diff --git a/app/api/index.ts b/app/api/index.ts
index bb79dc0a58..6952c0e57d 100644
--- a/app/api/index.ts
+++ b/app/api/index.ts
@@ -19,8 +19,6 @@ export * from './__generated__/Api'
 
 export type { ApiTypes }
 
-export * as PathParams from './path-params'
-
 export { ensurePrefetched, PAGE_SIZE, type PaginatedQuery, type ResultsPage } from './hooks'
 export type { ApiError } from './errors'
 export { navToLogin } from './nav-to-login'
diff --git a/app/api/path-params.ts b/app/api/path-params.ts
deleted file mode 100644
index eaeab465aa..0000000000
--- a/app/api/path-params.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, you can obtain one at https://mozilla.org/MPL/2.0/.
- *
- * Copyright Oxide Computer Company
- */
-import type { Merge } from 'type-fest'
-
-export type Project = { project?: string }
-export type Instance = Merge<Project, { instance?: string }>
-export type Disk = Merge<Project, { disk?: string }>
-export type Image = Merge<Project, { image?: string }>
-export type SiloImage = { image?: string }
-export type NetworkInterface = Merge<Instance, { interface?: string }>
-export type Snapshot = Merge<Project, { snapshot?: string }>
-export type Vpc = Merge<Project, { vpc?: string }>
-export type VpcRouter = Merge<Vpc, { router?: string }>
-export type VpcRouterRoute = Merge<VpcRouter, { route?: string }>
-export type VpcSubnet = Merge<Vpc, { subnet?: string }>
-export type FirewallRule = Merge<Vpc, { rule?: string }>
-export type Silo = { silo?: string }
-export type IdentityProvider = Merge<Silo, { provider: string }>
-export type SystemUpdate = { version: string }
-export type SshKey = { sshKey: string }
-export type Sled = { sledId?: string }
-export type IpPool = { pool?: string }
-export type FloatingIp = Merge<Project, { floatingIp?: string }>
-
-export type Id = { id: string }
diff --git a/app/api/selectors.ts b/app/api/selectors.ts
new file mode 100644
index 0000000000..47275576bb
--- /dev/null
+++ b/app/api/selectors.ts
@@ -0,0 +1,30 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * Copyright Oxide Computer Company
+ */
+import type { Merge } from 'type-fest'
+
+export type Project = Readonly<{ project?: string }>
+export type Instance = Readonly<Merge<Project, { instance?: string }>>
+export type Disk = Readonly<Merge<Project, { disk?: string }>>
+export type Image = Readonly<Merge<Project, { image?: string }>>
+export type SiloImage = Readonly<{ image?: string }>
+export type NetworkInterface = Readonly<Merge<Instance, { interface?: string }>>
+export type Snapshot = Readonly<Merge<Project, { snapshot?: string }>>
+export type Vpc = Readonly<Merge<Project, { vpc?: string }>>
+export type VpcRouter = Readonly<Merge<Vpc, { router?: string }>>
+export type VpcRouterRoute = Readonly<Merge<VpcRouter, { route?: string }>>
+export type VpcSubnet = Readonly<Merge<Vpc, { subnet?: string }>>
+export type FirewallRule = Readonly<Merge<Vpc, { rule?: string }>>
+export type Silo = Readonly<{ silo?: string }>
+export type IdentityProvider = Readonly<Merge<Silo, { provider: string }>>
+export type SystemUpdate = Readonly<{ version: string }>
+export type SshKey = Readonly<{ sshKey: string }>
+export type Sled = Readonly<{ sledId?: string }>
+export type IpPool = Readonly<{ pool?: string }>
+export type FloatingIp = Readonly<Merge<Project, { floatingIp?: string }>>
+
+export type Id = Readonly<{ id: string }>
diff --git a/app/components/ExternalIps.tsx b/app/components/ExternalIps.tsx
index c066c1727f..eb9e036932 100644
--- a/app/components/ExternalIps.tsx
+++ b/app/components/ExternalIps.tsx
@@ -11,10 +11,9 @@ import { useApiQuery } from '@oxide/api'
 import { EmptyCell, SkeletonCell } from '~/table/cells/EmptyCell'
 import { CopyableIp } from '~/ui/lib/CopyableIp'
 import { intersperse } from '~/util/array'
+import type * as PP from '~/util/path-params'
 
