From c05e542923b399e45dc7295744c07bd3a8d5f37d Mon Sep 17 00:00:00 2001
From: Tobias Brugger <tobias.brugger@bfh.ch>
Date: Thu, 10 Jul 2025 16:40:54 +0200
Subject: [PATCH 1/6] feat: add ability to map model names in the URLS/JSON
 response

primary use case is pluralization ie. model User exposed as /users
it is also  useful in case the internal and external names should be different.

TODO: adapt openapi plugin
---
 packages/server/src/api/rest/index.ts | 128 ++++++++++++++++++--------
 1 file changed, 91 insertions(+), 37 deletions(-)

diff --git a/packages/server/src/api/rest/index.ts b/packages/server/src/api/rest/index.ts
index 59558be98..ec7606769 100644
--- a/packages/server/src/api/rest/index.ts
+++ b/packages/server/src/api/rest/index.ts
@@ -50,6 +50,9 @@ export type Options = {
      * it should be included in the charset.
      */
     urlSegmentCharset?: string;
+
+    modelNameMapping?: Record<string, string>;
+    prefix?: string;
 };
 
 type RelationshipInfo = {
@@ -65,6 +68,19 @@ type ModelInfo = {
     relationships: Record<string, RelationshipInfo>;
 };
 
+type Match = {
+    type: string;
+    id: string;
+    relationship: string;
+};
+
+enum UrlPatterns {
+    SINGLE = 'single',
+    FETCH_RELATIONSHIP = 'fetchRelationship',
+    RELATIONSHIP = 'relationship',
+    COLLECTION = 'collection',
+}
+
 class InvalidValueError extends Error {
     constructor(public readonly message: string) {
         super(message);
@@ -220,29 +236,60 @@ class RequestHandler extends APIHandlerBase {
     // divider used to separate compound ID fields
     private idDivider;
 
-    private urlPatterns;
+    private urlPatternMap: Record<UrlPatterns, UrlPattern>;
+    private modelNameMapping: Record<string, string>;
+    private reverseModelNameMapping: Record<string, string>;
+    private prefix: string | undefined;
 
     constructor(private readonly options: Options) {
         super();
         this.idDivider = options.idDivider ?? prismaIdDivider;
         const segmentCharset = options.urlSegmentCharset ?? 'a-zA-Z0-9-_~ %';
-        this.urlPatterns = this.buildUrlPatterns(this.idDivider, segmentCharset);
+
+        this.prefix = options.prefix;
+        this.modelNameMapping = options.modelNameMapping ?? {};
+        this.reverseModelNameMapping = Object.fromEntries(
+            Object.entries(this.modelNameMapping).map(([k, v]) => [v, k])
+        );
+        this.urlPatternMap = this.buildUrlPatternMap(segmentCharset);
     }
 
-    buildUrlPatterns(idDivider: string, urlSegmentNameCharset: string) {
+    private buildUrlPatternMap(urlSegmentNameCharset: string): Record<UrlPatterns, UrlPattern> {
         const options = { segmentValueCharset: urlSegmentNameCharset };
+
+        const buildPath = (segments: string[]) => {
+            return (this.prefix ?? '') + '/' + segments.join('/');
+        };
+
         return {
-            // collection operations
-            collection: new UrlPattern('/:type', options),
-            // single resource operations
-            single: new UrlPattern('/:type/:id', options),
-            // related entity fetching
-            fetchRelationship: new UrlPattern('/:type/:id/:relationship', options),
-            // relationship operations
-            relationship: new UrlPattern('/:type/:id/relationships/:relationship', options),
+            [UrlPatterns.SINGLE]: new UrlPattern(buildPath([':type', ':id']), options),
+            [UrlPatterns.FETCH_RELATIONSHIP]: new UrlPattern(buildPath([':type', ':id', ':relationship']), options),
+            [UrlPatterns.RELATIONSHIP]: new UrlPattern(
+                buildPath([':type', ':id', 'relationships', ':relationship']),
+                options
+            ),
+            [UrlPatterns.COLLECTION]: new UrlPattern(buildPath([':type']), options),
         };
     }
 
