diff --git a/.github/workflows/example-api-only-transcriberj-hand-written-contract-tests-build.yml b/.github/workflows/example-api-only-transcriberj-hand-written-contract-tests-build.yml
new file mode 100644
index 0000000..475e36a
--- /dev/null
+++ b/.github/workflows/example-api-only-transcriberj-hand-written-contract-tests-build.yml
@@ -0,0 +1,48 @@
+name: Example - API-Only TranscriberJ Hand-Written Contract Tests Build
+on:
+  push:
+    paths:
+      - 'examples/api-only-transcriberj/hand-written-contract-tests/**/*.java'
+      - 'examples/api-only-transcriberj/hand-written-contract-tests/**/*.yaml'
+      - 'examples/api-only-transcriberj/hand-written-contract-tests/**/*.gradle'
+      - 'examples/api-only-transcriberj/hand-written-contract-tests/**/*.properties'
+      - 'examples/api-only-transcriberj/hand-written-contract-tests/**/libs.versions.toml'
+      - 'examples/api-only-transcriberj/hand-written-contract-tests/package.json'
+      - 'examples/api-only-transcriberj/hand-written-contract-tests/package-lock.json'
+      - '.github/workflows/example-api-only-transcriberj-hand-written-contract-tests-build.yml'
+
+permissions:
+  contents: read
+
+jobs:
+  Build-Example:
+    name: Build Example
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          fetch-depth: 1
+          persist-credentials: false
+
+      - name: Setup Java
+        uses: actions/setup-java@ad2b38190b15e4d6bdf0c97fb4fca8412226d287 # v5.3.0
+        with:
+          distribution: 'temurin'
+          java-version: 21
+
+      # The example builds its contract with the API-Only Publisher, which is a Node.js tool.
+      - name: Setup Node.js
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version: 24
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@3f131e8634966bd73d06cc69884922b02e6faf92 # v6.2.0
+
+      - name: Build example
+        run: |
+          cd examples/api-only-transcriberj/hand-written-contract-tests
+          chmod +x ./gradlew
+          ./gradlew check --no-daemon
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/.gitignore b/examples/api-only-transcriberj/hand-written-contract-tests/.gitignore
new file mode 100644
index 0000000..1facb38
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/.gitignore
@@ -0,0 +1,3 @@
+node_modules/
+build/
+.gradle/
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/.redocly.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/.redocly.yaml
new file mode 100644
index 0000000..c2373f5
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/.redocly.yaml
@@ -0,0 +1,2 @@
+extends:
+  - recommended
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/README.adoc b/examples/api-only-transcriberj/hand-written-contract-tests/README.adoc
new file mode 100644
index 0000000..caf824e
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/README.adoc
@@ -0,0 +1,89 @@
+= Example: contract tests the generator cannot write, on top of the classes it does
+:toc: left
+:toc-title: Contents
+:icons: font
+:source-highlighter: rouge
+
+A small Spring Boot service, and the contract tests of its one endpoint, built on the classes the API-Only TranscriberJ generates from its contract -- including where the generator stops.
+
+The request body is a `oneOf` whose branches are written inline, so the generator cannot write it: `RefundRequestV1.body(...)` throws.
+A refund must also go back the way the order was paid, a rule the schema cannot express, so a request can be valid against the schema and still be refused with a 422.
+The tests write the request by hand, from the generated pieces that are still there, and check every response against the generated REST Docs descriptors.
+
+The guide that walks through it is https://github.com/Arc-E-Tect/SoftwareEngineeringDoneRight-API/blob/main/docs/guides/hand-written-contract-tests/tutorial.adoc[the hand-written contract tests tutorial ↗]; the reference is https://github.com/Arc-E-Tect/SoftwareEngineeringDoneRight-API/blob/main/api-only-transcriberj/README.adoc#unrepresentable[the TranscriberJ's README ↗].
+
+== What is in it
+
+[cols="2,3", options="header"]
+|===
+|File |What it is
+
+|`src/main/api/openapi/`
+|The `refunds` contract: `POST /orders/{orderId}/refunds`, answered with 201, 400, 404 or 422.
+`RefundRequestV1` is the `oneOf` the generator cannot write.
+
+|`src/main/java/com/example/refunds/`
+|The service, written by hand.
+It never imports a generated class.
+
+|`src/test/java/com/example/contract/RefundRequests.java`
+|The request body, written by hand, in the generated package, from the generated constants.
+
+|`src/test/java/com/example/contract/RefundRequestsTest.java`
+|What keeps `RefundRequests` honest as the contract moves.
+
+|`src/test/java/com/example/refunds/CreateRefundContractTest.java`
+|The contract tests: one per response the contract lists, each checking the response's shape.
+
+|`src/test/java/com/example/refunds/RefundsTest.java`
+|The behaviour: every way a request can be invalid, and every business rule, as scenarios.
+|===
+
+[IMPORTANT]
+.Hand-written test code lives in the generated package, and owns what it types
+====
+`RefundRequests` is in `com.example.contract`, the generated package, in the test source set.
+That is the TranscriberJ's design: `ContractJson` and the scalar components it draws on, such as `AmountV1`, are package-private.
+They are regenerated on every build and are not a published API, so an upgrade may change them.
+
+`RefundRequests` also types what no generated class holds: the member names of the inline branches, and the `destination` values `card` and `bank-account`.
+Keeping those in line with the contract is this project's responsibility; `RefundRequestsTest` pins the class to the request schema's hash, which is the only thing that notices when one of them changes.
+https://github.com/Arc-E-Tect/SoftwareEngineeringDoneRight-API/blob/main/api-only-transcriberj/README.adoc#hand-written-code[Hand-written code beside the generated classes ↗] is the reference.
+====
+
+== Run it
+
+You need Java 21 and Node.js (`^22.14.0`, `^24.10.0` or `>=26.0.0`).
+
+[source,console]
+----
+./gradlew check
+----
+
+The build installs the Publisher, builds and publishes the contract, generates the classes, runs the tests, and checks the service's coverage.
+
+== What to look at
+
+`build/reports/transcriberj/refunds.txt`::
+The two methods the generator could not write, why, and the remedy.