-type InstanceSelector = { project: string; instance: string }
-
-export function ExternalIps({ project, instance }: InstanceSelector) {
+export function ExternalIps({ project, instance }: PP.Instance) {
   const { data, isPending } = useApiQuery('instanceExternalIpList', {
     path: { instance },
     query: { project },
diff --git a/app/forms/snapshot-create.tsx b/app/forms/snapshot-create.tsx
index 7424770a44..a886800709 100644
--- a/app/forms/snapshot-create.tsx
+++ b/app/forms/snapshot-create.tsx
@@ -14,7 +14,6 @@ import {
   useApiMutation,
   useApiQuery,
   useApiQueryClient,
-  type PathParams as PP,
   type SnapshotCreate,
 } from '@oxide/api'
 
@@ -28,10 +27,11 @@ import { addToast } from '~/stores/toast'
 import { toComboboxItems } from '~/ui/lib/Combobox'
 import { ALL_ISH } from '~/util/consts'
 import { pb } from '~/util/path-builder'
+import type * as PP from '~/util/path-params'
 
-const useSnapshotDiskItems = (projectSelector: PP.Project) => {
+const useSnapshotDiskItems = ({ project }: PP.Project) => {
   const { data: disks } = useApiQuery('diskList', {
-    query: { ...projectSelector, limit: ALL_ISH },
+    query: { project, limit: ALL_ISH },
   })
   return disks?.items.filter(diskCan.snapshot)
 }
diff --git a/app/pages/project/disks/DisksPage.tsx b/app/pages/project/disks/DisksPage.tsx
index adaa7e7cce..429530f7d7 100644
--- a/app/pages/project/disks/DisksPage.tsx
+++ b/app/pages/project/disks/DisksPage.tsx
@@ -37,6 +37,7 @@ import { PageHeader, PageTitle } from '~/ui/lib/PageHeader'
 import { TableActions } from '~/ui/lib/Table'
 import { docLinks } from '~/util/links'
 import { pb } from '~/util/path-builder'
+import type * as PP from '~/util/path-params'
 
 import { fancifyStates } from '../instances/instance/tabs/common'
 
@@ -50,12 +51,12 @@ const EmptyState = () => (
   />
 )
 
-const diskList = (project: string) => getListQFn('diskList', { query: { project } })
+const diskList = (query: PP.Project) => getListQFn('diskList', { query })
 
 DisksPage.loader = async ({ params }: LoaderFunctionArgs) => {
   const { project } = getProjectSelector(params)
   await Promise.all([
-    queryClient.prefetchQuery(diskList(project).optionsFn()),
+    queryClient.prefetchQuery(diskList({ project }).optionsFn()),
 
     // fetch instances and preload into RQ cache so fetches by ID in
     // InstanceLinkCell can be mostly instant yet gracefully fall back to
@@ -162,7 +163,7 @@ export function DisksPage() {
 
   const columns = useColsWithActions(staticCols, makeActions)
   const { table } = useQueryTable({
-    query: diskList(project),
+    query: diskList({ project }),
     columns,
     emptyState: <EmptyState />,
   })
diff --git a/app/pages/project/images/ImagesPage.tsx b/app/pages/project/images/ImagesPage.tsx
index 226848230b..736475c1f5 100644
--- a/app/pages/project/images/ImagesPage.tsx
+++ b/app/pages/project/images/ImagesPage.tsx
@@ -36,6 +36,7 @@ import { PageHeader, PageTitle } from '~/ui/lib/PageHeader'
 import { TableActions } from '~/ui/lib/Table'
 import { docLinks } from '~/util/links'
 import { pb } from '~/util/path-builder'
+import type * as PP from '~/util/path-params'
 
 const EmptyState = () => (
   <EmptyMessage
@@ -49,11 +50,11 @@ const EmptyState = () => (
 
 const colHelper = createColumnHelper<Image>()
 
-const imageList = (project: string) => getListQFn('imageList', { query: { project } })
+const imageList = (query: PP.Project) => getListQFn('imageList', { query })
 
 ImagesPage.loader = async ({ params }: LoaderFunctionArgs) => {
   const { project } = getProjectSelector(params)
-  await queryClient.prefetchQuery(imageList(project).optionsFn())
+  await queryClient.prefetchQuery(imageList({ project }).optionsFn())
   return null
 }
 
@@ -103,7 +104,7 @@ export function ImagesPage() {
   }, [project, makeActions])
 
   const { table } = useQueryTable({
-    query: imageList(project),
+    query: imageList({ project }),
     columns,
     emptyState: <EmptyState />,
   })
diff --git a/app/pages/project/vpcs/RouterPage.tsx b/app/pages/project/vpcs/RouterPage.tsx
index 33b04d1edd..54304780eb 100644
--- a/app/pages/project/vpcs/RouterPage.tsx
+++ b/app/pages/project/vpcs/RouterPage.tsx
@@ -43,13 +43,12 @@ import { PropertiesTable } from '~/ui/lib/PropertiesTable'
 import { TableControls, TableTitle } from '~/ui/lib/Table'
 import { docLinks } from '~/util/links'
 import { pb } from '~/util/path-builder'
+import type * as PP from '~/util/path-params'
 
