diff --git a/src/main/ipc/jira.ts b/src/main/ipc/jira.ts
index d12ae0e009f..0d78eec5f44 100644
--- a/src/main/ipc/jira.ts
+++ b/src/main/ipc/jira.ts
@@ -53,6 +53,7 @@ function normalizeStringArray(value: unknown): string[] | undefined {
   return Array.isArray(value) && value.every((item) => typeof item === 'string') ? value : undefined
 }
 
+/** Narrows an untrusted IPC payload to the issue-update fields the host accepts. */
 function normalizeIssueUpdate(value: unknown): JiraIssueUpdate | null {
   if (!value || typeof value !== 'object') {
     return null
@@ -84,6 +85,7 @@ function normalizeIssueUpdate(value: unknown): JiraIssueUpdate | null {
   return input
 }
 
+/** Registers every `jira:*` IPC handler on the main process. */
 export function registerJiraHandlers(): void {
   ipcMain.handle('jira:connect', async (_event, args: JiraConnectArgs) => {
     if (
diff --git a/src/main/jira/jira-issue-create-metadata.ts b/src/main/jira/jira-issue-create-metadata.ts
index 67291c1f197..90325930afa 100644
--- a/src/main/jira/jira-issue-create-metadata.ts
+++ b/src/main/jira/jira-issue-create-metadata.ts
@@ -55,6 +55,7 @@ export async function listIssueTypes(
   }
 }
 
+/** Lists the required create fields for a project and issue type. */
 export async function listCreateFields(
   projectIdOrKey: string,
   issueTypeId: string,
@@ -104,6 +105,7 @@ export async function listCreateFields(
   }
 }
 
+/** Lists the site's issue priorities. */
 export async function listPriorities(siteId?: string | null): Promise<JiraPriority[]> {
   const entry = getClients(siteId)[0]
   if (!entry) {
@@ -125,8 +127,11 @@ export async function listPriorities(siteId?: string | null): Promise<JiraPriori
   }
 }
 
-// Reporter and user-picker fields are not limited to assignable users, and no
-// issue key exists before create, so neither /user/assignable/search variant fits.
+/**
+ * Searches all users on the site. Reporter and user-picker create fields are not
+ * limited to assignable users and no issue key exists before create, so neither
+ * `/user/assignable/search` variant fits. Returns `[]` when browse-users is denied.
+ */
 export async function searchUsers(query?: string, siteId?: string | null): Promise<JiraUser[]> {
   const entry = getClients(siteId)[0]
   if (!entry) {
diff --git a/src/main/jira/jira-issue-mutations.ts b/src/main/jira/jira-issue-mutations.ts
index 555edcefbf2..f14e051f663 100644
--- a/src/main/jira/jira-issue-mutations.ts
+++ b/src/main/jira/jira-issue-mutations.ts
@@ -11,14 +11,19 @@ import { clearToken, getClients, isAuthError } from './client'
 import { issueUrl, toBodyText } from './jira-issue-mapping'
 import type { JiraRecord } from './jira-record-pages'
 
-// Server/DC identifies users by username (`name`), not accountId;
-// mapUser stores the Server username in the accountId slot.
+/**
+ * Wraps a user id in the reference object the site expects: `{accountId}` on
+ * Cloud, `{name}` on Server/DC, which identifies users by username and whose
+ * ids `mapUser` stores in the accountId slot.
+ */
 export function userFieldRef(site: JiraSite, id: string | null): JiraRecord {
   return site.authType === 'server' ? { name: id } : { accountId: id }
 }
 
-// Jira rejects a bare string for user-typed fields (reporter, user pickers) and
-// reports the field as missing, so shape it before it reaches the create body.
+/**
+ * Shapes a user-typed create value (scalar or array) into Jira's user reference
+ * objects. Jira rejects a bare string here and reports the field as missing.
+ */
 function toUserFieldValue(site: JiraSite, value: unknown): unknown {
   if (typeof value === 'string') {
     return userFieldRef(site, value)
@@ -29,6 +34,7 @@ function toUserFieldValue(site: JiraSite, value: unknown): unknown {
   return value
 }
 
