diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5ed53a54..7288e02e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,44 @@ All notable changes to `mostlyright`. The format follows [Keep a Changelog](http
 
 ## [Unreleased]
 
+## [1.12.1] — 2026-07-08 — #107 follow-ups: cross-SDK consistency + version metadata
+
+Patch release, dual-SDK. Resolves the P3 follow-ups from the 1.12.0 review
+loop (#107). No behavior change on any default path.
+
+### Fixed
+
+- **`__version__` now derived from dist metadata** in all three Python
+  packages via `importlib.metadata` (was hardcoded and stale: core/weather
+  reported `0.1.0rc1`, markets `0.0.1`, while dists shipped 1.12.x). Falls
+  back to `0.0.0+unknown` in metadata-less source trees. `DataVersion`
+  tokens computed via `for_research()` without an explicit `sdk_version`
+  now reflect the true SDK version (opt-in surface; not wired into
+  `research()`, no cache/settlement impact).
+- **Cross-SDK unknown-source error text unified** on the `research()`
+  surface: both SDKs now emit `research(): source must be one of [...]`,
+  exact-message-pinned in both test suites. `researchBySource`'s
+  `Mode 2 source must be one of` text is unchanged.
+- **TS `sources: null` honors the Phase 21 null-as-absent wire contract**
+  (was throwing the v0.3 deferred error for a JSON-round-tripped Python
+  `sources=None`); removed a dead TS mutual-exclusion check whose only
+  reachable firing was that same wire-contract bug, and the mirrored
+  unreachable Python `ValueError` block.
+- **Pinned-source provenance threads explicitly through the wrapper path**
+  (`wrap_result(source=...)`, mirroring `mode2.research_by_source`) —
+  defense-in-depth; unpinned wrapper calls byte-identical.
+
+### Added
+
+- TS public barrel now re-exports `RESEARCH_SOURCE_ALIASES`,
+  `RESEARCH_OBSERVATION_SOURCES`, `isResearchObservationSource`.
+- Coverage: `research(source=)` under `as_dataframe=False`, polars wrapper
+  (skip-guarded), empty-after-pin attrs; TS `sources: null` regression;
+  barrel surface test.
+- Weather TS bundle growth root-caused (hosted-shim root-barrel re-export,
+  a tree-shaking blocker — not data growth); shrink deferred to its own PR
+  since it contracts the root-barrel API (#107).
+
 ## [1.12.0] — 2026-07-08 — research(source=) pin + Mode 2 window fix
 