-type RouterParams = { project: string; vpc: string; router: string }
-
-const routerView = ({ project, vpc, router }: RouterParams) =>
+const routerView = ({ project, vpc, router }: PP.VpcRouter) =>
   apiq('vpcRouterView', { path: { router }, query: { vpc, project } })
 
-const routeList = (query: RouterParams) => getListQFn('vpcRouterRouteList', { query })
+const routeList = (query: PP.VpcRouter) => getListQFn('vpcRouterRouteList', { query })
 
 export async function loader({ params }: LoaderFunctionArgs) {
   const routerSelector = getVpcRouterSelector(params)
diff --git a/app/pages/project/vpcs/VpcPage/tabs/VpcRoutersTab.tsx b/app/pages/project/vpcs/VpcPage/tabs/VpcRoutersTab.tsx
index a91e2aaa73..a7486521ee 100644
--- a/app/pages/project/vpcs/VpcPage/tabs/VpcRoutersTab.tsx
+++ b/app/pages/project/vpcs/VpcPage/tabs/VpcRoutersTab.tsx
@@ -29,11 +29,11 @@ import { useQueryTable } from '~/table/QueryTable'
 import { CreateLink } from '~/ui/lib/CreateButton'
 import { EmptyMessage } from '~/ui/lib/EmptyMessage'
 import { pb } from '~/util/path-builder'
+import type * as PP from '~/util/path-params'
 
 const colHelper = createColumnHelper<VpcRouter>()
 
-const vpcRouterList = (params: { project: string; vpc: string }) =>
-  getListQFn('vpcRouterList', { query: params })
+const vpcRouterList = (query: PP.Vpc) => getListQFn('vpcRouterList', { query })
 
 export async function loader({ params }: LoaderFunctionArgs) {
   const { project, vpc } = getVpcSelector(params)
diff --git a/app/pages/project/vpcs/VpcPage/tabs/VpcSubnetsTab.tsx b/app/pages/project/vpcs/VpcPage/tabs/VpcSubnetsTab.tsx
index 754762d774..f3111bb605 100644
--- a/app/pages/project/vpcs/VpcPage/tabs/VpcSubnetsTab.tsx
+++ b/app/pages/project/vpcs/VpcPage/tabs/VpcSubnetsTab.tsx
@@ -29,11 +29,11 @@ import { useQueryTable } from '~/table/QueryTable'
 import { CreateLink } from '~/ui/lib/CreateButton'
 import { EmptyMessage } from '~/ui/lib/EmptyMessage'
 import { pb } from '~/util/path-builder'
+import type * as PP from '~/util/path-params'
 
 const colHelper = createColumnHelper<VpcSubnet>()
 
-const subnetList = (params: { project: string; vpc: string }) =>
-  getListQFn('vpcSubnetList', { query: params })
+const subnetList = (params: PP.Vpc) => getListQFn('vpcSubnetList', { query: params })
 
 export async function loader({ params }: LoaderFunctionArgs) {
   const { project, vpc } = getVpcSelector(params)
diff --git a/app/pages/project/vpcs/VpcsPage.tsx b/app/pages/project/vpcs/VpcsPage.tsx
index 6cb7a7704a..1b8282a4a4 100644
--- a/app/pages/project/vpcs/VpcsPage.tsx
+++ b/app/pages/project/vpcs/VpcsPage.tsx
@@ -37,6 +37,7 @@ import { PageHeader, PageTitle } from '~/ui/lib/PageHeader'
 import { TableActions } from '~/ui/lib/Table'
 import { docLinks } from '~/util/links'
 import { pb } from '~/util/path-builder'
+import type * as PP from '~/util/path-params'
 
 const vpcList = (project: string) => getListQFn('vpcList', { query: { project } })
 
@@ -59,7 +60,7 @@ export const VpcDocsPopover = () => (
   />
 )
 
