diff --git a/.eslintrc.json b/.eslintrc.json
index f07f74f..d93bd9e 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -5,7 +5,7 @@
   "parserOptions": {
     "ecmaVersion": 9,
     "sourceType": "module",
-    "project": "./tsconfig.json"
+    "project": [ "./tsconfig.base.json", "./tsconfig.json"]
   },
   "rules": {
     "i18n-text/no-en": "off",
diff --git a/.github/PULL_REQUEST_TEMPLATE/pull_request_template.md b/.github/pull_request_template.md
similarity index 100%
rename from .github/PULL_REQUEST_TEMPLATE/pull_request_template.md
rename to .github/pull_request_template.md
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 6d939fe..c700109 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -169,6 +169,10 @@ jobs:
         - os: windows-latest
           swift: '5.3'
           development: false
+        - os: ubuntu-22.04
+          swift: ${{ fromJSON(vars.SETUPSWIFT_CUSTOM_TOOLCHAINS).ubuntu2204 }}
+          development: true
+          noverify: true
 
     steps:
     - name: Checkout repository
@@ -201,10 +205,11 @@ jobs:
         cache-snapshot: ${{ !matrix.development }}
 
     - name: Verify Swift version in macos
-      if: runner.os == 'macOS'
+      if: runner.os == 'macOS' && matrix.noverify != 'true'
       run: xcrun --toolchain ${{ env.TOOLCHAINS || '""' }} swift --version | grep ${{ steps.setup-swift.outputs.swift-version }} || exit 1
 
     - name: Verify Swift version
+      if: matrix.noverify != 'true'
       run: swift --version | grep ${{ steps.setup-swift.outputs.swift-version }} || exit 1
 
   dry-run:
diff --git a/README.md b/README.md
index f81c870..3c9e5e2 100644
--- a/README.md
+++ b/README.md
@@ -99,6 +99,16 @@ In other words specifying...
 - `"4"` will resolve to latest minor and patch version (aka `4.2.4`)
 - `"4.0.0"` will resolve to version `4.0`
 
+<details>
+  <summary>Additionally, to use custom toolchains, download URL can be provided. The download URL must point to a `tar` archive for `Linux`, `pkg` file for `macOS` and `exe` file for `Windows`.</summary>
+
+  i.e. for `macOS`: https://github.com/swiftwasm/swift/releases/download/swift-wasm-5.10-SNAPSHOT-2024-03-30-a/swift-wasm-5.10-SNAPSHOT-2024-03-30-a-macos_x86_64.pkg
+  for `Linux`: https://github.com/swiftwasm/swift/releases/download/swift-wasm-5.10-SNAPSHOT-2024-03-30-a/swift-wasm-5.10-SNAPSHOT-2024-03-30-a-ubuntu22.04_x86_64.tar.gz
+
+  > [!IMPORTANT]  
+  > When using custom toolchains, please ensure that the toolchain can be installed and used on the GitHub runner, this action won't be able to validate this for custom toolchains.
+</details>
+
 ### Caveats
 
 YAML interprets eg. `4.0` as a float, this action will then interpret that as `4` which will result in eg. Swift `4.2.4` being resolved. Quote your inputs! Thus surround version input with quotations:
diff --git a/__tests__/installer/linux.test.ts b/__tests__/installer/linux.test.ts
index 56d66d0..cb07e2c 100644
--- a/__tests__/installer/linux.test.ts
+++ b/__tests__/installer/linux.test.ts
@@ -1,11 +1,16 @@
+import os from 'os'
 import * as path from 'path'
 import {promises as fs} from 'fs'
+// @ts-ignore
+import {__setos as setos} from 'getos'
 import * as core from '@actions/core'
 import * as exec from '@actions/exec'
 import * as cache from '@actions/cache'
 import * as toolCache from '@actions/tool-cache'
 import {coerce as parseSemVer} from 'semver'
 import {LinuxToolchainInstaller} from '../../src/installer/linux'
+import {ToolchainVersion} from '../../src/version'
+import {Platform} from '../../src/platform'
 
 describe('linux toolchain installation verification', () => {
   const env = process.env
@@ -17,7 +22,8 @@ describe('linux toolchain installation verification', () => {
     dir: 'swift-5.8-RELEASE',
     docker: '5.8-jammy',
     platform: 'ubuntu2204',
-    branch: 'swift-5.8-release'
+    branch: 'swift-5.8-release',
+    preventCaching: false
   }
 
   beforeEach(() => {
@@ -32,7 +38,7 @@ describe('linux toolchain installation verification', () => {
   it('tests download', async () => {
     const installer = new LinuxToolchainInstaller(toolchain)
     expect(installer['version']).toStrictEqual(parseSemVer('5.8'))
-    expect(installer['baseUrl']).toBe(
+    expect(installer['baseUrl'].href).toBe(
       'https://download.swift.org/swift-5.8-release/ubuntu2204/swift-5.8-RELEASE'
     )
 
@@ -127,4 +133,35 @@ describe('linux toolchain installation verification', () => {
     const devVersion = await installer.installedSwiftVersion()
     expect(devVersion).toBe('5.9-dev')
   })
+
+  it('tests custom swift tool caching', async () => {
+    setos({os: 'linux', dist: 'Ubuntu', release: '22.04'})
+    jest.spyOn(os, 'arch').mockReturnValue('x64')
+    const swiftwasm = 'https://github.com/swiftwasm/swift/releases/download'
+    const name = 'swift-wasm-5.10-SNAPSHOT-2024-03-30-a'
+    const resource = `${name}-ubuntu22.04_x86_64.tar.gz`
+    const toolchainUrl = `${swiftwasm}/${name}/${resource}`
+    const cVer = ToolchainVersion.create(toolchainUrl, false)
+    const download = path.resolve('tool', 'download', 'path')
+    const extracted = path.resolve('tool', 'extracted', 'path')
+    const cached = path.resolve('tool', 'cached', 'path')
+    jest.spyOn(core, 'getBooleanInput').mockReturnValue(true)
+    jest.spyOn(cache, 'restoreCache').mockResolvedValue(undefined)
+    jest.spyOn(toolCache, 'find').mockReturnValue('')
+    jest.spyOn(fs, 'cp').mockResolvedValue()
+    jest.spyOn(toolCache, 'downloadTool').mockResolvedValue(download)
+    jest.spyOn(toolCache, 'extractTar').mockResolvedValue(extracted)
+    jest.spyOn(toolCache, 'cacheDir').mockResolvedValue(cached)
+    jest.spyOn(exec, 'exec').mockResolvedValue(0)
+    const cacheSpy = jest.spyOn(cache, 'saveCache')
+    const installer = await Platform.install(cVer)
+    expect(cacheSpy).not.toHaveBeenCalled()
+    expect(installer.data.baseUrl?.href).toBe(path.posix.dirname(toolchainUrl))
+    expect(installer.data.preventCaching).toBe(true)
+    expect(installer.data.name).toBe('Swift Custom Snapshot')
+    expect(installer.data.platform).toBe('ubuntu2204')
+    expect(installer.data.download).toBe(resource)
+    expect(installer.data.dir).toBe(name)
+    expect(installer.data.branch).toBe('swiftwasm')
+  })
 })
diff --git a/__tests__/installer/windows.test.ts b/__tests__/installer/windows.test.ts
index f3aaaa0..a8c19e3 100644
--- a/__tests__/installer/windows.test.ts
+++ b/__tests__/installer/windows.test.ts
@@ -19,7 +19,8 @@ describe('windows toolchain installation verification', () => {
     dir: 'swift-5.8-RELEASE',
     platform: 'windows10',
     branch: 'swift-5.8-release',
-    windows: true
+    windows: true,
+    preventCaching: false
   }
   const visualStudio = VisualStudio.createFromJSON({
     installationPath: path.join('C:', 'Visual Studio'),
@@ -61,7 +62,7 @@ describe('windows toolchain installation verification', () => {
   it('tests download without caching', async () => {
     const installer = new WindowsToolchainInstaller(toolchain)
     expect(installer['version']).toStrictEqual(parseSemVer('5.8'))
-    expect(installer['baseUrl']).toBe(
+    expect(installer['baseUrl'].href).toBe(
       'https://download.swift.org/swift-5.8-release/windows10/swift-5.8-RELEASE'
     )
 
diff --git a/__tests__/installer/xcode.test.ts b/__tests__/installer/xcode.test.ts
index e8782f7..885f984 100644
--- a/__tests__/installer/xcode.test.ts
+++ b/__tests__/installer/xcode.test.ts
@@ -16,12 +16,13 @@ describe('macOS toolchain installation verification', () => {
     name: 'Xcode Swift 5.8.1',
     date: new Date('2023-05-31T18:30:00.000Z'),
     download: 'swift-5.8.1-RELEASE-osx.pkg',
-    symbols: 'swift-5.8.1-RELEASE-osx-symbols.pkg',
+    debug_info: 'swift-5.8.1-RELEASE-osx-symbols.pkg',
     dir: 'swift-5.8.1-RELEASE',
     xcode: '14.3.1',
     platform: 'xcode',
     branch: 'swift-5.8.1-release',
-    xcodePath: '/Applications/Xcode_14.3.1.app'
+    xcodePath: '/Applications/Xcode_14.3.1.app',
+    preventCaching: false
   }
 
   beforeEach(() => {
@@ -56,7 +57,7 @@ describe('macOS toolchain installation verification', () => {
   it('tests download', async () => {
     const installer = new XcodeToolchainInstaller(toolchain)
     expect(installer['version']).toStrictEqual(parseSemVer('5.8.1'))
-    expect(installer['baseUrl']).toBe(
+    expect(installer['baseUrl'].href).toBe(
       'https://download.swift.org/swift-5.8.1-release/xcode/swift-5.8.1-RELEASE'
     )
 