+/** Creates an issue, shaping the customFields keys named by `userFieldKeys`. */
 export async function createIssue(args: JiraCreateIssueArgs): Promise<JiraCreateIssueResult> {
   const entry = getClients(args.siteId)[0]
   if (!entry) {
@@ -76,6 +82,7 @@ export async function createIssue(args: JiraCreateIssueArgs): Promise<JiraCreate
   }
 }
 
+/** Applies field, assignee, and transition updates to an existing issue. */
 export async function updateIssue(
   key: string,
   updates: JiraIssueUpdate,
diff --git a/src/main/runtime/orca-runtime.ts b/src/main/runtime/orca-runtime.ts
index 6ebf04e08e4..50ae709f43d 100644
--- a/src/main/runtime/orca-runtime.ts
+++ b/src/main/runtime/orca-runtime.ts
@@ -40842,6 +40842,7 @@ export class OrcaRuntimeService {
     return listJiraAssignableUsers(key, query, siteId)
   }
 
+  /** Searches all users on the site, for reporter and user-picker create fields. */
   jiraSearchUsers(query?: string, siteId?: string): ReturnType<typeof searchJiraUsers> {
     return searchJiraUsers(query, siteId)
   }
diff --git a/src/main/runtime/rpc/methods/jira.ts b/src/main/runtime/rpc/methods/jira.ts
index 91f5099be3f..087aa25f36e 100644
--- a/src/main/runtime/rpc/methods/jira.ts
+++ b/src/main/runtime/rpc/methods/jira.ts
@@ -105,6 +105,7 @@ const ProjectStatusOrder = z.object({
   siteId: OptionalString
 })
 
+/** Emits a Jira result over RPC, normalizing it to the shape clients decode. */
 function emitJiraPayload(value: unknown, emit: (result: unknown) => void): void {
   const payload = JSON.stringify(value)
   if (payload.length > JIRA_PAYLOAD_MAX_CHARS) {
diff --git a/src/renderer/src/components/TaskPage.tsx b/src/renderer/src/components/TaskPage.tsx
index 5180bd0b352..340d9a9c8eb 100644
--- a/src/renderer/src/components/TaskPage.tsx
+++ b/src/renderer/src/components/TaskPage.tsx
@@ -1361,6 +1361,7 @@ export default function TaskPage(): React.JSX.Element {
     availableJiraProjects,
     jiraConnected,
     jiraViewer: jiraConnected ? jiraStatus.viewer : null,
+    jiraViewerSiteId: jiraConnected ? (jiraStatus.activeSiteId ?? null) : null,
     settings,
     jiraTaskSourceContext
   })
diff --git a/src/renderer/src/components/jira-issue-workspace-chrome.tsx b/src/renderer/src/components/jira-issue-workspace-chrome.tsx
index 492e5c7473e..3a868137dc4 100644
--- a/src/renderer/src/components/jira-issue-workspace-chrome.tsx
+++ b/src/renderer/src/components/jira-issue-workspace-chrome.tsx
@@ -24,6 +24,7 @@ function jiraStatusClass(categoryKey: string): string {
   return 'border-border/50 bg-muted/40 text-muted-foreground'
 }
 
+/** Header row for an open Jira issue: key, summary, and workspace actions. */
 export function JiraIssueWorkspaceHeader({
   displayed,
   issueLoading,
@@ -82,6 +83,7 @@ export function JiraIssueWorkspaceHeader({
   )
 }
 
+/** Status, assignee, and priority controls shown above an open Jira issue. */
 export function JiraIssueMetadataBar({
   displayed,
   pendingField,
diff --git a/src/renderer/src/components/jira-user-picker.tsx b/src/renderer/src/components/jira-user-picker.tsx
index 43c799535e7..249e295f262 100644
--- a/src/renderer/src/components/jira-user-picker.tsx
+++ b/src/renderer/src/components/jira-user-picker.tsx
@@ -11,6 +11,7 @@ import type { TaskSourceContext } from '../../../shared/task-source-context'
 
 const USER_SEARCH_DEBOUNCE_MS = 250
 
+/** Renders the selectable user rows inside the picker popover. */
 export function JiraUserOptionList({
   users,
   onSelect
@@ -37,8 +38,11 @@ export function JiraUserOptionList({
   )
 }
 