-const FirewallRuleCount = ({ project, vpc }: { project: string; vpc: string }) => {
+const FirewallRuleCount = ({ project, vpc }: PP.Vpc) => {
   const { data } = useApiQuery('vpcFirewallRulesView', { query: { project, vpc } })
 
   if (!data) return <SkeletonCell /> // loading
diff --git a/app/util/path-builder.ts b/app/util/path-builder.ts
index 2fb132d64a..55439bb067 100644
--- a/app/util/path-builder.ts
+++ b/app/util/path-builder.ts
@@ -5,48 +5,30 @@
  *
  * Copyright Oxide Computer Company
  */
-import type { PathParams as PP } from '@oxide/api'
-
-// TODO: required versions of path params probably belong somewhere else,
-// they're useful
-
-type Project = Required<PP.Project>
-type Instance = Required<PP.Instance>
-type Vpc = Required<PP.Vpc>
-type Silo = Required<PP.Silo>
-type IdentityProvider = Required<PP.IdentityProvider>
-type Sled = Required<PP.Sled>
-type Image = Required<PP.Image>
-type Snapshot = Required<PP.Snapshot>
-type SiloImage = Required<PP.SiloImage>
-type IpPool = Required<PP.IpPool>
-type FloatingIp = Required<PP.FloatingIp>
-type FirewallRule = Required<PP.FirewallRule>
-type VpcRouter = Required<PP.VpcRouter>
-type VpcRouterRoute = Required<PP.VpcRouterRoute>
-type VpcSubnet = Required<PP.VpcSubnet>
+import type * as PP from './path-params.ts'
 
 // these are used as the basis for many routes but are not themselves routes we
 // ever want to link to. so we use this to build the routes but pb.project() is
 // different (includes /instances)
-const projectBase = ({ project }: Project) => `${pb.projects()}/${project}`
-const instanceBase = ({ project, instance }: Instance) =>
+const projectBase = ({ project }: PP.Project) => `${pb.projects()}/${project}`
+const instanceBase = ({ project, instance }: PP.Instance) =>
   `${pb.instances({ project })}/${instance}`
-const vpcBase = ({ project, vpc }: Vpc) => `${pb.vpcs({ project })}/${vpc}`
+const vpcBase = ({ project, vpc }: PP.Vpc) => `${pb.vpcs({ project })}/${vpc}`
 
 export const pb = {
   projects: () => `/projects`,
   projectsNew: () => `/projects-new`,
-  project: (params: Project) => `${projectBase(params)}/instances`,
-  projectEdit: (params: Project) => `${projectBase(params)}/edit`,
+  project: (params: PP.Project) => `${projectBase(params)}/instances`,
+  projectEdit: (params: PP.Project) => `${projectBase(params)}/edit`,
 
-  projectAccess: (params: Project) => `${projectBase(params)}/access`,
-  projectImages: (params: Project) => `${projectBase(params)}/images`,
-  projectImagesNew: (params: Project) => `${projectBase(params)}/images-new`,
-  projectImageEdit: (params: Image) => `${pb.projectImages(params)}/${params.image}/edit`,
+  projectAccess: (params: PP.Project) => `${projectBase(params)}/access`,
+  projectImages: (params: PP.Project) => `${projectBase(params)}/images`,
+  projectImagesNew: (params: PP.Project) => `${projectBase(params)}/images-new`,
+  projectImageEdit: (params: PP.Image) =>
+    `${pb.projectImages(params)}/${params.image}/edit`,
 
-  instances: (params: Project) => `${projectBase(params)}/instances`,
-  instancesNew: (params: Project) => `${projectBase(params)}/instances-new`,
+  instances: (params: PP.Project) => `${projectBase(params)}/instances`,
+  instancesNew: (params: PP.Project) => `${projectBase(params)}/instances-new`,
 
   /**
    * This route exists as a direct link to the default tab of the instance page. Unfortunately
@@ -55,76 +37,77 @@ export const pb = {
    *
    * @see https://github.com/oxidecomputer/console/pull/1267#discussion_r1016766205
    */
-  instance: (params: Instance) => pb.instanceStorage(params),
+  instance: (params: PP.Instance) => pb.instanceStorage(params),
 
-  instanceMetrics: (params: Instance) => `${instanceBase(params)}/metrics`,
-  instanceStorage: (params: Instance) => `${instanceBase(params)}/storage`,
-  instanceConnect: (params: Instance) => `${instanceBase(params)}/connect`,
-  instanceNetworking: (params: Instance) => `${instanceBase(params)}/networking`,
-  serialConsole: (params: Instance) => `${instanceBase(params)}/serial-console`,
+  instanceMetrics: (params: PP.Instance) => `${instanceBase(params)}/metrics`,
+  instanceStorage: (params: PP.Instance) => `${instanceBase(params)}/storage`,
+  instanceConnect: (params: PP.Instance) => `${instanceBase(params)}/connect`,
+  instanceNetworking: (params: PP.Instance) => `${instanceBase(params)}/networking`,
+  serialConsole: (params: PP.Instance) => `${instanceBase(params)}/serial-console`,
 