diff --git a/__tests__/main.test.ts b/__tests__/main.test.ts
index c0f964b..d29167a 100644
--- a/__tests__/main.test.ts
+++ b/__tests__/main.test.ts
@@ -20,7 +20,8 @@ describe('setup-swift run validation', () => {
     dir: 'swift-5.8-RELEASE',
     docker: '5.8-jammy',
     platform: 'ubuntu2204',
-    branch: 'swift-5.8-release'
+    branch: 'swift-5.8-release',
+    preventCaching: false
   }
 
   it('tests dry run', async () => {
diff --git a/__tests__/snapshot/linux.test.ts b/__tests__/snapshot/linux.test.ts
index 51bbdd8..6aff2ef 100644
--- a/__tests__/snapshot/linux.test.ts
+++ b/__tests__/snapshot/linux.test.ts
@@ -1,4 +1,5 @@
 import os from 'os'
+import {posix} from 'path'
 // @ts-ignore
 import {__setos as setos} from 'getos'
 import {ToolchainVersion} from '../../src/version'
@@ -30,6 +31,7 @@ describe('fetch linux tool data based on options', () => {
       'swift-4.2.4-RELEASE-ubuntu18.04.tar.gz.sig'
     )
     expect(lTool.docker).toBeUndefined()
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 18.04 latest swift 5.0 tool', async () => {
@@ -46,6 +48,7 @@ describe('fetch linux tool data based on options', () => {
       'swift-5.0.3-RELEASE-ubuntu18.04.tar.gz.sig'
     )
     expect(lTool.docker).toBe('5.0.3-bionic')
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 18.04 latest swift 5.5.0 tool', async () => {
@@ -62,6 +65,7 @@ describe('fetch linux tool data based on options', () => {
       'swift-5.5-RELEASE-ubuntu18.04.tar.gz.sig'
     )
     expect(lTool.docker).toBe('5.5-bionic')
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 20.04 arm64 latest swift 5.6.0 tool', async () => {
@@ -79,6 +83,7 @@ describe('fetch linux tool data based on options', () => {
       'swift-5.6-RELEASE-ubuntu20.04-aarch64.tar.gz.sig'
     )
     expect(lTool.docker).toBe('5.6-focal')
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 18.04 latest swift 5.5 tool', async () => {
@@ -95,6 +100,7 @@ describe('fetch linux tool data based on options', () => {
       'swift-5.5.3-RELEASE-ubuntu18.04.tar.gz.sig'
     )
     expect(lTool.docker).toBe('5.5.3-bionic')
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 18.04 latest swift 5.5 tool including dev snapshot', async () => {
@@ -111,6 +117,7 @@ describe('fetch linux tool data based on options', () => {
       'swift-5.5.3-RELEASE-ubuntu18.04.tar.gz.sig'
     )
     expect(lTool.docker).toBe('5.5.3-bionic')
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 18.04 latest swift tool', async () => {
@@ -124,6 +131,7 @@ describe('fetch linux tool data based on options', () => {
     expect(lTool.platform).toBeTruthy()
     expect(lTool.branch).toBeTruthy()
     expect(lTool.download_signature).toBeTruthy()
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 18.04 latest swift tool including dev snapshot', async () => {
@@ -138,6 +146,7 @@ describe('fetch linux tool data based on options', () => {
     expect(lTool.branch).toBeTruthy()
     expect(lTool.download_signature).toBeTruthy()
     expect(lTool.docker).toBeTruthy()
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('handles swift tool version not present by returning undefined', async () => {
@@ -163,6 +172,7 @@ describe('fetch linux tool data based on options', () => {
       'swift-5.6.1-RELEASE-ubuntu20.04.tar.gz.sig'
     )
     expect(lTool.docker).toBe('5.6.1-focal')
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 20.04 latest swift 5.2 tool', async () => {
@@ -180,6 +190,7 @@ describe('fetch linux tool data based on options', () => {
       'swift-5.2.5-RELEASE-ubuntu20.04.tar.gz.sig'
     )
     expect(lTool.docker).toBe('5.2.5-focal')
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches centos 7 latest swift tool', async () => {
@@ -194,6 +205,7 @@ describe('fetch linux tool data based on options', () => {
     expect(lTool.branch).toBeTruthy()
     expect(lTool.download_signature).toBeTruthy()
     expect(lTool.docker).toBeTruthy()
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 22.04 named swift tool', async () => {
@@ -213,6 +225,7 @@ describe('fetch linux tool data based on options', () => {
     expect(lTool.download_signature).toBe(
       'swift-DEVELOPMENT-SNAPSHOT-2023-09-02-a-ubuntu22.04.tar.gz.sig'
     )
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 22.04 named versioned swift tool', async () => {
@@ -232,6 +245,7 @@ describe('fetch linux tool data based on options', () => {
     expect(lTool.download_signature).toBe(
       'swift-5.9-DEVELOPMENT-SNAPSHOT-2023-09-01-a-ubuntu22.04.tar.gz.sig'
     )
+    expect(lTool.preventCaching).toBe(false)
   })
 
   it('fetches ubuntu 18.04 latest swift 5.5 tools', async () => {
@@ -271,4 +285,24 @@ describe('fetch linux tool data based on options', () => {
     const tools = await Platform.toolchains(ver5_2)
     expect(tools.length).toBe(2)
   })
+
+  it('fetches ubuntu 22.04 custom swift tools', async () => {
+    setos({os: 'linux', dist: 'Ubuntu', release: '22.04'})
+    jest.spyOn(os, 'arch').mockReturnValue('x64')
+    const swiftwasm = 'https://github.com/swiftwasm/swift/releases/download'
+    const name = 'swift-wasm-5.10-SNAPSHOT-2024-03-30-a'
+    const resource = `${name}-ubuntu22.04_x86_64.tar.gz`
+    const toolchainUrl = `${swiftwasm}/${name}/${resource}`
+    const cVer = ToolchainVersion.create(toolchainUrl, false)
+    const tools = await Platform.toolchains(cVer)
+    expect(tools.length).toBe(1)
+    const tool = tools[0]
+    expect(tool.baseUrl?.href).toBe(posix.dirname(toolchainUrl))
+    expect(tool.preventCaching).toBe(true)
+    expect(tool.name).toBe('Swift Custom Snapshot')
+    expect(tool.platform).toBe('ubuntu2204')
+    expect(tool.download).toBe(resource)
+    expect(tool.dir).toBe(name)
+    expect(tool.branch).toBe('swiftwasm')
+  })
 })
diff --git a/__tests__/snapshot/windows.test.ts b/__tests__/snapshot/windows.test.ts
index d0eac82..78dc882 100644
--- a/__tests__/snapshot/windows.test.ts
+++ b/__tests__/snapshot/windows.test.ts
@@ -1,4 +1,5 @@
 import os from 'os'
+import {posix} from 'path'
 // @ts-ignore
 import {__setos as setos} from 'getos'
 import {ToolchainVersion} from '../../src/version'
@@ -27,6 +28,7 @@ describe('fetch windows tool data based on options', () => {
     expect(wTool.platform).toBe('windows10')
     expect(wTool.branch).toBeTruthy()
     expect(wTool.download_signature).toBeTruthy()
+    expect(wTool.preventCaching).toBe(false)
   })
 
   it('fetches windows 10 latest swift 5.0 tool', async () => {
@@ -47,6 +49,7 @@ describe('fetch windows tool data based on options', () => {
     expect(wTool.platform).toBe('windows10')
     expect(wTool.branch).toBe('swift-5.5-release')
     expect(wTool.download_signature).toBe('swift-5.5-RELEASE-windows10.exe.sig')
+    expect(wTool.preventCaching).toBe(false)
   })
 
   it('fetches windows 10 latest swift 5.5 tool', async () => {
@@ -62,6 +65,7 @@ describe('fetch windows tool data based on options', () => {
     expect(wTool.download_signature).toBe(
       'swift-5.5.3-RELEASE-windows10.exe.sig'
     )
+    expect(wTool.preventCaching).toBe(false)
   })
 
   it('fetches windows 10 latest swift 5.5 tool including dev snapshot', async () => {
@@ -77,6 +81,7 @@ describe('fetch windows tool data based on options', () => {
     expect(wTool.download_signature).toBe(
       'swift-5.5.3-RELEASE-windows10.exe.sig'
     )
+    expect(wTool.preventCaching).toBe(false)
   })
 
   it('fetches windows 10 latest swift tool', async () => {
@@ -91,6 +96,7 @@ describe('fetch windows tool data based on options', () => {
     expect(wTool.platform).toBeTruthy()
     expect(wTool.branch).toBeTruthy()
     expect(wTool.download_signature).toBeTruthy()
+    expect(wTool.preventCaching).toBe(false)
   })
 
   it('fetches windows 10 latest swift tool including dev snapshot', async () => {
@@ -103,6 +109,7 @@ describe('fetch windows tool data based on options', () => {
     expect(wTool.dir).toBeTruthy()
     expect(wTool.platform).toBeTruthy()
     expect(wTool.branch).toBeTruthy()
+    expect(wTool.preventCaching).toBe(false)
   })
 
