diff --git a/package-lock.json b/package-lock.json
index 332ee54152..a1901c98aa 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2447,24 +2447,6 @@
         "sinon": ">=20"
       }
     },
-    "node_modules/@heroku/api-client": {
-      "name": "@heroku/heroku-fetch",
-      "version": "0.1.0",
-      "resolved": "git+ssh://git@github.com/heroku/heroku-fetch.git#7e4cc4918e7995e9d499ec8d2f3dfeb0964e7a0d",
-      "license": "Apache-2.0",
-      "dependencies": {
-        "debug": "^4.3.4",
-        "ky": "^1.2.0"
-      },
-      "engines": {
-        "node": ">=22"
-      },
-      "optionalDependencies": {
-        "@heroku/heroku-cli-util": "^10.8.0",
-        "netrc-parser": "^3.1.6",
-        "open": "^10.0.3"
-      }
-    },
     "node_modules/@heroku/buildpack-registry": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/@heroku/buildpack-registry/-/buildpack-registry-1.0.1.tgz",
@@ -2592,6 +2574,23 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/@heroku/heroku-fetch": {
+      "version": "0.1.0",
+      "resolved": "git+ssh://git@github.com/heroku/heroku-fetch.git#90940bdb0191cafcd9571492b2145980643ba7f0",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "debug": "^4.3.4",
+        "ky": "^1.2.0"
+      },
+      "engines": {
+        "node": ">=22"
+      },
+      "optionalDependencies": {
+        "@heroku/heroku-cli-util": "^10.8.0",
+        "netrc-parser": "^3.1.6",
+        "open": "^10.0.3"
+      }
+    },
     "node_modules/@heroku/http-call": {
       "version": "5.5.1",
       "resolved": "https://registry.npmjs.org/@heroku/http-call/-/http-call-5.5.1.tgz",
@@ -2668,11 +2667,11 @@
       }
     },
     "node_modules/@heroku/sdk": {
-      "version": "0.2.0",
-      "resolved": "git+ssh://git@github.com/heroku/heroku-sdk.git#34fe268d74bfabad2dcbc62278ac70a624154420",
+      "version": "0.4.0",
+      "resolved": "git+ssh://git@github.com/heroku/heroku-sdk.git#efce1d4fffd1be97127f4fe78bc65b1e22d6d0de",
       "license": "Apache-2.0",
       "dependencies": {
-        "@heroku/api-client": "github:heroku/heroku-fetch",
+        "@heroku/heroku-fetch": "github:heroku/heroku-fetch",
         "@heroku/types": "github:heroku/heroku-types",
         "debug": "^4.4.0"
       },
diff --git a/src/commands/addons/create.ts b/src/commands/addons/create.ts
index 132d328392..62dd54b883 100644
--- a/src/commands/addons/create.ts
+++ b/src/commands/addons/create.ts
@@ -58,7 +58,7 @@ export default class Create extends Command {
     const config = parseConfig(argv)
     let addon: Heroku.AddOn
     try {
-      addon = await createAddon(this.heroku, app, servicePlan, confirm, wait, {as, config, name})
+      addon = await createAddon(app, servicePlan, confirm, wait, {as, config, name})
       if (wait) {
         Create.notifier(`heroku addons:create ${addon.name}`, 'Add-on successfully provisioned')
       }
diff --git a/src/commands/addons/detach.ts b/src/commands/addons/detach.ts
index 5892680efc..b549e99edd 100644
--- a/src/commands/addons/detach.ts
+++ b/src/commands/addons/detach.ts
@@ -1,6 +1,6 @@
 import {Command, flags} from '@heroku-cli/command'
-import * as Heroku from '@heroku-cli/schema'
 import * as color from '@heroku/heroku-cli-util/color'
+import {HerokuSDK} from '@heroku/sdk'
 import {Args, ux} from '@oclif/core'
 
 export default class Detach extends Command {
@@ -17,19 +17,20 @@ export default class Detach extends Command {
   public async run(): Promise<void> {
     const {args, flags} = await this.parse(Detach)
     const {app} = flags
-    const {body: attachment} = await this.heroku.get<Heroku.AddOnAttachment>(`/apps/${app}/addon-attachments/${args.attachment_name}`)
+    const {platform} = new HerokuSDK()
+    const attachment = await platform.addOnAttachment.infoByApp(app, args.attachment_name)
 
     ux.action.start(`Detaching ${color.attachment(attachment.name || '')} to ${color.addon(attachment.addon?.name || '')} from ${color.app(app)}`)
 
-    await this.heroku.delete(`/addon-attachments/${attachment.id}`)
+    await platform.addOnAttachment.delete(attachment.id!)
 
     ux.action.stop()
 
     ux.action.start(`Unsetting ${color.attachment(attachment.name || '')} config vars and restarting ${color.app(app)}`)
 
-    const {body: releases} = await this.heroku.get<Heroku.Release[]>(`/apps/${app}/releases`, {
-      headers: {Range: 'version ..; max=1, order=desc'}, partial: true,
-    })
+    const releases = await platform
+      .withHeaders({Range: 'version ..; max=1, order=desc'})
+      .release.list(app)
 
     ux.action.stop(`done, v${releases[0]?.version || ''}`)
   }
diff --git a/src/commands/addons/index.ts b/src/commands/addons/index.ts
index f34fc2525f..b9a9a04853 100644
--- a/src/commands/addons/index.ts
+++ b/src/commands/addons/index.ts
@@ -1,12 +1,19 @@
 import {APIClient, Command, flags} from '@heroku-cli/command'
 import * as Heroku from '@heroku-cli/schema'
 import {color, hux} from '@heroku/heroku-cli-util'
+import {HerokuSDK} from '@heroku/sdk'
 import {ux} from '@oclif/core/ux'
 import _ from 'lodash'
 
 import {formatPrice, formatState, grandfatheredPrice} from '../../lib/addons/util.js'
 import {huxTableNoWrapOptions} from '../../lib/utils/table-utils.js'
 
+// The Platform expands nested addon_service and plan when this header is set.
+const ADDON_EXPANSION_HEADERS = {
+  Accept: 'application/vnd.heroku+json; version=3.sdk',
+  'Accept-Expansion': 'addon_service,plan',
+}
+
 const topic = 'addons'
 
 export default class Addons extends Command {
@@ -58,43 +65,38 @@ export function renderAttachment(attachment: Heroku.AddOnAttachment, app: string
 }
 
 async function addonGetter(api: APIClient, app?: string) {
-  let attachmentsResponse: null | ReturnType<typeof api.get<Heroku.AddOnAttachment>> = null
-  let addonsResponse: ReturnType<typeof api.get<Heroku.AddOn[]>>
+  const {platform} = new HerokuSDK()
+  // Apply Accept-Expansion only on add-on list calls (the global list
+  // endpoint rejects it; the attachments endpoints don't need it).
+  const platformWithExpansion = platform.withHeaders(ADDON_EXPANSION_HEADERS)
+  let attachmentsResponse: null | Promise<Heroku.AddOnAttachment[]> = null
+  let addonsResponse: Promise<Heroku.AddOn[]>
   if (app) { // don't display attachments globally
-    addonsResponse = api.get<Heroku.AddOn[]>(`/apps/${app}/addons`, {
-      headers: {
-        Accept: 'application/vnd.heroku+json; version=3.sdk',
-        'Accept-Expansion': 'addon_service,plan',
-      },
-    })
+    addonsResponse = platformWithExpansion.addOn.listByApp(app) as unknown as Promise<Heroku.AddOn[]>
     const sudoHeaders = JSON.parse(process.env.HEROKU_HEADERS || '{}')
     // eslint-disable-next-line unicorn/prefer-ternary
     if (sudoHeaders['X-Heroku-Sudo'] && !sudoHeaders['X-Heroku-Sudo-User']) {
       // because the root /addon-attachments endpoint won't include relevant
       // attachments when sudo-ing for another app, we will use the more
       // specific API call and sacrifice listing foreign attachments.
-      attachmentsResponse = api.get<Heroku.AddOnAttachment>(`/apps/${app}/addon-attachments`)
+      attachmentsResponse = platform.addOnAttachment.listByApp(app) as unknown as Promise<Heroku.AddOnAttachment[]>
     } else {
       // In order to display all foreign attachments, we'll get out entire
       // attachment list
-      attachmentsResponse = api.get<Heroku.AddOnAttachment>('/addon-attachments')
+      attachmentsResponse = platform.addOnAttachment.list() as unknown as Promise<Heroku.AddOnAttachment[]>
     }
   } else {
-    addonsResponse = api.get<Heroku.AddOn[]>('/addons', {
-      headers: {
-        Accept: 'application/vnd.heroku+json; version=3.sdk',
-        'Accept-Expansion': 'addon_service,plan',
-      },
-    })
+    // The global /addons endpoint doesn't support Accept-Expansion.
+    addonsResponse = platform.addOn.list() as unknown as Promise<Heroku.AddOn[]>
   }
 
   // Get addons and attachments in parallel
-  const [{body: addonsRaw}, potentialAttachments] = await Promise.all([addonsResponse, attachmentsResponse])
+  const [addonsRaw, potentialAttachments] = await Promise.all([addonsResponse, attachmentsResponse])
   function isRelevantToApp(addon: Heroku.AddOn) {
     return !app || addon.app?.name === app || _.some(addon.attachments, att => att.app.name === app)
   }
 