 Minor release, dual-SDK (PyPI 1.12.0 + npm 1.12.0 in lockstep).
diff --git a/packages-ts/core/package.json b/packages-ts/core/package.json
index df013116..c82dc83a 100644
--- a/packages-ts/core/package.json
+++ b/packages-ts/core/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@mostlyrightmd/core",
-  "version": "1.12.0",
+  "version": "1.12.1",
   "description": "TypeScript SDK core for quants, ML pipelines, and AI agents: types, schemas, validators, temporal-safety primitives, and the research() join over weather data + prediction-market settlements. Local-first, no hosted backend.",
   "keywords": [
     "weather",
diff --git a/packages-ts/markets/package.json b/packages-ts/markets/package.json
index dbe5561e..6582cadc 100644
--- a/packages-ts/markets/package.json
+++ b/packages-ts/markets/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@mostlyrightmd/markets",
-  "version": "1.12.0",
+  "version": "1.12.1",
   "description": "Prediction-market data for TypeScript / Node — Kalshi NHIGH/NLOW weather-contract resolvers, Polymarket discovery + settlement, and Kalshi + Polymarket trade history. For quants, backtesting, and ML training pipelines.",
   "keywords": [
     "kalshi",
diff --git a/packages-ts/meta/package.json b/packages-ts/meta/package.json
index 0ae058d3..1a8fd79a 100644
--- a/packages-ts/meta/package.json
+++ b/packages-ts/meta/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mostlyright",
-  "version": "1.12.0",
+  "version": "1.12.1",
   "description": "Public-data SDK for TypeScript — one import for quants, ML pipelines, and AI agents. Adapters ship weather (METAR, ASOS, GHCNh, NWS CLI) and prediction-market settlements (Kalshi NHIGH/NLOW, Polymarket) today; SEC filings, Federal Reserve series, court filings, FDA approvals, and equities are next. Local-first, no hosted backend.",
   "keywords": [
     "weather",
diff --git a/packages-ts/meta/src/index.ts b/packages-ts/meta/src/index.ts
index b40fa674..279804c7 100644
--- a/packages-ts/meta/src/index.ts
+++ b/packages-ts/meta/src/index.ts
@@ -27,11 +27,21 @@ export { research, type ResearchOptions, type PairsRow } from "./research.js";
 // package alongside research() — the dispatch needs the @mostlyrightmd/weather
 // Observation type and assertSourceIdentity consumes it structurally;
 // @mostlyrightmd/core must NOT depend on weather (cycle).
+//
+// Also re-exports the WIDENED `research({ source })` filter vocabulary
+// (RESEARCH_SOURCE_ALIASES / RESEARCH_OBSERVATION_SOURCES /
+// isResearchObservationSource) — the Python-parity superset that
+// `research()`'s single-source pin validates against — so callers can
+// introspect the accepted names without a deep import, mirroring the
+// narrow-dispatch siblings (SOURCE_ALIASES / isMode2Source).
 export {
   MODE2_SOURCES,
+  RESEARCH_OBSERVATION_SOURCES,
+  RESEARCH_SOURCE_ALIASES,
   SOURCE_ALIASES,
   assertSourceIdentity,
   isMode2Source,
+  isResearchObservationSource,
   researchBySource,
   type Mode2Source,
   type ResearchBySourceOptions,
diff --git a/packages-ts/meta/src/mode2.ts b/packages-ts/meta/src/mode2.ts
index 2d950016..c27b5960 100644
--- a/packages-ts/meta/src/mode2.ts
+++ b/packages-ts/meta/src/mode2.ts
@@ -384,6 +384,10 @@ export async function researchBySource(
       // outside the caller's window; per-source Mode 2 callers expect rows
       // strictly inside [fromDate, toDate]. Python mode2.py parity.
       rows = parsed.filter((r) => {
+        // `observed_at` is a guaranteed non-empty ISO string on Observation,
+        // so `.slice(0, 10)` is safe without a runtime guard (same in the
+        // IEM/GHCNh branches below). Python's `_in_query_window` must drop
+        // falsy `observed_at` defensively; TS leans on the schema type.
         const d = r.observed_at.slice(0, 10);
         return d >= fromDate && d <= toDate;
       });
diff --git a/packages-ts/meta/src/research.ts b/packages-ts/meta/src/research.ts
index 5543a561..46c79db7 100644
--- a/packages-ts/meta/src/research.ts
+++ b/packages-ts/meta/src/research.ts
@@ -869,15 +869,27 @@ export async function research(
     if (hasContracts) names.push("contracts");
     throw new Error(`research(): selectors are mutually exclusive; got ${JSON.stringify(names)}`);
