchess").subject(botId).claim("type", "bot").claim("name", botName).expiresIn(3600).sign()
+
+  private def authed(token: String) =
+    g().header("Authorization", s"Bearer $token")
+
+  private def formAuthed(token: String) =
+    RestAssured.`given`().contentType(ContentType.URLENC).header("Authorization", s"Bearer $token")
+
+  private def createTournament(token: String, name: String = "Test Tour", nbRounds: Int = 3): String =
+    formAuthed(token)
+      .formParam("name", name)
+      .formParam("nbRounds", nbRounds)
+      .formParam("clockLimit", 300)
+      .formParam("clockIncrement", 5)
+      .formParam("rated", true)
+      .when().post("/api/tournament")
+      .`then`().statusCode(201).extract().path[String]("id")
+
+  private def postAndCheck(token: String, path: String, expectedStatus: Int): ValidatableResponse =
+    authed(token).when().post(path).`then`().statusCode(expectedStatus)
+
+  private def deleteAndCheck(token: String, path: String, expectedStatus: Int): ValidatableResponse =
+    authed(token).when().delete(path).`then`().statusCode(expectedStatus)
+
+  private def botJoin(tournamentId: String, botId: String, botName: String): ValidatableResponse =
+    val bt = botToken(botId, botName)
+    authed(bt).when().post(s"/api/tournament/$tournamentId/join").`then`().statusCode(200)
+
+  private def startTournament(token: String, tournamentId: String): ValidatableResponse =
+    authed(token).when().post(s"/api/tournament/$tournamentId/start").`then`().statusCode(200)
+
+  @Test
+  def createsTournamentWhenAuthenticated(): Unit =
+    formAuthed(directorToken())
+      .formParam("name", "Test Tour")
+      .formParam("nbRounds", 3)
+      .formParam("clockLimit", 300)
+      .formParam("clockIncrement", 5)
+      .formParam("rated", true)
+      .when().post("/api/tournament")
+      .`then`().statusCode(201)
+      .body("fullName", is("Test Tour"))
+      .body("status", is("created"))
+
+  @Test
+  def returns401WhenUnauthenticated(): Unit =
+    RestAssured.`given`().contentType(ContentType.URLENC)
+      .formParam("name", "Test Tour")
+      .formParam("nbRounds", 3)
+      .formParam("clockLimit", 300)
+      .formParam("clockIncrement", 5)
+      .when().post("/api/tournament")
+      .`then`().statusCode(401)
+
+  @Test
+  def returnsEmptyListsOnFreshStart(): Unit =
+    RestAssured.`given`().when().get("/api/tournament")
+      .`then`().statusCode(200)
+      .body("created", notNullValue())
+      .body("started", notNullValue())
+      .body("finished", notNullValue())
+
+  @Test
+  def returnsCreatedTournamentInCreatedList(): Unit =
+    val id = createTournament(directorToken("director-list"), "ListTour")
+    RestAssured.`given`().when().get("/api/tournament")
+      .`then`().statusCode(200)
+      .body("created.id", hasItem(id))
+
+  @Test
+  def returns404ForUnknownId(): Unit =
+    RestAssured.`given`().when().get("/api/tournament/XXXXXX").`then`().statusCode(404)
+
+  @Test
+  def returnsTournamentWithStandings(): Unit =
+    val id = createTournament(directorToken("dir-get"), "GetTour")
+    RestAssured.`given`().when().get(s"/api/tournament/$id")
+      .`then`().statusCode(200)
+      .body("id", is(id))
+      .body("standing", notNullValue())
+
+  @Test
+  def directorCanTerminateCreatedTournament(): Unit =
+    val token = directorToken("dir-term")
+    val id    = createTournament(token, "TermTour")
+    deleteAndCheck(token, s"/api/tournament/$id", 204)
+
+  @Test
+  def nonDirectorGets403OnTerminate(): Unit =
+    val id = createTournament(directorToken("dir-403"), "SecureTour")
+    deleteAndCheck(directorToken("other-user-403"), s"/api/tournament/$id", 403)
+
+  @Test
+  def cannotTerminateStartedTournament(): Unit =
+    val token = directorToken("dir-started")
+    val id    = createTournament(token, "StartedTour")
+    botJoin(id, "sbot-1", "StartBot1")