-  const groupedAttachments = _.groupBy<Heroku.AddOnAttachment>(potentialAttachments?.body, 'addon.id')
+  const groupedAttachments = _.groupBy<Heroku.AddOnAttachment>(potentialAttachments ?? [], 'addon.id')
   const addons: Heroku.AddOn[] = []
   addonsRaw.forEach((addon: Heroku.AddOn) => {
     addon.attachments = groupedAttachments[addon.id as string]  || []
@@ -114,7 +116,7 @@ async function addonGetter(api: APIClient, app?: string) {
   // if the attachment looks relevant to the app, and then render whatever
   for (const atts of _.values(groupedAttachments)) {
     const inaccessibleAddon = {
-      addon_service: {}, app: atts[0].addon.app, attachments: atts, name: atts[0].addon.name, plan: {},
+      addon_service: {}, app: atts[0].addon!.app, attachments: atts, name: atts[0].addon!.name, plan: {},
     }
     if (isRelevantToApp(inaccessibleAddon)) {
       addons.push(inaccessibleAddon)
diff --git a/src/commands/addons/info.ts b/src/commands/addons/info.ts
index dc90273d81..cdbdc260b7 100644
--- a/src/commands/addons/info.ts
+++ b/src/commands/addons/info.ts
@@ -1,10 +1,11 @@
 import {Command, flags} from '@heroku-cli/command'
 import * as Heroku from '@heroku-cli/schema'
 import {color, hux} from '@heroku/heroku-cli-util'
+import {HerokuSDK} from '@heroku/sdk'
+import {addOnExtensions} from '@heroku/sdk/extensions/platform'
 import {Args} from '@oclif/core'
 
-import {resolveAddon} from '../../lib/addons/resolve.js'
-import {formatPrice, formatState, grandfatheredPrice} from '../../lib/addons/util.js'
+import {formatPrice, formatState} from '../../lib/addons/util.js'
 
 const topic = 'addons'
 
@@ -24,21 +25,20 @@ export default class Info extends Command {
     const {args, flags} = await this.parse(Info)
     const {app} = flags
 
-    const addon = await resolveAddon(this.heroku, app, args.addon)
-    const {body: attachments} = await this.heroku.get<Heroku.AddOnAttachment[]>(`/addons/${addon.id}/addon-attachments`)
+    const {platform} = new HerokuSDK({extensions: [addOnExtensions]})
+    const addon = await platform.addOn.describe(args.addon, {appIdentity: app})
+    const plan = addon.plan as undefined | {name?: string; price?: Heroku.AddOn['price']}
 
-    addon.plan.price = grandfatheredPrice(addon)
-    addon.attachments = attachments
     hux.styledHeader(color.addon(addon.name ?? ''))
     /* eslint-disable perfectionist/sort-objects */
     hux.styledObject({
-      Plan: addon.plan.name,
-      Price: formatPrice({hourly: true, price: addon.plan.price}),
-      'Max Price': formatPrice({hourly: false, price: addon.plan.price}),
-      Attachments: addon.attachments.map((att: Heroku.AddOnAttachment) => [
+      Plan: plan?.name,
+      Price: formatPrice({hourly: true, price: plan?.price}),
+      'Max Price': formatPrice({hourly: false, price: plan?.price}),
+      Attachments: addon.attachments.map(att => [
         color.app(att.app?.name || ''), color.attachment(att.name || ''),
       ].join('::')).sort(),
-      'Owning app': color.app(addon.app?.name ?? ''),
+      'Owning app': color.app(addon.app.name ?? ''),
       'Installed at': (new Date(addon.created_at ?? ''))
         .toString(),
       State: formatState(addon.state),
diff --git a/src/commands/addons/plans.ts b/src/commands/addons/plans.ts
index 8f9e03bc39..394dfae8c2 100644
--- a/src/commands/addons/plans.ts
+++ b/src/commands/addons/plans.ts
@@ -1,8 +1,9 @@
 import {Command, flags} from '@heroku-cli/command'
 import {Plan} from '@heroku-cli/schema'
 import {hux} from '@heroku/heroku-cli-util'
+import {HerokuSDK} from '@heroku/sdk'
+import {addOnExtensions} from '@heroku/sdk/extensions/platform'
 import {Args} from '@oclif/core'
-import _ from 'lodash'
 import printf from 'printf'
 
 import {formatPrice} from '../../lib/addons/util.js'
@@ -29,12 +30,13 @@ export default class Plans extends Command {
   public async run(): Promise<void> {
     const {args, flags} = await this.parse(Plans)
     const {service} = args
-    let {body: plans} = await this.heroku.get<PlanWithMeteredPrice[]>(`/addon-services/${service}/plans`, {
-      headers: {
-        Accept: 'application/vnd.heroku+json; version=3.sdk',
-      },
-    })
-    plans = _.sortBy(plans, ['price.contract', 'price.cents'])
+    const {platform} = new HerokuSDK({extensions: [addOnExtensions]})
+    const plans = ((await platform.addOn.listPlans(service)) as unknown as PlanWithMeteredPrice[])
+      .sort((a, b) => {
+        const contractDelta = Number(a.price?.contract ?? false) - Number(b.price?.contract ?? false)
+        if (contractDelta !== 0) return contractDelta
+        return (a.price?.cents ?? 0) - (b.price?.cents ?? 0)
+      })
     if (flags.json) {
       hux.styledJSON(plans)
     } else {
diff --git a/src/commands/addons/rename.ts b/src/commands/addons/rename.ts
index 8e61747cee..2a603bb391 100644
--- a/src/commands/addons/rename.ts
+++ b/src/commands/addons/rename.ts
@@ -1,6 +1,6 @@
 import {Command} from '@heroku-cli/command'
-import * as Heroku from '@heroku-cli/schema'
 import * as color from '@heroku/heroku-cli-util/color'
+import {HerokuSDK} from '@heroku/sdk'
 import {Args, ux} from '@oclif/core'
 
 export default class Rename extends Command {
@@ -13,8 +13,9 @@ export default class Rename extends Command {
 
   public async run(): Promise<void> {
     const {args} = await this.parse(Rename)
-    const {body: addon} = await this.heroku.get<Heroku.AddOn>(`/addons/${encodeURIComponent(args.addon_name)}`)
-    await this.heroku.patch<Heroku.AddOn>(`/apps/${addon.app?.id}/addons/${addon.id}`, {body: {name: args.new_name}})
+    const {platform} = new HerokuSDK()
+    const addon = await platform.addOn.info(args.addon_name)
+    await platform.addOn.update(addon.app!.id!, addon.id!, {name: args.new_name, plan: addon.plan!.name!})
     ux.stdout(`${color.addon(args.addon_name)} successfully renamed to ${color.info(args.new_name)}.`)
   }
 }
diff --git a/src/commands/addons/services.ts b/src/commands/addons/services.ts
index fd1133e41f..786d39ed27 100644
--- a/src/commands/addons/services.ts
+++ b/src/commands/addons/services.ts
@@ -1,6 +1,6 @@
 import {Command, flags} from '@heroku-cli/command'
-import * as Heroku from '@heroku-cli/schema'
 import {color, hux} from '@heroku/heroku-cli-util'
+import {HerokuSDK} from '@heroku/sdk'
 import {ux} from '@oclif/core/ux'
 
 export default class Services extends Command {
@@ -12,12 +12,13 @@ export default class Services extends Command {
 
   public async run(): Promise<void> {
     const {flags} = await this.parse(Services)
-    const {body: services} = await this.heroku.get<Heroku.AddOnService[]>('/addon-services')
+    const {platform} = new HerokuSDK()
+    const services = await platform.addOnService.list()
     if (flags.json) {
       hux.styledJSON(services)
     } else {
       /* eslint-disable perfectionist/sort-objects */
-      hux.table(services, {
+      hux.table(services as Array<Record<string, unknown>>, {
         name: {
           header: 'Slug',
         },
diff --git a/src/commands/addons/upgrade.ts b/src/commands/addons/upgrade.ts
index 9644e58e71..e776b8d0f9 100644
--- a/src/commands/addons/upgrade.ts
+++ b/src/commands/addons/upgrade.ts
@@ -1,16 +1,18 @@
 import type {AddOn, Plan} from '@heroku-cli/schema'
 
 import {Command, flags} from '@heroku-cli/command'
-import {HerokuAPIError} from '@heroku-cli/command/lib/api-client.js'
 import * as color from '@heroku/heroku-cli-util/color'
-import {HTTP} from '@heroku/http-call'
+import {HerokuSDK} from '@heroku/sdk'
+import {addOnExtensions} from '@heroku/sdk/extensions/platform'
+import {AddonAmbiguousError} from '@heroku/sdk/resources/platform/add-on'
 import {Args, ux} from '@oclif/core'
 
-import type {ExtendedAddon} from '../../lib/pg/types.js'
-
-import {addonResolver} from '../../lib/addons/resolve.js'
 import {formatPriceText} from '../../lib/addons/util.js'
 
+function isApiError(error: unknown): error is Error & {statusCode: number} {
+  return error instanceof Error && 'statusCode' in error && typeof (error as {statusCode?: unknown}).statusCode === 'number'
+}
+
 export default class Upgrade extends Command {
   static aliases = ['addons:downgrade']
   static args = {
@@ -79,25 +81,13 @@ ${color.cyan('https://devcenter.heroku.com/articles/managing-add-ons')}`
   }
 
   protected async getPlans(addonServiceName: string | undefined): Promise<Plan[]> {
-    try {
-      const plansResponse: HTTP<Plan[]> = await this.heroku.get(`/addon-services/${addonServiceName}/plans`)
-      const {body: plans} = plansResponse
-      plans.sort((a, b) => {
-        if (a?.price?.cents === b?.price?.cents) {
-          return 0
-        }
-
-        if (!a?.price?.cents || !b?.price?.cents || a.price.cents > b.price.cents) {
-          return 1
-        }
-
-        if (a.price.cents < b.price.cents) {
-          return -1
-        }
+    if (!addonServiceName) {
+      return []
+    }
 
-        return 0
-      })
-      return plans
+    try {
+      const {platform} = new HerokuSDK({extensions: [addOnExtensions]})
+      return (await platform.addOn.listPlans(addonServiceName)) as unknown as Plan[]
     } catch {
       return []
     }
@@ -109,43 +99,32 @@ ${color.cyan('https://devcenter.heroku.com/articles/managing-add-ons')}`
     // called with just one argument in the form of `heroku addons:upgrade heroku-redis:hobby`
     const {addon, plan} = this.getAddonPartsFromArgs(args)
 
