diff --git a/api/doc/agg-query/schema.json b/api/doc/agg-query/schema.json
index 14db247..9056518 100644
--- a/api/doc/agg-query/schema.json
+++ b/api/doc/agg-query/schema.json
@@ -39,11 +39,16 @@
         {"type": "array", "items": {"type": "string"}, "minItems": 1}
       ]
     },
+    "refererCategory": {
+      "oneOf": [
+        {"type": "string"},
+        {"type": "array", "items": {"type": "string"}, "minItems": 1}
+      ]
+    },
     "topicId": {"type": "string"},
-    "processingId": {"type": "string"},
     "split": {
       "type": "array",
-      "items": { "type": "string", "enum": ["day", "refererApp", "processing", "resource", "refererDomain", "userClass"] }
+      "items": { "type": "string", "enum": ["day", "resource", "userClass", "refererApp", "refererDomain", "refererCategory"] }
     }
   }
 } 
\ No newline at end of file
diff --git a/api/doc/agg-result/schema.json b/api/doc/agg-result/schema.json
index 3583f03..8273dd9 100644
--- a/api/doc/agg-result/schema.json
+++ b/api/doc/agg-result/schema.json
@@ -35,9 +35,9 @@
           "additionalProperties": false,
           "properties": {
             "refererApp": {"type": "string"},
-            "processing": {"$ref": "https://github.com/data-fair/metrics/daily-api-metric#/$defs/processing"},
             "resource": {"$ref": "https://github.com/data-fair/metrics/daily-api-metric#/$defs/resourceDef"},
             "refererDomain": {"type": "string"},
+            "refererCategory": {"type": "string"},
             "userClass": {"$ref": "https://github.com/data-fair/metrics/daily-api-metric#/$defs/userClass"}
           }
         },
diff --git a/api/src/daily-api-metrics/service.ts b/api/src/daily-api-metrics/service.ts
index 7abc8ea..5d320f6 100644
--- a/api/src/daily-api-metrics/service.ts
+++ b/api/src/daily-api-metrics/service.ts
@@ -43,7 +43,11 @@ export const agg = async (account: Account, query: AggQuery) => {
   if (query.resourceType) $match['resource.type'] = query.resourceType
   if (query.resourceId) $match['resource.id'] = Array.isArray(query.resourceId) ? { $in: query.resourceId } : query.resourceId
   if (query.refererDomain) $match.refererDomain = Array.isArray(query.refererDomain) ? { $in: query.refererDomain } : query.refererDomain
-  if (query.processingId) $match['processing._id'] = query.processingId
+  if (query.refererCategory) {
+    const refererCategories = Array.isArray(query.refererCategory) ? query.refererCategory : [query.refererCategory]
+    // legacy data recorded before refererCategory was introduced has no such field, treat it as 'other'
+    $match.refererCategory = { $in: refererCategories.includes('other') ? [...refererCategories, null] : refererCategories }
+  }
 
   const $group: Record<string, any> = {
     _id: {},
@@ -60,17 +64,14 @@ export const agg = async (account: Account, query: AggQuery) => {
     if (part === 'refererApp') {
       $match.refererApp = { $ne: null }
     }
-    if (part === 'processing') {
-      $match['processing._id'] = { $ne: null }
-      $group._id.processingId = '$processing._id'
-      $group.processing = { $last: '$processing' }
-    } else if (part === 'resource') {
+    if (part === 'resource') {
       $group._id.resourceType = '$resource.type'
       $group._id.resourceId = '$resource.id'
       $group.resource = { $last: '$resource' }
     } else {
       if (part !== 'day') seriesKey.push(camelCase(part))
-      $group._id[camelCase(part)] = '$' + part
+      // legacy data recorded before refererCategory was introduced has no such field, group it with 'other'
+      $group._id[camelCase(part)] = part === 'refererCategory' ? { $ifNull: ['$' + part, 'other'] } : '$' + part
     }
   }
 