+    private reverseModelNameMap(type: string): string {
+        return this.reverseModelNameMapping[type] ?? type;
+    }
+
+    private matchUrlPattern(path: string, routeType: UrlPatterns): Match {
+        const pattern = this.urlPatternMap[routeType];
+        if (!pattern) {
+            throw new InvalidValueError(`Unknown route type: ${routeType}`);
+        }
+
+        const match = pattern.match(path);
+        if (match) {
+            match.type = this.modelNameMapping[match.type] ?? match.type;
+            match.relationship = this.modelNameMapping[match.relationship] ?? match.relationship;
+        }
+        return match;
+    }
+
     async handleRequest({
         prisma,
         method,
@@ -274,19 +321,18 @@ class RequestHandler extends APIHandlerBase {
         try {
             switch (method) {
                 case 'GET': {
-                    let match = this.urlPatterns.single.match(path);
+                    let match = this.matchUrlPattern(path, UrlPatterns.SINGLE);
                     if (match) {
                         // single resource read
                         return await this.processSingleRead(prisma, match.type, match.id, query);
                     }
-
-                    match = this.urlPatterns.fetchRelationship.match(path);
+                    match = this.matchUrlPattern(path, UrlPatterns.FETCH_RELATIONSHIP);
                     if (match) {
                         // fetch related resource(s)
                         return await this.processFetchRelated(prisma, match.type, match.id, match.relationship, query);
                     }
 
-                    match = this.urlPatterns.relationship.match(path);
+                    match = this.matchUrlPattern(path, UrlPatterns.RELATIONSHIP);
                     if (match) {
                         // read relationship
                         return await this.processReadRelationship(
@@ -298,7 +344,7 @@ class RequestHandler extends APIHandlerBase {
                         );
                     }
 
-                    match = this.urlPatterns.collection.match(path);
+                    match = this.matchUrlPattern(path, UrlPatterns.COLLECTION);
                     if (match) {
                         // collection read
                         return await this.processCollectionRead(prisma, match.type, query);
@@ -311,8 +357,7 @@ class RequestHandler extends APIHandlerBase {
                     if (!requestBody) {
                         return this.makeError('invalidPayload');
                     }
-
-                    let match = this.urlPatterns.collection.match(path);
+                    let match = this.matchUrlPattern(path, UrlPatterns.COLLECTION);
                     if (match) {
                         const body = requestBody as any;
                         const upsertMeta = this.upsertMetaSchema.safeParse(body);
@@ -338,8 +383,7 @@ class RequestHandler extends APIHandlerBase {
                             );
                         }
                     }
-
-                    match = this.urlPatterns.relationship.match(path);
+                    match = this.matchUrlPattern(path, UrlPatterns.RELATIONSHIP);
                     if (match) {
                         // relationship creation (collection relationship only)
                         return await this.processRelationshipCRUD(
@@ -362,8 +406,7 @@ class RequestHandler extends APIHandlerBase {
                     if (!requestBody) {
                         return this.makeError('invalidPayload');
                     }
-
-                    let match = this.urlPatterns.single.match(path);
+                    let match = this.matchUrlPattern(path, UrlPatterns.SINGLE);
                     if (match) {
                         // resource update
                         return await this.processUpdate(
@@ -376,8 +419,7 @@ class RequestHandler extends APIHandlerBase {
                             zodSchemas
                         );
                     }
-
-                    match = this.urlPatterns.relationship.match(path);
+                    match = this.matchUrlPattern(path, UrlPatterns.RELATIONSHIP);
                     if (match) {
                         // relationship update
                         return await this.processRelationshipCRUD(
@@ -395,13 +437,13 @@ class RequestHandler extends APIHandlerBase {
                 }
 
                 case 'DELETE': {
-                    let match = this.urlPatterns.single.match(path);
+                    let match = this.matchUrlPattern(path, UrlPatterns.SINGLE);
                     if (match) {
                         // resource deletion
                         return await this.processDelete(prisma, match.type, match.id);
                     }
 
-                    match = this.urlPatterns.relationship.match(path);
+                    match = this.matchUrlPattern(path, UrlPatterns.RELATIONSHIP);
                     if (match) {
                         // relationship deletion (collection relationship only)
                         return await this.processRelationshipCRUD(
@@ -531,11 +573,13 @@ class RequestHandler extends APIHandlerBase {
         }
 
         if (entity?.[relationship]) {
+            const mappedType = this.reverseModelNameMap(type);
+            const mappedRelationship = this.reverseModelNameMap(relationship);
             return {
                 status: 200,
                 body: await this.serializeItems(relationInfo.type, entity[relationship], {
                     linkers: {
-                        document: new Linker(() => this.makeLinkUrl(`/${type}/${resourceId}/${relationship}`)),
+                        document: new Linker(() => this.makeLinkUrl(`/${mappedType}/${resourceId}/${mappedRelationship}`)),
                         paginator,
                     },
                     include,
@@ -582,11 +626,13 @@ class RequestHandler extends APIHandlerBase {
         }
 