-    let resolvedAddon: ExtendedAddon | Required<AddOn>
-    try {
-      resolvedAddon = await addonResolver(this.heroku, app, addon)
-    } catch (error) {
-      if (error instanceof HerokuAPIError && error.http.statusCode === 422 && error.body.id === 'multiple_matches') {
-        throw new Error(this.buildApiErrorMessage(error.http.body.message, ctx))
-      }
-
-      throw error
-    }
-
-    const {name: addonServiceName} = resolvedAddon.addon_service
-    const {name: appName} = resolvedAddon.app
-    const {name: addonName, plan: resolvedAddonPlan} = resolvedAddon ?? {}
-    const updatedPlanName = `${addonServiceName}:${plan}`
-    ux.action.start(`Changing ${color.addon(addonName ?? '')} on ${color.app(appName ?? '')} from ${color.blue(resolvedAddonPlan?.name ?? '')} to ${color.blue(updatedPlanName)}`)
+    const {platform} = new HerokuSDK({extensions: [addOnExtensions]})
+    let addonServiceName: string | undefined
 
+    let updatedAddon: Required<AddOn>
     try {
-      const patchResult: HTTP<Required<AddOn>> = await this.heroku.patch(
-        `/apps/${appName}/addons/${addonName}`,
-        {
-          body: {plan: {name: updatedPlanName}},
-          headers: {
-            'Accept-Expansion': 'plan', 'X-Heroku-Legacy-Provider-Messages': 'true',
-          },
+      updatedAddon = await platform.addOn.upgrade(addon, plan, {
+        appIdentity: app,
+        onResolved(resolved) {
+          addonServiceName = (resolved.addon_service as undefined | {name?: string})?.name
+          const resolvedPlan = resolved.plan as undefined | {name?: string}
+          const updatedPlanName = plan.includes(':') ? plan : `${addonServiceName}:${plan}`
+          ux.action.start(`Changing ${color.addon(resolved.name ?? '')} on ${color.app(resolved.app.name ?? '')} from ${color.blue(resolvedPlan?.name ?? '')} to ${color.blue(updatedPlanName)}`)
         },
-      )
-      resolvedAddon = patchResult.body
+      }) as Required<AddOn>
     } catch (error) {
+      if (error instanceof AddonAmbiguousError) {
+        // eslint-disable-next-line unicorn/prefer-type-error
+        throw new Error(this.buildApiErrorMessage(error.message, ctx))
+      }
+
       let errorToThrow = error as Error
-      if (error instanceof HerokuAPIError) {
-        const {http} = error
-        if (http.statusCode === 422
-          && http.body.message
-          && http.body.message.startsWith('Couldn\'t find either the add-on')) {
+      if (isApiError(error)) {
+        const message = error.message || ''
+        if (error.statusCode === 422 && message.startsWith('Couldn\'t find either the add-on')) {
           const plans = await this.getPlans(addonServiceName)
-          errorToThrow = new Error(`${http.body.message}
+          errorToThrow = new Error(`${message}
 
 Here are the available plans for ${color.addon(addonServiceName || '')}:
 ${plans.map(plan => plan.name).join('\n')}\n\nSee more plan information with ${color.blue('heroku addons:plans ' + addonServiceName)}
@@ -156,11 +135,13 @@ ${color.cyan('https://devcenter.heroku.com/articles/managing-add-ons')}`)
         ux.action.stop()
         throw errorToThrow
       }
+
+      throw errorToThrow
     }
 
-    ux.action.stop(`done${resolvedAddon.plan?.price ? `, ${formatPriceText(resolvedAddon.plan.price)}` : ''}`)
-    if (resolvedAddon.provision_message) {
-      ux.stdout(resolvedAddon.provision_message)
+    ux.action.stop(`done${updatedAddon.plan?.price ? `, ${formatPriceText(updatedAddon.plan.price)}` : ''}`)
+    if (updatedAddon.provision_message) {
+      ux.stdout(updatedAddon.provision_message)
     }
   }
 }
diff --git a/src/commands/addons/wait.ts b/src/commands/addons/wait.ts
index e1124a7133..1eb29a39df 100644
--- a/src/commands/addons/wait.ts
+++ b/src/commands/addons/wait.ts
@@ -48,7 +48,7 @@ export default class Wait extends Command {
       if (addon.state === 'provisioning') {
         let addonResponse
         try {
-          addonResponse = await waitForAddonProvisioning(this.heroku, addon as Heroku.AddOn, interval)
+          addonResponse = await waitForAddonProvisioning(addon as Heroku.AddOn, interval)
         } catch (error) {
           Wait.notifier(`heroku addons:wait ${addonName}`, 'Add-on failed to provision', false)
           throw error
diff --git a/src/commands/data/pg/create.ts b/src/commands/data/pg/create.ts
index 1bbbd3c2fb..6f46b67db5 100644
--- a/src/commands/data/pg/create.ts
+++ b/src/commands/data/pg/create.ts
@@ -108,7 +108,7 @@ export default class DataPgCreate extends BaseCommand {
     }
 
     try {
-      this.addon = await createAddon(this.heroku, app, servicePlan, confirm, wait, {
+      this.addon = await createAddon(app, servicePlan, confirm, wait, {
         actionStartMessage: `Creating a ${color.addon(this.leaderLevel || '')} database on ${color.app(app)}`,
         actionStopMessage: 'done',
         as, config, name,
diff --git a/src/commands/data/pg/fork.ts b/src/commands/data/pg/fork.ts
index 1e41e44545..551ab9a405 100644
--- a/src/commands/data/pg/fork.ts
+++ b/src/commands/data/pg/fork.ts
@@ -156,7 +156,7 @@ export default class Fork extends BaseCommand {
       const actionStartMessage = recoveryTime
         ? `Creating a fork for ${color.addon(addon.name)} on ${color.app(app)} ${rollbackMessage}`
         : `Creating a fork for ${color.addon(addon.name)} on ${color.app(app)}`
-      await createAddon(this.heroku, app, addon.plan.name!, confirm, wait, {
+      await createAddon(app, addon.plan.name!, confirm, wait, {
         actionStartMessage, actionStopMessage: 'done', as, config, name,
       })
 
diff --git a/src/commands/data/pg/migrate.ts b/src/commands/data/pg/migrate.ts
index 6905206148..d4ed649b81 100644
--- a/src/commands/data/pg/migrate.ts
+++ b/src/commands/data/pg/migrate.ts
@@ -339,7 +339,7 @@ export default class DataPgMigrate extends BaseCommand {
 
     let addon: Heroku.AddOn | undefined
     try {
-      addon = await this.createAddon(this.heroku, sourceDatabase.app.name, servicePlan, undefined, false, {
+      addon = await this.createAddon(sourceDatabase.app.name, servicePlan, undefined, false, {
         actionStartMessage: `Creating a ${color.info(leaderLevel!)} database on ${color.app(sourceDatabase.app.name)}`,
         actionStopMessage: 'done',
         config,
diff --git a/src/commands/maintenance/index.ts b/src/commands/maintenance/index.ts
index 0a62aae33c..83c2a5a144 100644
--- a/src/commands/maintenance/index.ts
+++ b/src/commands/maintenance/index.ts
@@ -1,5 +1,5 @@
 import {Command, flags} from '@heroku-cli/command'
-import {createPlatformClient} from '@heroku/sdk/platform'
+import {HerokuSDK} from '@heroku/sdk'
 import {ux} from '@oclif/core/ux'
 
 export default class MaintenanceIndex extends Command {
@@ -12,8 +12,8 @@ export default class MaintenanceIndex extends Command {
 
   async run() {
     const {flags} = await this.parse(MaintenanceIndex)
-    const heroku = createPlatformClient()
-    const app = await heroku.app.info(flags.app)
+    const {platform} = new HerokuSDK()
+    const app = await platform.app.info(flags.app)
     ux.stdout(app.maintenance ? 'on' : 'off')
   }
 }
diff --git a/src/commands/maintenance/off.ts b/src/commands/maintenance/off.ts
index 0f28eaf034..c22f6a34d0 100644
--- a/src/commands/maintenance/off.ts
+++ b/src/commands/maintenance/off.ts
@@ -1,6 +1,7 @@
 import {Command, flags} from '@heroku-cli/command'
 import * as color from '@heroku/heroku-cli-util/color'
-import {disableMaintenanceMode} from '@heroku/sdk/compositions/app'
+import {HerokuSDK} from '@heroku/sdk'
+import {appExtensions} from '@heroku/sdk/extensions/platform'
 import {ux} from '@oclif/core/ux'
 
 export default class MaintenanceOff extends Command {
@@ -14,7 +15,8 @@ export default class MaintenanceOff extends Command {
   async run() {
     const {flags} = await this.parse(MaintenanceOff)
     ux.action.start(`Disabling maintenance mode for ${color.app(flags.app)}`)
-    await disableMaintenanceMode(flags.app)
+    const {platform} = new HerokuSDK({extensions: [appExtensions]})
+    await platform.app.disableMaintenance(flags.app)
     ux.action.stop()
   }
 }
diff --git a/src/commands/maintenance/on.ts b/src/commands/maintenance/on.ts
index dbbe98774f..8efacbee5f 100644
--- a/src/commands/maintenance/on.ts
+++ b/src/commands/maintenance/on.ts
@@ -1,6 +1,7 @@
 import {Command, flags} from '@heroku-cli/command'
 import * as color from '@heroku/heroku-cli-util/color'
-import {enableMaintenanceMode} from '@heroku/sdk/compositions/app'
+import {HerokuSDK} from '@heroku/sdk'
+import {appExtensions} from '@heroku/sdk/extensions/platform'
 import {ux} from '@oclif/core/ux'
 
 export default class MaintenanceOn extends Command {
@@ -14,7 +15,8 @@ export default class MaintenanceOn extends Command {
   async run() {
     const {flags} = await this.parse(MaintenanceOn)
     ux.action.start(`Enabling maintenance mode for ${color.app(flags.app)}`)
-    await enableMaintenanceMode(flags.app)
+    const {platform} = new HerokuSDK({extensions: [appExtensions]})
+    await platform.app.enableMaintenance(flags.app)
     ux.action.stop()
   }
 }
diff --git a/src/commands/pipelines/diff.ts b/src/commands/pipelines/diff.ts
index f1ce5cc0a6..8e8bca2487 100644
--- a/src/commands/pipelines/diff.ts
+++ b/src/commands/pipelines/diff.ts
@@ -1,7 +1,8 @@
 import {Command, flags} from '@heroku-cli/command'
 import {color, hux} from '@heroku/heroku-cli-util'
 import {HTTP} from '@heroku/http-call'
-import {listPipelineApps} from '@heroku/sdk/compositions/pipeline'
+import {HerokuSDK} from '@heroku/sdk'
+import {pipelineCouplingExtensions} from '@heroku/sdk/extensions/platform'
 import {ux} from '@oclif/core/ux'
 
 import type {OciImage, PipelineCoupling, Slug} from '../../lib/types/fir.js'
@@ -87,7 +88,8 @@ export default class PipelinesDiff extends Command {
     const generation = getGeneration(pipeline)!
 