   it('fetches windows 10 named swift tool', async () => {
@@ -112,16 +119,17 @@ describe('fetch windows tool data based on options', () => {
     const version = ToolchainVersion.create(name, false)
     const tool = await Platform.toolchain(version)
     expect(tool).toBeTruthy()
-    const lTool = tool as WindowsToolchainSnapshot
-    expect(lTool.download).toBe(
+    const wTool = tool as WindowsToolchainSnapshot
+    expect(wTool.download).toBe(
       'swift-DEVELOPMENT-SNAPSHOT-2023-08-10-a-windows10.exe'
     )
-    expect(lTool.dir).toBe('swift-DEVELOPMENT-SNAPSHOT-2023-08-10-a')
-    expect(lTool.platform).toBe('windows10')
-    expect(lTool.branch).toBe('development')
-    expect(lTool.download_signature).toBe(
+    expect(wTool.dir).toBe('swift-DEVELOPMENT-SNAPSHOT-2023-08-10-a')
+    expect(wTool.platform).toBe('windows10')
+    expect(wTool.branch).toBe('development')
+    expect(wTool.download_signature).toBe(
       'swift-DEVELOPMENT-SNAPSHOT-2023-08-10-a-windows10.exe.sig'
     )
+    expect(wTool.preventCaching).toBe(false)
   })
 
   it('fetches windows 10 named versioned swift tool', async () => {
@@ -131,16 +139,17 @@ describe('fetch windows tool data based on options', () => {
     const version = ToolchainVersion.create(name, false)
     const tool = await Platform.toolchain(version)
     expect(tool).toBeTruthy()
-    const lTool = tool as WindowsToolchainSnapshot
-    expect(lTool.download).toBe(
+    const wTool = tool as WindowsToolchainSnapshot
+    expect(wTool.download).toBe(
       'swift-5.9-DEVELOPMENT-SNAPSHOT-2023-05-11-a-windows10.exe'
     )
-    expect(lTool.dir).toBe('swift-5.9-DEVELOPMENT-SNAPSHOT-2023-05-11-a')
-    expect(lTool.platform).toBe('windows10')
-    expect(lTool.branch).toBe('swift-5.9-branch')
-    expect(lTool.download_signature).toBe(
+    expect(wTool.dir).toBe('swift-5.9-DEVELOPMENT-SNAPSHOT-2023-05-11-a')
+    expect(wTool.platform).toBe('windows10')
+    expect(wTool.branch).toBe('swift-5.9-branch')
+    expect(wTool.download_signature).toBe(
       'swift-5.9-DEVELOPMENT-SNAPSHOT-2023-05-11-a-windows10.exe.sig'
     )
+    expect(wTool.preventCaching).toBe(false)
   })
 
   it('fetches windows 10 latest swift 5.5 tools', async () => {
@@ -156,4 +165,24 @@ describe('fetch windows tool data based on options', () => {
     const tools = await Platform.toolchains(dev5_5)
     expect(tools.length).toBe(34)
   })
+
+  it('fetches windows 10 custom swift tools', async () => {
+    setos({os: 'win32', dist: 'Windows', release: '10.0.17063'})
+    jest.spyOn(os, 'arch').mockReturnValue('x64')
+    const swiftwasm = 'https://github.com/swiftwasm/swift/releases/download'
+    const name = 'swift-wasm-5.10-SNAPSHOT-2024-03-30-a'
+    const resource = `${name}-windows10.exe`
+    const toolchainUrl = `${swiftwasm}/${name}/${resource}`
+    const cVer = ToolchainVersion.create(toolchainUrl, false)
+    const tools = await Platform.toolchains(cVer)
+    expect(tools.length).toBe(1)
+    const tool = tools[0]
+    expect(tool.baseUrl?.href).toBe(posix.dirname(toolchainUrl))
+    expect(tool.preventCaching).toBe(true)
+    expect(tool.name).toBe('Swift Custom Snapshot')
+    expect(tool.platform).toBe('windows10')
+    expect(tool.download).toBe(resource)
+    expect(tool.dir).toBe(name)
+    expect(tool.branch).toBe('swiftwasm')
+  })
 })
diff --git a/__tests__/snapshot/xcode.test.ts b/__tests__/snapshot/xcode.test.ts
index 115ec44..2581239 100644
--- a/__tests__/snapshot/xcode.test.ts
+++ b/__tests__/snapshot/xcode.test.ts
@@ -1,4 +1,5 @@
 import os from 'os'
+import {posix} from 'path'
 import {glob} from 'glob'
 // @ts-ignore
 import {__setos as setos} from 'getos'
@@ -28,6 +29,7 @@ describe('fetch macos tool data based on options', () => {
     expect(xTool.platform).toBe('xcode')
     expect(xTool.branch).toBe('swift-4.2.4-release')
     expect(xTool.xcode).toBe('10.1')
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS latest swift 5.0 tool', async () => {
@@ -41,6 +43,7 @@ describe('fetch macos tool data based on options', () => {
     expect(xTool.platform).toBe('xcode')
     expect(xTool.branch).toBe('swift-5.0.3-release')
     expect(xTool.xcode).toBe('10.2.1')
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS latest swift 5.5.0 tool', async () => {
@@ -54,6 +57,7 @@ describe('fetch macos tool data based on options', () => {
     expect(xTool.platform).toBe('xcode')
     expect(xTool.branch).toBe('swift-5.5-release')
     expect(xTool.xcode).toBe('13')
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS latest swift 5.5 tool', async () => {
@@ -67,6 +71,7 @@ describe('fetch macos tool data based on options', () => {
     expect(xTool.platform).toBe('xcode')
     expect(xTool.branch).toBe('swift-5.5.3-release')
     expect(xTool.xcode).toBe('13.2')
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS latest swift 5.5 tool including dev snapshot', async () => {
@@ -80,6 +85,7 @@ describe('fetch macos tool data based on options', () => {
     expect(xTool.platform).toBe('xcode')
     expect(xTool.branch).toBe('swift-5.5.3-release')
     expect(xTool.xcode).toBe('13.2')
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS latest swift tool', async () => {
@@ -93,6 +99,7 @@ describe('fetch macos tool data based on options', () => {
     expect(xTool.platform).toBeTruthy()
     expect(xTool.branch).toBeTruthy()
     expect(xTool.xcode).toBeTruthy()
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS latest swift tool including dev snapshot', async () => {
@@ -105,6 +112,7 @@ describe('fetch macos tool data based on options', () => {
     expect(xTool.dir).toBeTruthy()
     expect(xTool.platform).toBeTruthy()
     expect(xTool.branch).toBeTruthy()
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS latest swift beta version tool', async () => {
@@ -135,6 +143,8 @@ describe('fetch macos tool data based on options', () => {
         ToolchainVersion.create(betaVersion, false)
       )
       expect(tool).toBeTruthy()
+      const xTool = tool as XcodeToolchainSnapshot
+      expect(xTool.preventCaching).toBe(false)
     }
   })
 
@@ -145,13 +155,14 @@ describe('fetch macos tool data based on options', () => {
     const version = ToolchainVersion.create(name, false)
     const tool = await Platform.toolchain(version)
     expect(tool).toBeTruthy()
-    const lTool = tool as XcodeToolchainSnapshot
-    expect(lTool.download).toBe(
+    const xTool = tool as XcodeToolchainSnapshot
+    expect(xTool.download).toBe(
       'swift-DEVELOPMENT-SNAPSHOT-2023-09-02-a-osx.pkg'
     )
-    expect(lTool.dir).toBe('swift-DEVELOPMENT-SNAPSHOT-2023-09-02-a')
-    expect(lTool.platform).toBe('xcode')
-    expect(lTool.branch).toBe('development')
+    expect(xTool.dir).toBe('swift-DEVELOPMENT-SNAPSHOT-2023-09-02-a')
+    expect(xTool.platform).toBe('xcode')
+    expect(xTool.branch).toBe('development')
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS named versioned swift tool', async () => {
@@ -161,13 +172,14 @@ describe('fetch macos tool data based on options', () => {
     const version = ToolchainVersion.create(name, false)
     const tool = await Platform.toolchain(version)
     expect(tool).toBeTruthy()
-    const lTool = tool as XcodeToolchainSnapshot
-    expect(lTool.download).toBe(
+    const xTool = tool as XcodeToolchainSnapshot
+    expect(xTool.download).toBe(
       'swift-5.9-DEVELOPMENT-SNAPSHOT-2023-09-01-a-osx.pkg'
     )
-    expect(lTool.dir).toBe('swift-5.9-DEVELOPMENT-SNAPSHOT-2023-09-01-a')
-    expect(lTool.platform).toBe('xcode')
-    expect(lTool.branch).toBe('swift-5.9-branch')
+    expect(xTool.dir).toBe('swift-5.9-DEVELOPMENT-SNAPSHOT-2023-09-01-a')
+    expect(xTool.platform).toBe('xcode')
+    expect(xTool.branch).toBe('swift-5.9-branch')
+    expect(xTool.preventCaching).toBe(false)
   })
 
   it('detects earliest toolchains', async () => {
@@ -181,6 +193,7 @@ describe('fetch macos tool data based on options', () => {
     expect(earliestTool.platform).toBe('xcode')
     expect(earliestTool.branch).toBe('swift-2.2-release')
     expect(earliestTool.download).toBe('swift-2.2-RELEASE-osx.pkg')
+    expect(earliestTool.preventCaching).toBe(false)
   })
 
   it('fetches macOS latest swift 5.5 tools', async () => {
@@ -196,4 +209,24 @@ describe('fetch macos tool data based on options', () => {
     const tools = await Platform.toolchains(dev5_5)
     expect(tools.length).toBe(103)
   })
+
+  it('fetches macOS custom swift tools', async () => {
+    setos({os: 'darwin', dist: 'macOS', release: '21'})
+    jest.spyOn(os, 'arch').mockReturnValue('x64')
+    const swiftwasm = 'https://github.com/swiftwasm/swift/releases/download'
+    const name = 'swift-wasm-5.10-SNAPSHOT-2024-03-30-a'
+    const resource = `${name}-macos_arm64.pkg`
+    const toolchainUrl = `${swiftwasm}/${name}/${resource}`
+    const cVer = ToolchainVersion.create(toolchainUrl, false)
+    const tools = await Platform.toolchains(cVer)
+    expect(tools.length).toBe(1)
+    const tool = tools[0]
+    expect(tool.baseUrl?.href).toBe(posix.dirname(toolchainUrl))
+    expect(tool.preventCaching).toBe(true)
+    expect(tool.name).toBe('Swift Custom Snapshot')
+    expect(tool.platform).toBe('xcode')
+    expect(tool.download).toBe(resource)
+    expect(tool.dir).toBe(name)
+    expect(tool.branch).toBe('swiftwasm')
+  })
 })
diff --git a/__tests__/swiftorg.test.ts b/__tests__/swiftorg.test.ts
index 86d0968..361e205 100644
--- a/__tests__/swiftorg.test.ts
+++ b/__tests__/swiftorg.test.ts
@@ -95,6 +95,23 @@ describe('swiftorg sync validation', () => {
     ])
   })
 