         const entity: any = await prisma[type].findUnique(args);
+        const mappedType = this.reverseModelNameMap(type);
+        const mappedRelationship = this.reverseModelNameMap(relationship);
 
         if (entity?._count?.[relationship] !== undefined) {
             // build up paginator
             const total = entity?._count?.[relationship] as number;
-            const url = this.makeNormalizedUrl(`/${type}/${resourceId}/relationships/${relationship}`, query);
+            const url = this.makeNormalizedUrl(`/${mappedType}/${resourceId}/relationships/${mappedRelationship}`, query);
             const { offset, limit } = this.getPagination(query);
             paginator = this.makePaginator(url, offset, limit, total);
         }
@@ -595,7 +641,7 @@ class RequestHandler extends APIHandlerBase {
             const serialized: any = await this.serializeItems(relationInfo.type, entity[relationship], {
                 linkers: {
                     document: new Linker(() =>
-                        this.makeLinkUrl(`/${type}/${resourceId}/relationships/${relationship}`)
+                        this.makeLinkUrl(`/${mappedType}/${resourceId}/relationships/${mappedRelationship}`)
                     ),
                     paginator,
                 },
@@ -680,7 +726,8 @@ class RequestHandler extends APIHandlerBase {
             ]);
             const total = count as number;
 
-            const url = this.makeNormalizedUrl(`/${type}`, query);
+            const mappedType = this.reverseModelNameMap(type);
+            const url = this.makeNormalizedUrl(`/${mappedType}`, query);
             const options: Partial<SerializerOptions> = {
                 include,
                 linkers: {
@@ -1009,9 +1056,12 @@ class RequestHandler extends APIHandlerBase {
 
         const entity: any = await prisma[type].update(updateArgs);
 
+        const mappedType = this.reverseModelNameMap(type);
+        const mappedRelationship = this.reverseModelNameMap(relationship);
+
         const serialized: any = await this.serializeItems(relationInfo.type, entity[relationship], {
             linkers: {
-                document: new Linker(() => this.makeLinkUrl(`/${type}/${resourceId}/relationships/${relationship}`)),
+                document: new Linker(() => this.makeLinkUrl(`/${mappedType}/${resourceId}/relationships/${mappedRelationship}`)),
             },
             onlyIdentifier: true,
         });
@@ -1147,7 +1197,7 @@ class RequestHandler extends APIHandlerBase {
     }
 
     private makeLinkUrl(path: string) {
-        return `${this.options.endpoint}${path}`;
+        return `${this.options.endpoint}${this.prefix}${path}`;
     }
 
     private buildSerializers(modelMeta: ModelMeta) {
@@ -1156,6 +1206,7 @@ class RequestHandler extends APIHandlerBase {
 
         for (const model of Object.keys(modelMeta.models)) {
             const ids = getIdFields(modelMeta, model);
+            const mappedModel = this.reverseModelNameMap(model);
 
             if (ids.length < 1) {
                 continue;
@@ -1163,8 +1214,8 @@ class RequestHandler extends APIHandlerBase {
 
             const linker = new Linker((items) =>
                 Array.isArray(items)
-                    ? this.makeLinkUrl(`/${model}`)
-                    : this.makeLinkUrl(`/${model}/${this.getId(model, items, modelMeta)}`)
+                    ? this.makeLinkUrl(`/${mappedModel}`)
+                    : this.makeLinkUrl(`/${mappedModel}/${this.getId(model, items, modelMeta)}`)
             );
             linkers[model] = linker;
 