-  disksNew: (params: Project) => `${projectBase(params)}/disks-new`,
-  disks: (params: Project) => `${projectBase(params)}/disks`,
+  disksNew: (params: PP.Project) => `${projectBase(params)}/disks-new`,
+  disks: (params: PP.Project) => `${projectBase(params)}/disks`,
 
-  snapshotsNew: (params: Project) => `${projectBase(params)}/snapshots-new`,
-  snapshots: (params: Project) => `${projectBase(params)}/snapshots`,
-  snapshotImagesNew: (params: Snapshot) =>
+  snapshotsNew: (params: PP.Project) => `${projectBase(params)}/snapshots-new`,
+  snapshots: (params: PP.Project) => `${projectBase(params)}/snapshots`,
+  snapshotImagesNew: (params: PP.Snapshot) =>
     `${projectBase(params)}/snapshots/${params.snapshot}/images-new`,
 
-  vpcsNew: (params: Project) => `${projectBase(params)}/vpcs-new`,
-  vpcs: (params: Project) => `${projectBase(params)}/vpcs`,
+  vpcsNew: (params: PP.Project) => `${projectBase(params)}/vpcs-new`,
+  vpcs: (params: PP.Project) => `${projectBase(params)}/vpcs`,
 
   // same deal as instance detail: go straight to first tab
-  vpc: (params: Vpc) => pb.vpcFirewallRules(params),
-  vpcEdit: (params: Vpc) => `${vpcBase(params)}/edit`,
+  vpc: (params: PP.Vpc) => pb.vpcFirewallRules(params),
+  vpcEdit: (params: PP.Vpc) => `${vpcBase(params)}/edit`,
 
-  vpcFirewallRules: (params: Vpc) => `${vpcBase(params)}/firewall-rules`,
-  vpcFirewallRulesNew: (params: Vpc) => `${vpcBase(params)}/firewall-rules-new`,
-  vpcFirewallRuleClone: (params: FirewallRule) =>
+  vpcFirewallRules: (params: PP.Vpc) => `${vpcBase(params)}/firewall-rules`,
+  vpcFirewallRulesNew: (params: PP.Vpc) => `${vpcBase(params)}/firewall-rules-new`,
+  vpcFirewallRuleClone: (params: PP.FirewallRule) =>
     `${pb.vpcFirewallRulesNew(params)}/${params.rule}`,
-  vpcFirewallRuleEdit: (params: FirewallRule) =>
+  vpcFirewallRuleEdit: (params: PP.FirewallRule) =>
     `${pb.vpcFirewallRules(params)}/${params.rule}/edit`,
-  vpcRouters: (params: Vpc) => `${vpcBase(params)}/routers`,
-  vpcRoutersNew: (params: Vpc) => `${vpcBase(params)}/routers-new`,
-  vpcRouter: (params: VpcRouter) => `${pb.vpcRouters(params)}/${params.router}`,
-  vpcRouterEdit: (params: VpcRouter) => `${pb.vpcRouter(params)}/edit`,
-  vpcRouterRouteEdit: (params: VpcRouterRoute) =>
+  vpcRouters: (params: PP.Vpc) => `${vpcBase(params)}/routers`,
+  vpcRoutersNew: (params: PP.Vpc) => `${vpcBase(params)}/routers-new`,
+  vpcRouter: (params: PP.VpcRouter) => `${pb.vpcRouters(params)}/${params.router}`,
+  vpcRouterEdit: (params: PP.VpcRouter) => `${pb.vpcRouter(params)}/edit`,
+  vpcRouterRouteEdit: (params: PP.VpcRouterRoute) =>
     `${pb.vpcRouter(params)}/routes/${params.route}/edit`,
-  vpcRouterRoutesNew: (params: VpcRouter) => `${pb.vpcRouter(params)}/routes-new`,
-
-  vpcSubnets: (params: Vpc) => `${vpcBase(params)}/subnets`,
-  vpcSubnetsNew: (params: Vpc) => `${vpcBase(params)}/subnets-new`,
-  vpcSubnetsEdit: (params: VpcSubnet) => `${pb.vpcSubnets(params)}/${params.subnet}/edit`,
-
-  floatingIps: (params: Project) => `${projectBase(params)}/floating-ips`,
-  floatingIpsNew: (params: Project) => `${projectBase(params)}/floating-ips-new`,
-  floatingIpEdit: (params: FloatingIp) =>
+  vpcRouterRoutesNew: (params: PP.VpcRouter) => `${pb.vpcRouter(params)}/routes-new`,
+
+  vpcSubnets: (params: PP.Vpc) => `${vpcBase(params)}/subnets`,
+  vpcSubnetsNew: (params: PP.Vpc) => `${vpcBase(params)}/subnets-new`,
+  vpcSubnetsEdit: (params: PP.VpcSubnet) =>
+    `${pb.vpcSubnets(params)}/${params.subnet}/edit`,
+  floatingIps: (params: PP.Project) => `${projectBase(params)}/floating-ips`,
+  floatingIpsNew: (params: PP.Project) => `${projectBase(params)}/floating-ips-new`,
+  floatingIpEdit: (params: PP.FloatingIp) =>
     `${pb.floatingIps(params)}/${params.floatingIp}/edit`,
 