     ux.action.start('Fetching apps from pipeline')
-    const allApps = await listPipelineApps(coupling!.pipeline!.id!)
+    const {platform} = new HerokuSDK({extensions: [pipelineCouplingExtensions]})
+    const allApps = await platform.pipelineCoupling.listApps(coupling!.pipeline!.id!)
     ux.action.stop()
 
     const sourceStage = coupling.stage
diff --git a/src/commands/pipelines/info.ts b/src/commands/pipelines/info.ts
index cf5246a1e1..df1ee06d40 100644
--- a/src/commands/pipelines/info.ts
+++ b/src/commands/pipelines/info.ts
@@ -1,7 +1,8 @@
 import {Command, flags} from '@heroku-cli/command'
 import * as Heroku from '@heroku-cli/schema'
 import {color, hux} from '@heroku/heroku-cli-util'
-import {listPipelineApps} from '@heroku/sdk/compositions/pipeline'
+import {HerokuSDK} from '@heroku/sdk'
+import {pipelineCouplingExtensions} from '@heroku/sdk/extensions/platform'
 import {Args} from '@oclif/core'
 
 import disambiguate from '../../lib/pipelines/disambiguate.js'
@@ -31,7 +32,8 @@ export default class PipelinesInfo extends Command {
   async run() {
     const {args, flags} = await this.parse(PipelinesInfo)
     const pipeline: Heroku.Pipeline = await disambiguate(this.heroku, args.pipeline)
-    const pipelineApps = await listPipelineApps(pipeline.id!)
+    const {platform} = new HerokuSDK({extensions: [pipelineCouplingExtensions]})
+    const pipelineApps = await platform.pipelineCoupling.listApps(pipeline.id!)
 
     if (flags.json) {
       // eslint-disable-next-line perfectionist/sort-objects
diff --git a/src/commands/pipelines/promote.ts b/src/commands/pipelines/promote.ts
index 003ee22226..7c9c8a03d0 100644
--- a/src/commands/pipelines/promote.ts
+++ b/src/commands/pipelines/promote.ts
@@ -1,12 +1,11 @@
+import type {AppWithPipelineCoupling} from '@heroku/sdk/resources/platform/pipeline-coupling'
+
 import {APIClient, Command, flags} from '@heroku-cli/command'
 import * as Heroku from '@heroku-cli/schema'
 import {color, hux} from '@heroku/heroku-cli-util'
-import {
-  type AppWithPipelineCoupling,
-  listPipelineApps,
-  promotePipeline,
-  type ReleaseStreamContext,
-} from '@heroku/sdk/compositions/pipeline'
+import {HerokuSDK} from '@heroku/sdk'
+import {pipelineCouplingExtensions} from '@heroku/sdk/extensions/platform'
+import {promotePipeline, type ReleaseStreamContext} from '@heroku/sdk/resources/platform/pipeline-promotion'
 import {ux} from '@oclif/core/ux'
 import assert from 'node:assert'
 
@@ -49,7 +48,9 @@ export default class Promote extends Command {
     const appNameOrId = flags.app
     const coupling = await getCoupling(this.heroku, appNameOrId)
     ux.stdout(`Fetching apps from ${color.pipeline(coupling.pipeline!.name)}...`)
-    const allApps = await listPipelineApps(coupling.pipeline!.id!)
+    const sdk = new HerokuSDK({extensions: [pipelineCouplingExtensions]})
+    const {platform} = sdk
+    const allApps = await platform.pipelineCoupling.listApps(coupling.pipeline!.id!)
     const sourceStage = coupling.stage
 
     let promotionActionName = ''
@@ -103,11 +104,15 @@ export default class Promote extends Command {
       }
     }
 
-    const {targets: promotionTargets} = await Promote.promotePipeline({
-      pipeline: {id: coupling.pipeline!.id!},
-      source: {app: {id: coupling.app!.id!}},
-      targets: targetApps.map(app => ({app: {id: app.id}})),
-    }, {onReleaseStream})
+    const {targets: promotionTargets} = await Promote.promotePipeline(
+      {platform},
+      {
+        pipeline: {id: coupling.pipeline!.id!},
+        source: {app: {id: coupling.app!.id!}},
+        targets: targetApps.map(app => ({app: {id: app.id}})),
+      },
+      {onReleaseStream},
+    )
 
     if (releaseStreamError) {
       ux.error(releaseStreamError as Error)
diff --git a/src/commands/pipelines/transfer.ts b/src/commands/pipelines/transfer.ts
index 276172e7d5..eb9a3fbfe1 100644
--- a/src/commands/pipelines/transfer.ts
+++ b/src/commands/pipelines/transfer.ts
@@ -1,6 +1,7 @@
 import {APIClient, Command, flags} from '@heroku-cli/command'
 import {color, hux} from '@heroku/heroku-cli-util'
-import {listPipelineApps} from '@heroku/sdk/compositions/pipeline'
+import {HerokuSDK} from '@heroku/sdk'
+import {pipelineCouplingExtensions} from '@heroku/sdk/extensions/platform'
 import {Args, ux} from '@oclif/core'
 
 import {
@@ -50,7 +51,8 @@ export default class PipelinesTransfer extends Command {
     const {args, flags} = await this.parse(PipelinesTransfer)
     const pipeline = await disambiguate(this.heroku, flags.pipeline)
     const newOwner = await getOwner(this.heroku, args.owner)
-    const apps = await listPipelineApps(pipeline.id!)
+    const {platform} = new HerokuSDK({extensions: [pipelineCouplingExtensions]})
+    const apps = await platform.pipelineCoupling.listApps(pipeline.id!)
     const displayType = newOwner.type === 'user' ? 'account' : newOwner.type
     let confirmName = flags.confirm
 
diff --git a/src/lib/addons/addons-wait.ts b/src/lib/addons/addons-wait.ts
index 9e395c709f..b768297c30 100644
--- a/src/lib/addons/addons-wait.ts
+++ b/src/lib/addons/addons-wait.ts
@@ -1,24 +1,23 @@
 import {APIClient} from '@heroku-cli/command'
 import * as Heroku from '@heroku-cli/schema'
 import * as color from '@heroku/heroku-cli-util/color'
+import {HerokuSDK} from '@heroku/sdk'
 import {ux} from '@oclif/core/ux'
 
-export const waitForAddonProvisioning = async function (api: APIClient, addon: Heroku.AddOn, interval: number) {
+export const waitForAddonProvisioning = async function (addon: Heroku.AddOn, interval: number) {
   const app = addon.app?.name || ''
   const addonName = addon.name
   let addonBody = {...addon}
 
   ux.action.start(`Creating ${color.addon(addonName || '')}`)
 
+  const {platform} = new HerokuSDK()
+  const platformWithExpansion = platform.withHeaders({'Accept-Expansion': 'addon_service,plan'})
   while (addonBody.state === 'provisioning') {
     // eslint-disable-next-line no-promise-executor-return
     await new Promise(resolve => setTimeout(resolve, interval * 1000))
 
-    const addonResponse = await api.get<Heroku.AddOn>(`/apps/${app}/addons/${addonName}`, {
-      headers: {'Accept-Expansion': 'addon_service,plan'},
-    })
-
-    addonBody = addonResponse?.body
+    addonBody = (await platformWithExpansion.addOn.infoByApp(app, addonName!)) as unknown as Heroku.AddOn
   }
 
   if (addonBody.state === 'deprovisioned') {
diff --git a/src/lib/addons/create-addon.ts b/src/lib/addons/create-addon.ts
index c18cf3f3c0..675e4edf67 100644
--- a/src/lib/addons/create-addon.ts
+++ b/src/lib/addons/create-addon.ts
@@ -1,9 +1,11 @@
-import {APIClient} from '@heroku-cli/command'
 import * as Heroku from '@heroku-cli/schema'
 import {color, utils} from '@heroku/heroku-cli-util'
+import {HerokuSDK} from '@heroku/sdk'
+import {addOnExtensions} from '@heroku/sdk/extensions/platform'
+import {AddonConfirmationRequiredError} from '@heroku/sdk/resources/platform/add-on'
 import {ux} from '@oclif/core/ux'
 
-import {waitForAddonProvisioning} from './addons-wait.js'
+import ConfirmCommand from '../confirm-command.js'
 import * as util from './util.js'
 
 function formatConfigVarsMessage(addon: Heroku.AddOn) {
@@ -18,7 +20,6 @@ function formatConfigVarsMessage(addon: Heroku.AddOn) {
 
 // eslint-disable-next-line max-params
 export default async function createAddon(
-  heroku: APIClient,
   app: string,
   plan: string,
   confirm: string | undefined,
@@ -30,57 +31,84 @@ export default async function createAddon(
     config: Record<string, boolean | string | undefined>,
     name?: string,
   },
-) {
-  async function createAddonRequest(confirmed?: string) {
-    const body = {
-      attachment: {name: options.as},
-      config: options.config,
-      confirm: confirmed,
-      name: options.name,
-      plan: {name: plan},
+): Promise<Heroku.AddOn> {
+  const {platform} = new HerokuSDK({extensions: [addOnExtensions]})
+  const buildBody = (confirmed?: string) => ({
+    attachment: {name: options.as},
+    config: options.config as Record<string, string>,
+    confirm: confirmed,
+    name: options.name,
+    plan,
+  })
+
+  // Two-phase UX during a wait: the first ux.action shows
+  // "Creating <plan>... <price>" wrapping the initial create call.
+  // onProvisioning closes that, prints provision_message + "Waiting"
+  // to stdout, then opens a second ux.action ("Creating <addonName>")
+  // that wraps the poll loop and is closed after createAndWait returns.
+  let inWaitPhase = false
+  const onProvisioning = (created: Heroku.AddOn) => {
+    ux.action.stop(options.actionStopMessage || color.green(util.formatPriceText(created.plan?.price || '')))
+    if (created.provision_message) {
+      ux.stdout(created.provision_message)
     }
 