@@ -1208,6 +1259,9 @@ class RequestHandler extends APIHandlerBase {
                 }
                 const fieldIds = getIdFields(modelMeta, fieldMeta.type);
                 if (fieldIds.length > 0) {
+                    const mappedModel = this.reverseModelNameMap(model);
+                    const mappedField = this.reverseModelNameMap(field);
+
                     const relator = new Relator(
                         async (data) => {
                             return (data as any)[field];
@@ -1218,16 +1272,16 @@ class RequestHandler extends APIHandlerBase {
                             linkers: {
                                 related: new Linker((primary) =>
                                     this.makeLinkUrl(
-                                        `/${lowerCaseFirst(model)}/${this.getId(model, primary, modelMeta)}/${field}`
+                                        `/${lowerCaseFirst(mappedModel)}/${this.getId(model, primary, modelMeta)}/${mappedField}`
                                     )
                                 ),
                                 relationship: new Linker((primary) =>
                                     this.makeLinkUrl(
-                                        `/${lowerCaseFirst(model)}/${this.getId(
+                                        `/${lowerCaseFirst(mappedModel)}/${this.getId(
                                             model,
                                             primary,
                                             modelMeta
-                                        )}/relationships/${field}`
+                                        )}/relationships/${mappedField}`
                                     )
                                 ),
                             },

From b9899318f8d67516d300eb43f5ad8a858891acae Mon Sep 17 00:00:00 2001
From: ymc9 <104139426+ymc9@users.noreply.github.com>
Date: Wed, 16 Jul 2025 11:07:41 +0800
Subject: [PATCH 2/6] add a sample test case

---
 packages/server/tests/api/rest.test.ts | 61 ++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/packages/server/tests/api/rest.test.ts b/packages/server/tests/api/rest.test.ts
index 642b3fcf8..2a5d96ed2 100644
--- a/packages/server/tests/api/rest.test.ts
+++ b/packages/server/tests/api/rest.test.ts
@@ -3013,4 +3013,65 @@ describe('REST server tests', () => {
             expect(r.body.data.attributes.enabled).toBe(false);
         });
     });
+
+    describe('REST server tests - model name mapping', () => {
+        const schema = `
+    model User {
+        id String @id @default(cuid())
+        name String
+        posts Post[]
+    }
+    
+    model Post {
+        id String @id @default(cuid())
+        title String
+        author User? @relation(fields: [authorId], references: [id])
+        authorId String?
+    }
+    `;
+        beforeAll(async () => {
+            const params = await loadSchema(schema);
+            prisma = params.prisma;
+            zodSchemas = params.zodSchemas;
+            modelMeta = params.modelMeta;
+
+            const _handler = makeHandler({
+                endpoint: 'http://localhost/api',
+                modelNameMapping: {
+                    myUser: 'user',
+                    myPost: 'post',
+                },
+            });
+            handler = (args) =>
+                _handler({ ...args, zodSchemas, modelMeta, url: new URL(`http://localhost/${args.path}`) });
+        });
+
+        it('works with name mapping', async () => {
+            // using original model name
+            await expect(
+                handler({
+                    method: 'post',
+                    path: '/user',
+                    query: {},
+                    requestBody: { data: { type: 'user', attributes: { name: 'User1' } } },
+                    prisma,
+                })
+            ).resolves.toMatchObject({
+                status: 400,
+            });
+
+            // using mapped model name
+            await expect(
+                handler({
+                    method: 'post',
+                    path: '/myUser',
+                    query: {},
+                    requestBody: { data: { type: 'user', attributes: { name: 'User1' } } },
+                    prisma,
+                })
+            ).resolves.toMatchObject({
+                status: 201,
+            });
+        });
+    });
 });

From 7d03fdbf75fd98213b81d72e0022b2886d152687 Mon Sep 17 00:00:00 2001
From: Tobias Brugger <tobias.brugger@bfh.ch>
Date: Thu, 10 Jul 2025 16:40:54 +0200
Subject: [PATCH 3/6] feat: add ability to map model names in the URLS/JSON
 response

primary use case is pluralization ie. model User exposed as /users
it is also  useful in case the internal and external names should be different.

TODO: adapt openapi plugin
---
 packages/server/src/api/rest/index.ts | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/packages/server/src/api/rest/index.ts b/packages/server/src/api/rest/index.ts
index ec7606769..06e63826b 100644
--- a/packages/server/src/api/rest/index.ts
+++ b/packages/server/src/api/rest/index.ts
@@ -52,7 +52,6 @@ export type Options = {
     urlSegmentCharset?: string;
 
     modelNameMapping?: Record<string, string>;
-    prefix?: string;
 };
 
 type RelationshipInfo = {
@@ -239,14 +238,12 @@ class RequestHandler extends APIHandlerBase {
     private urlPatternMap: Record<UrlPatterns, UrlPattern>;
     private modelNameMapping: Record<string, string>;
     private reverseModelNameMapping: Record<string, string>;
-    private prefix: string | undefined;
 
     constructor(private readonly options: Options) {
         super();
         this.idDivider = options.idDivider ?? prismaIdDivider;
         const segmentCharset = options.urlSegmentCharset ?? 'a-zA-Z0-9-_~ %';
 