+
+`build/generated/sources/transcriberj/refunds/com/example/contract/RefundRequestV1.java`::
+What is still there when `body(...)` throws: the provenance, and the fragment's hash.
+
+`build/generated-snippets/`::
+The REST Docs snippets of the four responses, from the generated descriptors.
+
+`build/reports/jacoco/test/html/index.html`::
+The service's coverage; the generated classes are excluded by their annotation.
+
+== Try it
+
+* Remove `maximum` from `AmountV1.yaml` and raise the contract's version in `refunds.bundle.properties` and `gradle.properties`.
+The tests no longer compile: `RefundRequests` and `RefundRequestsTest` use `AmountV1.MAXIMUM`, which is gone.
+* Put the `maximum` back, rename `cardLast4` to `lastFourDigits` in `RefundRequestV1.yaml`, and raise the version again.
+Everything compiles, and every contract test still passes, since the service is unchanged; only `theHandWrittenBodyWasWrittenAgainstTheRequestSchemaAsItIsNow` fails, and says what to do:
++
+[source,text]
+----
+[openapi/components/schemas/RefundRequestV1.yaml changed; check RefundRequests against it, then update WRITTEN_AGAINST]
+----
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/apionly.lock b/examples/api-only-transcriberj/hand-written-contract-tests/apionly.lock
new file mode 100644
index 0000000..00f046b
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/apionly.lock
@@ -0,0 +1,9 @@
+# apionly.lock -- the published contracts this project builds against.
+# Generated by the Arc-E-Tect API-Only Subscriber. Commit it; do not edit it.
+# Run `verifyApiSpec` to check that what is on disk still matches.
+format 1
+
+target refunds
+version 1.0.0
+channel file
+sha256 bf47b56e864e88a77e945985f730d108532fd29d19b610aa60594e688a0d7d01 openapi.yaml
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/apionly.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/apionly.yaml
new file mode 100644
index 0000000..bc6dbd5
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/apionly.yaml
@@ -0,0 +1,30 @@
+schemaVersion: 1
+
+sources:
+  root: src/main/api
+  openapi: openapi
+
+defaults:
+  openapi:
+    lint: .redocly.yaml
+    outputName: openapi.yaml
+
+build:
+  staging: build/api-only/staging
+  dist: build/api-only/dist
+
+reports:
+  lint: build/api-only/reports/lint
+
+toolchain:
+  redocly: "@redocly/cli@2.52.0"
+
+channels:
+  file:
+    directory: build/api-only/publish
+    clean: true
+
+targets:
+  refunds:
+    openapi:
+      bundle: bundles/refunds.yaml
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/build.gradle b/examples/api-only-transcriberj/hand-written-contract-tests/build.gradle
new file mode 100644
index 0000000..514b179
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/build.gradle
@@ -0,0 +1,113 @@
+import org.springframework.boot.gradle.plugin.SpringBootPlugin
+
+plugins {
+    id 'java'
+    id 'jacoco'
+    alias(libs.plugins.spring.boot)
+    alias(libs.plugins.api.only.transcriberj)
+}
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(21)
+    }
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    // The service: hand-written, and it never imports the generated classes.
+    implementation platform(SpringBootPlugin.BOM_COORDINATES)
+    implementation 'org.springframework.boot:spring-boot-starter-webmvc'
+
+    // The tests: the generated classes, their REST Docs companions, and MockMvc.
+    transcriberjEmitters libs.api.only.transcriberj.restdocs
+    testImplementation platform(SpringBootPlugin.BOM_COORDINATES)
+    testImplementation 'org.springframework.boot:spring-boot-starter-webmvc-test'
+    testImplementation 'org.springframework.boot:spring-boot-restdocs'
+    testImplementation 'org.springframework.restdocs:spring-restdocs-mockmvc'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+}
+
+tasks.named('test') {
+    useJUnitPlatform()
+    finalizedBy 'jacocoTestReport'
+}
+
+tasks.named('jacocoTestReport') {
+    reports {
+        xml.required = true
+        html.required = true
+    }
+}
+
+// The service's own code is measured; the generated tree is excluded by its annotation.
+tasks.named('jacocoTestCoverageVerification') {
+    violationRules {
+        rule {
+            limit {
+                minimum = 0.90
+            }
+        }
+    }
+}
+
+tasks.named('check') { dependsOn 'jacocoTestCoverageVerification' }
+
+// ---------------------------------------------------------------------------
+// The contract. The Publisher builds it into build/, and the Subscriber, which
+// the TranscriberJ applies, fetches it from there.
+// ---------------------------------------------------------------------------
+
+def npm = System.getProperty('os.name').toLowerCase().contains('windows') ? 'npm.cmd' : 'npm'
+
+def installApiOnlyPublisher = tasks.register('installApiOnlyPublisher', Exec) {
+    group = 'api-only'
+    description = 'Installs the API-Only Publisher at the version package-lock.json pins.'
+    inputs.files('package.json', 'package-lock.json').withPropertyName('manifests')
+    outputs.file('node_modules/.package-lock.json').withPropertyName('installation')
+    commandLine npm, 'ci', '--no-audit', '--no-fund'
+}
+
+def buildApiContract = tasks.register('buildApiContract', Exec) {
+    group = 'api-only'
+    description = 'Bundles, stamps and lints the refunds contract.'
+    dependsOn installApiOnlyPublisher
+    inputs.dir('src/main/api').withPropertyName('specification')
+    inputs.files('apionly.yaml', 'package-lock.json').withPropertyName('configuration')
+    outputs.dir('build/api-only/dist/refunds').withPropertyName('bundle')
+    commandLine npm, 'run', '--silent', 'apionly', '--', 'build', '--target', 'refunds'
+}
+
+def publishApiContract = tasks.register('publishApiContract', Exec) {
+    group = 'api-only'
+    description = 'Publishes the refunds contract to the file channel in build/api-only/publish.'