@@ -102,7 +103,6 @@ export const agg = async (account: Account, query: AggQuery) => {
   for (const item of items) {
     const key = seriesKey.reduce((a, key) => { a[key] = item[key]; return a }, {} as Record<string, string>)
     if (item.resource) key.resource = item.resource
-    if (item.processing) key.processing = item.processing
     let serie = result.series.find((s) => equal(s.key, key))
     if (!serie) {
       serie = {
diff --git a/api/types/daily-api-metric/schema.json b/api/types/daily-api-metric/schema.json
index e535f81..5bc26c2 100644
--- a/api/types/daily-api-metric/schema.json
+++ b/api/types/daily-api-metric/schema.json
@@ -12,6 +12,7 @@
     "statusClass",
     "userClass",
     "refererDomain",
+    "refererCategory",
     "nbRequests",
     "bytes",
     "duration"
@@ -28,6 +29,7 @@
     "userClass": {"$ref": "#/$defs/userClass"},
     "refererDomain":{"type":"string"},
     "refererApp":{"type":"string"},
+    "refererCategory":{"$ref": "#/$defs/refererCategory"},
     "processing":{"$ref": "#/$defs/processing"},
     "nbRequests":{
       "type":"integer",
@@ -107,6 +109,10 @@
     "userClass": {
       "type":"string",
       "enum": ["anonymous", "owner", "external", "ownerProcessing", "externalProcessing", "ownerAPIKey", "externalAPIKey"]
+    },
+    "refererCategory": {
+      "type": "string",
+      "enum": ["backoffice", "embed", "app", "mcp", "other"]
     }
   }
 }
\ No newline at end of file
diff --git a/daemon/src/mongo.ts b/daemon/src/mongo.ts
index 2e21a59..3b96182 100644
--- a/daemon/src/mongo.ts
+++ b/daemon/src/mongo.ts
@@ -33,6 +33,7 @@ export class MetricsMongo {
             userClass: 1,
             refererDomain: 1,
             refererApp: 1,
+            refererCategory: 1,
             'processing._id': 1
           },
           { unique: true }
diff --git a/daemon/src/service.ts b/daemon/src/service.ts
index b26ab10..01df3dc 100644
--- a/daemon/src/service.ts
+++ b/daemon/src/service.ts
@@ -63,11 +63,23 @@ const getUserClass = (line: LogLine, user: UserRef | null, ownerType: string, ow
   else userClass = 'external'
 
   if (user && line[8]) userClass += 'APIKey'
-  if (user && line[10]) userClass += 'Processing'
   return userClass
 }
 
-const getRefererInfo = (line: LogLine): [string, string | undefined] => {
+type RefererCategory = 'backoffice' | 'embed' | 'app' | 'mcp' | 'other'
+
+// classifies internal traffic by path; a referer whose host doesn't match our
+// own host can't be trusted to be internal, no matter what its path looks like
+const getRefererCategory = (url: URL, host: string): RefererCategory => {
+  if (url.hostname !== host) return 'other'
+  if (url.pathname.startsWith('/mcp')) return 'mcp'
+  if (url.pathname.startsWith('/data-fair/embed')) return 'embed'
+  if (url.pathname.startsWith('/data-fair/app/')) return 'app'
+  if (url.pathname.startsWith('/data-fair/')) return 'backoffice'
+  return 'other'
+}
+
+const getRefererInfo = (line: LogLine): [string, string | undefined, RefererCategory] => {
   if (line[1]) {
     try {
       const url = new URL(line[1])
@@ -78,19 +90,19 @@ const getRefererInfo = (line: LogLine): [string, string | undefined] => {
       const searchParamReferer = url.searchParams.get('referer')
       if (searchParamReferer) refererDomain = searchParamReferer
       if (url.pathname.startsWith('/data-fair/app/')) refererApp = /** @type {string} */(url.pathname.replace('/data-fair/app/', '').split('/').shift())
-      return [refererDomain, refererApp]
+      const refererCategory = getRefererCategory(url, line[0])
+      return [refererDomain, refererApp, refererCategory]
     } catch (err) {
-      return [line[1], undefined]
+      return [line[1], undefined, 'other']
     }
   } else {
-    return ['none', undefined]
+    return ['none', undefined, 'other']
   }
 }
 