-// Reporter and user-picker create fields need an accountId, not the display name
-// a plain text box would collect; Jira rejects a bare string for user fields.
+/**
+ * Searchable single-user combobox for Jira user fields. These need an accountId,
+ * not the display name a plain text box would collect, since Jira rejects a bare
+ * string for user fields.
+ */
 export function JiraUserPicker({
   providerSettings,
   siteId,
diff --git a/src/renderer/src/components/task-page-jira-create-fields.test.ts b/src/renderer/src/components/task-page-jira-create-fields.test.ts
index 6c4fc0f97fd..76707e54a0d 100644
--- a/src/renderer/src/components/task-page-jira-create-fields.test.ts
+++ b/src/renderer/src/components/task-page-jira-create-fields.test.ts
@@ -7,6 +7,7 @@ import {
   getJiraCreateAllowedValueLabel,
   getJiraCreateOptionPayload,
   getJiraUserCreateFieldKeys,
+  isJiraScalarUserCreateField,
   isJiraUserCreateField,
   isVisibleJiraCreateField
 } from './task-page-jira-create-fields'
@@ -49,6 +50,25 @@ describe('isJiraUserCreateField', () => {
   })
 })
 
+describe('isJiraScalarUserCreateField', () => {
+  it('matches single-user fields the picker can hold', () => {
+    expect(isJiraScalarUserCreateField(field({ key: 'reporter', schema: { type: 'user' } }))).toBe(
+      true
+    )
+  })
+
+  it('rejects array-of-user, which the single-value picker would collapse to one member', () => {
+    expect(isJiraScalarUserCreateField(field({ schema: { type: 'array', items: 'user' } }))).toBe(
+      false
+    )
+  })
+
+  it('ignores non-user fields', () => {
+    expect(isJiraScalarUserCreateField(field({ schema: { type: 'string' } }))).toBe(false)
+    expect(isJiraScalarUserCreateField(field())).toBe(false)
+  })
+})
+
 describe('getJiraUserCreateFieldKeys', () => {
   it('collects only the user-typed keys for the host to shape', () => {
     expect(
diff --git a/src/renderer/src/components/task-page-jira-create-fields.ts b/src/renderer/src/components/task-page-jira-create-fields.ts
index 7e5b8c537e7..958cda620ea 100644
--- a/src/renderer/src/components/task-page-jira-create-fields.ts
+++ b/src/renderer/src/components/task-page-jira-create-fields.ts
@@ -3,12 +3,18 @@ import type { JiraCreateField } from '../../../shared/jira-types'
 
 const JIRA_CREATE_SYSTEM_FIELD_KEYS = new Set(['project', 'issuetype', 'summary', 'description'])
 
+/** Jira's own create screen defaults only this field to the authenticated user. */
+export const JIRA_REPORTER_FIELD_KEY = 'reporter'
+
+/** True for required create fields the dialog must render (system fields excluded). */
 export function isVisibleJiraCreateField(field: JiraCreateField): boolean {
   return field.required && !JIRA_CREATE_SYSTEM_FIELD_KEYS.has(field.key)
 }
 
-// User pickers (reporter included) carry no allowedValues, so they must be
-// recognised by schema type or they fall through to the free-text branch.
+/**
+ * True for any user-typed field, scalar or array. User pickers carry no
+ * allowedValues, so schema type is the only way to tell them from free text.
+ */
 export function isJiraUserCreateField(field: JiraCreateField): boolean {
   return (
     field.schema?.type === 'user' ||
@@ -16,8 +22,19 @@ export function isJiraUserCreateField(field: JiraCreateField): boolean {
   )
 }
 