+    dependsOn buildApiContract
+    inputs.dir('build/api-only/dist/refunds').withPropertyName('bundle')
+    outputs.dir('build/api-only/publish/refunds').withPropertyName('archive')
+    commandLine npm, 'run', '--silent', 'apionly', '--', 'publish', '--target', 'refunds', '--channel', 'file'
+}
+
+apiOnlySubscriber {
+    channel {
+        type = 'file'
+        directory = file('build/api-only/publish').path
+    }
+    subscribe('refunds')
+}
+
+tasks.named('fetchApiSpecRefunds') { dependsOn publishApiContract }
+
+// ---------------------------------------------------------------------------
+// The generated classes, for the tests only.
+// ---------------------------------------------------------------------------
+
+apiOnlyTranscriberJ {
+    subscription('refunds') {
+        basePackage = 'com.example.contract'
+        // The REST Docs field tables show the contract's descriptions.
+        generateDocs = true
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/gradle.properties b/examples/api-only-transcriberj/hand-written-contract-tests/gradle.properties
new file mode 100644
index 0000000..07ea8dc
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/gradle.properties
@@ -0,0 +1,2 @@
+# The version of the refunds contract this project implements.
+apiContractVersion=1.0.0
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/gradle/libs.versions.toml b/examples/api-only-transcriberj/hand-written-contract-tests/gradle/libs.versions.toml
new file mode 100644
index 0000000..3072f6f
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/gradle/libs.versions.toml
@@ -0,0 +1,11 @@
+[versions]
+api-only-transcriberj = "0.3.3"
+api-only-transcriberj-restdocs = "0.1.1"
+spring-boot = "4.1.1"
+
+[libraries]
+api-only-transcriberj-restdocs = { module = "com.arc-e-tect:api-only-transcriberj-restdocs", version.ref = "api-only-transcriberj-restdocs" }
+
+[plugins]
+api-only-transcriberj = { id = "com.arc-e-tect.api-only-transcriberj", version.ref = "api-only-transcriberj" }
+spring-boot = { id = "org.springframework.boot", version.ref = "spring-boot" }
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/gradle/wrapper/gradle-wrapper.jar b/examples/api-only-transcriberj/hand-written-contract-tests/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..eddabd2
Binary files /dev/null and b/examples/api-only-transcriberj/hand-written-contract-tests/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/gradle/wrapper/gradle-wrapper.properties b/examples/api-only-transcriberj/hand-written-contract-tests/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..ad7845b
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,9 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.7.1-bin.zip
+networkTimeout=10000
+retries=0
+retryBackOffMs=500
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/gradlew b/examples/api-only-transcriberj/hand-written-contract-tests/gradlew
new file mode 100755
index 0000000..249efbb
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/gradlew
@@ -0,0 +1,248 @@
+#!/bin/sh
+
+#
+# Copyright © 2015 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   gradlew start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh gradlew
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/3d91ce3b8caaf77ad09f381f43615b715b53f72c/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/gradlew.bat b/examples/api-only-transcriberj/hand-written-contract-tests/gradlew.bat
new file mode 100644
index 0000000..a51ec4f
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/gradlew.bat
@@ -0,0 +1,82 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  gradlew startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables, and ensure extensions are enabled
+setlocal EnableExtensions
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+"%COMSPEC%" /c exit 1
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+"%COMSPEC%" /c exit 1
+
+:execute
+@rem Setup the command line
+
+
+
+@rem Execute gradlew
+@rem endlocal doesn't take effect until after the line is parsed and variables are expanded
+@rem which allows us to clear the local environment before executing the java command
+endlocal & "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %* & call :exitWithErrorLevel
+
+:exitWithErrorLevel
+@rem Use "%COMSPEC%" /c exit to allow operators to work properly in scripts
+"%COMSPEC%" /c exit %ERRORLEVEL%
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/package-lock.json b/examples/api-only-transcriberj/hand-written-contract-tests/package-lock.json
new file mode 100644
index 0000000..8d4b139
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/package-lock.json
@@ -0,0 +1,45 @@
+{
+  "name": "api-only-transcriberj-hand-written-contract-tests",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "api-only-transcriberj-hand-written-contract-tests",
+      "devDependencies": {
+        "@arc-e-tect/api-only-publisher": "0.5.0"
+      }
+    },
+    "node_modules/@arc-e-tect/api-only-publisher": {
+      "version": "0.5.0",
+      "resolved": "https://registry.npmjs.org/@arc-e-tect/api-only-publisher/-/api-only-publisher-0.5.0.tgz",
+      "integrity": "sha512-VKJzWTlm9TvquiS+9F7ipwFcP6dIknVyZfNHsw5qqpzau/iLHbuPipYdGXyFrPJUk2B9Uf0hZkVoP3IKyrkqJg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "yaml": "2.9.1"
+      },
+      "bin": {
+        "api-only-publisher": "src/cli.js"
+      },
+      "engines": {
+        "node": "^22.14.0 || ^24.10.0 || >=26.0.0"
+      }
+    },
+    "node_modules/yaml": {
+      "version": "2.9.1",
+      "resolved": "https://registry.npmjs.org/yaml/-/yaml-2.9.1.tgz",
+      "integrity": "sha512-3NxN8+78OdzbT7C/WjGsyfPAtJaN3FNDsWxv7Y7mcDsT/oOmgW8BpyQQFFBnvZE3j9Y2Sdz1ULFLezL7Eb2yFw==",
+      "dev": true,
+      "license": "ISC",
+      "bin": {
+        "yaml": "bin.mjs"
+      },
+      "engines": {
+        "node": ">= 14.6"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/eemeli"
+      }
+    }
+  }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/package.json b/examples/api-only-transcriberj/hand-written-contract-tests/package.json
new file mode 100644
index 0000000..5f55f17
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/package.json
@@ -0,0 +1,10 @@
+{
+  "name": "api-only-transcriberj-hand-written-contract-tests",
+  "private": true,
+  "scripts": {
+    "apionly": "api-only-publisher"
+  },
+  "devDependencies": {
+    "@arc-e-tect/api-only-publisher": "0.5.0"
+  }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/settings.gradle b/examples/api-only-transcriberj/hand-written-contract-tests/settings.gradle
new file mode 100644
index 0000000..b75222f
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/settings.gradle
@@ -0,0 +1,11 @@
+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+    }
+}
+
+plugins {
+    id 'org.gradle.toolchains.foojay-resolver-convention' version '1.0.0'
+}
+
+rootProject.name = 'api-only-transcriberj-hand-written-contract-tests'
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/bundles/refunds.bundle.properties b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/bundles/refunds.bundle.properties
new file mode 100644
index 0000000..d5249aa
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/bundles/refunds.bundle.properties
@@ -0,0 +1,2 @@
+# The version of the refunds contract.