-    try {
-      ux.action.start(options.actionStartMessage || `Creating ${plan} on ${color.app(app)}`)
-      const {body: addon} = await heroku.post<Heroku.AddOn>(`/apps/${app}/addons`, {
-        body,
-        headers: {
-          'accept-expansion': 'plan',
-          'x-heroku-legacy-provider-messages': 'true',
-        },
-      })
-      ux.action.stop(options.actionStopMessage || color.green(util.formatPriceText(addon.plan?.price || '')))
+    ux.stdout(`Waiting for ${color.addon(created.name || '')}...`)
+    ux.action.start(`Creating ${color.addon(created.name || '')}`)
+    inWaitPhase = true
+  }
+
+  async function callCreateAndWait(confirmed?: string): Promise<Heroku.AddOn> {
+    return (await platform.addOn.createAndWait(
+      app,
+      buildBody(confirmed),
+      {onProvisioning, wait},
+    )) as Heroku.AddOn
+  }
 
-      return addon
-    } catch (error: unknown) {
-      ux.action.stop(color.red('!'))
-      throw error
+  ux.action.start(options.actionStartMessage || `Creating ${plan} on ${color.app(app)}`)
+  let addon: Heroku.AddOn
+  try {
+    try {
+      addon = await callCreateAndWait(confirm)
+    } catch (error) {
+      if (error instanceof AddonConfirmationRequiredError) {
+        ux.action.stop(color.red('!'))
+        await new ConfirmCommand().confirm(app, confirm, error.message)
+        ux.action.start(options.actionStartMessage || `Creating ${plan} on ${color.app(app)}`)
+        addon = await callCreateAndWait(app)
+      } else {
+        throw error
+      }
     }
+  } catch (error) {
+    ux.action.stop(color.red('!'))
+    throw error
   }
 
-  let addon = await util.trapConfirmationRequired<Heroku.AddOn>(app, confirm, confirm => (createAddonRequest(confirm)))
+  if (inWaitPhase) {
+    // Closes the wait-phase action started in onProvisioning.
+    ux.action.stop()
+    ux.stdout(formatConfigVarsMessage(addon))
+  } else {
+    // No two-phase: close the create-phase action with the price line.
+    ux.action.stop(options.actionStopMessage || color.green(util.formatPriceText(addon.plan?.price || '')))
 
-  if (addon.provision_message) {
-    ux.stdout(addon.provision_message)
-  }
+    if (addon.provision_message) {
+      ux.stdout(addon.provision_message)
+    }
 
-  if (addon.state === 'provisioning') {
-    if (wait) {
-      ux.stdout(`Waiting for ${color.addon(addon.name || '')}...`)
-      addon = await waitForAddonProvisioning(heroku, addon, 5)
-      ux.stdout(formatConfigVarsMessage(addon))
-    } else {
+    if (addon.state === 'provisioning') {
+      // wait was false; surface guidance for the user to check progress.
       ux.stdout(`${color.addon(addon.name || '')} is being created in the background. The app will restart when complete...`)
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
       if (utils.pg.isAdvancedDatabase(addon as any))
         ux.stdout(`Run ${color.code('heroku data:pg:info ' + addon.name + ' -a ' + addon.app!.name)} to check creation progress.`)
       else
         ux.stdout(`Run ${color.code('heroku addons:info ' + addon.name)} to check creation progress.`)
+    } else {
+      ux.stdout(formatConfigVarsMessage(addon))
     }
-  } else if (addon.state === 'deprovisioned') {
-    throw new Error(`The add-on was unable to be created, with status ${addon.state}`)
-  } else {
-    ux.stdout(formatConfigVarsMessage(addon))
   }
 
   return addon
diff --git a/src/lib/pipelines/ownership.ts b/src/lib/pipelines/ownership.ts
index ba9c4e69a8..67302f0306 100644
--- a/src/lib/pipelines/ownership.ts
+++ b/src/lib/pipelines/ownership.ts
@@ -1,4 +1,4 @@
-import type {AppWithPipelineCoupling} from '@heroku/sdk/compositions/pipeline'
+import type {AppWithPipelineCoupling} from '@heroku/sdk/resources/platform/pipeline-coupling'
 
 import {APIClient} from '@heroku-cli/command'
 import * as Heroku from '@heroku-cli/schema'
diff --git a/src/lib/pipelines/render-pipeline.ts b/src/lib/pipelines/render-pipeline.ts
index 97fc15f25b..0da03a92f9 100644
--- a/src/lib/pipelines/render-pipeline.ts
+++ b/src/lib/pipelines/render-pipeline.ts
@@ -1,4 +1,4 @@
-import type {AppWithPipelineCoupling} from '@heroku/sdk/compositions/pipeline'
+import type {AppWithPipelineCoupling} from '@heroku/sdk/resources/platform/pipeline-coupling'
 
 import {APIClient} from '@heroku-cli/command'
 import * as Heroku from '@heroku-cli/schema'
diff --git a/test/unit/commands/addons/create.unit.test.ts b/test/unit/commands/addons/create.unit.test.ts
index 37afa7a7d1..2edf7971ce 100644
--- a/test/unit/commands/addons/create.unit.test.ts
+++ b/test/unit/commands/addons/create.unit.test.ts
@@ -4,7 +4,6 @@ import {HTTPError} from '@heroku/http-call'
 import ansis from 'ansis'
 import {expect} from 'chai'
 import _ from 'lodash'
-import lolex from 'lolex'
 import nock from 'nock'
 import {createSandbox} from 'sinon'
 
@@ -42,7 +41,7 @@ describe('addons:create', function () {
   context('creating a db with a name', function () {
     beforeEach(function () {
       api.post('/apps/myapp/addons', {
-        attachment: {}, config: {}, name: 'foobar', plan: {name: 'heroku-postgresql:standard-0'},
+        attachment: {}, config: {}, name: 'foobar', plan: 'heroku-postgresql:standard-0',
       })
         .reply(200, addon)
     })
@@ -76,7 +75,7 @@ describe('addons:create', function () {
       api.post('/apps/myapp/addons', {
         attachment: {name: 'mydb'},
         config: {follow: 'otherdb', foo: true, rollback: true},
-        plan: {name: 'heroku-postgresql:standard-0'},
+        plan: 'heroku-postgresql:standard-0',
       })
         .reply(200, addon)
     })
@@ -145,7 +144,7 @@ describe('addons:create', function () {
       beforeEach(function () {
         const asyncAddon = {..._.clone(addon), config_vars: [], state: 'provisioning'}
         api.post('/apps/myapp/addons', {
-          attachment: {name: 'mydb'}, config: {}, plan: {name: 'heroku-postgresql:standard-0'},
+          attachment: {name: 'mydb'}, config: {}, plan: 'heroku-postgresql:standard-0',
         })
           .reply(200, asyncAddon)
       })
@@ -167,7 +166,7 @@ describe('addons:create', function () {
           ..._.clone(addon), config_vars: [], provision_message: undefined, state: 'provisioning',
         }
         api.post('/apps/myapp/addons', {
-          attachment: {name: 'mydb'}, config: {}, plan: {name: 'heroku-postgresql:standard-0'},
+          attachment: {name: 'mydb'}, config: {}, plan: 'heroku-postgresql:standard-0',
         })
           .reply(200, asyncAddon)
       })
@@ -187,7 +186,7 @@ describe('addons:create', function () {
       beforeEach(function () {
         const asyncAddon = {..._.clone(addon), config_vars: undefined, state: 'provisioning'}
         api.post('/apps/myapp/addons', {
-          attachment: {name: 'mydb'}, config: {}, plan: {name: 'heroku-postgresql:standard-0'},
+          attachment: {name: 'mydb'}, config: {}, plan: 'heroku-postgresql:standard-0',
         })
           .reply(200, asyncAddon)
       })
@@ -204,25 +203,18 @@ describe('addons:create', function () {
       })
     })
     context('--wait', function () {
-      let clock: ReturnType<typeof lolex.install>
       let sandbox: ReturnType<typeof createSandbox>
       beforeEach(function () {
         sandbox = createSandbox()
-        clock = lolex.install()
-        clock.setTimeout = function (callback: () => void, _timeout: number, ..._args: any[]): number {
-          callback()
-          return 1
-        }
       })
       afterEach(function () {
-        clock.uninstall()
         sandbox.restore()
       })
       it('waits for response and notifies', async function () {
         const notifySpy = sandbox.spy(Cmd, 'notifier')
         const asyncAddon = {..._.clone(addon), state: 'provisioning'}
         const post = api.post('/apps/myapp/addons', {
-          attachment: {name: 'mydb'}, config: {wait: true}, plan: {name: 'heroku-postgresql:standard-0'},
+          attachment: {name: 'mydb'}, config: {wait: true}, plan: 'heroku-postgresql:standard-0',
         })
           .reply(200, asyncAddon)
         const provisioningResponse = api.get('/apps/myapp/addons/postgresql-swiftly-123')
@@ -253,7 +245,7 @@ describe('addons:create', function () {
         const asyncAddon = _.clone(addon)
         asyncAddon.state = 'provisioning'
         api.post('/apps/myapp/addons', {
-          attachment: {name: 'mydb'}, config: {wait: true}, plan: {name: 'heroku-postgresql:standard-0'},
+          attachment: {name: 'mydb'}, config: {wait: true}, plan: 'heroku-postgresql:standard-0',
         })
           .reply(200, asyncAddon)
         api.get('/apps/myapp/addons/postgresql-swiftly-123')
@@ -284,7 +276,7 @@ describe('addons:create', function () {
         const deprovisionedAddon = _.clone(addon)
         deprovisionedAddon.state = 'deprovisioned'
         api.post('/apps/myapp/addons', {
-          attachment: {name: 'mydb'}, config: {}, plan: {name: 'heroku-postgresql:standard-0'},
+          attachment: {name: 'mydb'}, config: {}, plan: 'heroku-postgresql:standard-0',
         })
           .reply(200, deprovisionedAddon)
         const {error} = await runCommand(Cmd, [
@@ -294,14 +286,14 @@ describe('addons:create', function () {
           'mydb',
           'heroku-postgresql:standard-0',
         ])
-        expect((error as HTTPError)?.message).to.equal('The add-on was unable to be created, with status deprovisioned')
+        expect((error as HTTPError)?.message).to.equal('The add-on was unable to be created, with status deprovisioned.')
       })
     })
   })
   context('creating a db requiring confirmation', function () {
     it('aborts if confirmation does not match', function () {
       api.post('/apps/myapp/addons', {
-        attachment: {name: 'mydb'}, config: {follow: 'otherdb', foo: true, rollback: true}, confirm: 'not-my-app', plan: {name: 'heroku-postgresql:standard-0'},
+        attachment: {name: 'mydb'}, config: {follow: 'otherdb', foo: true, rollback: true}, confirm: 'not-my-app', plan: 'heroku-postgresql:standard-0',
       })
         .reply(423, {id: 'confirmation_required', message: 'This add-on is not automatically networked with this Private Space. '}, {'X-Confirmation-Required': 'myapp-confirm'})
 
