Add input_cost_trend / input_cost_series MCP tools (EIA diesel)

Real input price + WoW/YoY change + seasonal for diesel ($/gal). Formatters now
handle the item/label payload shape. Changelog updated.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -26,8 +26,21 @@ not an index.
 - `GET /api/data/price-series?commodity=&geo=&start_year=&end_year=` — raw series.
 - `GET /api/data/price-geographies?commodity=` — which geos (US + states) exist.
 
-All grain: corn/soy/wheat, all 50 states + US. (Input-cost trends — diesel,
-fertilizer — coming next.)
+All grain: corn/soy/wheat, all 50 states + US.
+
+### Input-cost tools (real $ + change)
+
+- **`input_cost_trend(item, years=10)`** — real input price with the move.
+  Currently `item="diesel"` (EIA U.S. retail $/gal, weekly, back to 1994):
+  latest price + week-over-week and year-over-year change + seasonal
+  percentile/range. (For current fertilizer $/ton, `current_input_price` (DTN)
+  still applies; more inputs extend this same tool.)
+- **`input_cost_series(item)`** — raw historical series for an input.
+- API: `GET /api/data/input-cost-trend?item=&years=`,
+  `GET /api/data/input-cost-series?item=`.
+
+USDA stopped publishing dollar input prices in 2014, so these use real-dollar
+sources (EIA) rather than an index.
 
 ## 2026-05-30 — Source geo + many more locations
 

ag_bids_mcp/client.py

@@ -80,6 +80,14 @@ def price_series(commodity: str, geo: str = "US",
                 start_year=start_year, end_year=end_year)
 
 
+def input_cost_trend(item: str, years: int = 10) -> dict:
+    return _get("/api/data/input-cost-trend", item=item, years=years)
+
+
+def input_cost_series(item: str) -> dict:
+    return _get("/api/data/input-cost-series", item=item)
+
+
 def futures(commodity: str, delivery: str | None = None) -> dict:
     return _get("/api/data/futures", commodity=commodity, delivery=delivery)
 

ag_bids_mcp/format.py

@@ -130,14 +130,16 @@ _MONTH_NAMES_3 = ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
 
 
 def fmt_price_trend(payload: dict, label: str = "price received") -> str:
-    commodity = payload.get("commodity")
+    name = payload.get("commodity") or payload.get("item")
     geo = payload.get("geo")
+    label = payload.get("label") or label
     unit = payload.get("unit") or "$/bu"
     t = payload.get("trend")
+    loc = f" — {geo}" if geo else ""
     if not t:
-        return f"### {commodity} — {geo} — {label}\n\nNo data on file.\n"
+        return f"### {name}{loc} — {label}\n\nNo data on file.\n"
     when = _ym(t["period"])
-    lines = [f"### {commodity} — {geo} — {label}, {when}: {_unit_money(t['value_cents'], unit)}", ""]
+    lines = [f"### {name}{loc} — {label}, {when}: {_unit_money(t['value_cents'], unit)}", ""]
     arrow = _delta_arrow(t.get("change_cents"))
     lines.append(f"- **Change:** {arrow} {_signed(t.get('change_cents'))} ({_pct(t.get('change_pct'))}) vs prior period")
     if t.get("yoy_cents") is not None:
@@ -155,14 +157,15 @@ def fmt_price_trend(payload: dict, label: str = "price received") -> str:
 
 
 def fmt_price_series(payload: dict, max_points: int = 60) -> str:
-    commodity = payload.get("commodity")
+    name = payload.get("commodity") or payload.get("item")
     geo = payload.get("geo")
     unit = payload.get("unit") or "$/bu"
     series = payload.get("series") or []
+    loc = f" — {geo}" if geo else ""
     if not series:
-        return f"### {commodity} — {geo} series\n\nNo data on file.\n"
+        return f"### {name}{loc} series\n\nNo data on file.\n"
     shown = series[-max_points:]
-    head = [f"### {commodity} — {geo} — {payload.get('count', len(series))} periods "
+    head = [f"### {name}{loc} — {payload.get('count', len(series))} periods "
             f"(showing last {len(shown)})", "",
             "| Period | Price |", "|---|---:|"]
     body = [f"| {_ym(p['period'])} | {_unit_money(p['value_cents'], unit)} |" for p in shown]

ag_bids_mcp/server.py

@@ -303,6 +303,42 @@ def price_series(
         return fmt.fmt_price_series(payload)
 
 
+VALID_INPUTS = {"diesel"}
+
+
+@mcp.tool()
+def input_cost_trend(
+    item: Annotated[
+        str, Field(description="Input to price. Currently: 'diesel' (U.S. retail $/gal).")
+    ],
+    years: Annotated[
+        int, Field(ge=1, le=120, description="Baseline window for the seasonal normal/percentile."),
+    ] = 10,
+) -> str:
+    """Real input cost with the change — e.g. U.S. retail diesel ($/gal).
+
+    Latest real price + week-over-week and year-over-year moves + seasonal
+    percentile/range. Fills the input-cost side for the advisor (fuel). For
+    current fertilizer $/ton use current_input_price."""
+    it = item.strip().lower()
+    with track("input_cost_trend", item=it, years=years):
+        if it not in VALID_INPUTS:
+            return f"`item` must be one of: {sorted(VALID_INPUTS)}"
+        return fmt.fmt_price_trend(client.input_cost_trend(item=it, years=years))
+
+
+@mcp.tool()
+def input_cost_series(
+    item: Annotated[str, Field(description="Input: 'diesel'.")],
+) -> str:
+    """Raw historical series for a tracked input cost (diesel, $/gal)."""
+    it = item.strip().lower()
+    with track("input_cost_series", item=it):
+        if it not in VALID_INPUTS:
+            return f"`item` must be one of: {sorted(VALID_INPUTS)}"
+        return fmt.fmt_price_series(client.input_cost_series(item=it))
+
+
 @mcp.tool()
 def list_sources() -> str:
     """All active scrapers + their last-success timestamps and any pending failures."""

tests/test_format.py

@@ -118,6 +118,19 @@ def test_fmt_price_trend_diesel_units():
     assert "$5.520/gal" in out   # 3-decimal $/gal formatting
 
 
+def test_fmt_input_cost_payload_shape():
+    # Input-cost payload uses item/label and has no geo.
+    payload = {"item": "diesel", "label": "retail diesel", "unit": "$/gal", "source": "EIA",
+               "trend": {"period": "2026-05-25", "value_cents": 552, "prev_cents": 560,
+                         "change_cents": -8, "change_pct": -1.4, "yoy_cents": 349,
+                         "yoy_change_cents": 203, "yoy_pct": 58.2, "seasonal": None,
+                         "recent_direction": "down", "baseline_years": 10, "points": 1680}}
+    out = fmt.fmt_price_trend(payload)
+    assert "diesel — retail diesel" in out   # item/label header, no geo segment
+    assert "$5.520/gal" in out
+    assert "+58.2%" in out                   # YoY surfaced
+
+
 def test_fmt_inputs_lime_table():
     payload = {
         "product": "lime", "count": 2,