-// The host shapes these into Jira's {accountId} / {name} objects; it cannot
-// infer which keys hold user ids from the values alone.
+/**
+ * True only for single-user fields. `JiraUserPicker` holds one user, so
+ * array-of-user fields stay on the comma-separated text path until the dialog
+ * can collect and submit several.
+ */
+export function isJiraScalarUserCreateField(field: JiraCreateField): boolean {
+  return field.schema?.type === 'user'
+}
+
+/**
+ * Collects the user-typed field keys for the host to shape, which it cannot
+ * infer from the values alone since a user id is just a string.
+ */
 export function getJiraUserCreateFieldKeys(fields: readonly JiraCreateField[]): string[] {
   return fields.filter(isJiraUserCreateField).map((field) => field.key)
 }
diff --git a/src/renderer/src/components/task-page/dialogs/new-jira-issue-custom-fields.tsx b/src/renderer/src/components/task-page/dialogs/new-jira-issue-custom-fields.tsx
index cc11e5981dc..84ef5250c76 100644
--- a/src/renderer/src/components/task-page/dialogs/new-jira-issue-custom-fields.tsx
+++ b/src/renderer/src/components/task-page/dialogs/new-jira-issue-custom-fields.tsx
@@ -10,7 +10,7 @@ import {
 } from '@/components/ui/select'
 import {
   getJiraCreateAllowedValueLabel,
-  isJiraUserCreateField
+  isJiraScalarUserCreateField
 } from '@/components/task-page-jira-create-fields'
 import { JiraUserPicker } from '@/components/jira-user-picker'
 import { translate } from '@/i18n/i18n'
@@ -18,6 +18,7 @@ import type { GlobalSettings } from '../../../../../shared/global-settings-types
 import type { JiraCreateField, JiraUser } from '../../../../../shared/jira-types'
 import type { TaskSourceContext } from '../../../../../shared/task-source-context'
 
+/** Renders the required create fields, choosing a picker, select, or text input per schema. */
 export function NewJiraIssueCustomFields({
   visibleJiraCreateFields,
   newJiraIssueCustomFieldValues,
@@ -47,7 +48,7 @@ export function NewJiraIssueCustomFields({
         return (
           <div key={field.key} className="flex min-w-0 flex-col gap-1">
             <label className="text-[11px] font-medium text-muted-foreground">{field.name}</label>
-            {isJiraUserCreateField(field) && !field.allowedValues?.length ? (
+            {isJiraScalarUserCreateField(field) && !field.allowedValues?.length ? (
               <JiraUserPicker
                 providerSettings={providerSettings}
                 siteId={siteId}
diff --git a/src/renderer/src/components/task-page/dialogs/new-jira-issue-dialog.tsx b/src/renderer/src/components/task-page/dialogs/new-jira-issue-dialog.tsx
index 40b4fb6f42a..8462493fa9a 100644
--- a/src/renderer/src/components/task-page/dialogs/new-jira-issue-dialog.tsx
+++ b/src/renderer/src/components/task-page/dialogs/new-jira-issue-dialog.tsx
@@ -82,6 +82,7 @@ export type NewJiraIssueDialogProps = {
   submitShortcutLabel: string
 }
 
+/** Dialog for creating a Jira issue and opening a workspace for it. */
 export function NewJiraIssueDialog(props: NewJiraIssueDialogProps): React.JSX.Element {
   const {
     newJiraIssueOpen,
diff --git a/src/renderer/src/components/task-page/hooks/use-task-page-create-jira-submit.ts b/src/renderer/src/components/task-page/hooks/use-task-page-create-jira-submit.ts
index 29f419c7a72..66328377d9b 100644
--- a/src/renderer/src/components/task-page/hooks/use-task-page-create-jira-submit.ts
+++ b/src/renderer/src/components/task-page/hooks/use-task-page-create-jira-submit.ts
@@ -16,6 +16,7 @@ import type {
 } from '../../../../../shared/jira-types'
 import type { TaskSourceContext } from '../../../../../shared/task-source-context'
 
+/** Builds the create payload and submits it, flagging which keys hold user ids. */
 export function useTaskPageCreateJiraSubmit({
   newJiraIssueTargetProject,
   newJiraIssueTargetType,
diff --git a/src/renderer/src/components/task-page/hooks/use-task-page-jira-create-dialog.tsx b/src/renderer/src/components/task-page/hooks/use-task-page-jira-create-dialog.tsx
index 4856e72904c..0c873403b54 100644
--- a/src/renderer/src/components/task-page/hooks/use-task-page-jira-create-dialog.tsx
+++ b/src/renderer/src/components/task-page/hooks/use-task-page-jira-create-dialog.tsx
@@ -10,7 +10,8 @@ import {
   getJiraProjectSelectionKey
 } from '@/components/task-page-jira-project-selection'
 import {
-  isJiraUserCreateField,
+  JIRA_REPORTER_FIELD_KEY,
+  isJiraScalarUserCreateField,
   isVisibleJiraCreateField
 } from '@/components/task-page-jira-create-fields'
 import { writeNewJiraIssueDraft } from '@/components/task-page/dialogs/task-creation-draft-writers'
@@ -25,11 +26,13 @@ import type {
 } from '../../../../../shared/jira-types'
 import type { TaskSourceContext } from '../../../../../shared/task-source-context'
 