   }
-  if (opts.sources !== undefined && opts.source != null) {
-    throw new Error("research(): sources and source are mutually exclusive");
-  }
+  // NOTE: the `sources=`/`source=` mutual-exclusion guard that used to live
+  // here was DEAD and is removed (mirrors the Python parallel cleanup that
+  // drops the duplicate `sources is not None and source is not None`
+  // ValueError in research.py). `validateResearchKwargs()` above (~line 822)
+  // already throws a TypeError for the both-provided combo with nullish
+  // (`!= null`) presence semantics BEFORE this point — proven by
+  // research.kwargs.test.ts ("raises TypeError on sources + source
+  // together"). The old check used `sources !== undefined`, so its ONLY
+  // reachable firing was `sources: null` + a real `source` — which the wire
+  // contract treats as `sources` ABSENT, so that firing was itself a bug.
+  //
   // `sources` (plural) — the Mode 1 multi-source SUBSET selector — is
   // validated in Phase 10 v0.2 but its dedupe-within-subset wiring lands in
   // v0.3; passing it throws. NOTE: `source` (singular) is now FUNCTIONAL
   // (single-source pin, wired below) — only the multi-source subset remains
-  // deferred.
-  if (opts.sources !== undefined) {
+  // deferred. Presence is nullish (`!= null`), NOT `!== undefined`: per the
+  // Phase 21 wire contract (research.types.ts `present()` / Python
+  // `sources is not None`), a JSON-round-tripped Python `sources=None`
+  // arrives as `null` and must behave as ABSENT — `!== undefined` would
+  // wrongly throw the v0.3-deferred error for it.
+  if (opts.sources != null) {
     throw new Error(
       "research(): the `sources` multi-source subset selector is validated in " +
         "Phase 10 v0.2 but its dedupe-within-subset wiring lands in v0.3. For " +
@@ -887,15 +899,20 @@ export async function research(
   }
   // `source` (singular) — Mode 2 single-source pin. Validate against the
   // widened Mode 2 vocabulary BEFORE any network fetch so invalid input
-  // never burns API quota. Mirrors Python `research_by_source`'s ValueError
-  // guard (packages/core/src/mostlyright/mode2.py:112-115); the accepted
-  // names are byte-identical across SDKs (RESEARCH_OBSERVATION_SOURCES).
+  // never burns API quota. Mirrors Python `research()`'s own source guard
+  // (packages/core/src/mostlyright/research.py:1750-1754): the canonical
+  // `research(): source must be one of ...` text and the accepted names
+  // (RESEARCH_OBSERVATION_SOURCES) are byte-identical across SDKs — each SDK
+  // pins its native quote style via its own stringify (JSON.stringify here,
+  // Python `repr` there). This is distinct from `researchBySource`'s
+  // narrower "Mode 2 source must be one of ..." guard (mode2.ts), which
+  // stays lockstep and is intentionally left untouched.
   // Presence is nullish (`!= null`), NOT `!== undefined`: per the Phase 21
   // wire contract (research.types.ts `present()`), a JSON-round-tripped
   // Python `source=None` arrives as `null` and must behave as ABSENT.
   if (opts.source != null && !isResearchObservationSource(opts.source)) {
     throw new Error(
-      `Mode 2 source must be one of ${JSON.stringify(
+      `research(): source must be one of ${JSON.stringify(
         [...RESEARCH_OBSERVATION_SOURCES].sort(),
       )}; got ${JSON.stringify(opts.source)}`,
     );
diff --git a/packages-ts/meta/tests/compose.test.ts b/packages-ts/meta/tests/compose.test.ts
index 44b93665..f39e6314 100644
--- a/packages-ts/meta/tests/compose.test.ts
+++ b/packages-ts/meta/tests/compose.test.ts
@@ -247,7 +247,11 @@ describe("research() Phase 10 signature validation", () => {
     // covered in research.test.ts.
     await expect(
       research("KNYC", "2025-01-06", "2025-01-12", { source: "not-a-real-source" }),
-    ).rejects.toThrow(/Mode 2 source must be one of/);
+    ).rejects.toThrow(
+      // Item 1 (v1.12.1): canonical cross-SDK `research(): source must be one
+      // of ...` text (each SDK pins its native quote style — JSON here).
+      'research(): source must be one of ["awc","awc.live","ghcnh","ghcnh.archive","iem","iem.archive","iem.live"]; got "not-a-real-source"',
+    );
   });
 