@@ -326,7 +318,7 @@ describe('addons:create', function () {
 
     it('succeeds if confirmation does match', async function () {
       api.post('/apps/myapp/addons', {
-        attachment: {name: 'mydb'}, config: {follow: 'otherdb', foo: true, rollback: true}, confirm: 'myapp', plan: {name: 'heroku-postgresql:standard-0'},
+        attachment: {name: 'mydb'}, config: {follow: 'otherdb', foo: true, rollback: true}, confirm: 'myapp', plan: 'heroku-postgresql:standard-0',
       })
         .reply(200, addon)
       const {stderr, stdout} = await runCommand(Cmd, [
@@ -350,7 +342,7 @@ describe('addons:create', function () {
   context('--follow=--otherdb', function () {
     beforeEach(function () {
       api.post('/apps/myapp/addons', {
-        attachment: {name: 'mydb'}, config: {follow: '--otherdb', foo: true, rollback: true}, plan: {name: 'heroku-postgresql:standard-0'},
+        attachment: {name: 'mydb'}, config: {follow: '--otherdb', foo: true, rollback: true}, plan: 'heroku-postgresql:standard-0',
       })
         .reply(200, addon)
     })
@@ -373,7 +365,7 @@ describe('addons:create', function () {
       const noConfigAddon = {..._.clone(addon), config_vars: undefined}
 
       api.post('/apps/myapp/addons', {
-        attachment: {name: 'mydb'}, config: {}, plan: {name: 'heroku-postgresql:standard-0'},
+        attachment: {name: 'mydb'}, config: {}, plan: 'heroku-postgresql:standard-0',
       })
         .reply(200, noConfigAddon)
     })
diff --git a/test/unit/commands/addons/detach.unit.test.ts b/test/unit/commands/addons/detach.unit.test.ts
index f9c6887150..fd86b61d5e 100644
--- a/test/unit/commands/addons/detach.unit.test.ts
+++ b/test/unit/commands/addons/detach.unit.test.ts
@@ -21,7 +21,7 @@ describe('addons:detach', function () {
       .get('/apps/myapp/addon-attachments/redis-123')
       .reply(200, {addon: {name: 'redis'}, id: 100, name: 'redis-123'})
       .delete('/addon-attachments/100')
-      .reply(200)
+      .reply(200, {id: 100, name: 'redis-123'})
       .get('/apps/myapp/releases')
       .reply(200, [{version: 10}])
 
diff --git a/test/unit/commands/addons/index.unit.test.ts b/test/unit/commands/addons/index.unit.test.ts
index 7765fa5198..3de313e195 100644
--- a/test/unit/commands/addons/index.unit.test.ts
+++ b/test/unit/commands/addons/index.unit.test.ts
@@ -39,7 +39,9 @@ describe('addons', function () {
 
     context('with add-ons', function () {
       beforeEach(function () {
-        api
+        // Global /addons doesn't accept Accept-Expansion, so use a
+        // separate scope without the expansion reqheaders.
+        nock('https://api.heroku.com')
           .get('/addons')
           .reply(200, addons)
       })
@@ -82,7 +84,7 @@ describe('addons', function () {
       beforeEach(function () {
         const addon = fixtures.addons['dwh-db']
         addon.billed_price = {cents: 10_000}
-        api
+        nock('https://api.heroku.com')
           .get('/addons')
           .reply(200, [addon])
       })
@@ -101,7 +103,7 @@ describe('addons', function () {
       beforeEach(function () {
         const addon = fixtures.addons['dwh-db']
         addon.billed_price = {cents: 0, contract: true}
-        api
+        nock('https://api.heroku.com')
           .get('/addons')
           .reply(200, [addon])
       })
diff --git a/test/unit/commands/addons/info.unit.test.ts b/test/unit/commands/addons/info.unit.test.ts
index b660180d3f..a6a5c16f25 100644
--- a/test/unit/commands/addons/info.unit.test.ts
+++ b/test/unit/commands/addons/info.unit.test.ts
@@ -2,11 +2,8 @@ import {expectOutput, runCommand} from '@heroku-cli/test-utils'
 import nock from 'nock'
 
 import Cmd from '../../../../src/commands/addons/info.js'
-import  {resolveAddon} from '../../../../src/lib/addons/resolve.js'
 import * as fixtures from '../../../fixtures/addons/fixtures.js'
 
-const {cache} = resolveAddon
-
 describe('addons:info', function () {
   let api: nock.Scope
   let apiSdk: nock.Scope
@@ -19,7 +16,6 @@ describe('addons:info', function () {
         'Accept-Expansion': 'addon_service,plan',
       },
     })
-    cache.clear()
   })
 
   afterEach(function () {
@@ -31,7 +27,7 @@ describe('addons:info', function () {
   context('with add-ons', function () {
     beforeEach(function () {
       apiSdk
-        .post('/actions/addons/resolve', {addon: 'www-db', app: null})
+        .post('/actions/addons/resolve', {addon: 'www-db'})
         .reply(200, [fixtures.addons['www-db']])
       api.get(`/addons/${fixtures.addons['www-db'].id}/addon-attachments`).reply(200, [fixtures.attachments['acme-inc-www::DATABASE']])
     })
@@ -57,13 +53,6 @@ State:        created\n
       apiSdk
         .post('/actions/addons/resolve', {addon: 'www-db', app: 'example'})
         .reply(200, [fixtures.addons['www-db']])
-      nock('https://api.heroku.com', {
-        reqheaders: {
-          'Accept-Expansion': 'addon_service,plan',
-        },
-      })
-        .get(`/addons/${fixtures.addons['www-db'].id}`)
-        .reply(200, fixtures.addons['www-db'])
       api
         .get(`/addons/${fixtures.addons['www-db'].id}/addon-attachments`)
         .reply(200, [fixtures.attachments['acme-inc-www::DATABASE']])
@@ -89,18 +78,13 @@ State:        created\n
   })
   context('with app but not an app add-on', function () {
     beforeEach(function () {
+      // The SDK's resolver tries app-scoped first, falls back to global on 404 add_on.
       apiSdk
         .post('/actions/addons/resolve', {addon: 'www-db', app: 'example'})
+        .reply(404, {id: 'not_found', resource: 'add_on'})
+      apiSdk
+        .post('/actions/addons/resolve', {addon: 'www-db'})
         .reply(200, [fixtures.addons['www-db']])
-      nock('https://api.heroku.com', {reqheaders: {'Accept-Expansion': 'addon_service,plan'}})
-        .get('/apps/example/addons/www-db')
-        .reply(404)
-      nock('https://api.heroku.com', {reqheaders: {'Accept-Expansion': 'addon_service,plan'}})
-        .get('/addons/www-db')
-        .reply(200, fixtures.addons['www-db'])
-      nock('https://api.heroku.com', {reqheaders: {'Accept-Expansion': 'addon_service,plan'}})
-        .get(`/addons/${fixtures.addons['www-db'].id}`)
-        .reply(200, fixtures.addons['www-db'])
       api
         .get(`/addons/${fixtures.addons['www-db'].id}/addon-attachments`)
         .reply(200, [fixtures.attachments['acme-inc-www::DATABASE']])
@@ -130,15 +114,8 @@ State:        created\n
       const addon = fixtures.addons['dwh-db']
       addon.billed_price = {cents: 10_000}
       apiSdk
-        .post('/actions/addons/resolve', {addon: 'dwh-db', app: null})
+        .post('/actions/addons/resolve', {addon: 'dwh-db'})
         .reply(200, [addon])
-      nock('https://api.heroku.com', {
-        reqheaders: {
-          'Accept-Expansion': 'addon_service,plan',
-        },
-      })
-        .get(`/addons/${addon.id}`)
-        .reply(200, addon)
       api
         .get(`/addons/${fixtures.addons['dwh-db'].id}/addon-attachments`)
         .reply(200, [fixtures.attachments['acme-inc-dwh::DATABASE']])
@@ -166,15 +143,8 @@ State:        created\n
       const addon = fixtures.addons['dwh-db']
       addon.billed_price = {cents: 0, contract: true}
       apiSdk
-        .post('/actions/addons/resolve', {addon: 'dwh-db', app: null})
+        .post('/actions/addons/resolve', {addon: 'dwh-db'})
         .reply(200, [addon])
-      nock('https://api.heroku.com', {
-        reqheaders: {
-          'Accept-Expansion': 'addon_service,plan',
-        },
-      })
-        .get(`/addons/${addon.id}`)
-        .reply(200, addon)
       api
         .get(`/addons/${fixtures.addons['dwh-db'].id}/addon-attachments`)
         .reply(200, [fixtures.attachments['acme-inc-dwh::DATABASE']])
@@ -201,11 +171,8 @@ State:        created\n
     beforeEach(function () {
       const provisioningAddon = fixtures.addons['www-redis']
       apiSdk
-        .post('/actions/addons/resolve', {addon: 'www-redis', app: null})
+        .post('/actions/addons/resolve', {addon: 'www-redis'})
         .reply(200, [provisioningAddon])
-      nock('https://api.heroku.com', {reqheaders: {'Accept-Expansion': 'addon_service,plan'}})
-        .get(`/addons/${provisioningAddon.id}`)
-        .reply(200, provisioningAddon)
       api
         .get(`/addons/${provisioningAddon.id}/addon-attachments`)
         .reply(200, [fixtures.attachments['acme-inc-www::REDIS']])
@@ -232,11 +199,8 @@ State:        creating\n
     beforeEach(function () {
       const deprovisioningAddon = fixtures.addons['www-redis-2']
       apiSdk
-        .post('/actions/addons/resolve', {addon: 'www-redis-2', app: null})
+        .post('/actions/addons/resolve', {addon: 'www-redis-2'})
         .reply(200, [deprovisioningAddon])
-      nock('https://api.heroku.com', {reqheaders: {'Accept-Expansion': 'addon_service,plan'}})
-        .get(`/addons/${deprovisioningAddon.id}`)
-        .reply(200, deprovisioningAddon)
       api
         .get(`/addons/${deprovisioningAddon.id}/addon-attachments`)
         .reply(200, [fixtures.attachments['acme-inc-www::REDIS']])
diff --git a/test/unit/commands/addons/rename.unit.test.ts b/test/unit/commands/addons/rename.unit.test.ts
index b75eb0f4a0..615418fff7 100644
--- a/test/unit/commands/addons/rename.unit.test.ts
+++ b/test/unit/commands/addons/rename.unit.test.ts
@@ -17,8 +17,8 @@ describe('addons:rename', function () {
         .get(`/addons/${redis.name}`)
         .reply(200, redis)
       renameRequest = nock('https://api.heroku.com')
-        .patch(`/apps/${redis.app?.id}/addons/${redis.id}`, {name: 'cache-redis'})
-        .reply(201, '')
+        .patch(`/apps/${redis.app?.id}/addons/${redis.id}`, {name: 'cache-redis', plan: redis.plan!.name})
+        .reply(201, {...redis, name: 'cache-redis'})
     })
     it('renames the add-on', async function () {
       const {stdout} = await runCommand(Cmd, [redis_name, 'cache-redis'])
diff --git a/test/unit/commands/addons/upgrade.unit.test.ts b/test/unit/commands/addons/upgrade.unit.test.ts
index 9721d8c9f6..1150439d12 100644
--- a/test/unit/commands/addons/upgrade.unit.test.ts
+++ b/test/unit/commands/addons/upgrade.unit.test.ts
@@ -21,14 +21,15 @@ describe('addons:upgrade', function () {
   it('upgrades an add-on', async function () {
     const addon: AddOn = {
       addon_service: {name: 'heroku-kafka'},
-      app: {name: 'myapp'},
+      app: {id: 'app-1', name: 'myapp'},
+      id: 'addon-1',
       name: 'kafka-swiftly-123',
       plan: {name: 'premium-0'},
     }
     api
       .post('/actions/addons/resolve', {addon: 'heroku-kafka', app: 'myapp'})
       .reply(200, [addon])
-      .patch('/apps/myapp/addons/kafka-swiftly-123', {plan: {name: 'heroku-kafka:hobby'}})
+      .patch('/apps/app-1/addons/addon-1', {plan: 'heroku-kafka:hobby'})
       .reply(200, {plan: {price: {cents: 0}}, provision_message: 'provision msg'})
 