-        this.prefix = options.prefix;
         this.modelNameMapping = options.modelNameMapping ?? {};
         this.reverseModelNameMapping = Object.fromEntries(
             Object.entries(this.modelNameMapping).map(([k, v]) => [v, k])
@@ -258,7 +255,7 @@ class RequestHandler extends APIHandlerBase {
         const options = { segmentValueCharset: urlSegmentNameCharset };
 
         const buildPath = (segments: string[]) => {
-            return (this.prefix ?? '') + '/' + segments.join('/');
+            return '/' + segments.join('/');
         };
 
         return {
@@ -285,7 +282,6 @@ class RequestHandler extends APIHandlerBase {
         const match = pattern.match(path);
         if (match) {
             match.type = this.modelNameMapping[match.type] ?? match.type;
-            match.relationship = this.modelNameMapping[match.relationship] ?? match.relationship;
         }
         return match;
     }
@@ -574,12 +570,11 @@ class RequestHandler extends APIHandlerBase {
 
         if (entity?.[relationship]) {
             const mappedType = this.reverseModelNameMap(type);
-            const mappedRelationship = this.reverseModelNameMap(relationship);
             return {
                 status: 200,
                 body: await this.serializeItems(relationInfo.type, entity[relationship], {
                     linkers: {
-                        document: new Linker(() => this.makeLinkUrl(`/${mappedType}/${resourceId}/${mappedRelationship}`)),
+                        document: new Linker(() => this.makeLinkUrl(`/${mappedType}/${resourceId}/${relationship}`)),
                         paginator,
                     },
                     include,
@@ -627,12 +622,11 @@ class RequestHandler extends APIHandlerBase {
 
         const entity: any = await prisma[type].findUnique(args);
         const mappedType = this.reverseModelNameMap(type);
-        const mappedRelationship = this.reverseModelNameMap(relationship);
 
         if (entity?._count?.[relationship] !== undefined) {
             // build up paginator
             const total = entity?._count?.[relationship] as number;
-            const url = this.makeNormalizedUrl(`/${mappedType}/${resourceId}/relationships/${mappedRelationship}`, query);
+            const url = this.makeNormalizedUrl(`/${mappedType}/${resourceId}/relationships/${relationship}`, query);
             const { offset, limit } = this.getPagination(query);
             paginator = this.makePaginator(url, offset, limit, total);
         }
@@ -641,7 +635,7 @@ class RequestHandler extends APIHandlerBase {
             const serialized: any = await this.serializeItems(relationInfo.type, entity[relationship], {
                 linkers: {
                     document: new Linker(() =>
-                        this.makeLinkUrl(`/${mappedType}/${resourceId}/relationships/${mappedRelationship}`)
+                        this.makeLinkUrl(`/${mappedType}/${resourceId}/relationships/${relationship}`)
                     ),
                     paginator,
                 },
@@ -1057,11 +1051,12 @@ class RequestHandler extends APIHandlerBase {
         const entity: any = await prisma[type].update(updateArgs);
 
         const mappedType = this.reverseModelNameMap(type);
-        const mappedRelationship = this.reverseModelNameMap(relationship);
 
         const serialized: any = await this.serializeItems(relationInfo.type, entity[relationship], {
             linkers: {
-                document: new Linker(() => this.makeLinkUrl(`/${mappedType}/${resourceId}/relationships/${mappedRelationship}`)),
+                document: new Linker(() =>
+                    this.makeLinkUrl(`/${mappedType}/${resourceId}/relationships/${relationship}`)
+                ),
             },
             onlyIdentifier: true,
         });
@@ -1197,7 +1192,7 @@ class RequestHandler extends APIHandlerBase {
     }
 
     private makeLinkUrl(path: string) {
-        return `${this.options.endpoint}${this.prefix}${path}`;
+        return `${this.options.endpoint}${path}`;
     }
 
     private buildSerializers(modelMeta: ModelMeta) {
@@ -1260,7 +1255,6 @@ class RequestHandler extends APIHandlerBase {
                 const fieldIds = getIdFields(modelMeta, fieldMeta.type);
                 if (fieldIds.length > 0) {
                     const mappedModel = this.reverseModelNameMap(model);
-                    const mappedField = this.reverseModelNameMap(field);
 