+    botJoin(id, "sbot-2", "StartBot2")
+    startTournament(token, id)
+    deleteAndCheck(token, s"/api/tournament/$id", 409)
+
+  @Test
+  def botJoinsSuccessfully(): Unit =
+    val id = createTournament(directorToken("dir-join"), "JoinTour")
+    authed(botToken("joinbot-1", "JoinBot1"))
+      .when().post(s"/api/tournament/$id/join")
+      .`then`().statusCode(200)
+      .body("ok", is(true))
+
+  @Test
+  def nonBotTokenReturns403OnJoin(): Unit =
+    val id = createTournament(directorToken("dir-nbjoin"), "NbJoinTour")
+    postAndCheck(directorToken("regular-user"), s"/api/tournament/$id/join", 403)
+
+  @Test
+  def alreadyJoinedReturns409(): Unit =
+    val id = createTournament(directorToken("dir-dbl"), "DblJoinTour")
+    val bt = botToken("dblbot-1", "DblBot1")
+    botJoin(id, "dblbot-1", "DblBot1")
+    authed(bt).when().post(s"/api/tournament/$id/join").`then`().statusCode(409)
+
+  @Test
+  def startedTournamentReturns409OnJoin(): Unit =
+    val token = directorToken("dir-sjoin")
+    val id    = createTournament(token, "SjoinTour")
+    botJoin(id, "sjbot-1", "SjBot1")
+    botJoin(id, "sjbot-2", "SjBot2")
+    startTournament(token, id)
+    authed(botToken("sjbot-3", "SjBot3")).when().post(s"/api/tournament/$id/join").`then`().statusCode(409)
+
+  @Test
+  def joinedBotCanWithdraw(): Unit =
+    val id = createTournament(directorToken("dir-wd"), "WdTour")
+    val bt = botToken("wdbot-1", "WdBot1")
+    botJoin(id, "wdbot-1", "WdBot1")
+    authed(bt).when().post(s"/api/tournament/$id/withdraw")
+      .`then`().statusCode(200)
+      .body("ok", is(true))
+
+  @Test
+  def notJoinedBotReturns409OnWithdraw(): Unit =
+    val id = createTournament(directorToken("dir-wdnj"), "WdnjTour")
+    val bt = botToken("wdnjbot-1", "WdnjBot1")
+    authed(bt).when().post(s"/api/tournament/$id/withdraw").`then`().statusCode(409)
+
+  @Test
+  def directorStartsWith2Bots(): Unit =
+    val token = directorToken("dir-start")
+    val id    = createTournament(token, "StartTour2")
+    botJoin(id, "stbot-1", "StBot1")
+    botJoin(id, "stbot-2", "StBot2")
+    postAndCheck(token, s"/api/tournament/$id/start", 200)
+
+  @Test
+  def nonDirectorReturns403OnStart(): Unit =
+    val id = createTournament(directorToken("dir-ndstart"), "NdStartTour")
+    botJoin(id, "ndstbot-1", "NdstBot1")
+    botJoin(id, "ndstbot-2", "NdstBot2")
+    postAndCheck(directorToken("other-ndstart"), s"/api/tournament/$id/start", 403)
+
+  @Test
+  def fewerThan2BotsReturns409OnStart(): Unit =
+    val token = directorToken("dir-1bot")
+    val id    = createTournament(token, "1BotTour")
+    botJoin(id, "onebot-1", "OneBot1")
+    postAndCheck(token, s"/api/tournament/$id/start", 409)
+
+  @Test
+  def resultsReturns200WithNdjsonContentType(): Unit =
+    val id = createTournament(directorToken("dir-res"), "ResTour")
+    RestAssured.`given`().when().get(s"/api/tournament/$id/results")
+      .`then`().statusCode(200)
+      .contentType("application/x-ndjson")
+
+  @Test
+  def returnsPairingsForRoundAfterStart(): Unit =
+    val token = directorToken("dir-round")
+    val id    = createTournament(token, "RoundTour")
+    botJoin(id, "rndbot-1", "RndBot1")
+    botJoin(id, "rndbot-2", "RndBot2")
+    startTournament(token, id)
+    RestAssured.`given`().when().get(s"/api/tournament/$id/round/1").`then`().statusCode(200)
+
+  @Test
+  def returns404ForUnknownTournamentRound(): Unit =
+    RestAssured.`given`().when().get("/api/tournament/XXXXXX/round/1").`then`().statusCode(404)
+
+  @Test
+  def returnsPgnByDefault(): Unit =
+    val id = createTournament(directorToken("dir-pgn"), "PgnTour")
+    RestAssured.`given`().when().get(s"/api/tournament/$id/export/games").`then`().statusCode(200)
+
+  @Test
+  def returnsNdjsonWhenAcceptApplicationXNdjson(): Unit =
+    val id = createTournament(directorToken("dir-ndjson"), "NdjsonTour")
+    RestAssured.`given`()