     const {stderr, stdout} = await runCommand(Cmd, [
@@ -44,7 +45,8 @@ describe('addons:upgrade', function () {
   it('displays hourly and monthly price when upgrading an add-on', async function () {
     const addon: AddOn = {
       addon_service: {name: 'heroku-kafka'},
-      app: {name: 'myapp'},
+      app: {id: 'app-1', name: 'myapp'},
+      id: 'addon-1',
       name: 'kafka-swiftly-123',
       plan: {name: 'premium-0'},
     }
@@ -52,7 +54,7 @@ describe('addons:upgrade', function () {
     api
       .post('/actions/addons/resolve', {addon: 'heroku-kafka', app: 'myapp'})
       .reply(200, [addon])
-      .patch('/apps/myapp/addons/kafka-swiftly-123', {plan: {name: 'heroku-kafka:standard'}})
+      .patch('/apps/app-1/addons/addon-1', {plan: 'heroku-kafka:standard'})
       .reply(200, {plan: {price: {cents: 2500, unit: 'month'}}, provision_message: 'provision msg'})
 
     const {stderr, stdout} = await runCommand(Cmd, [
@@ -68,7 +70,8 @@ describe('addons:upgrade', function () {
   it('does not display a price when upgrading an add-on and no price is returned from the api', async function () {
     const addon = {
       addon_service: {name: 'heroku-kafka'},
-      app: {name: 'myapp'},
+      app: {id: 'app-1', name: 'myapp'},
+      id: 'addon-1',
       name: 'kafka-swiftly-123',
       plan: {name: 'premium-0'},
     }
@@ -76,7 +79,7 @@ describe('addons:upgrade', function () {
     api
       .post('/actions/addons/resolve', {addon: 'heroku-kafka', app: 'myapp'})
       .reply(200, [addon])
-      .patch('/apps/myapp/addons/kafka-swiftly-123', {plan: {name: 'heroku-kafka:hobby'}})
+      .patch('/apps/app-1/addons/addon-1', {plan: 'heroku-kafka:hobby'})
       .reply(200, {plan: {}, provision_message: 'provision msg'})
 
     const {stderr, stdout} = await runCommand(Cmd, [
@@ -92,7 +95,8 @@ describe('addons:upgrade', function () {
   it('upgrades to a contract add-on', async function () {
     const addon = {
       addon_service: {name: 'heroku-connect'},
-      app: {name: 'myapp'},
+      app: {id: 'app-1', name: 'myapp'},
+      id: 'addon-1',
       name: 'connect-swiftly-123',
       plan: {name: 'free'},
     }
@@ -100,7 +104,7 @@ describe('addons:upgrade', function () {
     api
       .post('/actions/addons/resolve', {addon: 'heroku-connect', app: 'myapp'})
       .reply(200, [addon])
-      .patch('/apps/myapp/addons/connect-swiftly-123', {plan: {name: 'heroku-connect:contract'}})
+      .patch('/apps/app-1/addons/addon-1', {plan: 'heroku-connect:contract'})
       .reply(200, {plan: {price: {cents: 0, contract: true}}, provision_message: 'provision msg'})
 
     const {stderr, stdout} = await runCommand(Cmd, [
@@ -116,14 +120,15 @@ describe('addons:upgrade', function () {
   it('upgrades an add-on with only one argument', async function () {
     const addon = {
       addon_service: {name: 'heroku-postgresql'},
-      app: {name: 'myapp'},
+      app: {id: 'app-1', name: 'myapp'},
+      id: 'addon-1',
       name: 'postgresql-swiftly-123',
       plan: {name: 'premium-0'},
     }
     api
       .post('/actions/addons/resolve', {addon: 'heroku-postgresql', app: 'myapp'})
       .reply(200, [addon])
-      .patch('/apps/myapp/addons/postgresql-swiftly-123', {plan: {name: 'heroku-postgresql:hobby'}})
+      .patch('/apps/app-1/addons/addon-1', {plan: 'heroku-postgresql:hobby'})
       .reply(200, {plan: {price: {cents: 0}}})
 
     const {stderr, stdout} = await runCommand(Cmd, [
@@ -152,7 +157,8 @@ describe('addons:upgrade', function () {
   it('errors with invalid plan', async function () {
     const addon = {
       addon_service: {name: 'heroku-db1'},
-      app: {name: 'myapp'},
+      app: {id: 'app-1', name: 'myapp'},
+      id: 'addon-1',
       name: 'db1-swiftly-123',
       plan: {name: 'premium-0'},
     }
@@ -166,7 +172,7 @@ describe('addons:upgrade', function () {
         {name: 'heroku-db1:basic', plan: {cents: 25}},
         {name: 'heroku-db1:premium-0', price: {cents: 3500}},
       ])
-      .patch('/apps/myapp/addons/db1-swiftly-123', {plan: {name: 'heroku-db1:invalid'}})
+      .patch('/apps/app-1/addons/addon-1', {plan: 'heroku-db1:invalid'})
       .reply(422, {message: 'Couldn\'t find either the add-on service or the add-on plan of "heroku-db1:invalid".'})
 
     try {
@@ -199,7 +205,7 @@ describe('addons:upgrade', function () {
   })
 
   it('handles multiple add-ons', async function () {
-    api.post('/actions/addons/resolve', {addon: 'heroku-redis', app: null})
+    api.post('/actions/addons/resolve', {addon: 'heroku-redis'})
       .reply(200, [{name: 'db1-swiftly-123'}, {name: 'db1-swiftly-456'}])
     try {
       await runCommand(Cmd, [
diff --git a/test/unit/commands/addons/wait.unit.test.ts b/test/unit/commands/addons/wait.unit.test.ts
index 7384991779..22c5daf98e 100644
--- a/test/unit/commands/addons/wait.unit.test.ts
+++ b/test/unit/commands/addons/wait.unit.test.ts
@@ -1,29 +1,28 @@
 import {expectOutput, runCommand} from '@heroku-cli/test-utils'
 import {expect} from 'chai'
 import _ from 'lodash'
-import lolex from 'lolex'
 import nock from 'nock'
-import {createSandbox} from 'sinon'
+import {createSandbox, type SinonFakeTimers} from 'sinon'
 