                     const relator = new Relator(
                         async (data) => {
@@ -1272,7 +1266,7 @@ class RequestHandler extends APIHandlerBase {
                             linkers: {
                                 related: new Linker((primary) =>
                                     this.makeLinkUrl(
-                                        `/${lowerCaseFirst(mappedModel)}/${this.getId(model, primary, modelMeta)}/${mappedField}`
+                                        `/${lowerCaseFirst(model)}/${this.getId(model, primary, modelMeta)}/${field}`
                                     )
                                 ),
                                 relationship: new Linker((primary) =>
@@ -1281,7 +1275,7 @@ class RequestHandler extends APIHandlerBase {
                                             model,
                                             primary,
                                             modelMeta
-                                        )}/relationships/${mappedField}`
+                                        )}/relationships/${field}`
                                     )
                                 ),
                             },

From 92fdd9a508b70a952aa510f7378141ae09b01323 Mon Sep 17 00:00:00 2001
From: Lukas Kahwe Smith <smith@pooteeweet.org>
Date: Wed, 16 Jul 2025 13:35:01 +0200
Subject: [PATCH 4/6] update openapi plugin

---
 .../plugins/openapi/src/rest-generator.ts     | 21 +++++++++++++-----
 packages/server/src/api/rest/index.ts         | 22 +++++++++----------
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/packages/plugins/openapi/src/rest-generator.ts b/packages/plugins/openapi/src/rest-generator.ts
index 5a1344c2b..30e2607ae 100644
--- a/packages/plugins/openapi/src/rest-generator.ts
+++ b/packages/plugins/openapi/src/rest-generator.ts
@@ -44,6 +44,7 @@ type Policies = ReturnType<typeof analyzePolicies>;
  */
 export class RESTfulOpenAPIGenerator extends OpenAPIGeneratorBase {
     private warnings: string[] = [];
+    private modelNameMapping: Record<string, string>;
 
     constructor(protected model: Model, protected options: PluginOptions, protected dmmf: DMMF.Document) {
         super(model, options, dmmf);
@@ -51,6 +52,8 @@ export class RESTfulOpenAPIGenerator extends OpenAPIGeneratorBase {
         if (this.options.omitInputDetails !== undefined) {
             throw new PluginError(name, '"omitInputDetails" option is not supported for "rest" flavor');
         }
+
+        this.modelNameMapping = this.getOption('modelNameMapping', {} as Record<string, string>);
     }
 
     generate() {
@@ -126,6 +129,10 @@ export class RESTfulOpenAPIGenerator extends OpenAPIGeneratorBase {
         return result;
     }
 
+    private mapModelName(modelName: string): string {
+        return this.modelNameMapping[modelName] ?? modelName;
+    }
+
     private generatePathsForModel(model: DMMF.Model, zmodel: DataModel): OAPI.PathItemObject | undefined {
         const result: Record<string, OAPI.PathItemObject> = {};
 
@@ -139,9 +146,11 @@ export class RESTfulOpenAPIGenerator extends OpenAPIGeneratorBase {
 
         const resourceMeta = getModelResourceMeta(zmodel);
 
+        const modelName = this.mapModelName(model.name);
+
         // GET /resource
         // POST /resource
-        result[`${prefix}/${lowerCaseFirst(model.name)}`] = {
+        result[`${prefix}/${lowerCaseFirst(modelName)}`] = {
             get: this.makeResourceList(zmodel, policies, resourceMeta),
             post: this.makeResourceCreate(zmodel, policies, resourceMeta),
         };
@@ -150,10 +159,10 @@ export class RESTfulOpenAPIGenerator extends OpenAPIGeneratorBase {
         // PUT /resource/{id}
         // PATCH /resource/{id}
         // DELETE /resource/{id}
-        result[`${prefix}/${lowerCaseFirst(model.name)}/{id}`] = {
+        result[`${prefix}/${lowerCaseFirst(modelName)}/{id}`] = {
             get: this.makeResourceFetch(zmodel, policies, resourceMeta),
-            put: this.makeResourceUpdate(zmodel, policies, `update-${model.name}-put`, resourceMeta),
-            patch: this.makeResourceUpdate(zmodel, policies, `update-${model.name}-patch`, resourceMeta),
+            put: this.makeResourceUpdate(zmodel, policies, `update-${modelName}-put`, resourceMeta),
+            patch: this.makeResourceUpdate(zmodel, policies, `update-${modelName}-patch`, resourceMeta),
             delete: this.makeResourceDelete(zmodel, policies, resourceMeta),
         };
 
