Initial: Gradio app + SEO-optimized README

README.md

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 ---
-title: Calcfi Yield Curve Spread
-emoji: 🌖
-colorFrom: gray
-colorTo: blue
+title: US Treasury Yield Curve Spread
+emoji: 📉
+colorFrom: purple
+colorTo: indigo
 sdk: gradio
-sdk_version: 6.14.0
-python_version: '3.13'
+sdk_version: 4.44.0
+python_version: '3.10'
 app_file: app.py
-pinned: false
+pinned: true
 license: cc-by-4.0
+short_description: 2Y vs 10Y Treasury — recession indicator.
+datasets:
+- iizy/calcfi-open-data
+tags:
+- finance
+- treasury
+- yield-curve
+- recession
+- federal-reserve
+- data-viz
+- open-data
+- gradio
 ---
 
-Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
+# US Treasury Yield Curve Spread
+
+[![Figshare DOI](https://img.shields.io/badge/Figshare%20DOI-10.6084%2Fm9.figshare.32332290-blue)](https://doi.org/10.6084/m9.figshare.32332290)
+[![Zenodo DOI](https://img.shields.io/badge/Zenodo%20DOI-10.5281%2Fzenodo.20302283-1682D4)](https://doi.org/10.5281/zenodo.20302283)
+[![CC BY 4.0](https://img.shields.io/badge/License-CC%20BY%204.0-lightgrey)](https://creativecommons.org/licenses/by/4.0/)
+
+Visualize the 2-year vs 10-year Treasury yield spread alongside the Federal Funds Rate. When the 10Y drops below the 2Y, the curve inverts — historically a leading indicator of US recessions with a 12-24 month lead time.
+
+## Why these series matter
+
+The 2s/10s yield curve has inverted before every US recession since 1955, with a single false signal in the mid-1960s. The inversion itself is not the cause; it is the bond market pricing in expected Fed rate cuts in response to slowing growth. The lead time from inversion to recession averages 14 months but has ranged from 6 to 24 months. Pair this with the Federal Funds Rate to see how Fed policy itself drives the front end of the curve.
+
+A library of free, primary-source-cited financial calculators that use these macro indicators as inputs is available at [calcfi.app](https://calcfi.app).
+
+## Methodology
+
+- **Federal Funds Rate (Effective)** — Federal Reserve via FRED, series `DFF` — [https://fred.stlouisfed.org/series/DFF](https://fred.stlouisfed.org/series/DFF)
+- **2-Year Treasury Constant Maturity** — US Treasury via FRED, series `DGS2` — [https://fred.stlouisfed.org/series/DGS2](https://fred.stlouisfed.org/series/DGS2)
+- **10-Year Treasury Constant Maturity** — US Treasury via FRED, series `DGS10` — [https://fred.stlouisfed.org/series/DGS10](https://fred.stlouisfed.org/series/DGS10)
+
+No smoothing, no imputation, no seasonal adjustment. Each observation passes through verbatim from the primary source. Provenance headers are preserved in the underlying [CalcFi Open Data](https://huggingface.co/datasets/iizy/calcfi-open-data) dataset.
+
+## Data source
+
+The Space loads data live from the CalcFi Open Data dataset on Hugging Face:
+[`iizy/calcfi-open-data`](https://huggingface.co/datasets/iizy/calcfi-open-data).
+
+The same dataset is mirrored with permanent DOIs at:
+
+- Figshare: [10.6084/m9.figshare.32332290](https://doi.org/10.6084/m9.figshare.32332290)
+- Zenodo (CERN-backed): [10.5281/zenodo.20302283](https://doi.org/10.5281/zenodo.20302283)
+- OSF: [10.17605/OSF.IO/PUMKT](https://doi.org/10.17605/OSF.IO/PUMKT)
+- Kaggle: [10.34740/kaggle/dsv/16356447](https://doi.org/10.34740/kaggle/dsv/16356447)
+- Mendeley Data: [10.17632/jsnwhy6vjn.1](https://doi.org/10.17632/jsnwhy6vjn.1)
+
+## Related Spaces
+
+Part of a small collection of CalcFi Open Data interactive explorers:
+
+- [US Mortgage Rate Explorer](https://huggingface.co/spaces/iizy/calcfi-mortgage-rate-explorer)
+- [Inflation vs Wage Growth Tracker](https://huggingface.co/spaces/iizy/calcfi-inflation-wage-tracker)
+- [US Treasury Yield Curve Spread](https://huggingface.co/spaces/iizy/calcfi-yield-curve-spread)
+- [Fed Funds Rate Cycle Explorer](https://huggingface.co/spaces/iizy/calcfi-fed-funds-cycle)
+- [Oil and Gas Price Tracker](https://huggingface.co/spaces/iizy/calcfi-oil-gas-tracker)
+
+## Citation
+
+> Salmisto, J. (2026). *CalcFi Open Data: 34 Free CC-BY Financial and Macro Time Series Mirrored from Primary Sources* [Dataset]. Figshare. https://doi.org/10.6084/m9.figshare.32332290
+
+## License
+
+Code: CC0 1.0. Data: CC BY 4.0 — attribution to [CalcFi](https://calcfi.app/developers) and the named primary source per series.
+
+## Live tools
+
+Free calculators that use these series as inputs at [calcfi.app](https://calcfi.app). No signup, every formula cited to a primary source.