   siloUtilization: () => '/utilization',
   siloAccess: () => '/access',
   siloImages: () => '/images',
-  siloImageEdit: (params: SiloImage) => `${pb.siloImages()}/${params.image}/edit`,
+  siloImageEdit: (params: PP.SiloImage) => `${pb.siloImages()}/${params.image}/edit`,
 
   systemUtilization: () => '/system/utilization',
 
   ipPools: () => '/system/networking/ip-pools',
   ipPoolsNew: () => '/system/networking/ip-pools-new',
-  ipPool: (params: IpPool) => `${pb.ipPools()}/${params.pool}`,
-  ipPoolEdit: (params: IpPool) => `${pb.ipPool(params)}/edit`,
-  ipPoolRangeAdd: (params: IpPool) => `${pb.ipPool(params)}/ranges-add`,
+  ipPool: (params: PP.IpPool) => `${pb.ipPools()}/${params.pool}`,
+  ipPoolEdit: (params: PP.IpPool) => `${pb.ipPool(params)}/edit`,
+  ipPoolRangeAdd: (params: PP.IpPool) => `${pb.ipPool(params)}/ranges-add`,
 
   sledInventory: () => '/system/inventory/sleds',
   diskInventory: () => '/system/inventory/disks',
-  sled: ({ sledId }: Sled) => `/system/inventory/sleds/${sledId}/instances`,
-  sledInstances: ({ sledId }: Sled) => `/system/inventory/sleds/${sledId}/instances`,
+  sled: ({ sledId }: PP.Sled) => `/system/inventory/sleds/${sledId}/instances`,
+  sledInstances: ({ sledId }: PP.Sled) => `/system/inventory/sleds/${sledId}/instances`,
 
   silos: () => '/system/silos',
   silosNew: () => '/system/silos-new',
-  silo: ({ silo }: Silo) => `/system/silos/${silo}`,
-  siloIpPools: (params: Silo) => `${pb.silo(params)}?tab=ip-pools`,
-  siloIdpsNew: (params: Silo) => `${pb.silo(params)}/idps-new`,
-  samlIdp: (params: IdentityProvider) => `${pb.silo(params)}/idps/saml/${params.provider}`,
+  silo: ({ silo }: PP.Silo) => `/system/silos/${silo}`,
+  siloIpPools: (params: PP.Silo) => `${pb.silo(params)}?tab=ip-pools`,
+  siloIdpsNew: (params: PP.Silo) => `${pb.silo(params)}/idps-new`,
+  samlIdp: (params: PP.IdentityProvider) =>
+    `${pb.silo(params)}/idps/saml/${params.provider}`,
 
   profile: () => '/settings/profile',
   sshKeys: () => '/settings/ssh-keys',
diff --git a/app/util/path-params.ts b/app/util/path-params.ts
new file mode 100644
index 0000000000..2a153512ad
--- /dev/null
+++ b/app/util/path-params.ts
@@ -0,0 +1,26 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * Copyright Oxide Computer Company
+ */
+import type * as Sel from '~/api/selectors'
+
+// The path versions simply have all params required
+
+export type Project = Required<Sel.Project>
+export type Instance = Required<Sel.Instance>
+export type Vpc = Required<Sel.Vpc>
+export type Silo = Required<Sel.Silo>
+export type IdentityProvider = Required<Sel.IdentityProvider>
+export type Sled = Required<Sel.Sled>
+export type Image = Required<Sel.Image>
+export type Snapshot = Required<Sel.Snapshot>
+export type SiloImage = Required<Sel.SiloImage>
+export type IpPool = Required<Sel.IpPool>
+export type FloatingIp = Required<Sel.FloatingIp>
+export type FirewallRule = Required<Sel.FirewallRule>
+export type VpcRouter = Required<Sel.VpcRouter>
+export type VpcRouterRoute = Required<Sel.VpcRouterRoute>
+export type VpcSubnet = Required<Sel.VpcSubnet>
diff --git a/mock-api/msw/db.ts b/mock-api/msw/db.ts
index f9e1b26ed7..13efe3d9b5 100644
--- a/mock-api/msw/db.ts
+++ b/mock-api/msw/db.ts
@@ -10,10 +10,11 @@
 import * as R from 'remeda'
 import { validate as isUuid } from 'uuid'
 