@@ -165,14 +174,14 @@ export class RESTfulOpenAPIGenerator extends OpenAPIGeneratorBase {
             }
 
             // GET /resource/{id}/{relationship}
-            const relatedDataPath = `${prefix}/${lowerCaseFirst(model.name)}/{id}/${field.name}`;
+            const relatedDataPath = `${prefix}/${lowerCaseFirst(modelName)}/{id}/${field.name}`;
             let container = result[relatedDataPath];
             if (!container) {
                 container = result[relatedDataPath] = {};
             }
             container.get = this.makeRelatedFetch(zmodel, field, relationDecl, resourceMeta);
 
-            const relationshipPath = `${prefix}/${lowerCaseFirst(model.name)}/{id}/relationships/${field.name}`;
+            const relationshipPath = `${prefix}/${lowerCaseFirst(modelName)}/{id}/relationships/${field.name}`;
             container = result[relationshipPath];
             if (!container) {
                 container = result[relationshipPath] = {};
diff --git a/packages/server/src/api/rest/index.ts b/packages/server/src/api/rest/index.ts
index 06e63826b..653ec7680 100644
--- a/packages/server/src/api/rest/index.ts
+++ b/packages/server/src/api/rest/index.ts
@@ -245,9 +245,7 @@ class RequestHandler extends APIHandlerBase {
         const segmentCharset = options.urlSegmentCharset ?? 'a-zA-Z0-9-_~ %';
 
         this.modelNameMapping = options.modelNameMapping ?? {};
-        this.reverseModelNameMapping = Object.fromEntries(
-            Object.entries(this.modelNameMapping).map(([k, v]) => [v, k])
-        );
+        this.reverseModelNameMapping = Object.fromEntries(Object.entries(this.modelNameMapping).map(([k, v]) => [v, k]));
         this.urlPatternMap = this.buildUrlPatternMap(segmentCharset);
     }
 
@@ -269,8 +267,8 @@ class RequestHandler extends APIHandlerBase {
         };
     }
 
-    private reverseModelNameMap(type: string): string {
-        return this.reverseModelNameMapping[type] ?? type;
+    private mapModelName(modelName: string): string {
+        return this.modelNameMapping[modelName] ?? modelName;
     }
 
     private matchUrlPattern(path: string, routeType: UrlPatterns): Match {
@@ -281,7 +279,7 @@ class RequestHandler extends APIHandlerBase {
 
         const match = pattern.match(path);
         if (match) {
-            match.type = this.modelNameMapping[match.type] ?? match.type;
+            match.type = this.reverseModelNameMapping[match.type] ?? match.type;
         }
         return match;
     }
@@ -569,7 +567,7 @@ class RequestHandler extends APIHandlerBase {
         }
 
         if (entity?.[relationship]) {
-            const mappedType = this.reverseModelNameMap(type);
+            const mappedType = this.mapModelName(type);
             return {
                 status: 200,
                 body: await this.serializeItems(relationInfo.type, entity[relationship], {
@@ -621,7 +619,7 @@ class RequestHandler extends APIHandlerBase {
         }
 
         const entity: any = await prisma[type].findUnique(args);
-        const mappedType = this.reverseModelNameMap(type);
+        const mappedType = this.mapModelName(type);
 
         if (entity?._count?.[relationship] !== undefined) {
             // build up paginator
@@ -720,7 +718,7 @@ class RequestHandler extends APIHandlerBase {
             ]);
             const total = count as number;
 
-            const mappedType = this.reverseModelNameMap(type);
+            const mappedType = this.mapModelName(type);
             const url = this.makeNormalizedUrl(`/${mappedType}`, query);
             const options: Partial<SerializerOptions> = {
                 include,
@@ -1050,7 +1048,7 @@ class RequestHandler extends APIHandlerBase {
 
         const entity: any = await prisma[type].update(updateArgs);
 
