diff --git a/README.md b/README.md
index d378b66..bbebdd0 100644
--- a/README.md
+++ b/README.md
@@ -33,15 +33,28 @@ if uploaded_file is not None:
     st.pdf(uploaded_file)
 ```
 
+`st.pdf` wraps this package's `pdf_viewer`. You can also call the package API directly:
+
+```python
+import streamlit_pdf
+
+streamlit_pdf.pdf_viewer(
+    "report.pdf",
+    alt="Q3 2026 financial report",
+)
+```
+
 ---
 
 ## ⚙️ API Reference
 
-### `st.pdf(data, height=600)`
+### `streamlit_pdf.pdf_viewer(file, height=600, key=None, *, alt=None)`
+
+Most apps use `st.pdf(...)`, which wraps this component.
 
 #### Parameters:
 
-- **`data`** (_str | Path | bytes | BytesIO_): The PDF file to show. This can be one of the following:
+- **`file`** (_str | Path | bytes | BytesIO_): The PDF file to show. This can be one of the following:
 
   - A URL (string) for a hosted PDF file (`"https://example.com/doc.pdf"`)
   - A path to a local PDF file (`"./documents/sample.pdf"`)
@@ -50,6 +63,10 @@ if uploaded_file is not None:
 
 - **`height`** (_int_, optional): Height of the PDF viewer in pixels. Default: 600
 
+- **`key`** (_str | None_, optional): An optional key that uniquely identifies this component instance.
+
+- **`alt`** (_str | None_, optional): An accessible name for the PDF viewer. When provided (and non-blank), it is exposed as `aria-label` on the viewer root. Empty or whitespace-only values are omitted. Keyword-only.
+
 ---
 
 ## 🖼️ Examples
@@ -89,6 +106,17 @@ st.pdf("document.pdf", height=800)
 st.pdf("document.pdf")
 ```
 
+### Accessible name
+
+```python
+import streamlit_pdf
+
+streamlit_pdf.pdf_viewer(
+    "document.pdf",
+    alt="Q3 2026 financial report",
+)
+```
+
 ### Reading from Local File
 
 ```python