Bug(?) with st.page_link()

Using Streamlit
1

Just created a new streamlit app (1.45.1). The file tree is as follows:

├── .gitignore
├── .python-version
├── README.md
├── another-page.py
├── main.py
├── pyproject.toml
└── uv.lock

contents of main.py:

import streamlit as st

def main():
    st.page_link("another-page.py")

if __name__ == "__main__":
    main()

contents of another-page.py:

import streamlit as st

st.title("Another Page", label="another page")

When I streamlit run main.py, this error pops up:

2025-05-28 18:07:00.697 Uncaught app execution
Traceback (most recent call last):
  File "/streamlit-test/.venv/lib/python3.13/site-packages/streamlit/runtime/scriptrunner/exec_code.py", line 121, in exec_func_with_error_handling
    result = func()
  File "streamlit-test/.venv/lib/python3.13/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 645, in code_to_exec
    exec(code, module.__dict__)
    ~~~~^^^^^^^^^^^^^^^^^^^^^^^
  File "streamlit-test/main.py", line 7, in <module>
    main()
    ~~~~^^
  File "streamlit-test/main.py", line 4, in main
    st.page_link("another-page.py")
    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
  File "streamlit-test/.venv/lib/python3.13/site-packages/streamlit/runtime/metrics_util.py", line 444, in wrapped_func
    result = non_optional_func(*args, **kwargs)
  File "streamlit-test/.venv/lib/python3.13/site-packages/streamlit/elements/widgets/button.py", line 773, in page_link
    return self._page_link(
           ~~~~~~~~~~~~~~~^
        page=page,
        ^^^^^^^^^^
    ...<4 lines>...
        use_container_width=use_container_width,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "streamlit-test/.venv/lib/python3.13/site-packages/streamlit/elements/widgets/button.py", line 961, in _page_link
    url_pathname = page_data["url_pathname"]
                   ~~~~~~~~~^^^^^^^^^^^^^^^^
KeyError: 'url_pathname'

There’s no clear error message and I can’t find anything in the docs for this. Could this be a bug?

2

You need to create a pages folder and put the another-page.py file inside so Streamlit recognizes that as a website page.

Another option is to explicitly create a st.Page pointing to the path of another-page.py, then, pass that page to st.navigation.