diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000..e84ce8b
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,19 @@
+name: Release
+on:
+  push:
+    branches: [cli]
+    tags: ["*"]
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: olafurpg/setup-scala@v10
+      - uses: coursier/cache-action@v3
+      - uses: olafurpg/setup-gpg@v3
+      - run: sbt ci-release
+        env:
+          PGP_PASSPHRASE: ${{ secrets.PGP_PASSPHRASE }}
+          PGP_SECRET: ${{ secrets.PGP_SECRET }}
+          SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
+          SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
diff --git a/.github/workflows/scala.yml b/.github/workflows/scala.yml
new file mode 100644
index 0000000..e473d53
--- /dev/null
+++ b/.github/workflows/scala.yml
@@ -0,0 +1,10 @@
+name: build
+on: [push, pull_request]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: olafurpg/setup-scala@v10
+      - uses: coursier/cache-action@v3
+      - run: sbt clean headerCheck +test
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..675ff7f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,52 @@
+*.class
+*.log
+
+# these are moved into the doc project by the build
+modules/docs/src/main/tut/changelog.md
+modules/docs/src/main/tut/license.md
+
+# sbt specific
+dist/*
+target/
+lib_managed/
+src_managed/
+project/boot/
+project/plugins/project/
+project/hydra.sbt
+
+# Scala-IDE specific
+.scala_dependencies
+.cache
+.classpath
+.project
+.worksheet/
+.settings/
+
+# OS X
+.DS_Store
+
+# Ctags
+.tags
+
+# ENSIME
+.ensime
+.ensime_cache/
+
+# IntelliJ
+.idea/
+
+# Mill
+out/
+
+# Bloop/Metals/vscode
+.bloop/
+.metals/
+.vscode/
+metals.sbt
+
+# Transient workspace
+modules/docs/src/main/scala/
+*.worksheet.sc
+
+# bsp
+.bsp/
\ No newline at end of file
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..7614b25
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2020 by Rob Norris
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..2258fd4
--- /dev/null
+++ b/README.md
@@ -0,0 +1,39 @@
+# SourcePos
+
+This is a Scala micro-library that provides:
+
+- a `SourcePos` class that specifies a source file and line number, and
+- an implicit macro that forges a `SourcePos` at the call site if none is available.
+
+SourcePos is compiled for Scala **2.12**, **2.13**, and **3.0** (see release notes for exact versions).
+
+
+```scala
+libraryDependencies += "org.tpolecat" %% "sourcepos" % <version>
+```
+
+#### Example
+
+If you want to know where a method call originated, demand an implicit `SourcePos`. It has fields for both `file` and `line`, and a `toString` that prints them as `<file>:<line>`, which most editors will hyperlink for you.
+
+```scala
+import org.tpolecat.sourcepos._
+
+object Example {
+
+  def method(n: Int)(implicit sp: SourcePos): String =
+    s"You called me with $n from $sp"
+
+  def main(args: Array[String]): Unit =
+    println(method(42))
+
+}
+```
+
+Running this program on my computer yields:
+
+```
+You called me with 42 from /Users/rnorris/Scala/SourcePos/src/test/scala/Example.scala:9
+```
+
+
diff --git a/build.sbt b/build.sbt
new file mode 100644
index 0000000..1b5866d
--- /dev/null
+++ b/build.sbt
@@ -0,0 +1,73 @@
+
+// Our Scala versions.
+lazy val `scala-3.0`      = "3.0.0-M3"
+lazy val `scala-3.0-prev` = "3.0.0-M2"
+lazy val `scala-2.12`     = "2.12.12"
+lazy val `scala-2.13`     = "2.13.3"
+
+// Publishing
+name         := "sourcepos"
+organization := "org.tpolecat"
+licenses    ++= Seq(("MIT", url("http://opensource.org/licenses/MIT")))
+homepage     := Some(url("https://github.com/tpolecat/sourcepos"))
+developers   := List(
+  Developer("tpolecat", "Rob Norris", "rob_norris@mac.com", url("http://www.tpolecat.org"))
+)
+
+// Headers
+headerMappings := headerMappings.value + (HeaderFileType.scala -> HeaderCommentStyle.cppStyleLineComment)
+headerLicense  := Some(HeaderLicense.Custom(
+  """|Copyright (c) 2020 by Rob Norris
+     |This software is licensed under the MIT License (MIT).