   it("stationOverride requires contract", async () => {
diff --git a/packages-ts/meta/tests/mode2.barrel.test.ts b/packages-ts/meta/tests/mode2.barrel.test.ts
index fb9cd0f9..37e1f3db 100644
--- a/packages-ts/meta/tests/mode2.barrel.test.ts
+++ b/packages-ts/meta/tests/mode2.barrel.test.ts
@@ -14,10 +14,13 @@ import { describe, expect, it } from "vitest";
 import {
   MODE2_SOURCES,
   type Mode2Source,
+  RESEARCH_OBSERVATION_SOURCES,
+  RESEARCH_SOURCE_ALIASES,
   SOURCE_ALIASES,
   type SourceMismatchRole,
   assertSourceIdentity,
   isMode2Source,
+  isResearchObservationSource,
   researchBySource,
 } from "../src/index.js";
 
@@ -45,6 +48,22 @@ describe("meta barrel — TS-W4 Wave 1 Mode 2 surface", () => {
     expect(isMode2Source("iem")).toBe(false);
   });
 
+  it("re-exports the widened research({ source }) filter vocabulary (Item 2, v1.12.1)", () => {
+    // RESEARCH_* is the Python-parity SUPERSET that research()'s single-source
+    // pin validates against — 7 names = the 4 dotted forms + 3 bare tags.
+    expect(RESEARCH_OBSERVATION_SOURCES.size).toBe(7);
+    expect(RESEARCH_SOURCE_ALIASES.size).toBe(7);
+    // Bare parser tags are accepted here but NOT by isMode2Source (narrower).
+    expect(isResearchObservationSource("iem")).toBe(true);
+    expect(isMode2Source("iem")).toBe(false);
+    // Dotted forms accepted by both.
+    expect(isResearchObservationSource("iem.archive")).toBe(true);
+    // Unknown rejected.
+    expect(isResearchObservationSource("banana")).toBe(false);
+    // Alias table carries the bare-tag → alias-set rows.
+    expect(RESEARCH_SOURCE_ALIASES.get("awc")?.has("awc.live")).toBe(true);
+  });
+
   it("Mode2Source + SourceMismatchRole types are accessible from the barrel", () => {
     // Type-level check — assignments compile iff the type re-exports are wired.
     const canon: Mode2Source = "iem.archive";
diff --git a/packages-ts/meta/tests/research.test.ts b/packages-ts/meta/tests/research.test.ts
index 2466a097..aa2c887c 100644
--- a/packages-ts/meta/tests/research.test.ts
+++ b/packages-ts/meta/tests/research.test.ts
@@ -481,7 +481,11 @@ describe("research() — Mode 2 single-source pin (opts.source)", () => {
     const fetchSpy = installMixedSourceMock();
     await expect(
       research("NYC", PIN_DAY, PIN_DAY, { source: "banana", now: PIN_NOW, cache: null }),
-    ).rejects.toThrow(/Mode 2 source must be one of/);
+    ).rejects.toThrow(
+      // Item 1 (v1.12.1): canonical cross-SDK text — `research(): source must
+      // be one of ...` (NOT the narrower researchBySource "Mode 2 source ...").
+      'research(): source must be one of ["awc","awc.live","ghcnh","ghcnh.archive","iem","iem.archive","iem.live"]; got "banana"',
+    );
     expect(fetchSpy).not.toHaveBeenCalled();
   });
 
@@ -547,4 +551,25 @@ describe("research() — Mode 2 single-source pin (opts.source)", () => {
     expect(row?.obs_low_f).toBe(68);
     expect(row?.obs_mean_f).toBe(80.5);
   });
+
+  it("sources: null (JSON round-trip of Python None) behaves as ABSENT — full merge, no throw", async () => {
+    // Item 4 (v1.12.1): the Phase 21 wire contract (research.types.ts
+    // `present()` / Python `sources is not None`) treats a JSON-round-tripped
+    // Python `sources=None` (arriving as `null`) as not-provided. The
+    // deferred-`sources` guard previously used `!== undefined`, which threw
+    // the v0.3 NotImplemented-style error for `sources: null`; `!= null` lets
+    // the full merge proceed. Mirrors the `source: null` guard above.
+    installMixedSourceMock();
+    const rows = await research("NYC", PIN_DAY, PIN_DAY, {
+      sources: null as unknown as string[],
+      now: PIN_NOW,
+      cache: null,
+    });
+    expect(rows).toHaveLength(1);
+    const row = rows[0];
+    expect(row?.obs_count).toBe(4);
+    expect(row?.obs_high_f).toBe(104);
+    expect(row?.obs_low_f).toBe(68);
+    expect(row?.obs_mean_f).toBe(80.5);
+  });
 });
diff --git a/packages-ts/weather/package.json b/packages-ts/weather/package.json
index eae22685..f21108da 100644
--- a/packages-ts/weather/package.json
+++ b/packages-ts/weather/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@mostlyrightmd/weather",
-  "version": "1.12.0",
+  "version": "1.12.1",
   "description": "Weather data for TypeScript / Node — live METAR (AWC), ASOS archive (IEM), historical observations (GHCNh), and NWS climate text products (CLI). For quants, ML training pipelines, and weather-bot agents. Direct public-API access, no hosted backend.",
   "keywords": [
     "weather",
diff --git a/packages/core/pyproject.toml b/packages/core/pyproject.toml
index 3096be2f..ce207f87 100644
--- a/packages/core/pyproject.toml
+++ b/packages/core/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "mostlyrightmd"
-version = "1.12.0"
+version = "1.12.1"
 description = "Python SDK for quants, ML engineers, and AI agents — one interface to public data. Adapters ship weather + prediction-market settlements (Kalshi NHIGH/NLOW, Polymarket) today; SEC filings, Federal Reserve series, court filings, FDA approvals, and equities are next. Schema-versioned, leakage-free, local-first. Imports as `mostlyright`."
 readme = "README.md"
 license = "MIT"
diff --git a/packages/core/src/mostlyright/__init__.py b/packages/core/src/mostlyright/__init__.py
index 9e31ef23..569db045 100644
--- a/packages/core/src/mostlyright/__init__.py
+++ b/packages/core/src/mostlyright/__init__.py
@@ -20,7 +20,13 @@
 # Split-distribution namespace: extend __path__ to discover sibling packages' contributions.
 __path__ = __import__("pkgutil").extend_path(__path__, __name__)
 