+version=1.0.0
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/bundles/refunds.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/bundles/refunds.yaml
new file mode 100644
index 0000000..e16ff8f
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/bundles/refunds.yaml
@@ -0,0 +1,13 @@
+openapi: 3.1.1
+info:
+  title: Refunds API
+  version: 0.0.0
+  license:
+    name: MIT
+    identifier: MIT
+servers:
+  - url: https://api.refunds.test
+security: []
+paths:
+  /orders/{orderId}/refunds:
+    $ref: ../paths/Refunds.yaml
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/AmountV1.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/AmountV1.yaml
new file mode 100644
index 0000000..1d9e09c
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/AmountV1.yaml
@@ -0,0 +1,4 @@
+type: integer
+description: An amount of money, in cents.
+minimum: 1
+maximum: 1000000
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/CardLast4V1.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/CardLast4V1.yaml
new file mode 100644
index 0000000..80b5203
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/CardLast4V1.yaml
@@ -0,0 +1,3 @@
+type: string
+description: The last four digits of a card number.
+pattern: '^[0-9]{4}$'
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/IbanV1.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/IbanV1.yaml
new file mode 100644
index 0000000..73d38de
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/IbanV1.yaml
@@ -0,0 +1,3 @@
+type: string
+description: An international bank account number, without spaces.
+pattern: '^[A-Z]{2}[0-9]{2}[A-Z0-9]{11,30}$'
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/ProblemV1.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/ProblemV1.yaml
new file mode 100644
index 0000000..7f9f9d8
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/ProblemV1.yaml
@@ -0,0 +1,30 @@
+type: object
+description: What went wrong with a request, as RFC 9457 describes it.
+required:
+  - title
+  - status
+properties:
+  title:
+    type: string
+    description: A short summary of the problem.
+  status:
+    type: integer
+    description: The HTTP status code.
+  detail:
+    type: string
+    description: What went wrong with this request.
+  errors:
+    type: array
+    description: The individual problems, one per field.
+    items:
+      type: object
+      required:
+        - field
+        - message
+      properties:
+        field:
+          type: string
+          description: The field that was wrong.
+        message:
+          type: string
+          description: What was wrong with it.
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/RefundRequestV1.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/RefundRequestV1.yaml
new file mode 100644
index 0000000..7aea1d5
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/RefundRequestV1.yaml
@@ -0,0 +1,29 @@
+type: object
+description: Where a refund goes, and how much of the order it returns.
+oneOf:
+  - type: object
+    description: A refund to the card the order was paid with.
+    required:
+      - destination
+      - amount
+      - cardLast4
+    properties:
+      destination:
+        const: card
+      amount:
+        $ref: AmountV1.yaml
+      cardLast4:
+        $ref: CardLast4V1.yaml
+  - type: object
+    description: A refund to a bank account, for an order paid by bank transfer.
+    required:
+      - destination
+      - amount
+      - iban
+    properties:
+      destination:
+        const: bank-account
+      amount:
+        $ref: AmountV1.yaml
+      iban:
+        $ref: IbanV1.yaml
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/RefundV1.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/RefundV1.yaml
new file mode 100644
index 0000000..cbeb7a1
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/components/schemas/RefundV1.yaml
@@ -0,0 +1,19 @@
+type: object
+description: A refund the shop accepted.
+required:
+  - id
+  - orderId
+  - amount
+  - destination
+properties:
+  id:
+    type: string
+    description: The refund's identifier.
+  orderId:
+    type: string
+    description: The order the refund is for.
+  amount:
+    $ref: AmountV1.yaml
+  destination:
+    type: string
+    description: Where the money goes, `card` or `bank-account`.
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/paths/Refunds.yaml b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/paths/Refunds.yaml
new file mode 100644
index 0000000..bae71eb
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/api/openapi/paths/Refunds.yaml
@@ -0,0 +1,45 @@
+post:
+  operationId: createRefund
+  summary: Refund part or all of an order.
+  description: >-
+    A refund goes back the way the order was paid, and never exceeds what is
+    left of the order to refund. Neither rule can be written in the schema; a
+    request that breaks one is answered with 422.
+  parameters:
+    - name: orderId
+      in: path
+      required: true
+      description: The order's identifier.
+      schema:
+        type: string
+  requestBody:
+    required: true
+    content:
+      application/json:
+        schema:
+          $ref: ../components/schemas/RefundRequestV1.yaml
+  responses:
+    '201':
+      description: The refund was accepted.
+      content:
+        application/json:
+          schema:
+            $ref: ../components/schemas/RefundV1.yaml
+    '400':
+      description: The request does not match the contract.
+      content:
+        application/problem+json:
+          schema:
+            $ref: ../components/schemas/ProblemV1.yaml
+    '404':
+      description: No order has that identifier.
+      content:
+        application/problem+json:
+          schema:
+            $ref: ../components/schemas/ProblemV1.yaml
+    '422':
+      description: The request matches the contract, but breaks a business rule.
+      content:
+        application/problem+json:
+          schema:
+            $ref: ../components/schemas/ProblemV1.yaml
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/FieldError.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/FieldError.java
new file mode 100644
index 0000000..eef823c
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/FieldError.java
@@ -0,0 +1,10 @@
+package com.example.refunds;
+
+/**
+ * What is wrong with one member of a request.
+ *
+ * @param field   the member
+ * @param message what is wrong with it
+ */
+public record FieldError(String field, String message) {
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Orders.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Orders.java
new file mode 100644
index 0000000..67217e4
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Orders.java
@@ -0,0 +1,66 @@
+package com.example.refunds;
+
+import org.springframework.stereotype.Component;
+
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * The orders a refund can be for, and how much of each is refunded so far.
+ * Two orders, in memory: enough for an example.