+     |For more information see LICENSE or https://opensource.org/licenses/MIT
+     |""".stripMargin
+  )
+)
+
+// Compilation
+scalaVersion       := `scala-2.13`
+crossScalaVersions := Seq(`scala-2.12`, `scala-2.13`, `scala-3.0-prev`, `scala-3.0`)
+Compile / doc     / scalacOptions --= Seq("-Xfatal-warnings")
+Compile / doc     / scalacOptions ++= Seq(
+  "-groups",
+  "-sourcepath", (baseDirectory in LocalRootProject).value.getAbsolutePath,
+  "-doc-source-url", "https://github.com/tpolecat/sourcepos/blob/v" + version.value + "€{FILE_PATH}.scala",
+)
+
+// MUnit
+libraryDependencies += "org.scalameta" %% "munit" % "0.7.20" % Test
+testFrameworks += new TestFramework("munit.Framework")
+
+// Scala 2 needs scala-reflect
+libraryDependencies ++= Seq("org.scala-lang" % "scala-reflect" % scalaVersion.value).filterNot(_ => isDotty.value)
+
+// Add some more source directories
+unmanagedSourceDirectories in Compile ++= {
+  val sourceDir = (sourceDirectory in Compile).value
+  CrossVersion.partialVersion(scalaVersion.value) match {
+    case Some((3, _))  => Seq(sourceDir / "scala-3")
+    case Some((2, _))  => Seq(sourceDir / "scala-2")
+    case _             => Seq()
+  }
+}
+
+// Also for test
+unmanagedSourceDirectories in Test ++= {
+  val sourceDir = (sourceDirectory in Test).value
+  CrossVersion.partialVersion(scalaVersion.value) match {
+    case Some((3, _))  => Seq(sourceDir / "scala-3")
+    case Some((2, _))  => Seq(sourceDir / "scala-2")
+    case _             => Seq()
+  }
+}
+
+// dottydoc really doesn't work at all right now
+Compile / doc / sources := {
+  val old = (Compile / doc / sources).value
+  if (isDotty.value)
+    Seq()
+  else
+    old
+}
+
+enablePlugins(AutomateHeaderPlugin)
diff --git a/project/build.properties b/project/build.properties
new file mode 100644
index 0000000..d91c272
--- /dev/null
+++ b/project/build.properties
@@ -0,0 +1 @@
+sbt.version=1.4.6
diff --git a/project/plugins.sbt b/project/plugins.sbt
new file mode 100644
index 0000000..76e7d10
--- /dev/null
+++ b/project/plugins.sbt
@@ -0,0 +1,10 @@
+addSbtPlugin("com.geirsson"              % "sbt-ci-release" % "1.5.5")
+addSbtPlugin("de.heikoseeberger"         % "sbt-header"     % "5.6.0")
+addSbtPlugin("com.lightbend.paradox"     % "sbt-paradox"    % "0.9.1")
+addSbtPlugin("com.typesafe.sbt"          % "sbt-site"       % "1.4.1")
+addSbtPlugin("com.typesafe.sbt"          % "sbt-ghpages"    % "0.6.3")
+addSbtPlugin("com.timushev.sbt"          % "sbt-updates"    % "0.5.1")
+addSbtPlugin("io.github.davidgregory084" % "sbt-tpolecat"   % "0.1.16")
+addSbtPlugin("org.scalameta"             % "sbt-mdoc"       % "2.2.14")
+addSbtPlugin("org.scoverage"             % "sbt-scoverage"  % "1.6.1")
+addSbtPlugin("ch.epfl.lamp"              % "sbt-dotty"      % "0.5.1")
diff --git a/project/project/plugins.sbt b/project/project/plugins.sbt
new file mode 100644
index 0000000..8eaec21
--- /dev/null
+++ b/project/project/plugins.sbt
@@ -0,0 +1 @@
+addSbtPlugin("com.timushev.sbt" % "sbt-updates" % "0.4.3")
diff --git a/src/main/scala-2/SourcePosPlatform.scala b/src/main/scala-2/SourcePosPlatform.scala
new file mode 100644
index 0000000..1bec024
--- /dev/null
+++ b/src/main/scala-2/SourcePosPlatform.scala
@@ -0,0 +1,21 @@
+// Copyright (c) 2020 by Rob Norris
+// This software is licensed under the MIT License (MIT).