-__version__ = "0.1.0rc1"
+from importlib.metadata import PackageNotFoundError
+from importlib.metadata import version as _dist_version
+
+try:
+    __version__ = _dist_version("mostlyrightmd")
+except PackageNotFoundError:  # editable/source tree without installed dist metadata
+    __version__ = "0.0.0+unknown"
 
 from mostlyright.discover import discover
 from mostlyright.research import research
diff --git a/packages/core/src/mostlyright/research.py b/packages/core/src/mostlyright/research.py
index b073b424..c66acd62 100644
--- a/packages/core/src/mostlyright/research.py
+++ b/packages/core/src/mostlyright/research.py
@@ -46,6 +46,7 @@
 
 from __future__ import annotations
 
+import contextlib
 import json
 import logging
 from datetime import UTC, datetime, timedelta
@@ -1718,10 +1719,6 @@ def research(
         ]
         raise ValueError(f"research(): selectors are mutually exclusive; got {provided!r}")
 
-    # `sources=` (plural) vs `source=` (singular) are mutually exclusive.
-    if sources is not None and source is not None:
-        raise ValueError("research(): sources= and source= are mutually exclusive")
-
     # `sources=` (plural, multi-source subset) is validated at the
     # mutual-exclusion boundary but its data-selection wiring lands in
     # v0.3. The singular `source=` pin IS wired below (a post-fetch
@@ -1960,8 +1957,6 @@ def research(
     # Phase 3.4: surface qc summary on df.attrs when the qc=True opt-in
     # ran. Mode 1 parity rows themselves are unchanged (only attrs).
     if qc_summary is not None and as_dataframe:
-        import contextlib
-
         with contextlib.suppress(AttributeError):
             result.attrs["qc"] = qc_summary
 
@@ -1970,8 +1965,6 @@ def research(
     # df.attrs["source"]). No attrs change when source is None — the
     # parity firewall keeps the default path untouched.
     if source is not None and as_dataframe:
-        import contextlib
-
         with contextlib.suppress(AttributeError):
             result.attrs["source"] = source
 
@@ -1990,11 +1983,21 @@ def research(
     # stamp this (pairs are heterogeneous), so the fallback to now()
     # is acceptable here — but future pairs-level provenance work
     # should populate result.attrs["retrieved_at"] for consistency.
+    # Mode 2 provenance parity: when source= is pinned, thread it explicitly
+    # into the wrapper the same way mode2.research_by_source does
+    # (source=source), so the wrapper contract doesn't depend on the
+    # df.attrs round-trip above. On this path the round-trip also works
+    # (as_dataframe=True guarantees a real DataFrame), so this is
+    # defense-in-depth, not a behavior fix. When source is None the default
+    # path is byte-identical (unchanged attrs-derived string).
+    wrap_source = (
+        source if source is not None else str(result.attrs.get("source", "mostlyright.research"))
+    )
     return wrap_result(
         result,
         backend=backend,  # type: ignore[arg-type]
         return_type=return_type,  # type: ignore[arg-type]
-        source=str(result.attrs.get("source", "mostlyright.research")),
+        source=wrap_source,
         retrieved_at=result.attrs.get("retrieved_at"),
         schema_id=None,  # research() returns heterogeneous pairs, not a single schema
         qc=qc_summary,
diff --git a/packages/core/tests/test_namespace.py b/packages/core/tests/test_namespace.py
index 8f80dee4..6c4a78d5 100644
--- a/packages/core/tests/test_namespace.py
+++ b/packages/core/tests/test_namespace.py
@@ -10,11 +10,15 @@
 ``import mostlyright.weather`` for users who installed both distributions.
 """
 
+from importlib.metadata import version as _dist_version
+
 import mostlyright
 
 
 def test_core_importable():
-    assert mostlyright.__version__ == "0.1.0rc1"
+    # __version__ is derived from the installed dist metadata (mostlyrightmd),
+    # not a hardcoded literal — keeps it in lockstep with pyproject on bumps.
+    assert mostlyright.__version__ == _dist_version("mostlyrightmd")
 
 
 def test_path_extended_for_split_distribution():
@@ -29,11 +33,11 @@ def test_weather_subpackage_importable():
     """``import mostlyright.weather`` must succeed when mostlyrightmd-weather is installed."""
     import mostlyright.weather
 