+/** Owns new-issue dialog state: project and type selection, create fields, and reporter seeding. */
 export function useTaskPageJiraCreateDialog({
   selectedJiraSiteId,
   availableJiraProjects,
   jiraConnected,
   jiraViewer,
+  jiraViewerSiteId,
   settings,
   jiraTaskSourceContext
 }: {
@@ -37,6 +40,7 @@ export function useTaskPageJiraCreateDialog({
   availableJiraProjects: JiraProject[]
   jiraConnected: boolean
   jiraViewer: JiraViewer | null
+  jiraViewerSiteId: string | null
   settings: GlobalSettings | null
   jiraTaskSourceContext: TaskSourceContext | null
 }) {
@@ -252,29 +256,39 @@ export function useTaskPageJiraCreateDialog({
         }
         setJiraCreateFields(fields)
         // Jira defaults the reporter to the authenticated user; match that so a
-        // required user field is satisfied without forcing a lookup.
+        // required reporter is satisfied without forcing a lookup. Only reporter
+        // is seeded — Jira defaults no other user field, so filling one would
+        // write a person the user never chose.
         if (!jiraViewer) {
           return
         }
+        // The viewer belongs to the active site; an id from another site names a
+        // different person there (or, on Server/DC, silently collides by username).
+        const targetSiteId = newJiraIssueTargetProject.siteId
+        if (targetSiteId && jiraViewerSiteId && targetSiteId !== jiraViewerSiteId) {
+          return
+        }
+        const reporterField = fields.find(
+          (field) =>
+            field.key === JIRA_REPORTER_FIELD_KEY &&
+            isVisibleJiraCreateField(field) &&
+            isJiraScalarUserCreateField(field)
+        )
+        if (!reporterField) {
+          return
+        }
         const seededUser: JiraUser = {
           accountId: jiraViewer.accountId,
           displayName: jiraViewer.displayName,
           email: jiraViewer.email,
           avatarUrl: jiraViewer.avatarUrl
         }
-        const seededKeys = fields
-          .filter((field) => isVisibleJiraCreateField(field) && isJiraUserCreateField(field))
-          .filter((field) => field.schema?.type !== 'array')
-          .map((field) => field.key)
-        if (seededKeys.length === 0) {
-          return
-        }
         setNewJiraIssueCustomFieldValues((prev) => ({
-          ...Object.fromEntries(seededKeys.map((key) => [key, seededUser.accountId])),
+          [reporterField.key]: seededUser.accountId,
           ...prev
         }))
         setJiraUserFieldSelections((prev) => ({
-          ...Object.fromEntries(seededKeys.map((key) => [key, seededUser])),
+          [reporterField.key]: seededUser,
           ...prev
         }))
       })
@@ -301,6 +315,7 @@ export function useTaskPageJiraCreateDialog({
     settings,
     jiraConnected,
     jiraViewer,
+    jiraViewerSiteId,
     newJiraIssueOpen,
     newJiraIssueTargetProject,
     newJiraIssueTargetType,
diff --git a/src/renderer/src/runtime/runtime-jira-client.ts b/src/renderer/src/runtime/runtime-jira-client.ts
index 709264f16b8..48c65265c06 100644
--- a/src/renderer/src/runtime/runtime-jira-client.ts
+++ b/src/renderer/src/runtime/runtime-jira-client.ts
@@ -264,6 +264,7 @@ export async function jiraListPriorities(
     : window.api.jira.listPriorities(siteId ? { siteId } : undefined)
 }
 
+/** Lists users assignable to an existing issue, via the active runtime. */
 export async function jiraListAssignableUsers(
   settings: RuntimeJiraSettings,
   key: string,
@@ -280,6 +281,7 @@ export async function jiraListAssignableUsers(
     : window.api.jira.listAssignableUsers(args)
 }
 
+/** Searches Jira users through the active runtime (remote RPC or local IPC). */
 export async function jiraSearchUsers(
   settings: RuntimeJiraSettings,
   query?: string,