 // cf https://stackoverflow.com/a/14350155
 // using regexp is faster and prevents lots of object affectations, garbage collecting, etc
 const idPropRegexp = /"id":"((\\"|[^"])*)"/
-const _idPropRegexp = /"_id":"((\\"|[^"])*)"/
 const depPropRegexp = /"department":"((\\"|[^"])*)"/
 const typePropRegexp = /"type":"((\\"|[^"])*)"/
 const trackPropRegexp = /"track":"((\\"|[^"])*)"/
@@ -113,11 +125,10 @@ export function pushLogLine (line: LogLine) {
   const resourceId = line[12].match(idPropRegexp)?.[1]
   if (!operationId || !operationTrack || !ownerType || !ownerId || !resourceType || !resourceId) return
   const ownerDep = line[1].match(depPropRegexp)?.[1]
-  const processingId = line[10].match(_idPropRegexp)?.[1]
   const statusClass = getStatusClass(line[4])
   const user = getUser(line)
   const userClass = getUserClass(line, user, ownerType, ownerId)
-  const [refererDomain, refererApp] = getRefererInfo(line)
+  const [refererDomain, refererApp, refererCategory] = getRefererInfo(line)
 
   let bytesSent = line[3]
   if (line[14] && line[14] !== '-') {
@@ -139,11 +150,11 @@ export function pushLogLine (line: LogLine) {
     operationTrack,
     statusClass,
     userClass,
-    refererDomain
+    refererDomain,
+    refererCategory
   }
   if (refererApp) patchKey.refererApp = refererApp
   if (ownerDep) patchKey['owner.department'] = ownerDep
-  if (processingId) patchKey['processing._id'] = processingId
 
   const existingPatch = patches.find(p => equal(p[0], patchKey))
   if (existingPatch) {
@@ -153,8 +164,6 @@ export function pushLogLine (line: LogLine) {
   } else {
     const resource = JSON.parse(line[12])
     if (resource.title) resource.title = decodeURIComponent(resource.title)
-    const processing = line[10] ? JSON.parse(line[10]) : undefined
-    if (processing?.title) processing.title = decodeURIComponent(processing.title)
 
     const set: Record<string, any> = {
       owner: JSON.parse(line[5]),
@@ -163,9 +172,9 @@ export function pushLogLine (line: LogLine) {
       operationTrack,
       statusClass,
       userClass,
-      refererDomain
+      refererDomain,
+      refererCategory
     }
-    if (processing) set.processing = processing
     if (refererApp) set.refererApp = refererApp
 
     patches.push([patchKey, {
diff --git a/test-it/01-daily-api-metrics.ts b/test-it/01-daily-api-metrics.ts
index 84d5b37..b31429f 100644
--- a/test-it/01-daily-api-metrics.ts
+++ b/test-it/01-daily-api-metrics.ts
@@ -1,6 +1,7 @@
 import { describe, it, before, after, beforeEach } from 'node:test'
 import { strict as assert } from 'node:assert'
 import * as testSpies from '@data-fair/lib-node/test-spies.js'
+import mongo from '@data-fair/lib-node/mongo.js'
 import { axiosAuth, clean, startApiServer, stopApiServer, startDaemonServer, stopDaemonServer } from './utils/index.ts'
 