-    assert mostlyright.weather.__version__ == "0.1.0rc1"
+    assert mostlyright.weather.__version__ == _dist_version("mostlyrightmd-weather")
 
 
 def test_markets_subpackage_importable():
     """``import mostlyright.markets`` must succeed when mostlyrightmd-markets is installed."""
     import mostlyright.markets
 
-    assert mostlyright.markets.__version__ == "0.0.1"
+    assert mostlyright.markets.__version__ == _dist_version("mostlyrightmd-markets")
diff --git a/packages/core/tests/test_research_source_pin.py b/packages/core/tests/test_research_source_pin.py
index 232db6fa..07b1d7b3 100644
--- a/packages/core/tests/test_research_source_pin.py
+++ b/packages/core/tests/test_research_source_pin.py
@@ -188,3 +188,191 @@ def test_source_pin_noop_when_all_rows_already_match(tmp_path, monkeypatch) -> N
         df_pinned[["obs_high_f", "obs_low_f", "obs_count"]],
         df_unpinned[["obs_high_f", "obs_low_f", "obs_count"]],
     )
+
+
+# Four-source window shared by several coverage tests below. Jan 8 (EST) is
+# the settlement bucket; iem carries the 45/40 spread, awc the 99 high and
+# ghcnh the 20 low — both of which the pin must exclude.
+_FOUR_SOURCE_OBS = [
+    {
+        "station_code": "KNYC",
+        "observed_at": "2025-01-08T15:00:00Z",
+        "source": "iem",
+        "temp_f": 40.0,
+    },
+    {
+        "station_code": "KNYC",
+        "observed_at": "2025-01-08T18:00:00Z",
+        "source": "iem",
+        "temp_f": 45.0,
+    },
+    {
+        "station_code": "KNYC",
+        "observed_at": "2025-01-08T16:00:00Z",
+        "source": "awc",
+        "temp_f": 99.0,
+    },
+    {
+        "station_code": "KNYC",
+        "observed_at": "2025-01-08T17:00:00Z",
+        "source": "ghcnh",
+        "temp_f": 20.0,
+    },
+]
+
+
+def test_unknown_source_message_is_canonical(tmp_path, monkeypatch) -> None:
+    """P3-1: the unknown-source ValueError text is the pinned cross-SDK contract.
+
+    Both SDKs raise exactly ``research(): source must be one of <sorted
+    names>; got <repr>``. The prefix ``research(): source must be one of``
+    is the shared locked substring; each SDK renders the vocabulary list +
+    the offending value in its own native repr/quote style (Python here).
+    """
+    research_module = _load()
+    monkeypatch.setenv("MOSTLYRIGHT_CACHE_DIR", str(tmp_path))
+    monkeypatch.setattr(
+        research_module,
+        "_fetch_observations_range",
+        lambda *a, **kw: (_ for _ in ()).throw(AssertionError("fetch must not run")),
+    )
+    monkeypatch.setattr(research_module, "_all_caches_warm", lambda *a, **kw: True)
+
+    from mostlyright.mode2 import _VALID_OBSERVATION_SOURCES
+
+    with pytest.raises(ValueError) as exc:
+        research_module.research("KNYC", "2025-01-06", "2025-01-12", source="bogus.source")
+
+    msg = str(exc.value)
+    expected = (
+        "research(): source must be one of "
+        f"{sorted(_VALID_OBSERVATION_SOURCES)}; got {'bogus.source'!r}"
+    )
+    assert msg == expected
+    # Pin the shared cross-SDK prefix independently so a reword of the
+    # locked substring fails loudly even if the suffix drifts.
+    assert msg.startswith("research(): source must be one of")
+
+
+def test_source_pin_as_dataframe_false_filters_rows(tmp_path, monkeypatch) -> None:
+    """P3-6a: as_dataframe=False + source pin returns list[dict] pair rows whose
+    aggregates were fed ONLY by the pinned-source observations."""
+    research_module = _load()
+    _patch_fetchers(research_module, monkeypatch, tmp_path, _FOUR_SOURCE_OBS)
+
+    rows = research_module.research(
+        "KNYC", "2025-01-06", "2025-01-12", source="iem", as_dataframe=False
+    )
+    assert isinstance(rows, list)
+    assert all(isinstance(r, dict) for r in rows)
+
+    jan8 = next(r for r in rows if r["date"] == "2025-01-08")
+    # iem-only spread — the awc 99 high and ghcnh 20 low are excluded.
+    assert jan8["obs_high_f"] == 45.0
+    assert jan8["obs_low_f"] == 40.0
+    assert jan8["obs_count"] == 2
+    # as_dataframe=False returns raw pair dicts — no df.attrs surface here.
+
+
+def test_source_pin_polars_wrapper_filters_aggregates(tmp_path, monkeypatch) -> None:
+    """P3-6b: backend="polars" + source pin. polars requires
+    return_type="wrapper" (polars frames have no df.attrs); the pin
+    provenance rides on MostlyRightResult.source and the aggregates
+    reflect only the pinned-source rows.
+
+    Skip-guarded: the CI fast suite runs WITHOUT the [polars] extra.