+ */
+@Component
+public class Orders {
+
+    /** An order of 5000 cents, paid by card. */
+    public static final String PAID_BY_CARD = "order-paid-by-card";
+
+    /** An order of 5000 cents, paid by bank transfer. */
+    public static final String PAID_BY_BANK_TRANSFER = "order-paid-by-bank-transfer";
+
+    /**
+     * An order.
+     *
+     * @param id       its identifier
+     * @param paidWith how it was paid: {@code card} or {@code bank-account}
+     * @param total    what it cost, in cents
+     * @param refunded how much of that is refunded so far
+     */
+    public record Order(String id, String paidWith, int total, int refunded) {
+
+        /**
+         * What is left to refund.
+         *
+         * @return the amount, in cents
+         */
+        public int left() {
+            return total - refunded;
+        }
+    }
+
+    private final Map<String, Order> orders = new ConcurrentHashMap<>(Map.of(
+            PAID_BY_CARD, new Order(PAID_BY_CARD, "card", 5000, 0),
+            PAID_BY_BANK_TRANSFER, new Order(PAID_BY_BANK_TRANSFER, "bank-account", 5000, 0)));
+
+    /**
+     * An order, if there is one with that identifier.
+     *
+     * @param id the identifier
+     * @return the order
+     */
+    public Optional<Order> find(String id) {
+        return Optional.ofNullable(orders.get(id));
+    }
+
+    /**
+     * Records a refund against an order.
+     *
+     * @param id     the order's identifier
+     * @param amount the amount refunded, in cents
+     */
+    public void refund(String id, int amount) {
+        orders.computeIfPresent(id, (key, order) ->
+                new Order(order.id(), order.paidWith(), order.total(), order.refunded() + amount));
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Outcome.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Outcome.java
new file mode 100644
index 0000000..63cd360
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Outcome.java
@@ -0,0 +1,37 @@
+package com.example.refunds;
+
+import java.util.List;
+
+/**
+ * What became of a refund request.
+ */
+public sealed interface Outcome {
+
+    /**
+     * The refund was accepted.
+     *
+     * @param refund the refund
+     */
+    record Accepted(Refund refund) implements Outcome {
+    }
+
+    /**
+     * The request is not one the contract allows.
+     *
+     * @param errors what is wrong with it, member by member
+     */
+    record Invalid(List<FieldError> errors) implements Outcome {
+    }
+
+    /** No order has the identifier the request names. */
+    record UnknownOrder() implements Outcome {
+    }
+
+    /**
+     * The request is one the contract allows, and it breaks a business rule.
+     *
+     * @param detail which rule, and how
+     */
+    record Rejected(String detail) implements Outcome {
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Problem.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Problem.java
new file mode 100644
index 0000000..f5baeb5
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Problem.java
@@ -0,0 +1,17 @@
+package com.example.refunds;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+import java.util.List;
+
+/**
+ * What went wrong with a request, as RFC 9457 describes it.
+ *
+ * @param title  a short summary
+ * @param status the HTTP status code
+ * @param detail what went wrong with this request, if there is more to say
+ * @param errors what is wrong with each member, for an invalid request
+ */
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public record Problem(String title, int status, String detail, List<FieldError> errors) {
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Refund.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Refund.java
new file mode 100644
index 0000000..4d5ae87
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Refund.java
@@ -0,0 +1,12 @@
+package com.example.refunds;
+
+/**
+ * A refund the shop accepted.
+ *
+ * @param id          its identifier
+ * @param orderId     the order it is for
+ * @param amount      the amount, in cents
+ * @param destination where the money goes
+ */
+public record Refund(String id, String orderId, int amount, String destination) {
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundController.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundController.java
new file mode 100644
index 0000000..e30172c
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundController.java
@@ -0,0 +1,54 @@
+package com.example.refunds;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * {@code POST /orders/{orderId}/refunds}.
+ */
+@RestController
+public class RefundController {
+
+    private final Refunds refunds;
+
+    /**
+     * A controller over this service.
+     *
+     * @param refunds the service
+     */
+    public RefundController(Refunds refunds) {
+        this.refunds = refunds;
+    }
+
+    /**
+     * Refunds part or all of an order.
+     *
+     * @param orderId the order
+     * @param request the request
+     * @return the refund, or the problem
+     */
+    @PostMapping(path = "/orders/{orderId}/refunds", consumes = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<?> refund(@PathVariable String orderId, @RequestBody RefundRequest request) {
+        return switch (refunds.refund(orderId, request)) {
+            case Outcome.Accepted accepted -> ResponseEntity.status(HttpStatus.CREATED)
+                    .contentType(MediaType.APPLICATION_JSON).body(accepted.refund());
+            case Outcome.Invalid invalid -> problem(HttpStatus.BAD_REQUEST,
+                    "The request does not match the contract.", null, invalid.errors());
+            case Outcome.UnknownOrder unknown -> problem(HttpStatus.NOT_FOUND,
+                    "No order has that identifier.", "There is no order " + orderId + ".", null);
+            case Outcome.Rejected rejected -> problem(HttpStatus.UNPROCESSABLE_CONTENT,
+                    "The refund breaks a business rule.", rejected.detail(), null);
+        };
+    }
+
+    private static ResponseEntity<Problem> problem(HttpStatus status, String title, String detail,
+                                                   java.util.List<FieldError> errors) {
+        return ResponseEntity.status(status).contentType(MediaType.APPLICATION_PROBLEM_JSON)
+                .body(new Problem(title, status.value(), detail, errors));
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundRequest.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundRequest.java
new file mode 100644
index 0000000..5c57fe2
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundRequest.java
@@ -0,0 +1,13 @@
+package com.example.refunds;
+
+/**
+ * A refund request as it arrives: any member may be missing, since checking it is the
+ * service's job.
+ *
+ * @param destination {@code card} or {@code bank-account}
+ * @param amount      the amount, in cents
+ * @param cardLast4   the card's last four digits, for a refund to a card
+ * @param iban        the account, for a refund to a bank account
+ */
+public record RefundRequest(String destination, Integer amount, String cardLast4, String iban) {
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Refunds.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Refunds.java
new file mode 100644
index 0000000..7e43897
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/Refunds.java
@@ -0,0 +1,84 @@
+package com.example.refunds;
+
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.regex.Pattern;
+
+/**
+ * Decides what becomes of a refund request.
