dmealing · Oct 4, 2026 · Oct 4, 2026 · Oct 4, 2026 · Oct 4, 2026 · Oct 4, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -18,6 +18,17 @@ it until 1.1 ships._
 
 ### Added
 
+- **Python: a run-time validator runner, `run_validators`.** `metaobjects.runtime.run_validators(entity, data)`
+  validates a data mapping against an entity's metadata with no generated code and no database,
+  and `ObjectManager.validate(entity_name, data)` does the same for a loaded entity. It is the
+  port of TypeScript's `runValidators`: it never raises, collects every failure as
+  `{field, rule, message, expected, received}`, and uses the same rules and message text. Both
+  runners now run `fixtures/validation-conformance/`, and the new `runtime-errors.json` there
+  pins the exact failure list each must produce. See `docs/ports/python.md`, "Run-time
+  validation".
+- **TypeScript: `runValidators` is exported from `@metaobjectsdev/runtime-ts`**, with
+  `RunValidatorsOpts`. It was reachable only through `ObjectManager.validate()` before.
+
 - **Metamodel 1.1: the reporting vocabulary (FR-044), loader-validated in all five ports.**
   Registered: `dimension.attribute`, `dimension.time` (`@grains`: `hour, day, week, month,
   quarter, year`, weeks start Monday), `measure.aggregate` (`@agg`: `count, sum, avg, min, max`),
@@ -62,6 +73,32 @@ it until 1.1 ships._
   (`executeQuery`) with a report as its result class builds rows from the report's derived
   fields.
 
+### Changed
+
+- **TypeScript: `runValidators` rejects more than it did — a behaviour change for
+  `ObjectManager` users.** `ObjectManager.create`, `createMany`, `update`, `updateMany` and
+  `validate` all go through it, so data that was accepted before can now raise a
+  `ValidationError`. The run-time runner had fallen behind the generated Zod schema; it now
+  passes the same `validation-conformance` corpus. What is newly enforced:
+  - `validator.numeric @min`/`@max` on `field.int`, `long`, `currency`, `double` and `float`
+    (rule `numeric`). These bounds were ignored at run time.
+  - `validator.array @min`/`@max` on an array field's element count (rule `array`). Also
+    ignored before.
+  - `field.uri` must be an absolute URI and `field.inet` an IPv4 or IPv6 literal (rule
+    `format`); a non-string value for either is a `type` failure. `@lenient: true` opts out
+    of the format check.
+  - An assigned primary key (no `@generation: increment` or `uuid`, no `@default`) is
+    `required` on insert. `create` already refused this; `validate()` now reports it too.
+  - `@maxLength` and `validator.length @max` on one field are strictest-wins. The runner
+    used `@maxLength` alone, so a tighter validator bound was not applied.
+
+  One resolution is corrected: a package-qualified `@objectRef` (`billing::Address`) on a
+  value-object field now resolves to the object in that package. It resolved to the first
+  object of that bare name, so with two same-named value objects the wrong one's rules ran.
+
+  One rule is relaxed: an authored `validator.length @min: 0` on a `@required` string now
+  admits the empty string, as the generated schema already did.
+
 ### Fixed
 
 - **Java OMDB reads a projection whose view is named by `@view`.** The read mapping took the

diff --git a/docs/CONFORMANCE.md b/docs/CONFORMANCE.md
@@ -35,7 +35,7 @@ regenerate with `ls -d fixtures/<corpus>/*/ | wc -l` for directory-shaped corpor
 | [`fixtures/output-prompt-conformance/`](../fixtures/output-prompt-conformance/) | 17 | ✓ | ✓ | ✓ | ✓ | ✓ |
 | [`fixtures/persistence-conformance/`](../fixtures/persistence-conformance/) | 39 (33 query + 6 migration) | all 39 | 33 query (migrations TS-only, ADR-0015) | 33 query (via Exposed) | 33 query | 33 query |
 | [`fixtures/api-contract-conformance/`](../fixtures/api-contract-conformance/) | 61 (31 core + 10 tph + 9 m2m + 2 jsonb + 2 write-through + 7 projection) | ✓ (Fastify reference + generated lane) | ✓ (embedded HTTP + JDBC) | ✓ (embedded HTTP + Exposed) | ✓ (HttpListener + Npgsql) | ✓ (FastAPI + pg8000) |
-| [`fixtures/validation-conformance/`](../fixtures/validation-conformance/) | 16 cases | ✓ | ✓ | ✓ | ✓ | ✓ |
+| [`fixtures/validation-conformance/`](../fixtures/validation-conformance/) | 42 cases | ✓ (generated Zod + run-time `runValidators`) | ✓ | ✓ | ✓ | ✓ (generated Pydantic + run-time `run_validators`) |
 | [`fixtures/registry-conformance/`](../fixtures/registry-conformance/) | 1 canonical manifest | ✓ (reference emitter) | ✓ | ✓ | ✓ | ✓ |
 | [`fixtures/object-model-conformance/`](../fixtures/object-model-conformance/) | 1 shared metadata fixture (per-port scenarios) | ✓ | ✓ | ✓ | ✓ | ✓ |
 | [`fixtures/codegen-conformance/`](../fixtures/codegen-conformance/) | 4 | ✓ | ✓ | ✓ | ✓ | ✓ |