+  it('tests without latest sync success with matadata fetch', async () => {
+    execSpy.mockResolvedValue(0)
+    process.env.SETUPSWIFT_SWIFTORG_METADATA = undefined
+    const commit = '74caef941bc8ed6a01b9572ab6149e1d1f8a2d69'
+    const swiftorg = new Swiftorg(false)
+    nock(SWIFTORG_METADATA)
+      .get(/.*/)
+      .reply(200, {commit}, {'content-type': 'application/json'})
+    await swiftorg.update()
+    expect(execSpy).toHaveBeenCalledTimes(3)
+    expect(execSpy.mock.calls[1]).toStrictEqual([
+      'git',
+      ['fetch', SWIFTORG_ORIGIN, commit, '--depth=1', '--no-tags'],
+      {cwd: path.join(MODULE_DIR, SWIFTORG)}
+    ])
+  })
+
   it('tests without latest sync failure with matadata fetch failure', async () => {
     execSpy.mockResolvedValue(0)
     process.env.SETUPSWIFT_SWIFTORG_METADATA = undefined
@@ -109,7 +126,7 @@ describe('swiftorg sync validation', () => {
     expect(execSpy).toHaveBeenCalledTimes(0)
   })
 
-  it('tests without latest sync failure with invalid matadata', async () => {
+  it('tests without latest sync failure with invalid matadata content type', async () => {
     execSpy.mockResolvedValue(0)
     process.env.SETUPSWIFT_SWIFTORG_METADATA = undefined
     const contentType = 'application/txt'
@@ -122,4 +139,15 @@ describe('swiftorg sync validation', () => {
     )
     expect(execSpy).toHaveBeenCalledTimes(0)
   })
+
+  it('tests without latest sync failure with invalid matadata content', async () => {
+    execSpy.mockResolvedValue(0)
+    process.env.SETUPSWIFT_SWIFTORG_METADATA = undefined
+    const swiftorg = new Swiftorg(false)
+    nock(SWIFTORG_METADATA)
+      .get(/.*/)
+      .reply(200, 'invalid', {'content-type': 'application/json'})
+    await expect(swiftorg.update()).rejects.toBeInstanceOf(SyntaxError)
+    expect(execSpy).toHaveBeenCalledTimes(0)
+  })
 })
diff --git a/__tests__/utils/gpg.test.ts b/__tests__/utils/gpg.test.ts
index ae53dea..b4c3583 100644
--- a/__tests__/utils/gpg.test.ts
+++ b/__tests__/utils/gpg.test.ts
@@ -14,7 +14,7 @@ describe('gpg setup validation', () => {
     const execSpy = jest.spyOn(exec, 'exec')
     execSpy.mockRejectedValueOnce(new Error())
     execSpy.mockResolvedValue(0)
-    await expect(gpg.setupKeys()).resolves
+    await gpg.setupKeys()
   })
 
   it('tests keys refresh retry', async () => {
@@ -22,7 +22,7 @@ describe('gpg setup validation', () => {
     execSpy.mockResolvedValueOnce(0)
     execSpy.mockRejectedValueOnce(new Error())
     execSpy.mockResolvedValue(0)
-    await expect(gpg.setupKeys()).resolves
+    await gpg.setupKeys()
   })
 
   it('tests keys refresh error', async () => {
diff --git a/__tests__/version.test.ts b/__tests__/version.test.ts
index 2c5c5e2..a27cfea 100644
--- a/__tests__/version.test.ts
+++ b/__tests__/version.test.ts
@@ -2,7 +2,8 @@ import {
   ToolchainVersion,
   SemanticToolchainVersion,
   LatestToolchainVersion,
-  ToolchainSnapshotName
+  ToolchainSnapshotName,
+  ToolchainSnapshotLocation
 } from '../src/version'
 
 describe('parse version from provided string', () => {
@@ -10,11 +11,13 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create('latest', false)
     expect(version).toBeInstanceOf(LatestToolchainVersion)
     expect(version.dev).toBe(false)
+    expect(version.requiresSwiftOrg).toBe(true)
     expect(`${version}`).toBe('latest version')
 
     const devVersion = ToolchainVersion.create('latest', true)
     expect(devVersion).toBeInstanceOf(LatestToolchainVersion)
     expect(devVersion.dev).toBe(true)
+    expect(version.requiresSwiftOrg).toBe(true)
     expect(`${devVersion}`).toBe('latest dev version')
   })
 
@@ -22,11 +25,13 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create('current', false)
     expect(version).toBeInstanceOf(LatestToolchainVersion)
     expect(version.dev).toBe(false)
+    expect(version.requiresSwiftOrg).toBe(true)
     expect(`${version}`).toBe('latest version')
 
     const devVersion = ToolchainVersion.create('current', true)
     expect(devVersion).toBeInstanceOf(LatestToolchainVersion)
     expect(devVersion.dev).toBe(true)
+    expect(version.requiresSwiftOrg).toBe(true)
     expect(`${devVersion}`).toBe('latest dev version')
   })
 
@@ -34,6 +39,7 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create('5', false)
     expect(version).toBeInstanceOf(SemanticToolchainVersion)
     expect(version.dev).toBe(false)
+    expect(version.requiresSwiftOrg).toBe(true)
     expect(`${version}`).toBe('version: 5.0.0, dev: false')
     const sVersion = version as SemanticToolchainVersion
     expect(sVersion['dirGlob']).toBe('swift-5*')
@@ -44,6 +50,7 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create('5.0', false)
     expect(version).toBeInstanceOf(SemanticToolchainVersion)
     expect(version.dev).toBe(false)
+    expect(version.requiresSwiftOrg).toBe(true)
     const sVersion = version as SemanticToolchainVersion
     expect(sVersion['dirGlob']).toBe('swift-5_0*')
     expect(sVersion['dirRegex']).toStrictEqual(/swift-5.0/)
@@ -53,6 +60,7 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create('5.0.0', false)
     expect(version).toBeInstanceOf(SemanticToolchainVersion)
     expect(version.dev).toBe(false)
+    expect(version.requiresSwiftOrg).toBe(true)
     const sVersion = version as SemanticToolchainVersion
     expect(sVersion['dirGlob']).toBe('swift-5_0-*')
     expect(sVersion['dirRegex']).toStrictEqual(/swift-5.0-/)
@@ -62,6 +70,7 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create('5.5', false)
     expect(version).toBeInstanceOf(SemanticToolchainVersion)
     expect(version.dev).toBe(false)
+    expect(version.requiresSwiftOrg).toBe(true)
     const sVersion = version as SemanticToolchainVersion
     expect(sVersion['dirGlob']).toBe('swift-5_5*')
     expect(sVersion['dirRegex']).toStrictEqual(/swift-5.5/)
@@ -71,6 +80,7 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create('5.5.0', false)
     expect(version).toBeInstanceOf(SemanticToolchainVersion)
     expect(version.dev).toBe(false)
+    expect(version.requiresSwiftOrg).toBe(true)
     const sVersion = version as SemanticToolchainVersion
     expect(sVersion['dirGlob']).toBe('swift-5_5-*')
     expect(sVersion['dirRegex']).toStrictEqual(/swift-5.5-/)
@@ -80,6 +90,7 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create('5.5.1', false)
     expect(version).toBeInstanceOf(SemanticToolchainVersion)
     expect(version.dev).toBe(false)
+    expect(version.requiresSwiftOrg).toBe(true)
     const sVersion = version as SemanticToolchainVersion
     expect(sVersion['dirGlob']).toBe('swift-5_5_1*')
     expect(sVersion['dirRegex']).toStrictEqual(/swift-5.5.1/)
@@ -90,6 +101,7 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create(name, false)
     expect(version).toBeInstanceOf(ToolchainSnapshotName)
     expect(version.dev).toBe(true)
+    expect(version.requiresSwiftOrg).toBe(true)
     const lVersion = version as ToolchainSnapshotName
     expect(lVersion['dirGlob']).toBe('*')
     expect(lVersion['dirRegex']).toStrictEqual(new RegExp(name))
@@ -101,11 +113,25 @@ describe('parse version from provided string', () => {
     const version = ToolchainVersion.create(input, false)
     expect(version).toBeInstanceOf(ToolchainSnapshotName)
     expect(version.dev).toBe(true)
+    expect(version.requiresSwiftOrg).toBe(true)
     const lVersion = version as ToolchainSnapshotName
     expect(lVersion['dirGlob']).toBe('swift-5_9-*')
     expect(lVersion['dirRegex']).toStrictEqual(new RegExp(name))
   })
 
