diff --git a/README.md b/README.md
index 3d35971..cc89e6f 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ working across different projects via [VisualMode](https://www.visualmode.dev/).
 
 For a steady stream of TILs, [sign up for my newsletter](https://visualmode.kit.com/newsletter).
 
-_1840 TILs and counting..._
+_1841 TILs and counting..._
 
 See some of the other learning resources I work on:
 
@@ -732,6 +732,7 @@ If you've learned something here, support my efforts writing daily TILs by
 ### LLM
 
 - [Count Number Of Tokens In A File](llm/count-number-of-tokens-in-a-file.md)
+- [Include A File With Message To `ant`](llm/include-a-file-with-message-to-ant.md)
 - [Send cURL To Claude Text Completion API](llm/send-curl-to-claude-text-completion-api.md)
 - [Use The llm CLI With Claude Models](llm/use-the-llm-cli-with-claude-models.md)
 
diff --git a/llm/include-a-file-with-message-to-ant.md b/llm/include-a-file-with-message-to-ant.md
new file mode 100644
index 0000000..1544e31
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+++ b/llm/include-a-file-with-message-to-ant.md
@@ -0,0 +1,50 @@
+# Include A File With Message To `ant`
+
+The [Anthropic CLI tool](https://github.com/anthropics/anthropic-cli) (`ant`)
+allows including files, such as images, directly in the message being sent to
+the model. This is done with the `@` symbol followed by a relative path to the
+image on the file system.
+
+I have a file `parameterized-behavioral-tests.png` in my current directory that
+I'd like to include. In the `content` array of the message I include an object
+of type `image` along with some `source` metadata. Within `source` the image
+file is referenced with the `data` field.
+
+With that set, I then include a `text` object with my prompt asking for alt text
+of this image.
+
+```bash
+❯ ant messages create \
+  --model claude-opus-5 \
+  --max-tokens 1024 \
+  --message '{role: user, content: [
+    {type: image, source: {type: base64, media_type: image/png, data: "@./parameterized-behavioral-tests.png"}},
+    {type: text, text: "Produce a concise, but descriptive alt text for this image."}
+  ]}' \
+  --transform 'content.#(type=="text").text' --raw-output
+
+A hand-drawn style diagram comparing two testing approaches, split by a vertical
+line.
+
+On the left, under the heading "Behavioral Tests," is a single column of six
+rounded rectangular test rows: four outlined in green with green check-mark
+icons (passing) and two outlined in red with red X icons (failing), each
+containing black scribble lines representing text.
+
+On the right, under the heading "Parameterized Behavioral Tests," a bracketed
+list of three purple parameter symbols — a circle, a triangle, and a diamond —
+sits at the top, with arrows pointing down to three separate columns of six test
+rows each. Every row in a column is tagged with its corresponding parameter
+shape on the right edge. The circle column shows all six rows passing (green
+with check marks). The triangle column shows three passing and three failing
+(red with X marks). The diamond column shows five passing and one failing. The
+illustration conveys that a single behavioral test, when parameterized, expands
+into multiple variants whose pass/fail outcomes can differ per parameter.
+```
+
+This is for [the image toward the top of this post on parameterized tests in
+pytest](https://www.visualmode.dev/parameterize-a-fixture-instead-of-a-test-case-with-pytest).
+The description is a bit wordier than I would have liked, but it is spot on. It
+is both visually descriptive and conveys what is being conceptually illustrated.
+
+This whole thing was 3800 input tokens, 328 output tokens, and cost ~$0.02.