+      .header("Accept", "application/x-ndjson")
+      .when().get(s"/api/tournament/$id/export/games")
+      .`then`().statusCode(200)
+      .contentType("application/x-ndjson")
diff --git a/modules/tournament/src/test/scala/de/nowchess/tournament/service/SwissPairingServiceTest.scala b/modules/tournament/src/test/scala/de/nowchess/tournament/service/SwissPairingServiceTest.scala
new file mode 100644
index 0000000..9b03166
--- /dev/null
+++ b/modules/tournament/src/test/scala/de/nowchess/tournament/service/SwissPairingServiceTest.scala
@@ -0,0 +1,73 @@
+package de.nowchess.tournament.service
+
+import de.nowchess.tournament.domain.{TournamentPairing, TournamentParticipant}
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.Assertions.*
+
+class SwissPairingServiceTest:
+
+  private def makeParticipant(botId: String, botName: String, points: Double = 0.0, byeCount: Int = 0): TournamentParticipant =
+    val p = new TournamentParticipant()
+    p.botId = botId
+    p.botName = botName
+    p.points = points
+    p.byeCount = byeCount
+    p
+
+  @Test
+  def pairs2PlayersRandomlyAssignsColors(): Unit =
+    val p1 = makeParticipant("b1", "BotOne")
+    val p2 = makeParticipant("b2", "BotTwo")
+    val (pairs, bye) = SwissPairingService.computePairings(List(p1, p2), Nil)
+    assertEquals(1, pairs.size)
+    assertTrue(bye.isEmpty)
+    val (white, black) = pairs.head
+    val ids = Set(white.botId, black.botId)
+    assertEquals(Set("b1", "b2"), ids)
+
+  @Test
+  def pairs4PlayersTopVsEachOther(): Unit =
+    val p1 = makeParticipant("b1", "A", points = 2.0)
+    val p2 = makeParticipant("b2", "B", points = 1.5)
+    val p3 = makeParticipant("b3", "C", points = 1.0)
+    val p4 = makeParticipant("b4", "D", points = 0.0)
+    val (pairs, bye) = SwissPairingService.computePairings(List(p1, p2, p3, p4), Nil)
+    assertEquals(2, pairs.size)
+    assertTrue(bye.isEmpty)
+    val pair1Ids = Set(pairs(0)._1.botId, pairs(0)._2.botId)
+    val pair2Ids = Set(pairs(1)._1.botId, pairs(1)._2.botId)
+    assertEquals(Set("b1", "b2"), pair1Ids)
+    assertEquals(Set("b3", "b4"), pair2Ids)
+
+  @Test
+  def oddCountLowestRankedGetsBye(): Unit =
+    val p1 = makeParticipant("b1", "A", points = 2.0)
+    val p2 = makeParticipant("b2", "B", points = 1.0)
+    val p3 = makeParticipant("b3", "C", points = 0.0)
+    val (pairs, bye) = SwissPairingService.computePairings(List(p1, p2, p3), Nil)
+    assertEquals(1, pairs.size)
+    assertTrue(bye.isDefined)
+    assertEquals("b3", bye.get.botId)
+
+  @Test
+  def avoidsRematchSwapsWhenPairAlreadyPlayed(): Unit =
+    val p1 = makeParticipant("b1", "A", points = 2.0)
+    val p2 = makeParticipant("b2", "B", points = 1.5)
+    val p3 = makeParticipant("b3", "C", points = 1.5)
+    val p4 = makeParticipant("b4", "D", points = 0.0)
+    val pastPairing = new TournamentPairing()
+    pastPairing.whiteId = "b1"
+    pastPairing.blackId = "b2"
+    val (pairs, _) = SwissPairingService.computePairings(List(p1, p2, p3, p4), List(pastPairing))
+    val pair1Ids = Set(pairs(0)._1.botId, pairs(0)._2.botId)
+    assertFalse(pair1Ids == Set("b1", "b2"), "b1 and b2 should not be paired again")
+
+  @Test
+  def playerWithFewerByesGetsTheByeFirst(): Unit =
+    val p1 = makeParticipant("b1", "A", points = 1.0, byeCount = 1)
+    val p2 = makeParticipant("b2", "B", points = 0.5, byeCount = 0)
+    val p3 = makeParticipant("b3", "C", points = 0.0, byeCount = 0)
+    val (pairs, bye) = SwissPairingService.computePairings(List(p1, p2, p3), Nil)
+    assertEquals(1, pairs.size)
+    assertTrue(bye.isDefined)
+    assertEquals("b3", bye.get.botId)
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 5912991..7a018a5 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -26,4 +26,5 @@ include(
     "modules:ws",
     "modules:store",
     "modules:coordinator",
+    "modules:tournament",
 )
\ No newline at end of file