+  it('parses toolchain URL', async () => {
+    const swiftwasm = 'https://github.com/swiftwasm/swift/releases/download'
+    const name = 'swift-wasm-5.10-SNAPSHOT-2024-03-30-a'
+    const toolchainUrl = `${swiftwasm}/${name}/${name}-ubuntu22.04_x86_64.tar.gz`
+    const version = ToolchainVersion.create(toolchainUrl, false)
+    expect(version).toBeInstanceOf(ToolchainSnapshotLocation)
+    const lVersion = version as ToolchainSnapshotLocation
+    expect(lVersion['dirGlob']).toBe('')
+    expect(lVersion['dirRegex']).toStrictEqual(/a^/)
+    expect(lVersion.requiresSwiftOrg).toBe(false)
+    expect(lVersion.url.href).toBe(toolchainUrl)
+  })
+
   it('parses invalid input', async () => {
     const creation = () => ToolchainVersion.create('invalid', false)
     expect(creation).toThrow()
diff --git a/action.yml b/action.yml
index 370997e..9f8009f 100644
--- a/action.yml
+++ b/action.yml
@@ -9,6 +9,9 @@ inputs:
       i.e. configures 5.1.1 for 5.1, configures 4.2.4 for 4.
       Provide exact semantic version to configure the same version,
       i.e. configures 5.1 for 5.1.0, configures 5.0 for 5.0.0.
+      Provide toolchain download URL to configure custom toolchains,
+      i.e. https://github.com/swiftwasm/swift/releases/download/swift-wasm-5.10-SNAPSHOT-2024-03-30-a/swift-wasm-5.10-SNAPSHOT-2024-03-30-a-ubuntu22.04_x86_64.tar.gz,
+      https://github.com/swiftwasm/swift/releases/download/swift-wasm-5.10-SNAPSHOT-2024-03-30-a/swift-wasm-5.10-SNAPSHOT-2024-03-30-a-macos_x86_64.pkg
     required: false
     default: 'latest'
   development:
diff --git a/dist/index.js b/dist/index.js
index 1f9c5fe..75513c3 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -81,6 +81,7 @@ exports.ToolchainInstaller = void 0;
 const os = __importStar(__nccwpck_require__(2037));
 const path = __importStar(__nccwpck_require__(1017));
 const fs_1 = __nccwpck_require__(7147);
+const url_1 = __nccwpck_require__(7310);
 const core = __importStar(__nccwpck_require__(2186));
 const exec_1 = __nccwpck_require__(1514);
 const cache = __importStar(__nccwpck_require__(7799));
@@ -96,7 +97,12 @@ class ToolchainInstaller {
         return match && match.length > 1 ? (0, semver_1.coerce)(match[1]) : undefined;
     }
     get baseUrl() {
-        return `https://download.swift.org/${this.data.branch}/${this.data.platform}/${this.data.dir}`;
+        const data = this.data;
+        if (data.baseUrl) {
+            return data.baseUrl;
+        }
+        const base = 'https://download.swift.org';
+        return new url_1.URL(path.posix.join(base, data.branch, data.platform, data.dir));
     }
     swiftVersionCommand() {
         return {
@@ -138,7 +144,9 @@ class ToolchainInstaller {
                 tool = yield toolCache.cacheDir(tool, key, version, arch);
                 core.debug(`Added to tool cache at "${tool}"`);
             }
-            if (core.getBooleanInput('cache-snapshot') && !cacheHit) {
+            if (core.getBooleanInput('cache-snapshot') &&
+                !cacheHit &&
+                !this.data.preventCaching) {
                 yield fs_1.promises.cp(tool, restore, { recursive: true });
                 yield cache.saveCache([restore], key);
                 core.debug(`Saved to cache with key "${key}"`);
@@ -148,7 +156,8 @@ class ToolchainInstaller {
     }
     download() {
         return __awaiter(this, void 0, void 0, function* () {
-            const url = `${this.baseUrl}/${this.data.download}`;
+            var _a;
+            const url = path.posix.join((_a = this.baseUrl) === null || _a === void 0 ? void 0 : _a.href, this.data.download);
             core.debug(`Downloading snapshot from "${url}"`);
             return yield toolCache.downloadTool(url);
         });
@@ -400,6 +409,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.VerifyingToolchainInstaller = void 0;
+const path_1 = __nccwpck_require__(1017);
 const core = __importStar(__nccwpck_require__(2186));
 const toolCache = __importStar(__nccwpck_require__(7784));
 const gpg = __importStar(__nccwpck_require__(9787));
@@ -407,18 +417,19 @@ const base_1 = __nccwpck_require__(5686);
 class VerifyingToolchainInstaller extends base_1.ToolchainInstaller {
     get signatureUrl() {
         const signature = this.data.download_signature;
-        return signature ? `${this.baseUrl}/${signature}` : undefined;
+        return signature ? path_1.posix.join(this.baseUrl.href, signature) : undefined;
     }
     downloadSignature() {
         return __awaiter(this, void 0, void 0, function* () {
             try {
-                if (this.signatureUrl) {
-                    return yield toolCache.downloadTool(this.signatureUrl);
-                }
+                return this.signatureUrl
+                    ? yield toolCache.downloadTool(this.signatureUrl)
+                    : undefined;
             }
             catch (error) {
                 if (error instanceof toolCache.HTTPError &&
                     error.httpStatusCode === 404) {
+                    core.warning(`No signature at "${this.signatureUrl}"`);
                     return undefined;
                 }
                 throw error;
@@ -541,16 +552,24 @@ class WindowsToolchainInstaller extends verify_1.VerifyingToolchainInstaller {
         return __awaiter(this, void 0, void 0, function* () {
             function env() {
                 return __awaiter(this, void 0, void 0, function* () {
-                    const { stdout } = yield (0, exec_1.getExecOutput)('cmd', ['/c', 'set'], {
-                        failOnStdErr: true
-                    });
-                    return stdout;
+                    for (const target of ['Machine', 'User']) {
+                        const { stdout } = yield (0, exec_1.getExecOutput)('powershell', [
+                            '-NoProfile',
+                            '-Command',
+                            `& {[Environment]::GetEnvironmentVariables('${target}') | ConvertTo-Json}`
+                        ], { failOnStdErr: true });
+                        core.debug(`${target} variables: "${stdout}"`);
+                    }
                 });
             }
             core.debug(`Installing toolchain from "${exe}"`);
-            core.debug(`Environment variables before installation: ${yield env()}`);
+            core.startGroup('Environment variables before installation');
+            yield env();
+            core.endGroup();
             yield (0, exec_1.exec)(`"${exe}"`, ['-q']);
-            core.debug(`Environment variables after installation: ${yield env()}`);
+            core.startGroup('Environment variables after installation');
+            yield env();
+            core.endGroup();
             const installation = yield installation_1.Installation.detect();
             return installation.location;
         });
@@ -903,11 +922,13 @@ function run() {
             const requestedVersion = (_a = core.getInput('swift-version')) !== null && _a !== void 0 ? _a : 'latest';
             const development = core.getBooleanInput('development');
             const version = version_1.ToolchainVersion.create(requestedVersion, development);
-            core.startGroup('Syncing swift.org data');
-            const checkLatest = core.getInput('check-latest');
-            const submodule = new swiftorg_1.Swiftorg(checkLatest);
-            yield submodule.update();
-            core.endGroup();
+            if (version.requiresSwiftOrg) {
+                core.startGroup('Syncing swift.org data');
+                const checkLatest = core.getInput('check-latest');
+                const submodule = new swiftorg_1.Swiftorg(checkLatest);
+                yield submodule.update();
+                core.endGroup();
+            }
             const dryRun = core.getBooleanInput('dry-run');
             let snapshot;
             let installedVersion;
@@ -1035,6 +1056,10 @@ class Platform {
     }
     tools(version) {
         return __awaiter(this, void 0, void 0, function* () {
+            const verSnapshot = version.toolchainSnapshot(this.file);
+            if (verSnapshot) {
+                return [this.snapshotFor(verSnapshot)];
+            }
             const snapshots = yield this.releasedTools(version);
             if (snapshots.length && !version.dev) {
                 return this.sortSnapshots(snapshots);
@@ -1055,7 +1080,7 @@ class Platform {
             const devSnapshots = snapshotsCollection
                 .flatMap(collection => {
                 return collection.data.map(data => {
-                    return Object.assign(Object.assign({}, data), { platform: collection.platform, branch: collection.branch });
+                    return Object.assign(Object.assign({}, data), { platform: collection.platform, branch: collection.branch, preventCaching: false });
                 });
             })
                 .filter(item => version.satisfiedBy(item.dir));
@@ -1251,6 +1276,9 @@ class LinuxPlatform extends versioned_1.VersionedPlatform {
             return content;
         });
     }
+    snapshotFor(snapshot) {
+        return Object.assign(Object.assign({}, snapshot), { download_signature: `${snapshot.download}.sig` });
+    }
     tools(version) {
         const _super = Object.create(null, {
             tools: { get: () => super.tools }
@@ -1457,7 +1485,8 @@ class VersionedPlatform extends base_1.Platform {
                             platform: pName + this.archSuffix,
                             branch: release.tag.toLocaleLowerCase(),
                             docker: platform.docker,
-                            windows: pName.startsWith('windows')
+                            windows: pName.startsWith('windows'),
+                            preventCaching: false
                         }
                         : [];
                 });
@@ -1507,6 +1536,9 @@ class WindowsPlatform extends versioned_1.VersionedPlatform {
     get downloadExtension() {
         return 'exe';
     }
+    snapshotFor(snapshot) {
+        return Object.assign(Object.assign({}, snapshot), { download_signature: `${snapshot.download}.sig`, windows: true });
+    }
     install(data) {
         return __awaiter(this, void 0, void 0, function* () {
             const installer = new installer_1.WindowsToolchainInstaller(data);
@@ -1525,6 +1557,29 @@ exports.WindowsPlatform = WindowsPlatform;
 