+    """
+    pytest.importorskip("polars")
+    from mostlyright.core.result import MostlyRightResult
+
+    research_module = _load()
+    _patch_fetchers(research_module, monkeypatch, tmp_path, _FOUR_SOURCE_OBS)
+
+    out = research_module.research(
+        "KNYC",
+        "2025-01-06",
+        "2025-01-12",
+        source="iem",
+        backend="polars",
+        return_type="wrapper",
+    )
+    assert isinstance(out, MostlyRightResult)
+    import polars as pl
+
+    assert isinstance(out.frame, pl.DataFrame)
+    assert out.source == "iem"
+
+    pdf = out.frame_as_pandas()
+    jan8 = pdf.loc[pdf["date"] == pd.Timestamp("2025-01-08")].iloc[0]
+    assert jan8["obs_high_f"] == 45.0
+    assert jan8["obs_low_f"] == 40.0
+    assert jan8["obs_count"] == 2
+
+
+def test_source_pin_pandas_wrapper_carries_pin(tmp_path, monkeypatch) -> None:
+    """P3-6 / wrapper-path provenance: backend="pandas", return_type="wrapper"
+    exercises the wrap_result path WITHOUT needing the polars extra. The
+    pinned source is threaded explicitly (mode2 parity), so the wrapper
+    carries source="iem" rather than degrading to the generic default."""
+    from mostlyright.core.result import MostlyRightResult
+
+    research_module = _load()
+    _patch_fetchers(research_module, monkeypatch, tmp_path, _FOUR_SOURCE_OBS)
+
+    out = research_module.research(
+        "KNYC",
+        "2025-01-06",
+        "2025-01-12",
+        source="iem",
+        backend="pandas",
+        return_type="wrapper",
+    )
+    assert isinstance(out, MostlyRightResult)
+    assert out.source == "iem"
+
+    pdf = out.frame_as_pandas()
+    jan8 = pdf.loc[pd.Timestamp("2025-01-08")]
+    assert jan8["obs_high_f"] == 45.0
+    assert jan8["obs_low_f"] == 40.0
+    assert jan8["obs_count"] == 2
+
+
+def test_source_pin_unpinned_wrapper_source_default_unchanged(tmp_path, monkeypatch) -> None:
+    """Wrapper-path default byte-identity: with NO source pin the wrapper
+    still reports the generic "mostlyright.research" provenance — the
+    explicit-pin threading must not perturb the unpinned default."""
+    from mostlyright.core.result import MostlyRightResult
+
+    research_module = _load()
+    _patch_fetchers(research_module, monkeypatch, tmp_path, _FOUR_SOURCE_OBS)
+
+    out = research_module.research(
+        "KNYC",
+        "2025-01-06",
+        "2025-01-12",
+        backend="pandas",
+        return_type="wrapper",
+    )
+    assert isinstance(out, MostlyRightResult)
+    assert out.source == "mostlyright.research"
+
+
+def test_source_pin_empty_result_carries_attrs_and_columns(tmp_path, monkeypatch) -> None:
+    """P3-6c: pinning a source that NO fetched row matches yields an empty
+    aggregate (obs_count 0, null highs/lows) but still returns the standard
+    frame — attrs["source"] stamped, standard columns present, no crash."""
+    research_module = _load()
+    # Only awc/ghcnh rows in the window; pinning "iem" filters them all out.
+    obs = [r for r in _FOUR_SOURCE_OBS if r["source"] != "iem"]
+    _patch_fetchers(research_module, monkeypatch, tmp_path, obs)
+
+    df = research_module.research("KNYC", "2025-01-06", "2025-01-12", source="iem")
+
+    assert df.attrs["source"] == "iem"
+    for col in ("station", "cli_high_f", "cli_low_f", "obs_high_f", "obs_low_f", "obs_count"):
+        assert col in df.columns, f"missing standard column {col!r}"
+
+    row = df.loc[pd.Timestamp("2025-01-08")]
+    assert row["obs_count"] == 0
+    assert pd.isna(row["obs_high_f"])
+    assert pd.isna(row["obs_low_f"])
diff --git a/packages/markets/pyproject.toml b/packages/markets/pyproject.toml
index b56ee0db..e2eb4b50 100644
--- a/packages/markets/pyproject.toml
+++ b/packages/markets/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "mostlyrightmd-markets"
-version = "1.12.0"
+version = "1.12.1"
 description = "Prediction-market data for Python — Kalshi NHIGH/NLOW weather-contract resolvers, Polymarket discovery + settlement, and Kalshi + Polymarket trade history. For quants, backtesting, and ML training pipelines. Imports as `mostlyright.markets`."
 readme = "README.md"
 license = "MIT"
diff --git a/packages/markets/src/mostlyright/markets/__init__.py b/packages/markets/src/mostlyright/markets/__init__.py
index 803f109d..b09f99fc 100644
--- a/packages/markets/src/mostlyright/markets/__init__.py
+++ b/packages/markets/src/mostlyright/markets/__init__.py
@@ -15,5 +15,12 @@
   ``monorepo-v0.14.1/src/mostlyright/_polymarket.py``)
 """
 