app.py

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+"""
+US Treasury Yield Curve Spread — CalcFi Open Data.
+
+Data loaded live from the CalcFi Open Data dataset on Hugging Face.
+"""
+
+import gradio as gr
+import pandas as pd
+
+DATASET_BASE = (
+    "https://huggingface.co/datasets/iizy/calcfi-open-data/resolve/main/datasets"
+)
+
+SERIES = [
+    {"slug": "federal-funds-rate", "label": "Federal Funds Rate"},
+    {"slug": "2-year-treasury", "label": "2-Year Treasury Yield"},
+    {"slug": "10-year-treasury", "label": "10-Year Treasury Yield"},
+]
+
+
+def load_series(slug: str, label: str) -> pd.DataFrame:
+    url = f"{DATASET_BASE}/{slug}/data.csv"
+    df = pd.read_csv(url, comment="#", parse_dates=["date"])
+    df["series"] = label
+    return df[["date", "value", "series"]]
+
+
+def load_all() -> pd.DataFrame:
+    frames = []
+    for s in SERIES:
+        try:
+            frames.append(load_series(s["slug"], s["label"]))
+        except Exception as e:
+            print(f"failed to load {s['slug']}: {e}")
+    if not frames:
+        return pd.DataFrame(columns=["date", "value", "series"])
+    return pd.concat(frames, ignore_index=True).sort_values("date")
+
+
+def filter_view(start_year: int, end_year: int, selected_series: list[str]) -> pd.DataFrame:
+    df = load_all()
+    if start_year > end_year:
+        start_year, end_year = end_year, start_year
+    mask = (df["date"].dt.year >= start_year) & (df["date"].dt.year <= end_year)
+    df = df[mask]
+    if selected_series:
+        df = df[df["series"].isin(selected_series)]
+    return df
+
+
+INITIAL_DF = load_all()
+MIN_YEAR = int(INITIAL_DF["date"].dt.year.min()) if not INITIAL_DF.empty else 1970
+MAX_YEAR = int(INITIAL_DF["date"].dt.year.max()) if not INITIAL_DF.empty else 2026
+ALL_LABELS = [s["label"] for s in SERIES]
+
+
+with gr.Blocks(
+    title="US Treasury Yield Curve Spread — CalcFi Open Data",
+    theme=gr.themes.Soft(),
+) as demo:
+    gr.Markdown("# US Treasury Yield Curve Spread")
+    gr.Markdown("Visualize the 2-year vs 10-year Treasury yield spread alongside the Federal Funds Rate. When the 10Y drops below the 2Y, the curve inverts — historically a leading indicator of US recessions with a 12-24 month lead time. Released under CC BY 4.0. Source dataset: [calcfi-open-data](https://huggingface.co/datasets/iizy/calcfi-open-data).")
+
+    with gr.Row():
+        with gr.Column(scale=1):
+            start_year = gr.Slider(
+                MIN_YEAR, MAX_YEAR, value=max(MIN_YEAR, MAX_YEAR - 25),
+                step=1, label="Start year",
+            )
+            end_year = gr.Slider(
+                MIN_YEAR, MAX_YEAR, value=MAX_YEAR, step=1, label="End year",
+            )
+            series_picker = gr.CheckboxGroup(
+                ALL_LABELS, value=ALL_LABELS, label="Series",
+            )
+
+    chart = gr.LinePlot(
+        filter_view(max(MIN_YEAR, MAX_YEAR - 25), MAX_YEAR, ALL_LABELS),
+        x="date",
+        y="value",
+        color="series",
+        title="US Treasury Yield Curve Spread",
+        x_title="Date",
+        y_title="Value",
+        height=500,
+        width=900,
+        tooltip=["date", "value", "series"],
+    )
+
+    inputs = [start_year, end_year, series_picker]
+    for inp in inputs:
+        inp.change(filter_view, inputs, chart)
+
+
+if __name__ == "__main__":
+    demo.launch()

requirements.txt

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+gradio>=4.44.0
+pandas>=2.0.0