diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,12 +1,17 @@
 # Changelog
 
-All notable changes to atex will be documented in this file.
+All notable changes to elixir-dasl will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-<!--## [Unreleased] -->
+## [Unreleased]
+
+### Added
+
+- `~CID` sigil for easily constructing known CIDs.
+- New inspect string for CIDs using the new sigil.
 
 ## [0.1.0] - 2026-04-08
 
diff --git a/lib/dasl/cid.ex b/lib/dasl/cid.ex
--- a/lib/dasl/cid.ex
+++ b/lib/dasl/cid.ex
@@ -153,6 +153,34 @@ end
   end
 
   @doc """
+  Constructs a `DASL.CID` from a string-encoded CID, raising on failure.
+
+  Equivalent to `new/1` but raises `ArgumentError` instead of returning
+  `{:error, reason}`. Useful in contexts where an invalid CID is a
+  programming error rather than expected user input.
+
+  ## Examples
+
+      iex> cid = DASL.CID.new!("bafkreifzjut3te2nhyekklss27nh3k72ysco7y32koao5eei66wof36n5e")
+      iex> cid.codec
+      :raw
+
+      iex> DASL.CID.new!("not-a-cid")
+      ** (ArgumentError) invalid CID 'not-a-cid': "CID must start with 'b'"
+
+  """
+  @spec new!(String.t()) :: t()
+  def new!(cid_string) when is_binary(cid_string) do
+    case new(cid_string) do
+      {:ok, cid} ->
+        cid
+
+      {:error, reason} ->
+        raise ArgumentError, message: "invalid CID '#{cid_string}': #{inspect(reason)}"
+    end
+  end
+
+  @doc """
   Encodes a `DASL.CID` back to its canonical string form.
 
   ## Examples
@@ -279,6 +307,26 @@ candidate = :crypto.hash(:sha256, data)
     :crypto.hash_equals(digest, candidate)
   end
 
+  @doc """
+  Sigil for constructing a `DASL.CID` from a compile-time string literal.
+
+  Delegates to `new!/1`, so it raises `ArgumentError` on an invalid CID
+  string. Import `DASL.CID` (or `import DASL.CID, only: [sigil_CID: 2]`) to
+  bring the sigil into scope.
+
+  ## Examples
+
+      iex> import DASL.CID
+      iex> cid = ~CID"bafkreifzjut3te2nhyekklss27nh3k72ysco7y32koao5eei66wof36n5e"
+      iex> cid.codec
+      :raw
+      iex> cid.version
+      1
+
+  """
+  @spec sigil_CID(String.t(), list()) :: t()
+  def sigil_CID(string, _), do: new!(string)
+
   defp decode_codec(@codec_raw), do: {:ok, :raw}
   defp decode_codec(@codec_drisl), do: {:ok, :drisl}
 
@@ -296,6 +344,6 @@
 defimpl Inspect, for: DASL.CID do
   def inspect(cid, _opts) do
     cid = DASL.CID.encode(cid)
-    ~s'DASL.CID.new("#{cid}")'
+    ~s'~CID"#{cid}"'
   end
 end
diff --git a/test/dasl/cid_test.exs b/test/dasl/cid_test.exs
--- a/test/dasl/cid_test.exs
+++ b/test/dasl/cid_test.exs
@@ -108,6 +108,71 @@ assert {:error, "unsupported CID version: 2"} = DASL.CID.new(bad_str)
     end
   end
 
+  describe "new!/1" do
+    test "returns a CID struct on a valid string" do
+      assert %DASL.CID{} = DASL.CID.new!(@raw_cid)
+    end
+
+    test "returned struct matches new/1" do
+      {:ok, expected} = DASL.CID.new(@raw_cid)
+      assert DASL.CID.new!(@raw_cid) == expected
+    end
+
+    test "raises ArgumentError on an invalid prefix" do
+      assert_raise ArgumentError, ~r/invalid CID 'not-a-cid'/, fn ->
+        DASL.CID.new!("not-a-cid")
+      end
+    end
+
+    test "raises ArgumentError on malformed base32" do
+      assert_raise ArgumentError, ~r/invalid CID/, fn ->
+        DASL.CID.new!("b!!!!!")
+      end
+    end
+
+    test "raises ArgumentError on an invalid CID version embedded in the bytes" do
+      bad_bytes = <<2, 0x55, 0x12, 0x20>> <> @digest
+      bad_str = "b" <> Base.encode32(bad_bytes, case: :lower, padding: false)
+
+      assert_raise ArgumentError, ~r/unsupported CID version/, fn ->
+        DASL.CID.new!(bad_str)
+      end
+    end
+  end
+
+  describe "~CID sigil" do
+    import DASL.CID, only: [sigil_CID: 2]
+
+    test "constructs a CID struct from a literal string" do
+      assert %DASL.CID{} =
+               ~CID"bafkreifzjut3te2nhyekklss27nh3k72ysco7y32koao5eei66wof36n5e"
+    end
+
+    test "produced struct equals new!/1" do
+      assert ~CID"bafkreifzjut3te2nhyekklss27nh3k72ysco7y32koao5eei66wof36n5e" ==
+               DASL.CID.new!(@raw_cid)
+    end
+
+    test "codec is preserved for raw" do
+      assert ~CID"bafkreifzjut3te2nhyekklss27nh3k72ysco7y32koao5eei66wof36n5e".codec == :raw
+    end
+
+    test "codec is preserved for drisl" do
+      assert ~CID"bafyreifzjut3te2nhyekklss27nh3k72ysco7y32koao5eei66wof36n5e".codec == :drisl
+    end
+
+    test "round-trips through encode" do
+      assert DASL.CID.encode(~CID"bafkreifzjut3te2nhyekklss27nh3k72ysco7y32koao5eei66wof36n5e") ==
+               @raw_cid
+    end
+
+    test "raises ArgumentError on an invalid CID string" do
+      assert_raise ArgumentError, ~r/invalid CID/, fn ->
+        DASL.CID.sigil_CID("not-a-cid", [])
+      end
+    end
+  end
+
   describe "encode/1" do
     test "round-trips a raw CID" do
       {:ok, cid} = DASL.CID.new(@raw_cid)