+ */
+@Service
+public class Refunds {
+
+    private static final int MINIMUM = 1;
+    private static final int MAXIMUM = 1_000_000;
+    private static final Pattern CARD_LAST4 = Pattern.compile("^[0-9]{4}$");
+    private static final Pattern IBAN = Pattern.compile("^[A-Z]{2}[0-9]{2}[A-Z0-9]{11,30}$");
+
+    private final Orders orders;
+
+    /**
+     * A service over these orders.
+     *
+     * @param orders the orders
+     */
+    public Refunds(Orders orders) {
+        this.orders = orders;
+    }
+
+    /**
+     * Refunds part or all of an order.
+     *
+     * @param orderId the order
+     * @param request the request
+     * @return what became of it
+     */
+    public Outcome refund(String orderId, RefundRequest request) {
+        List<FieldError> errors = check(request);
+        if (!errors.isEmpty()) {
+            return new Outcome.Invalid(errors);
+        }
+        Orders.Order order = orders.find(orderId).orElse(null);
+        if (order == null) {
+            return new Outcome.UnknownOrder();
+        }
+        if (!order.paidWith().equals(request.destination())) {
+            return new Outcome.Rejected("The order was paid by " + order.paidWith()
+                    + ", so its refunds go back to the " + order.paidWith() + ".");
+        }
+        if (request.amount() > order.left()) {
+            return new Outcome.Rejected("Only " + order.left() + " of the order is left to refund.");
+        }
+        orders.refund(orderId, request.amount());
+        return new Outcome.Accepted(new Refund(UUID.randomUUID().toString(), orderId, request.amount(),
+                request.destination()));
+    }
+
+    private static List<FieldError> check(RefundRequest request) {
+        List<FieldError> errors = new ArrayList<>();
+        String destination = request.destination();
+        if (!"card".equals(destination) && !"bank-account".equals(destination)) {
+            errors.add(new FieldError("destination", "must be card or bank-account"));
+            return errors;
+        }
+        if (request.amount() == null) {
+            errors.add(new FieldError("amount", "is required"));
+        } else if (request.amount() < MINIMUM || request.amount() > MAXIMUM) {
+            errors.add(new FieldError("amount", "must be between " + MINIMUM + " and " + MAXIMUM));
+        }
+        if (destination.equals("card") && !matches(CARD_LAST4, request.cardLast4())) {
+            errors.add(new FieldError("cardLast4", "must be the last four digits of the card"));
+        }
+        if (destination.equals("bank-account") && !matches(IBAN, request.iban())) {
+            errors.add(new FieldError("iban", "must be an IBAN without spaces"));
+        }
+        return errors;
+    }
+
+    private static boolean matches(Pattern pattern, String value) {
+        return value != null && pattern.matcher(value).matches();
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundsApplication.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundsApplication.java
new file mode 100644
index 0000000..f60f54a
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/main/java/com/example/refunds/RefundsApplication.java
@@ -0,0 +1,20 @@
+package com.example.refunds;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * A shop's refunds service: the application the contract describes, written by hand.
+ */
+@SpringBootApplication
+public class RefundsApplication {
+
+    /**
+     * Starts the service.
+     *
+     * @param args the command line
+     */
+    public static void main(String[] args) {
+        SpringApplication.run(RefundsApplication.class, args);
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/contract/RefundRequests.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/contract/RefundRequests.java
new file mode 100644
index 0000000..9f760e6
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/contract/RefundRequests.java
@@ -0,0 +1,65 @@
+package com.example.contract;
+
+/**
+ * Refund requests, written by hand: {@link RefundRequestV1#body(Object...)} cannot be
+ * generated, because the contract's {@code oneOf} branches are inline.
+ *
+ * <p>It sits in the generated package, in the test source set, so it writes JSON with the
+ * same {@link ContractJson} the generated bodies do, and it takes everything else it can
+ * from the generated classes. The member names and the two {@code destination} values are
+ * the only things typed here; {@link #WRITTEN_AGAINST} is how a change to them is noticed.
+ */
+public final class RefundRequests {
+
+    /**
+     * The {@link RefundRequestV1#FRAGMENT_SHA256} this class was written against. When the
+     * request schema changes, a test fails until this class is checked against it again.
+     */
+    public static final String WRITTEN_AGAINST =
+            "f20b627c2a6f8effb19706bfc3bc3b2854a494c0b8bcf79598c46db8666529b6";
+
+    /** An amount the contract accepts: the smallest. */
+    public static final int SOME_AMOUNT = AmountV1.MINIMUM;
+
+    /** An amount the contract rejects: one more than the largest. */
+    public static final int TOO_LARGE_AN_AMOUNT = AmountV1.MAXIMUM + 1;
+
+    /** Card digits the contract accepts; checked against {@link CardLast4V1#PATTERN}. */
+    public static final String SOME_CARD_LAST4 = "4242";
+
+    /** An account the contract accepts; checked against {@link IbanV1#PATTERN}. */
+    public static final String SOME_IBAN = "NL91ABNA0417164300";
+
+    private RefundRequests() {
+    }
+
+    /**
+     * A refund to the card the order was paid with.
+     *
+     * @param amount    the amount, in cents; see {@link AmountV1}
+     * @param cardLast4 the card's last four digits; see {@link CardLast4V1#PATTERN}
+     * @return the request body
+     */
+    public static String toCard(int amount, String cardLast4) {
+        StringBuilder json = new StringBuilder("{");
+        ContractJson.member(json, "destination", ContractJson.string("card"));
+        ContractJson.member(json, "amount", String.valueOf(amount));
+        ContractJson.member(json, "cardLast4", ContractJson.string(cardLast4));
+        return ContractJson.close(json);
+    }
+
+    /**
+     * A refund to a bank account.