 "use strict";
 
+var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+      desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
+}) : (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    o[k2] = m[k];
+}));
+var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
+    Object.defineProperty(o, "default", { enumerable: true, value: v });
+}) : function(o, v) {
+    o["default"] = v;
+});
+var __importStar = (this && this.__importStar) || function (mod) {
+    if (mod && mod.__esModule) return mod;
+    var result = {};
+    if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
+    __setModuleDefault(result, mod);
+    return result;
+};
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
     function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
@@ -1536,6 +1591,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.XcodePlatform = void 0;
+const path = __importStar(__nccwpck_require__(1017));
 const base_1 = __nccwpck_require__(1568);
 const installer_1 = __nccwpck_require__(8979);
 class XcodePlatform extends base_1.Platform {
@@ -1552,6 +1608,11 @@ class XcodePlatform extends base_1.Platform {
     get fileGlob() {
         return this.name;
     }
+    snapshotFor(snapshot) {
+        const fileExt = path.extname(snapshot.download);
+        const fileName = path.basename(snapshot.download, fileExt);
+        return Object.assign(Object.assign({}, snapshot), { debug_info: `${fileName}-symbols.${fileExt}` });
+    }
     releasedTools(version) {
         return __awaiter(this, void 0, void 0, function* () {
             const releases = yield this.releases();
@@ -1563,11 +1624,12 @@ class XcodePlatform extends base_1.Platform {
                     name: `Xcode Swift ${release.name}`,
                     date: release.date,
                     download: `${release.tag}-osx.pkg`,
-                    symbols: `${release.tag}-osx-symbols.pkg`,
+                    debug_info: `${release.tag}-osx-symbols.pkg`,
                     dir: release.tag,
                     xcode: xMatch && xMatch.length > 1 ? xMatch[1] : undefined,
                     platform: this.name,
-                    branch: release.tag.toLocaleLowerCase()
+                    branch: release.tag.toLocaleLowerCase(),
+                    preventCaching: false
                 };
             });
         });
@@ -1916,7 +1978,7 @@ class VisualStudio {
         this.catalog = catalog;
         this.properties = properties;
     }
-    // eslint-disable-next-line no-explicit-any
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
     static createFromJSON(json) {
         return new VisualStudio(json.installationPath, json.installationVersion, json.catalog, json.properties);
     }
@@ -2295,12 +2357,20 @@ const glob_1 = __nccwpck_require__(8211);
 const const_1 = __nccwpck_require__(6695);
 exports.SWIFT_RELEASE_REGEX = /swift-(.*)-release/;
 class ToolchainVersion {
+    get requiresSwiftOrg() {
+        return true;
+    }
     constructor(dev) {
         this.dev = dev;
     }
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    toolchainSnapshot(platform) {
+        return undefined;
+    }
     toolFiles(fileGlob) {
         return __awaiter(this, void 0, void 0, function* () {
-            const pattern = `swiftorg/_data/builds/${this.dirGlob}/${fileGlob}.yml`;
+            const builds = 'swiftorg/_data/builds';
+            const pattern = path.posix.join(builds, this.dirGlob, `${fileGlob}.yml`);
             core.debug(`Searching for glob "${pattern}"`);
             let files = yield (0, glob_1.glob)(pattern, { absolute: true, cwd: const_1.MODULE_DIR });
             core.debug(`Retrieved files "${files}" for glob "${pattern}"`);
@@ -2356,13 +2426,22 @@ var __exportStar = (this && this.__exportStar) || function(m, exports) {
     for (var p in m) if (p !== "default" && !Object.prototype.hasOwnProperty.call(exports, p)) __createBinding(exports, m, p);
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
+const url_1 = __nccwpck_require__(7310);
 const core = __importStar(__nccwpck_require__(2186));
 const semver_1 = __nccwpck_require__(1383);
 const base_1 = __nccwpck_require__(2120);
 const latest_1 = __nccwpck_require__(8363);
 const semver_2 = __nccwpck_require__(916);
 const name_1 = __nccwpck_require__(3987);
+const location_1 = __nccwpck_require__(9785);
 base_1.ToolchainVersion.create = (requested, dev = false) => {
+    try {
+        const toolchainUrl = new url_1.URL(requested);
+        return new location_1.ToolchainSnapshotLocation(toolchainUrl, dev);
+    }
+    catch (_a) {
+        core.debug(`Input "${requested}" not an URL`);
+    }
     if (requested === 'latest' || requested === 'current') {
         core.debug(`Using latest ${dev ? 'development ' : ''}toolchain requirement`);
         return new latest_1.LatestToolchainVersion(dev);
@@ -2391,6 +2470,7 @@ __exportStar(__nccwpck_require__(2120), exports);
 __exportStar(__nccwpck_require__(8363), exports);
 __exportStar(__nccwpck_require__(916), exports);
 __exportStar(__nccwpck_require__(3987), exports);
+__exportStar(__nccwpck_require__(9785), exports);
 
 
 /***/ }),
@@ -2417,6 +2497,57 @@ class LatestToolchainVersion extends base_1.ToolchainVersion {
 exports.LatestToolchainVersion = LatestToolchainVersion;
 
 
+/***/ }),
+
+/***/ 9785:
+/***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
+
+"use strict";
+
+Object.defineProperty(exports, "__esModule", ({ value: true }));
+exports.ToolchainSnapshotLocation = void 0;
+const url_1 = __nccwpck_require__(7310);
+const path_1 = __nccwpck_require__(1017);
+const base_1 = __nccwpck_require__(2120);
+class ToolchainSnapshotLocation extends base_1.ToolchainVersion {
+    constructor(url, dev) {
+        super(dev);
+        this.url = url;
+    }
+    get dirGlob() {
+        return '';
+    }
+    get dirRegex() {
+        return /a^/;
+    }
+    get requiresSwiftOrg() {
+        return false;
+    }
+    toolchainSnapshot(platform) {
+        try {
+            const baseUrl = path_1.posix.dirname(this.url.href);
+            return {
+                name: 'Swift Custom Snapshot',
+                date: new Date(),
+                download: path_1.posix.basename(this.url.href),
+                dir: path_1.posix.basename(baseUrl),
+                platform,
+                branch: this.url.pathname.split(path_1.posix.sep)[1],
+                baseUrl: new url_1.URL(baseUrl),
+                preventCaching: true
+            };
+        }
+        catch (e) {
+            throw new Error(`Swift resource: "${this.url}" failed with error ${e}`);
+        }
+    }
+    toString() {
+        return `url: "${this.url}", dev: ${this.dev}`;
+    }
+}
+exports.ToolchainSnapshotLocation = ToolchainSnapshotLocation;
+
+
 /***/ }),
 
 /***/ 3987:
@@ -74588,35 +74719,43 @@ const coerce = (version, options) => {
 
   let match = null
   if (!options.rtl) {
-    match = version.match(re[t.COERCE])
+    match = version.match(options.includePrerelease ? re[t.COERCEFULL] : re[t.COERCE])
   } else {
     // Find the right-most coercible string that does not share
     // a terminus with a more left-ward coercible string.
     // Eg, '1.2.3.4' wants to coerce '2.3.4', not '3.4' or '4'
+    // With includePrerelease option set, '1.2.3.4-rc' wants to coerce '2.3.4-rc', not '2.3.4'
     //
     // Walk through the string checking with a /g regexp
     // Manually set the index so as to pick up overlapping matches.
     // Stop when we get a match that ends at the string end, since no
     // coercible string can be more right-ward without the same terminus.
+    const coerceRtlRegex = options.includePrerelease ? re[t.COERCERTLFULL] : re[t.COERCERTL]
     let next
-    while ((next = re[t.COERCERTL].exec(version)) &&
+    while ((next = coerceRtlRegex.exec(version)) &&
         (!match || match.index + match[0].length !== version.length)
     ) {
       if (!match ||
             next.index + next[0].length !== match.index + match[0].length) {
         match = next
       }
-      re[t.COERCERTL].lastIndex = next.index + next[1].length + next[2].length
+      coerceRtlRegex.lastIndex = next.index + next[1].length + next[2].length
     }
     // leave it in a clean state
-    re[t.COERCERTL].lastIndex = -1
+    coerceRtlRegex.lastIndex = -1
   }
 
   if (match === null) {
     return null
   }
 
-  return parse(`${match[2]}.${match[3] || '0'}.${match[4] || '0'}`, options)
+  const major = match[2]
+  const minor = match[3] || '0'
+  const patch = match[4] || '0'
+  const prerelease = options.includePrerelease && match[5] ? `-${match[5]}` : ''
+  const build = options.includePrerelease && match[6] ? `+${match[6]}` : ''
+
+  return parse(`${major}.${minor}.${patch}${prerelease}${build}`, options)
 }
 module.exports = coerce
 
@@ -75308,12 +75447,17 @@ createToken('XRANGELOOSE', `^${src[t.GTLT]}\\s*${src[t.XRANGEPLAINLOOSE]}$`)
 