-import type { ApiTypes as Api, PathParams as PP } from '@oxide/api'
+import type { ApiTypes as Api } from '@oxide/api'
 import * as mock from '@oxide/api-mocks'
 
 import { json } from '~/api/__generated__/msw-handlers'
+import type * as Sel from '~/api/selectors'
 import { commaSeries } from '~/util/str'
 
 import type { Json } from '../json-type'
@@ -64,7 +65,7 @@ export const getIpFromPool = (poolName: string | undefined) => {
 }
 
 export const lookup = {
-  project({ project: id }: PP.Project): Json<Api.Project> {
+  project({ project: id }: Sel.Project): Json<Api.Project> {
     if (!id) throw notFoundErr('no project specified')
 
     if (isUuid(id)) return lookupById(db.projects, id)
@@ -74,7 +75,7 @@ export const lookup = {
 
     return project
   },
-  instance({ instance: id, ...projectSelector }: PP.Instance): Json<Api.Instance> {
+  instance({ instance: id, ...projectSelector }: Sel.Instance): Json<Api.Instance> {
     if (!id) throw notFoundErr('no instance specified')
 
     if (isUuid(id)) {
@@ -91,7 +92,7 @@ export const lookup = {
   networkInterface({
     interface: id,
     ...instanceSelector
-  }: PP.NetworkInterface): Json<Api.InstanceNetworkInterface> {
+  }: Sel.NetworkInterface): Json<Api.InstanceNetworkInterface> {
     if (!id) throw notFoundErr('no NIC specified')
 
     if (isUuid(id)) {
@@ -108,7 +109,7 @@ export const lookup = {
 
     return nic
   },
-  disk({ disk: id, ...projectSelector }: PP.Disk): Json<Api.Disk> {
+  disk({ disk: id, ...projectSelector }: Sel.Disk): Json<Api.Disk> {
     if (!id) throw notFoundErr('no disk specified')
 
     if (isUuid(id)) {
@@ -123,7 +124,7 @@ export const lookup = {
 
     return disk
   },
-  floatingIp({ floatingIp: id, ...projectSelector }: PP.FloatingIp): Json<Api.FloatingIp> {
+  floatingIp({ floatingIp: id, ...projectSelector }: Sel.FloatingIp): Json<Api.FloatingIp> {
     if (!id) throw notFoundErr('no floating IP specified')
 
     if (isUuid(id)) {
@@ -139,7 +140,7 @@ export const lookup = {
 
     return floatingIp
   },
-  snapshot({ snapshot: id, ...projectSelector }: PP.Snapshot): Json<Api.Snapshot> {
+  snapshot({ snapshot: id, ...projectSelector }: Sel.Snapshot): Json<Api.Snapshot> {
     if (!id) throw notFoundErr('no snapshot specified')
 
     if (isUuid(id)) {
@@ -153,7 +154,7 @@ export const lookup = {
 
     return snapshot
   },
-  vpc({ vpc: id, ...projectSelector }: PP.Vpc): Json<Api.Vpc> {
+  vpc({ vpc: id, ...projectSelector }: Sel.Vpc): Json<Api.Vpc> {
     if (!id) throw notFoundErr('no VPC specified')
 
     if (isUuid(id)) {
@@ -167,7 +168,7 @@ export const lookup = {
 
     return vpc
   },
-  vpcRouter({ router: id, ...vpcSelector }: PP.VpcRouter): Json<Api.VpcRouter> {
+  vpcRouter({ router: id, ...vpcSelector }: Sel.VpcRouter): Json<Api.VpcRouter> {
     if (!id) throw notFoundErr('no router specified')
 
     if (isUuid(id)) {
@@ -184,7 +185,7 @@ export const lookup = {
   vpcRouterRoute({
     route: id,
     ...routerSelector
-  }: PP.VpcRouterRoute): Json<Api.RouterRoute> {
+  }: Sel.VpcRouterRoute): Json<Api.RouterRoute> {
     if (!id) throw notFoundErr('no route specified')
 
     if (isUuid(id)) {
@@ -200,7 +201,7 @@ export const lookup = {
 
     return route
   },
-  vpcSubnet({ subnet: id, ...vpcSelector }: PP.VpcSubnet): Json<Api.VpcSubnet> {
+  vpcSubnet({ subnet: id, ...vpcSelector }: Sel.VpcSubnet): Json<Api.VpcSubnet> {
     if (!id) throw notFoundErr('no subnet specified')
 
     if (isUuid(id)) {
@@ -214,7 +215,7 @@ export const lookup = {
 
     return subnet
   },
-  image({ image: id, project: projectId }: PP.Image): Json<Api.Image> {
+  image({ image: id, project: projectId }: Sel.Image): Json<Api.Image> {
     if (!id) throw notFoundErr('no image specified')
 