+     *
+     * @param amount the amount, in cents; see {@link AmountV1}
+     * @param iban   the account; see {@link IbanV1#PATTERN}
+     * @return the request body
+     */
+    public static String toBankAccount(int amount, String iban) {
+        StringBuilder json = new StringBuilder("{");
+        ContractJson.member(json, "destination", ContractJson.string("bank-account"));
+        ContractJson.member(json, "amount", String.valueOf(amount));
+        ContractJson.member(json, "iban", ContractJson.string(iban));
+        return ContractJson.close(json);
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/contract/RefundRequestsTest.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/contract/RefundRequestsTest.java
new file mode 100644
index 0000000..9280fbb
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/contract/RefundRequestsTest.java
@@ -0,0 +1,46 @@
+package com.example.contract;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+/**
+ * What keeps the hand-written {@link RefundRequests} honest as the contract moves.
+ */
+class RefundRequestsTest {
+
+    @Test
+    void theHandWrittenBodyWasWrittenAgainstTheRequestSchemaAsItIsNow() {
+        assertThat(RefundRequestV1.FRAGMENT_SHA256)
+                .as("%s changed; check RefundRequests against it, then update WRITTEN_AGAINST",
+                        RefundRequestV1.FRAGMENT_PATH)
+                .isEqualTo(RefundRequests.WRITTEN_AGAINST);
+    }
+
+    @Test
+    void theGeneratorStillCannotWriteThisBody() {
+        // When this fails, the contract names its branches and the generator writes the
+        // body itself: use the generated classes, and delete RefundRequests.
+        assertThatThrownBy(RefundRequestV1::body)
+                .isInstanceOf(UnsupportedOperationException.class)
+                .hasMessageContaining("ONE_OF_INLINE_BRANCHES");
+    }
+
+    @Test
+    void theSampleValuesAreOnesTheContractAccepts() {
+        // CardLast4V1 and IbanV1 are package-private: nothing public in the generated tree
+        // takes them, because the body that would have is the one that could not be generated.
+        assertThat(RefundRequests.SOME_AMOUNT).isBetween(AmountV1.MINIMUM, AmountV1.MAXIMUM);
+        assertThat(RefundRequests.SOME_CARD_LAST4).matches(CardLast4V1.PATTERN);
+        assertThat(RefundRequests.SOME_IBAN).matches(IbanV1.PATTERN);
+    }
+
+    @Test
+    void itWritesTheMembersEachBranchRequires() {
+        assertThat(RefundRequests.toCard(RefundRequests.SOME_AMOUNT, RefundRequests.SOME_CARD_LAST4))
+                .isEqualTo("{\"destination\":\"card\",\"amount\":1,\"cardLast4\":\"4242\"}\n");
+        assertThat(RefundRequests.toBankAccount(RefundRequests.SOME_AMOUNT, RefundRequests.SOME_IBAN))
+                .isEqualTo("{\"destination\":\"bank-account\",\"amount\":1,\"iban\":\"NL91ABNA0417164300\"}\n");
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/refunds/CreateRefundContractTest.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/refunds/CreateRefundContractTest.java
new file mode 100644
index 0000000..9cdb6a9
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/refunds/CreateRefundContractTest.java
@@ -0,0 +1,78 @@
+package com.example.refunds;
+
+import com.example.contract.CreateRefundOperation;
+import com.example.contract.RefundRequests;
+import com.example.contract.restdocs.ProblemV1Docs;
+import com.example.contract.restdocs.RefundV1Docs;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.restdocs.test.autoconfigure.AutoConfigureRestDocs;
+import org.springframework.boot.webmvc.test.autoconfigure.WebMvcTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.document;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * The contract tests of {@code createRefund}: one per response the contract lists, each
+ * checking the response's shape -- its status, its content type and its fields -- against
+ * the contract. Which requests the service rejects, and why, is behaviour, and is tested
+ * in {@link RefundsTest}.
+ */
+// The service itself, not a stand-in: the answers are the ones a client gets.
+@WebMvcTest(RefundController.class)
+@Import({Refunds.class, Orders.class})
+@AutoConfigureRestDocs
+class CreateRefundContractTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Test
+    void anAcceptedRefundIsAnsweredInTheShapeTheContractDescribes() throws Exception {
+        mockMvc.perform(post(CreateRefundOperation.PATH, Orders.PAID_BY_CARD)
+                        .contentType(CreateRefundOperation.REQUEST_CONTENT_TYPE)
+                        .content(RefundRequests.toCard(RefundRequests.SOME_AMOUNT, RefundRequests.SOME_CARD_LAST4)))
+                .andExpect(status().is(CreateRefundOperation.STATUS_201))
+                .andExpect(content().contentType(CreateRefundOperation.CONTENT_TYPE_201))
+                .andDo(document("create-refund", RefundV1Docs.responseFields()));
+    }
+
+    @Test
+    void aRequestTheContractRejectsIsAnsweredWithAProblem() throws Exception {
+        // One example of a request the contract does not allow is enough to see the shape
+        // of the answer. Every other way to be invalid is behaviour: see RefundsTest.
+        mockMvc.perform(post(CreateRefundOperation.PATH, Orders.PAID_BY_CARD)
+                        .contentType(CreateRefundOperation.REQUEST_CONTENT_TYPE)
+                        .content(RefundRequests.toCard(RefundRequests.TOO_LARGE_AN_AMOUNT, RefundRequests.SOME_CARD_LAST4)))
+                .andExpect(status().is(CreateRefundOperation.STATUS_400))
+                .andExpect(content().contentType(CreateRefundOperation.CONTENT_TYPE_400))
+                .andDo(document("create-refund-invalid", ProblemV1Docs.responseFields()));
+    }
+
+    @Test
+    void anUnknownOrderIsAnsweredWithAProblem() throws Exception {
+        mockMvc.perform(post(CreateRefundOperation.PATH, "no-such-order")
+                        .contentType(CreateRefundOperation.REQUEST_CONTENT_TYPE)
+                        .content(RefundRequests.toCard(RefundRequests.SOME_AMOUNT, RefundRequests.SOME_CARD_LAST4)))
+                .andExpect(status().is(CreateRefundOperation.STATUS_404))
+                .andExpect(content().contentType(CreateRefundOperation.CONTENT_TYPE_404))
+                .andDo(document("create-refund-unknown-order", ProblemV1Docs.responseFields()));
+    }
+
+    @Test
+    void aRefundThatBreaksABusinessRuleIsAnsweredWithAProblem() throws Exception {
+        // Valid against the schema, and still refused: the order was paid by card, so its
+        // refund goes back to the card. The schema cannot say that; the 422 is how the
+        // contract tells a client, and its shape is what this test checks.