+// For more information see LICENSE or https://opensource.org/licenses/MIT
+
+package org.tpolecat.sourcepos
+
+import scala.reflect.macros.blackbox
+
+trait SourcePosPlatform {
+  implicit def instance: SourcePos =
+    macro SourcePosPlatform.sourcePos_impl
+}
+
+object SourcePosPlatform {
+  def sourcePos_impl(c: blackbox.Context): c.Tree = {
+    import c.universe._
+    val file = c.enclosingPosition.source.path
+    val line = c.enclosingPosition.line
+    q"_root_.org.tpolecat.sourcepos.SourcePos($file, $line)"
+  }
+}
diff --git a/src/main/scala-3.0.0-M2/SourcPosPlatform.scala b/src/main/scala-3.0.0-M2/SourcPosPlatform.scala
new file mode 100644
index 0000000..877a67c
--- /dev/null
+++ b/src/main/scala-3.0.0-M2/SourcPosPlatform.scala
@@ -0,0 +1,25 @@
+// Copyright (c) 2020 by Rob Norris
+// This software is licensed under the MIT License (MIT).
+// For more information see LICENSE or https://opensource.org/licenses/MIT
+
+package org.tpolecat.sourcepos
+
+import scala.quoted._
+
+trait SourcePosPlatform {
+
+  implicit inline def instance: SourcePos =
+    ${SourcePosPlatform.sourcePos_impl}
+
+}
+
+object SourcePosPlatform {
+
+  def sourcePos_impl(using ctx: Quotes): Expr[SourcePos] = {
+    val rootPosition = ctx.reflect.Position.ofMacroExpansion
+    val file = Expr(rootPosition.sourceFile.jpath.toString)
+    val line = Expr(rootPosition.startLine + 1)
+    '{SourcePos($file, $line)}
+  }
+
+}
diff --git a/src/main/scala-3.0.0-M3/SourcPosPlatform.scala b/src/main/scala-3.0.0-M3/SourcPosPlatform.scala
new file mode 100644
index 0000000..877a67c
--- /dev/null
+++ b/src/main/scala-3.0.0-M3/SourcPosPlatform.scala
@@ -0,0 +1,25 @@
+// Copyright (c) 2020 by Rob Norris
+// This software is licensed under the MIT License (MIT).
+// For more information see LICENSE or https://opensource.org/licenses/MIT
+
+package org.tpolecat.sourcepos
+
+import scala.quoted._
+
+trait SourcePosPlatform {
+
+  implicit inline def instance: SourcePos =
+    ${SourcePosPlatform.sourcePos_impl}
+
+}
+
+object SourcePosPlatform {
+
+  def sourcePos_impl(using ctx: Quotes): Expr[SourcePos] = {
+    val rootPosition = ctx.reflect.Position.ofMacroExpansion
+    val file = Expr(rootPosition.sourceFile.jpath.toString)
+    val line = Expr(rootPosition.startLine + 1)
+    '{SourcePos($file, $line)}
+  }
+
+}
diff --git a/src/main/scala/SourcePos.scala b/src/main/scala/SourcePos.scala
new file mode 100644
index 0000000..9f66eb1
--- /dev/null
+++ b/src/main/scala/SourcePos.scala
@@ -0,0 +1,12 @@
+// Copyright (c) 2020 by Rob Norris
+// This software is licensed under the MIT License (MIT).
+// For more information see LICENSE or https://opensource.org/licenses/MIT
+
+package org.tpolecat.sourcepos
+
+final case class SourcePos(file: String, line: Int) {
+  override def toString =
+    s"$file:$line"
+}
+
+object SourcePos extends SourcePosPlatform
\ No newline at end of file
diff --git a/src/test/scala/Example.scala b/src/test/scala/Example.scala
new file mode 100644
index 0000000..51325d1
--- /dev/null
+++ b/src/test/scala/Example.scala
@@ -0,0 +1,15 @@
+// Copyright (c) 2020 by Rob Norris
+// This software is licensed under the MIT License (MIT).
+// For more information see LICENSE or https://opensource.org/licenses/MIT
+
+import org.tpolecat.sourcepos._
+
+object Example {
+
+  def method(n: Int)(implicit sp: SourcePos): String =
+    s"You called me with $n from $sp"
+
+  def main(args: Array[String]): Unit =
+    println(method(42))
+
+}
\ No newline at end of file
diff --git a/src/test/scala/Test.scala b/src/test/scala/Test.scala
new file mode 100644
index 0000000..e08c588
--- /dev/null
+++ b/src/test/scala/Test.scala
@@ -0,0 +1,17 @@
+// Copyright (c) 2020 by Rob Norris
+// This software is licensed under the MIT License (MIT).
+// For more information see LICENSE or https://opensource.org/licenses/MIT
+
+package test
+
+import org.tpolecat.sourcepos._
+
+class Test extends munit.FunSuite {
+
+  test("pos") {
+    val pos = implicitly[SourcePos]
+    assert(pos.file.endsWith("src/test/scala/Test.scala"))
+    assert(pos.line == 12)
+  }
+
+}
\ No newline at end of file