 // Coercion.
 // Extract anything that could conceivably be a part of a valid semver
-createToken('COERCE', `${'(^|[^\\d])' +
+createToken('COERCEPLAIN', `${'(^|[^\\d])' +
               '(\\d{1,'}${MAX_SAFE_COMPONENT_LENGTH}})` +
               `(?:\\.(\\d{1,${MAX_SAFE_COMPONENT_LENGTH}}))?` +
-              `(?:\\.(\\d{1,${MAX_SAFE_COMPONENT_LENGTH}}))?` +
+              `(?:\\.(\\d{1,${MAX_SAFE_COMPONENT_LENGTH}}))?`)
+createToken('COERCE', `${src[t.COERCEPLAIN]}(?:$|[^\\d])`)
+createToken('COERCEFULL', src[t.COERCEPLAIN] +
+              `(?:${src[t.PRERELEASE]})?` +
+              `(?:${src[t.BUILD]})?` +
               `(?:$|[^\\d])`)
 createToken('COERCERTL', src[t.COERCE], true)
+createToken('COERCERTLFULL', src[t.COERCEFULL], true)
 
 // Tilde ranges.
 // Meaning is "reasonably at or greater than"
diff --git a/src/installer/base.ts b/src/installer/base.ts
index fa18418..098c3cd 100644
--- a/src/installer/base.ts
+++ b/src/installer/base.ts
@@ -1,6 +1,7 @@
 import * as os from 'os'
 import * as path from 'path'
 import {promises as fs} from 'fs'
+import {URL} from 'url'
 import * as core from '@actions/core'
 import {getExecOutput} from '@actions/exec'
 import * as cache from '@actions/cache'
@@ -23,7 +24,12 @@ export abstract class ToolchainInstaller<Snapshot extends ToolchainSnapshot> {
   }
 
   protected get baseUrl() {
-    return `https://download.swift.org/${this.data.branch}/${this.data.platform}/${this.data.dir}`
+    const data = this.data
+    if (data.baseUrl) {
+      return data.baseUrl
+    }
+    const base = 'https://download.swift.org'
+    return new URL(path.posix.join(base, data.branch, data.platform, data.dir))
   }
 
   protected swiftVersionCommand() {
@@ -67,7 +73,11 @@ export abstract class ToolchainInstaller<Snapshot extends ToolchainSnapshot> {
       tool = await toolCache.cacheDir(tool, key, version, arch)
       core.debug(`Added to tool cache at "${tool}"`)
     }
-    if (core.getBooleanInput('cache-snapshot') && !cacheHit) {
+    if (
+      core.getBooleanInput('cache-snapshot') &&
+      !cacheHit &&
+      !this.data.preventCaching
+    ) {
       await fs.cp(tool, restore, {recursive: true})
       await cache.saveCache([restore], key)
       core.debug(`Saved to cache with key "${key}"`)
@@ -76,7 +86,7 @@ export abstract class ToolchainInstaller<Snapshot extends ToolchainSnapshot> {
   }
 
   protected async download() {
-    const url = `${this.baseUrl}/${this.data.download}`
+    const url = path.posix.join(this.baseUrl?.href, this.data.download)
     core.debug(`Downloading snapshot from "${url}"`)
     return await toolCache.downloadTool(url)
   }
diff --git a/src/installer/verify.ts b/src/installer/verify.ts
index bec8b25..1153508 100644
--- a/src/installer/verify.ts
+++ b/src/installer/verify.ts
@@ -1,3 +1,4 @@
+import {posix} from 'path'
 import * as core from '@actions/core'
 import * as toolCache from '@actions/tool-cache'
 import * as gpg from '../utils/gpg'
@@ -9,19 +10,20 @@ export abstract class VerifyingToolchainInstaller<
 > extends ToolchainInstaller<Snapshot> {
   private get signatureUrl() {
     const signature = this.data.download_signature
-    return signature ? `${this.baseUrl}/${signature}` : undefined
+    return signature ? posix.join(this.baseUrl.href, signature) : undefined
   }
 
   private async downloadSignature() {
     try {
-      if (this.signatureUrl) {
-        return await toolCache.downloadTool(this.signatureUrl)
-      }
+      return this.signatureUrl
+        ? await toolCache.downloadTool(this.signatureUrl)
+        : undefined
     } catch (error) {
       if (
         error instanceof toolCache.HTTPError &&
         error.httpStatusCode === 404
       ) {
+        core.warning(`No signature at "${this.signatureUrl}"`)
         return undefined
       }
       throw error
diff --git a/src/installer/windows/index.ts b/src/installer/windows/index.ts
index 9cf222f..226ef45 100644
--- a/src/installer/windows/index.ts
+++ b/src/installer/windows/index.ts
@@ -41,15 +41,27 @@ export class WindowsToolchainInstaller extends VerifyingToolchainInstaller<Windo
 
   protected async unpack(exe: string) {
     async function env() {
-      const {stdout} = await getExecOutput('cmd', ['/c', 'set'], {
-        failOnStdErr: true
-      })
-      return stdout
+      for (const target of ['Machine', 'User']) {
+        const {stdout} = await getExecOutput(
+          'powershell',
+          [
+            '-NoProfile',
+            '-Command',
+            `& {[Environment]::GetEnvironmentVariables('${target}') | ConvertTo-Json}`
+          ],
+          {failOnStdErr: true}
+        )
+        core.debug(`${target} variables: "${stdout}"`)
+      }
     }
     core.debug(`Installing toolchain from "${exe}"`)
-    core.debug(`Environment variables before installation: ${await env()}`)
+    core.startGroup('Environment variables before installation')
+    await env()
+    core.endGroup()
     await exec(`"${exe}"`, ['-q'])
-    core.debug(`Environment variables after installation: ${await env()}`)
+    core.startGroup('Environment variables after installation')
+    await env()
+    core.endGroup()
     const installation = await Installation.detect()
     return installation.location
   }
diff --git a/src/main.ts b/src/main.ts
index 34cf4dd..a471e85 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -10,11 +10,13 @@ export async function run() {
     const development = core.getBooleanInput('development')
     const version = ToolchainVersion.create(requestedVersion, development)
 
-    core.startGroup('Syncing swift.org data')
-    const checkLatest = core.getInput('check-latest')
-    const submodule = new Swiftorg(checkLatest)
-    await submodule.update()
-    core.endGroup()
+    if (version.requiresSwiftOrg) {
+      core.startGroup('Syncing swift.org data')
+      const checkLatest = core.getInput('check-latest')
+      const submodule = new Swiftorg(checkLatest)
+      await submodule.update()
+      core.endGroup()
+    }
 
     const dryRun = core.getBooleanInput('dry-run')
     let snapshot: ToolchainSnapshot
diff --git a/src/platform/base.ts b/src/platform/base.ts
index d90b628..4381fdf 100644
--- a/src/platform/base.ts
+++ b/src/platform/base.ts
@@ -33,6 +33,10 @@ export abstract class Platform<
     return yaml.load(data) as SwiftRelease[]
   }
 
+  abstract snapshotFor(
+    snapshot: ToolchainSnapshot
+  ): SnapshotForInstaller<Installer>
+
   private sortSnapshots(snapshots: SnapshotForInstaller<Installer>[]) {
     return snapshots.sort((item1, item2) => {
       const t1 = item1 as ToolchainSnapshot
@@ -65,6 +69,11 @@ export abstract class Platform<
   async tools(
     version: ToolchainVersion
   ): Promise<SnapshotForInstaller<Installer>[]> {
+    const verSnapshot = version.toolchainSnapshot(this.file)
+    if (verSnapshot) {
+      return [this.snapshotFor(verSnapshot)]
+    }
+
     const snapshots = await this.releasedTools(version)
     if (snapshots.length && !version.dev) {
       return this.sortSnapshots(snapshots)
@@ -92,7 +101,8 @@ export abstract class Platform<
           return {
             ...data,
             platform: collection.platform,
-            branch: collection.branch
+            branch: collection.branch,
+            preventCaching: false
           } as SnapshotForInstaller<Installer>
         })
       })
diff --git a/src/platform/linux.ts b/src/platform/linux.ts
index 0ea5c18..c67ae8f 100644
--- a/src/platform/linux.ts
+++ b/src/platform/linux.ts
@@ -2,7 +2,7 @@ import * as path from 'path'
 import {promises as fs} from 'fs'
 import {VersionedPlatform} from './versioned'
 import {ToolchainVersion, SWIFT_BRANCH_REGEX} from '../version'
-import {LinuxToolchainSnapshot} from '../snapshot'
+import {LinuxToolchainSnapshot, ToolchainSnapshot} from '../snapshot'
 import {LinuxToolchainInstaller} from '../installer'
 import {MODULE_DIR} from '../const'
 
@@ -17,6 +17,10 @@ export class LinuxPlatform extends VersionedPlatform<LinuxToolchainInstaller> {
     return content
   }
 
+  snapshotFor(snapshot: ToolchainSnapshot) {
+    return {...snapshot, download_signature: `${snapshot.download}.sig`}
+  }
+
   async tools(version: ToolchainVersion) {
     let html: string
     const tools = await super.tools(version)
diff --git a/src/platform/versioned.ts b/src/platform/versioned.ts
index ac8344e..212722c 100644
--- a/src/platform/versioned.ts
+++ b/src/platform/versioned.ts
@@ -119,7 +119,8 @@ export abstract class VersionedPlatform<
                 platform: pName + this.archSuffix,
                 branch: release.tag.toLocaleLowerCase(),
                 docker: platform.docker,
-                windows: pName.startsWith('windows')
+                windows: pName.startsWith('windows'),
+                preventCaching: false
               } as ToolchainSnapshot)
             : []
         })
diff --git a/src/platform/windows.ts b/src/platform/windows.ts
index e7a847b..8417991 100644
--- a/src/platform/windows.ts
+++ b/src/platform/windows.ts
@@ -1,12 +1,20 @@
 import {VersionedPlatform} from './versioned'
 import {WindowsToolchainInstaller} from '../installer'
-import {WindowsToolchainSnapshot} from '../snapshot'
+import {WindowsToolchainSnapshot, ToolchainSnapshot} from '../snapshot'
 
 export class WindowsPlatform extends VersionedPlatform<WindowsToolchainInstaller> {
   protected get downloadExtension() {
     return 'exe'
   }
 