+        mockMvc.perform(post(CreateRefundOperation.PATH, Orders.PAID_BY_CARD)
+                        .contentType(CreateRefundOperation.REQUEST_CONTENT_TYPE)
+                        .content(RefundRequests.toBankAccount(RefundRequests.SOME_AMOUNT, RefundRequests.SOME_IBAN)))
+                .andExpect(status().is(CreateRefundOperation.STATUS_422))
+                .andExpect(content().contentType(CreateRefundOperation.CONTENT_TYPE_422))
+                .andDo(document("create-refund-rejected", ProblemV1Docs.responseFields()));
+    }
+}
diff --git a/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/refunds/RefundsTest.java b/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/refunds/RefundsTest.java
new file mode 100644
index 0000000..7ada168
--- /dev/null
+++ b/examples/api-only-transcriberj/hand-written-contract-tests/src/test/java/com/example/refunds/RefundsTest.java
@@ -0,0 +1,91 @@
+package com.example.refunds;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * What the service does with a refund request: which ones it refuses, and why. These are
+ * scenarios, one per rule, and they are the place for every way a request can be wrong --
+ * {@link CreateRefundContractTest} needs only one of them to check the shape of the answer.
+ */
+class RefundsTest {
+
+    private final Refunds refunds = new Refunds(new Orders());
+
+    private static RefundRequest toCard(Integer amount, String cardLast4) {
+        return new RefundRequest("card", amount, cardLast4, null);
+    }
+
+    private static RefundRequest toBankAccount(Integer amount, String iban) {
+        return new RefundRequest("bank-account", amount, null, iban);
+    }
+
+    @ParameterizedTest(name = "{0}")
+    @CsvSource(delimiter = '|', nullValues = "null", textBlock = """
+            no amount            | card   | null    | 4242 | null               | amount    | is required
+            a zero amount        | card   | 0       | 4242 | null               | amount    | must be between 1 and 1000000
+            too large an amount  | card   | 1000001 | 4242 | null               | amount    | must be between 1 and 1000000
+            no card digits       | card   | 100     | null | null               | cardLast4 | must be the last four digits of the card
+            three card digits    | card   | 100     | 424  | null               | cardLast4 | must be the last four digits of the card
+            letters for digits   | card   | 100     | abcd | null               | cardLast4 | must be the last four digits of the card
+            no IBAN              | bank-account | 100 | null | null             | iban      | must be an IBAN without spaces
+            an IBAN with spaces  | bank-account | 100 | null | NL91 ABNA 0417 1643 00 | iban | must be an IBAN without spaces
+            no destination       | null   | 100     | 4242 | null               | destination | must be card or bank-account
+            an unknown destination | cash | 100     | 4242 | null               | destination | must be card or bank-account
+            """)
+    void aRequestTheContractDoesNotAllowIsInvalid(String scenario, String destination, Integer amount,
+                                                  String cardLast4, String iban, String field, String message) {
+        Outcome outcome = refunds.refund(Orders.PAID_BY_CARD, new RefundRequest(destination, amount, cardLast4, iban));
+
+        assertThat(outcome).isEqualTo(new Outcome.Invalid(List.of(new FieldError(field, message))));
+    }
+
+    @Test
+    void everyProblemWithARequestIsReportedAtOnce() {
+        Outcome outcome = refunds.refund(Orders.PAID_BY_CARD, toCard(0, "abcd"));
+
+        assertThat(outcome).isEqualTo(new Outcome.Invalid(List.of(
+                new FieldError("amount", "must be between 1 and 1000000"),
+                new FieldError("cardLast4", "must be the last four digits of the card"))));
+    }
+
+    @Test
+    void aRefundGoesBackTheWayTheOrderWasPaid() {
+        assertThat(refunds.refund(Orders.PAID_BY_CARD, toBankAccount(100, "NL91ABNA0417164300")))
+                .isEqualTo(new Outcome.Rejected("The order was paid by card, so its refunds go back to the card."));
+        assertThat(refunds.refund(Orders.PAID_BY_BANK_TRANSFER, toCard(100, "4242")))
+                .isEqualTo(new Outcome.Rejected(
+                        "The order was paid by bank-account, so its refunds go back to the bank-account."));
+    }
+
+    @Test
+    void refundsNeverAddUpToMoreThanTheOrder() {
+        assertThat(refunds.refund(Orders.PAID_BY_CARD, toCard(3000, "4242"))).isInstanceOf(Outcome.Accepted.class);
+
+        assertThat(refunds.refund(Orders.PAID_BY_CARD, toCard(2500, "4242")))
+                .isEqualTo(new Outcome.Rejected("Only 2000 of the order is left to refund."));
+        assertThat(refunds.refund(Orders.PAID_BY_CARD, toCard(2000, "4242"))).isInstanceOf(Outcome.Accepted.class);
+    }
+
+    @Test
+    void anAcceptedRefundSaysWhatWasRefundedAndWhere() {
+        Outcome outcome = refunds.refund(Orders.PAID_BY_BANK_TRANSFER, toBankAccount(1250, "NL91ABNA0417164300"));
+
+        assertThat(outcome).isInstanceOfSatisfying(Outcome.Accepted.class, accepted -> {
+            assertThat(accepted.refund().id()).isNotBlank();
+            assertThat(accepted.refund().orderId()).isEqualTo(Orders.PAID_BY_BANK_TRANSFER);
+            assertThat(accepted.refund().amount()).isEqualTo(1250);
+            assertThat(accepted.refund().destination()).isEqualTo("bank-account");
+        });
+    }
+
+    @Test
+    void anOrderThatDoesNotExistCannotBeRefunded() {
+        assertThat(refunds.refund("no-such-order", toCard(100, "4242"))).isEqualTo(new Outcome.UnknownOrder());
+    }
+}