-__version__ = "0.0.1"
+from importlib.metadata import PackageNotFoundError
+from importlib.metadata import version as _dist_version
+
+try:
+    __version__ = _dist_version("mostlyrightmd-markets")
+except PackageNotFoundError:  # editable/source tree without installed dist metadata
+    __version__ = "0.0.0+unknown"
+
 __all__ = ["__version__"]
diff --git a/packages/weather/pyproject.toml b/packages/weather/pyproject.toml
index 2189c1a8..1d6a8a6b 100644
--- a/packages/weather/pyproject.toml
+++ b/packages/weather/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "mostlyrightmd-weather"
-version = "1.12.0"
+version = "1.12.1"
 description = "Weather data for Python — live METAR (AWC), ASOS archive (IEM), historical observations (GHCNh), and NWS climate text products (CLI). For quants, ML training pipelines, and weather-bot agents. Direct public-API access, no hosted backend. Imports as `mostlyright.weather`."
 readme = "README.md"
 license = "MIT"
diff --git a/packages/weather/src/mostlyright/weather/__init__.py b/packages/weather/src/mostlyright/weather/__init__.py
index 6b896c90..b92dd4d9 100644
--- a/packages/weather/src/mostlyright/weather/__init__.py
+++ b/packages/weather/src/mostlyright/weather/__init__.py
@@ -30,6 +30,8 @@
 keeps working without preprocessing in v0.1.0.
 """
 
+from importlib.metadata import PackageNotFoundError
+from importlib.metadata import version as _dist_version
 from typing import TYPE_CHECKING, Any
 
 from mostlyright.weather._fetchers._open_meteo import fetch_open_meteo
@@ -39,7 +41,10 @@
 if TYPE_CHECKING:
     from mostlyright.weather import cwop as cwop
 
-__version__ = "0.1.0rc1"
+try:
+    __version__ = _dist_version("mostlyrightmd-weather")
+except PackageNotFoundError:  # editable/source tree without installed dist metadata
+    __version__ = "0.0.0+unknown"
 __all__ = ["__version__", "cwop", "fetch_open_meteo", "obs", "satellite"]
 
 
diff --git a/uv.lock b/uv.lock
index 44414400..8d58d0ca 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1628,7 +1628,7 @@ wheels = [
 
 [[package]]
 name = "mostlyrightmd"
-version = "1.12.0"
+version = "1.12.1"
 source = { editable = "packages/core" }
 dependencies = [
     { name = "httpx" },
@@ -1672,7 +1672,7 @@ provides-extras = ["parquet", "research", "polars"]
 
 [[package]]
 name = "mostlyrightmd-markets"
-version = "1.12.0"
+version = "1.12.1"
 source = { editable = "packages/markets" }
 dependencies = [
     { name = "httpx" },
@@ -1726,7 +1726,7 @@ provides-extras = ["parquet", "polymarket", "trades", "earnings", "polars"]
 
 [[package]]
 name = "mostlyrightmd-weather"
-version = "1.12.0"
+version = "1.12.1"
 source = { editable = "packages/weather" }
 dependencies = [
     { name = "filelock" },