+  snapshotFor(snapshot: ToolchainSnapshot) {
+    return {
+      ...snapshot,
+      download_signature: `${snapshot.download}.sig`,
+      windows: true
+    }
+  }
+
   async install(data: WindowsToolchainSnapshot) {
     const installer = new WindowsToolchainInstaller(data)
     await installer.install(this.arch)
diff --git a/src/platform/xcode.ts b/src/platform/xcode.ts
index 7c79028..2b041f9 100644
--- a/src/platform/xcode.ts
+++ b/src/platform/xcode.ts
@@ -1,6 +1,7 @@
+import * as path from 'path'
 import {Platform} from './base'
 import {ToolchainVersion} from '../version'
-import {XcodeToolchainSnapshot} from '../snapshot'
+import {XcodeToolchainSnapshot, ToolchainSnapshot} from '../snapshot'
 import {XcodeToolchainInstaller} from '../installer'
 
 export class XcodePlatform extends Platform<XcodeToolchainInstaller> {
@@ -18,6 +19,15 @@ export class XcodePlatform extends Platform<XcodeToolchainInstaller> {
     return this.name
   }
 
+  snapshotFor(snapshot: ToolchainSnapshot) {
+    const fileExt = path.extname(snapshot.download)
+    const fileName = path.basename(snapshot.download, fileExt)
+    return {
+      ...snapshot,
+      debug_info: `${fileName}-symbols.${fileExt}`
+    }
+  }
+
   protected async releasedTools(version: ToolchainVersion) {
     const releases = await this.releases()
     return releases
@@ -28,11 +38,12 @@ export class XcodePlatform extends Platform<XcodeToolchainInstaller> {
           name: `Xcode Swift ${release.name}`,
           date: release.date,
           download: `${release.tag}-osx.pkg`,
-          symbols: `${release.tag}-osx-symbols.pkg`,
+          debug_info: `${release.tag}-osx-symbols.pkg`,
           dir: release.tag,
           xcode: xMatch && xMatch.length > 1 ? xMatch[1] : undefined,
           platform: this.name,
-          branch: release.tag.toLocaleLowerCase()
+          branch: release.tag.toLocaleLowerCase(),
+          preventCaching: false
         } as XcodeToolchainSnapshot
       })
   }
diff --git a/src/snapshot/base.ts b/src/snapshot/base.ts
index 07bb2db..6042f7b 100644
--- a/src/snapshot/base.ts
+++ b/src/snapshot/base.ts
@@ -1,3 +1,5 @@
+import {URL} from 'url'
+
 export interface ToolchainSnapshot {
   readonly name: string
   readonly date: Date
@@ -5,4 +7,6 @@ export interface ToolchainSnapshot {
   readonly dir: string
   readonly platform: string
   readonly branch: string
+  readonly baseUrl?: URL
+  readonly preventCaching: boolean
 }
diff --git a/src/snapshot/xcode.ts b/src/snapshot/xcode.ts
index 4d66d2b..30cc427 100644
--- a/src/snapshot/xcode.ts
+++ b/src/snapshot/xcode.ts
@@ -1,6 +1,6 @@
 import {ToolchainSnapshot} from './base'
 
 export interface XcodeToolchainSnapshot extends ToolchainSnapshot {
-  readonly symbols?: string
+  readonly debug_info?: string
   readonly xcode?: string
 }
diff --git a/src/utils/visual_studio/base.ts b/src/utils/visual_studio/base.ts
index a2598ce..c456690 100644
--- a/src/utils/visual_studio/base.ts
+++ b/src/utils/visual_studio/base.ts
@@ -10,7 +10,7 @@ export class VisualStudio {
     readonly properties: VisualStudioProperties
   ) {}
 
-  // eslint-disable-next-line no-explicit-any
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   static createFromJSON(json: any) {
     return new VisualStudio(
       json.installationPath,
diff --git a/src/version/base.ts b/src/version/base.ts
index 2f69e87..d45586c 100644
--- a/src/version/base.ts
+++ b/src/version/base.ts
@@ -2,6 +2,7 @@ import * as path from 'path'
 import * as core from '@actions/core'
 import {glob} from 'glob'
 import {MODULE_DIR} from '../const'
+import {ToolchainSnapshot} from '../snapshot'
 
 export const SWIFT_RELEASE_REGEX = /swift-(.*)-release/
 
@@ -9,10 +10,20 @@ export abstract class ToolchainVersion {
   protected abstract readonly dirGlob: string
   protected abstract readonly dirRegex: RegExp
 
+  get requiresSwiftOrg() {
+    return true
+  }
+
   constructor(readonly dev: boolean) {}
 
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  toolchainSnapshot(platform: string): ToolchainSnapshot | undefined {
+    return undefined
+  }
+
   async toolFiles(fileGlob: string) {
-    const pattern = `swiftorg/_data/builds/${this.dirGlob}/${fileGlob}.yml`
+    const builds = 'swiftorg/_data/builds'
+    const pattern = path.posix.join(builds, this.dirGlob, `${fileGlob}.yml`)
     core.debug(`Searching for glob "${pattern}"`)
     let files = await glob(pattern, {absolute: true, cwd: MODULE_DIR})
     core.debug(`Retrieved files "${files}" for glob "${pattern}"`)
diff --git a/src/version/index.ts b/src/version/index.ts
index c01e8a9..a928e96 100644
--- a/src/version/index.ts
+++ b/src/version/index.ts
@@ -1,9 +1,11 @@
+import {URL} from 'url'
 import * as core from '@actions/core'
 import {SemVer, coerce as parseSemVer} from 'semver'
 import {ToolchainVersion} from './base'
 import {LatestToolchainVersion} from './latest'
 import {SemanticToolchainVersion} from './semver'
 import {ToolchainSnapshotName, DEVELOPMENT_SNAPSHOT} from './name'
+import {ToolchainSnapshotLocation} from './location'
 
 declare module './base' {
   // eslint-disable-next-line no-shadow
@@ -13,6 +15,13 @@ declare module './base' {
 }
 
 ToolchainVersion.create = (requested: string, dev = false) => {
+  try {
+    const toolchainUrl = new URL(requested)
+    return new ToolchainSnapshotLocation(toolchainUrl, dev)
+  } catch {
+    core.debug(`Input "${requested}" not an URL`)
+  }
+
   if (requested === 'latest' || requested === 'current') {
     core.debug(`Using latest ${dev ? 'development ' : ''}toolchain requirement`)
     return new LatestToolchainVersion(dev)
@@ -47,3 +56,4 @@ export * from './base'
 export * from './latest'
 export * from './semver'
 export * from './name'
+export * from './location'
diff --git a/src/version/location.ts b/src/version/location.ts
new file mode 100644
index 0000000..c02e8b4
--- /dev/null
+++ b/src/version/location.ts
@@ -0,0 +1,46 @@
+import {URL} from 'url'
+import {posix} from 'path'
+import {ToolchainVersion} from './base'
+
+export class ToolchainSnapshotLocation extends ToolchainVersion {
+  constructor(
+    readonly url: URL,
+    dev: boolean
+  ) {
+    super(dev)
+  }
+
+  protected get dirGlob() {
+    return ''
+  }
+
+  protected get dirRegex() {
+    return /a^/
+  }
+
+  get requiresSwiftOrg() {
+    return false
+  }
+
+  toolchainSnapshot(platform: string) {
+    try {
+      const baseUrl = posix.dirname(this.url.href)
+      return {
+        name: 'Swift Custom Snapshot',
+        date: new Date(),
+        download: posix.basename(this.url.href),
+        dir: posix.basename(baseUrl),
+        platform,
+        branch: this.url.pathname.split(posix.sep)[1],
+        baseUrl: new URL(baseUrl),
+        preventCaching: true
+      }
+    } catch (e) {
+      throw new Error(`Swift resource: "${this.url}" failed with error ${e}`)
+    }
+  }
+
+  toString() {
+    return `url: "${this.url}", dev: ${this.dev}`
+  }
+}
diff --git a/tsconfig.base.json b/tsconfig.base.json
new file mode 100644
index 0000000..e7634c5
--- /dev/null
+++ b/tsconfig.base.json
@@ -0,0 +1,19 @@
+{
+    "compilerOptions": {
+        "target": "es6",
+        "module": "nodenext",
+        "moduleResolution": "nodenext",
+        "strict": true,
+        "noImplicitAny": true,
+        "esModuleInterop": true,
+        "allowUnreachableCode": false,
+        "allowUnusedLabels": false,
+        "noImplicitReturns": true,
+        "lib": [
+            "ES2021.String",
+        ]
+    },
+    "exclude": [
+        "node_modules"
+    ]
+}
diff --git a/tsconfig.json b/tsconfig.json
index 3baa27a..8516854 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,19 +1,10 @@
 {
+    "extends": "./tsconfig.base.json",
     "compilerOptions": {
-        "target": "es6",
-        "module": "nodenext",
-        "moduleResolution": "nodenext",
         "outDir": "lib",
-        "rootDir": "src",
-        "strict": true,
-        "noImplicitAny": true,
-        "esModuleInterop": true,
-        "lib": [
-            "ES2021.String",
-        ]
+        "rootDir": "src"
     },
     "exclude": [
-        "node_modules",
         "**/*.test.ts",
         "**/__mocks__/*",
         "lib",