 import Cmd from '../../../../src/commands/addons/wait.js'
 import * as fixtures from '../../../fixtures/addons/fixtures.js'
-let clock: any
+
 const expansionHeaders = {'Accept-Expansion': 'addon_service,plan'}
 
 describe('addons:wait', function () {
   let sandbox: any
+  let clock: SinonFakeTimers
 
   beforeEach(function () {
     sandbox = createSandbox()
     nock.cleanAll()
-    clock = lolex.install()
-    clock.setTimeout = function (fn: any) {
-      process.nextTick(fn)
-    }
+    // Fake only Date so the >5s notifier threshold can be advanced
+    // synchronously without faking setTimeout (the SDK's polling loop
+    // needs real setTimeout to drive the test forward).
+    clock = sandbox.useFakeTimers({shouldAdvanceTime: true, toFake: ['Date']})
   })
 
   afterEach(function () {
-    clock.uninstall()
     sandbox.restore()
   })
   context('waiting for an individual add-on to provision', function () {
diff --git a/test/unit/commands/data/pg/create.unit.test.ts b/test/unit/commands/data/pg/create.unit.test.ts
index d9f2b75ea6..0a0ce937e6 100644
--- a/test/unit/commands/data/pg/create.unit.test.ts
+++ b/test/unit/commands/data/pg/create.unit.test.ts
@@ -73,7 +73,7 @@ describe('data:pg:create', function () {
         .post('/apps/myapp/addons', {
           attachment: {},
           config: {level: '4G-Performance'},
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createAddonResponse)
       const dataApi = nock('https://api.data.heroku.com')
@@ -105,7 +105,7 @@ describe('data:pg:create', function () {
         .post('/apps/myapp/addons', {
           attachment: {},
           config: {level: '4G-Performance'},
-          plan: {name: 'heroku-postgresql:advanced-private'},
+          plan: 'heroku-postgresql:advanced-private',
         })
         .reply(200, createAddonResponse)
 
@@ -131,7 +131,7 @@ describe('data:pg:create', function () {
         .post('/apps/myapp/addons', {
           attachment: {},
           config: {level: '4G-Performance'},
-          plan: {name: 'heroku-postgresql:advanced-shield'},
+          plan: 'heroku-postgresql:advanced-shield',
         })
         .reply(200, createAddonResponse)
 
@@ -187,7 +187,7 @@ describe('data:pg:create', function () {
             level: '4G-Performance',
           },
           confirm: 'myapp',
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createAddonResponse)
 
@@ -214,7 +214,7 @@ describe('data:pg:create', function () {
             'high-availability': true,
             level: levelsResponse.items[0].name,
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createAddonResponse)
 
@@ -284,7 +284,7 @@ describe('data:pg:create', function () {
             'high-availability': false,
             level: levelsResponse.items[0].name,
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createAddonResponse)
 
@@ -321,7 +321,7 @@ describe('data:pg:create', function () {
             'high-availability': true,
             level: levelsResponse.items[0].name,
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createAddonResponse)
 
@@ -374,7 +374,7 @@ describe('data:pg:create', function () {
             'high-availability': true,
             level: levelsResponse.items[0].name,
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createAddonResponse)
 
@@ -450,7 +450,7 @@ describe('data:pg:create', function () {
             'high-availability': true,
             level: levelsResponse.items[0].name,
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createAddonResponse)
 
diff --git a/test/unit/commands/data/pg/fork.unit.test.ts b/test/unit/commands/data/pg/fork.unit.test.ts
index a12071cf1f..6f3b6e8e7c 100644
--- a/test/unit/commands/data/pg/fork.unit.test.ts
+++ b/test/unit/commands/data/pg/fork.unit.test.ts
@@ -44,7 +44,7 @@ describe('data:pg:fork', function () {
             fork: 'advanced-horizontal-01234',
             level: '4G-Performance',
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createForkResponse)
 
@@ -80,7 +80,7 @@ describe('data:pg:fork', function () {
             level: '4G-Performance',
           },
           name: 'my-forked-db',
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createForkResponse)
 
@@ -117,7 +117,7 @@ describe('data:pg:fork', function () {
             fork: 'advanced-horizontal-01234',
             level: '8G-Performance',
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createForkResponse)
 
@@ -182,7 +182,7 @@ describe('data:pg:fork', function () {
             'recovery-time': '2025-01-11T12:35:00',
             rollback: 'advanced-horizontal-01234',
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createForkResponse)
 
@@ -225,7 +225,7 @@ describe('data:pg:fork', function () {
             'recovery-time': '2025-01-30T00:00:00',
             rollback: 'advanced-horizontal-01234',
           },
-          plan: {name: 'heroku-postgresql:advanced'},
+          plan: 'heroku-postgresql:advanced',
         })
         .reply(200, createForkResponse)
 
diff --git a/test/unit/commands/data/pg/migrate.unit.test.ts b/test/unit/commands/data/pg/migrate.unit.test.ts
index 03046e32e8..afbafe5968 100644
--- a/test/unit/commands/data/pg/migrate.unit.test.ts
+++ b/test/unit/commands/data/pg/migrate.unit.test.ts
@@ -525,10 +525,10 @@ describe('data:pg:migrate', function () {
       expect(stderr).to.equal('Configuring migration... done\n')
       expect(stdout).to.contain('→ Configure Leader Pool')
       expect(createAddonStub.calledOnce).to.be.true
-      expect(createAddonStub.args[0][1]).to.equal(premiumDbAttachment.addon.app.name)
+      expect(createAddonStub.args[0][0]).to.equal(premiumDbAttachment.addon.app.name)
       // Verify the service plan is correct (no private or shield networking)
-      expect(createAddonStub.args[0][2]).to.equal('heroku-postgresql:advanced')
-      expect(createAddonStub.args[0][5]).to.deep.include({
+      expect(createAddonStub.args[0][1]).to.equal('heroku-postgresql:advanced')
+      expect(createAddonStub.args[0][4]).to.deep.include({
         config: {
           from: premiumDbAttachment.addon.id,
           'high-availability': true,
@@ -596,10 +596,10 @@ describe('data:pg:migrate', function () {
       expect(stderr).to.equal('Configuring migration... done\n')
       expect(stdout).to.contain('→ Configure Leader Pool')
       expect(createAddonStub.calledOnce)
-      expect(createAddonStub.args[0][1]).to.equal(privateDbAttachment.addon.app.name)
+      expect(createAddonStub.args[0][0]).to.equal(privateDbAttachment.addon.app.name)
       // Verify the service plan is correct (private networking)
-      expect(createAddonStub.args[0][2]).to.equal('heroku-postgresql:advanced-private')
-      expect(createAddonStub.args[0][5]).to.deep.include({
+      expect(createAddonStub.args[0][1]).to.equal('heroku-postgresql:advanced-private')
+      expect(createAddonStub.args[0][4]).to.deep.include({
         config: {
           from: privateDbAttachment.addon.id,
           'high-availability': true,
@@ -667,10 +667,10 @@ describe('data:pg:migrate', function () {
       expect(stderr).to.equal('Configuring migration... done\n')
       expect(stdout).to.contain('→ Configure Leader Pool')
       expect(createAddonStub.calledOnce)
-      expect(createAddonStub.args[0][1]).to.equal(shieldDbAttachment.addon.app.name)
+      expect(createAddonStub.args[0][0]).to.equal(shieldDbAttachment.addon.app.name)
       // Verify the service plan is correct (shield networking)
-      expect(createAddonStub.args[0][2]).to.equal('heroku-postgresql:advanced-shield')
-      expect(createAddonStub.args[0][5]).to.deep.include({
+      expect(createAddonStub.args[0][1]).to.equal('heroku-postgresql:advanced-shield')
+      expect(createAddonStub.args[0][4]).to.deep.include({
         config: {
           from: shieldDbAttachment.addon.id,
           'high-availability': true,
diff --git a/test/unit/commands/pipelines/promote.unit.test.ts b/test/unit/commands/pipelines/promote.unit.test.ts
index 7e28fdb345..5d0a48320c 100644
--- a/test/unit/commands/pipelines/promote.unit.test.ts
+++ b/test/unit/commands/pipelines/promote.unit.test.ts
@@ -103,7 +103,7 @@ describe('pipelines:promote', function () {
     const {stdout} = await runCommand(Cmd, [`--app=${sourceApp.name}`])
 
     expect(promoteStub.calledOnce).to.be.true
-    expect(promoteStub.firstCall.args[0]).to.deep.equal({
+    expect(promoteStub.firstCall.args[1]).to.deep.equal({
       pipeline: {id: pipeline.id},
       source: {app: {id: sourceApp.id}},
       targets: [
@@ -128,7 +128,7 @@ describe('pipelines:promote', function () {
 
       const {stdout} = await runCommand(Cmd, [`--app=${sourceApp.name}`, `--to=${targetApp1.name}`])
 
-      expect(promoteStub.firstCall.args[0].targets).to.deep.equal([{app: {id: targetApp1.id}}])
+      expect(promoteStub.firstCall.args[1].targets).to.deep.equal([{app: {id: targetApp1.id}}])
       expect(stdout).to.contain('failed')
       expect(stdout).to.contain('Because reasons')
     })
@@ -145,7 +145,7 @@ describe('pipelines:promote', function () {
 
       const {stdout} = await runCommand(Cmd, [`--app=${sourceApp.name}`, `--to=${targetApp1.id}`])
 
-      expect(promoteStub.firstCall.args[0].targets).to.deep.equal([{app: {id: targetApp1.id}}])
+      expect(promoteStub.firstCall.args[1].targets).to.deep.equal([{app: {id: targetApp1.id}}])
       expect(stdout).to.contain('failed')
       expect(stdout).to.contain('Because reasons')
     })
@@ -160,7 +160,7 @@ describe('pipelines:promote', function () {
           controller.close()
         },
       })
-      const promoteStub = stub(Cmd, 'promotePipeline').callsFake(async (_body, options) => {
+      const promoteStub = stub(Cmd, 'promotePipeline').callsFake(async (_ctx, _body, options) => {
         await options!.onReleaseStream!({
           stream: streamBody,
           target: {app: {id: targetApp1.id}, status: 'pending'},