     // We match the API logic:
@@ -249,7 +250,7 @@ export const lookup = {
     if (!image) throw notFoundErr(`image '${id}'`)
     return image
   },
-  ipPool({ pool: id }: PP.IpPool): Json<Api.IpPool> {
+  ipPool({ pool: id }: Sel.IpPool): Json<Api.IpPool> {
     if (!id) throw notFoundErr('no pool specified')
 
     if (isUuid(id)) return lookupById(db.ipPools, id)
@@ -263,7 +264,7 @@ export const lookup = {
   ipPoolSiloLink({
     pool: poolId,
     silo: siloId,
-  }: PP.IpPool & PP.Silo): Json<Api.IpPoolSiloLink> {
+  }: Sel.IpPool & Sel.Silo): Json<Api.IpPoolSiloLink> {
     const pool = lookup.ipPool({ pool: poolId })
     const silo = lookup.silo({ silo: siloId })
 
@@ -275,7 +276,7 @@ export const lookup = {
     return ipPoolSilo
   },
   // unusual because it returns a list, but we need it for multiple endpoints
-  siloIpPools(path: PP.Silo): Json<Api.SiloIpPool>[] {
+  siloIpPools(path: Sel.Silo): Json<Api.SiloIpPool>[] {
     const silo = lookup.silo(path)
 
     // effectively join db.ipPools and db.ipPoolSilos on ip_pool_id
@@ -294,7 +295,7 @@ export const lookup = {
         return { ...pool, is_default: link.is_default }
       })
   },
-  siloIpPool(path: PP.Silo & PP.IpPool): Json<Api.SiloIpPool> {
+  siloIpPool(path: Sel.Silo & Sel.IpPool): Json<Api.SiloIpPool> {
     const silo = lookup.silo(path)
     const pool = lookup.ipPool(path)
 
@@ -308,7 +309,7 @@ export const lookup = {
 
     return { ...pool, is_default: ipPoolSilo.is_default }
   },
-  siloDefaultIpPool(path: PP.Silo): Json<Api.IpPool> {
+  siloDefaultIpPool(path: Sel.Silo): Json<Api.IpPool> {
     const silo = lookup.silo(path)
 
     const link = db.ipPoolSilos.find((ips) => ips.silo_id === silo.id && ips.is_default)
@@ -316,7 +317,7 @@ export const lookup = {
 
     return lookupById(db.ipPools, link.ip_pool_id)
   },
-  samlIdp({ provider: id, silo }: PP.IdentityProvider): Json<Api.SamlIdentityProvider> {
+  samlIdp({ provider: id, silo }: Sel.IdentityProvider): Json<Api.SamlIdentityProvider> {
     if (!id) throw notFoundErr('no IdP specified')
 
     if (isUuid(id)) {
@@ -337,7 +338,7 @@ export const lookup = {
 
     return dbIdp.provider
   },
-  silo({ silo: id }: PP.Silo): Json<Api.Silo> {
+  silo({ silo: id }: Sel.Silo): Json<Api.Silo> {
     if (!id) throw notFoundErr('silo not specified')
 
     if (isUuid(id)) return lookupById(db.silos, id)
@@ -346,17 +347,17 @@ export const lookup = {
     if (!silo) throw notFoundErr(`silo '${id}'`)
     return silo
   },
-  siloQuotas(params: PP.Silo): Json<Api.SiloQuotas> {
+  siloQuotas(params: Sel.Silo): Json<Api.SiloQuotas> {
     const silo = lookup.silo(params)
     const quotas = db.siloQuotas.find((q) => q.silo_id === silo.id)
     if (!quotas) throw internalError(`Silo ${silo.name} has no quotas`)
     return quotas
   },
-  sled({ sledId: id }: PP.Sled): Json<Api.Sled> {
+  sled({ sledId: id }: Sel.Sled): Json<Api.Sled> {
     if (!id) throw notFoundErr('sled not specified')
     return lookupById(db.sleds, id)
   },
-  sshKey({ sshKey: id }: PP.SshKey): Json<Api.SshKey> {
+  sshKey({ sshKey: id }: Sel.SshKey): Json<Api.SshKey> {
     // we don't have a concept of mock session. assume the user is user1
     const userSshKeys = db.sshKeys.filter((key) => key.silo_user_id === mock.user1.id)