-        const mappedType = this.reverseModelNameMap(type);
+        const mappedType = this.mapModelName(type);
 
         const serialized: any = await this.serializeItems(relationInfo.type, entity[relationship], {
             linkers: {
@@ -1201,7 +1199,7 @@ class RequestHandler extends APIHandlerBase {
 
         for (const model of Object.keys(modelMeta.models)) {
             const ids = getIdFields(modelMeta, model);
-            const mappedModel = this.reverseModelNameMap(model);
+            const mappedModel = this.mapModelName(model);
 
             if (ids.length < 1) {
                 continue;
@@ -1254,7 +1252,7 @@ class RequestHandler extends APIHandlerBase {
                 }
                 const fieldIds = getIdFields(modelMeta, fieldMeta.type);
                 if (fieldIds.length > 0) {
-                    const mappedModel = this.reverseModelNameMap(model);
+                    const mappedModel = this.mapModelName(model);
 
                     const relator = new Relator(
                         async (data) => {

From 1c32b85a7702248113a0281f2c660de1f7c0c4c8 Mon Sep 17 00:00:00 2001
From: Lukas Kahwe Smith <smith@pooteeweet.org>
Date: Thu, 17 Jul 2025 11:30:35 +0200
Subject: [PATCH 5/6] ensure model name has the first char lower cased

---
 packages/server/src/api/rest/index.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/packages/server/src/api/rest/index.ts b/packages/server/src/api/rest/index.ts
index 653ec7680..e5dc9be9c 100644
--- a/packages/server/src/api/rest/index.ts
+++ b/packages/server/src/api/rest/index.ts
@@ -245,7 +245,12 @@ class RequestHandler extends APIHandlerBase {
         const segmentCharset = options.urlSegmentCharset ?? 'a-zA-Z0-9-_~ %';
 
         this.modelNameMapping = options.modelNameMapping ?? {};
-        this.reverseModelNameMapping = Object.fromEntries(Object.entries(this.modelNameMapping).map(([k, v]) => [v, k]));
+        this.modelNameMapping = Object.fromEntries(
+            Object.entries(this.modelNameMapping).map(([k, v]) => [lowerCaseFirst(k), v])
+        );
+        this.reverseModelNameMapping = Object.fromEntries(
+            Object.entries(this.modelNameMapping).map(([k, v]) => [v, k])
+        );
         this.urlPatternMap = this.buildUrlPatternMap(segmentCharset);
     }
 

From 5bc08d613b077229e556c923be6ff4f2d42e0e2d Mon Sep 17 00:00:00 2001
From: Lukas Kahwe Smith <smith@pooteeweet.org>
Date: Fri, 18 Jul 2025 11:20:01 +0200
Subject: [PATCH 6/6] update tests, explicitly check for old path when using
 model name mapping

---
 packages/server/src/api/rest/index.ts  | 17 ++++++++++++++---
 packages/server/tests/api/rest.test.ts |  4 ++--
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/packages/server/src/api/rest/index.ts b/packages/server/src/api/rest/index.ts
index e5dc9be9c..75196b1ac 100644
--- a/packages/server/src/api/rest/index.ts
+++ b/packages/server/src/api/rest/index.ts
@@ -276,16 +276,27 @@ class RequestHandler extends APIHandlerBase {
         return this.modelNameMapping[modelName] ?? modelName;
     }
 
-    private matchUrlPattern(path: string, routeType: UrlPatterns): Match {
+    private matchUrlPattern(path: string, routeType: UrlPatterns): Match | undefined {
         const pattern = this.urlPatternMap[routeType];
         if (!pattern) {
             throw new InvalidValueError(`Unknown route type: ${routeType}`);
         }
 
         const match = pattern.match(path);
-        if (match) {
-            match.type = this.reverseModelNameMapping[match.type] ?? match.type;
+        if (!match) {
+            return;
+        }
+
+        if (match.type in this.modelNameMapping) {
+            throw new InvalidValueError(
+                `use the mapped model name: ${this.modelNameMapping[match.type]} and not ${match.type}`
+            );
         }
+
+        if (match.type in this.reverseModelNameMapping) {
+            match.type = this.reverseModelNameMapping[match.type];
+        }
+
         return match;
     }
 
diff --git a/packages/server/tests/api/rest.test.ts b/packages/server/tests/api/rest.test.ts
index 2a5d96ed2..264a97e41 100644
--- a/packages/server/tests/api/rest.test.ts
+++ b/packages/server/tests/api/rest.test.ts
@@ -3038,8 +3038,8 @@ describe('REST server tests', () => {
             const _handler = makeHandler({
                 endpoint: 'http://localhost/api',
                 modelNameMapping: {
-                    myUser: 'user',
-                    myPost: 'post',
+                    user: 'myUser',
+                    post: 'myPost',
                 },
             });
             handler = (args) =>