 testSpies.registerModuleHooks()
@@ -34,4 +35,31 @@ describe('daily api metrics', () => {
     const bulk1 = await testSpies.waitFor('sentBulkDelay')
     assert.equal(bulk1, 1)
   })
+
+  describe('referer category classification', () => {
+    const cases: Array<{ referer?: string, expected: string }> = [
+      { referer: 'http://localhost/data-fair/dataset/some-dataset', expected: 'backoffice' },
+      { referer: 'http://localhost/data-fair/embed/dataset/some-dataset', expected: 'embed' },
+      { referer: 'http://localhost/data-fair/app/507f1f77bcf86cd799439011/', expected: 'app' },
+      { referer: 'http://localhost/mcp', expected: 'mcp' },
+      { referer: 'http://external-site.com/data-fair/embed/dataset/some-dataset', expected: 'other' },
+      { referer: undefined, expected: 'other' }
+    ]
+
+    for (const { referer, expected } of cases) {
+      it(`classifies referer "${referer ?? 'none'}" as "${expected}"`, async () => {
+        const dataset = (await adminAx.post('http://localhost:5600/data-fair/api/v1/datasets', {
+          isRest: true,
+          title: 'd1',
+          schema: [{ key: 'prop1', type: 'string' }]
+        })).data
+        await Promise.all([
+          testSpies.waitFor('sentBulkDelay'),
+          adminAx.get(`/data-fair/api/v1/datasets/${dataset.id}/lines`, referer ? { headers: { Referer: referer } } : {})
+        ])
+        const doc = await mongo.db.collection('daily-api-metrics').findOne({ 'resource.id': dataset.id })
+        assert.equal(doc?.refererCategory, expected)
+      })
+    }
+  })
 })
diff --git a/ui/src/components/chart/chart-categories.vue b/ui/src/components/chart/chart-categories.vue
index d302222..8448d61 100644
--- a/ui/src/components/chart/chart-categories.vue
+++ b/ui/src/components/chart/chart-categories.vue
@@ -20,15 +20,12 @@ const userClasses: Record<string, string> = {
   owner: 'Propriétaire',
   external: 'Utilisateur externe',
   ownerAPIKey: "Propriétaire (clé d'API)",
-  externalAPIKey: "Utilisateur externe (clé d'API)",
-  ownerProcessing: 'Propriétaire (traitement)',
-  externalProcessing: 'Utilisateur externe (traitement)'
+  externalAPIKey: "Utilisateur externe (clé d'API)"
 }
 
 const getLabel = (serie: any, category: string, labels: Record<string, string> | null) => {
   if (serie.label) return serie.label
   if (category === 'resource') return safeDecodeUriComponent(serie.key.resource.title)
-  if (category === 'processing') return safeDecodeUriComponent(serie.key.processing.title)
   if (category === 'userClass') return userClasses[serie.key.userClass] || serie.key.userClass
   if (serie.key[category] === 'none') return 'Inconnu'
   if (serie.key[category] === null || serie.key[category] === undefined) return 'Aucune'
diff --git a/ui/src/components/daily-api-metrics.vue b/ui/src/components/daily-api-metrics.vue
index cd9aa0f..823c3ee 100644
--- a/ui/src/components/daily-api-metrics.vue
+++ b/ui/src/components/daily-api-metrics.vue
@@ -73,9 +73,7 @@ const userClasses = [
   { value: 'owner', title: 'Propriétaire' },
   { value: 'external', title: 'utilisateur externe' },
   { value: 'ownerAPIKey', title: "Propriétaire (clé d'API)" },
-  { value: 'externalAPIKey', title: "utilisateur externe (clé d'API)" },
-  { value: 'ownerProcessing', title: 'Propriétaire (traitement)' },
-  { value: 'externalProcessing', title: 'utilisateur externe (traitement)' }
+  { value: 'externalAPIKey', title: "utilisateur externe (clé d'API)" }
 ]
 
 const splitItems = [
diff --git a/ui/src/pages/embed/home.vue b/ui/src/pages/embed/home.vue
index cf49a1b..0a10934 100644
--- a/ui/src/pages/embed/home.vue
+++ b/ui/src/pages/embed/home.vue
@@ -197,10 +197,11 @@
           :labels="appLabels"
         />
         <chart-categories
-          title="Requêtes / traitement"
-          category="processing"
+          title="Requêtes / consommateurs"
+          category="refererCategory"
           :filter="baseFilter"
           :periods="periods"
+          :labels="refererCategoryLabels"
         />
       </v-row>
     </template>
@@ -229,9 +230,15 @@ const userClassLabels: Record<string, string> = {
   owner: 'Propriétaire',
   external: 'Utilisateur externe',
   ownerAPIKey: "Propriétaire (clé d'API)",
-  externalAPIKey: "Utilisateur externe (clé d'API)",
-  ownerProcessing: 'Propriétaire (traitement)',
-  externalProcessing: 'Utilisateur externe (traitement)'
+  externalAPIKey: "Utilisateur externe (clé d'API)"
+}
+
+const refererCategoryLabels: Record<string, string> = {
+  backoffice: 'Back-office',
+  embed: 'Vues embarquées',
+  app: 'Applications',
+  mcp: 'MCP',
+  other: 'Autre'
 }
 
 const datasetItems = computed(() => {