diff --git a/docs/ports/python.md b/docs/ports/python.md
@@ -437,6 +437,52 @@ name_field = [f for f in author.children() if f.name == "name"][0]
 print(name_field.get_meta_attr("maxLength"))   # -> 200
 ```
 
+### Run-time validation
+
+`run_validators` checks a data mapping against an entity's metadata, with no generated
+code and no database. It is the Python port of TypeScript's `runValidators`: the same
+rules, the same failure structure and the same message text.
+
+```python
+from metaobjects.runtime import run_validators
+
+account = next(c for c in result.root.children() if c.name == "Account")
+outcome = run_validators(account, {"name": "", "score": 101})
+outcome.ok                                # -> False
+[e.to_dict() for e in outcome.errors]
+# [{"field": "name", "rule": "length", "message": "'name' must be at least 1 chars (got 0)",
+#   "expected": {"min": 1}, "received": 0},
+#  {"field": "score", "rule": "numeric", "message": "'score' must be at most 100 (got 101)",
+#   "expected": {"max": 100}, "received": 101}]
+```
+
+It never raises. Every failure on every field is collected; a `required` or `type`
+failure stops further checks on that one value only. The rules, by `rule` name:
+
+| `rule` | Fires when |
+|---|---|
+| `required` | a `@required` field, a field with `validator.required`, or an assigned primary key (no `@generation: increment` or `uuid`) is absent or `None` |
+| `type` | the value is not the field subtype's type; an array field is not a list; a value-object field is not a mapping |
+| `length` | a string is longer than `min(@maxLength, validator.length @max)` or shorter than `validator.length @min`. A `@required` string has a floor of 1 unless a `@min` is authored |
+| `regex` | a string does not fully match `validator.regex @pattern` |
+| `numeric` | a number is outside `validator.numeric @min`/`@max` (inclusive) |
+| `array` | an array's element count is outside `validator.array @min`/`@max` |
+| `format` | a `field.uri` is not an absolute URI, or a `field.inet` is not an IPv4/IPv6 literal. `@lenient: true` opts out |
+
+Keyword options: `partial=True` is update mode, where an absent key is untouched and
+only present keys are checked. `store_filled=[...]` names fields the store fills on
+insert, which are then exempt from `required` when absent. A field with a `@default` is
+also exempt when absent. A value object is validated in full, and its failures are
+labelled `field.member` or `field[i].member`.
+
+`ObjectManager.validate(entity_name, data)` returns the same result for a loaded entity.
+The `ObjectManager` write methods do not call it, so validate first when the data is
+untrusted.
+
+Three details follow JavaScript so that both runners report identical failures: string
+length counts UTF-16 code units, a `bool` is not accepted as a number, and a number in a
+message prints as JavaScript prints it (`2.0` as `2`, `1e-07` as `1e-7`).
+
 ## FR-004 — render
 
 `render` takes a `RenderRequest` (only `payload` + `provider` are required; `ref`

diff --git a/docs/superpowers/plans/2026-10-04-python-validator-runner.md b/docs/superpowers/plans/2026-10-04-python-validator-runner.md
@@ -0,0 +1,105 @@
+# Python Run-time Validator Runner Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Give the Python port a run-time validator runner equal to TypeScript's `runValidators`, and make both runners pass `fixtures/validation-conformance/`.
+
+**Architecture:** One pure function per port — it never raises, it collects every failure as `{field, rule, message, expected?, received?}`. TypeScript's `runValidators` is the contract. The corpus gates boolean verdicts; a new sibling file `runtime-errors.json` pins the exact failure list so the two runners cannot drift in structure or message text.
+
+**Tech Stack:** Python 3 standard library only (`re`), pytest; TypeScript, `bun test`.
+
+**Spec:** no separate spec. The contract is `server/typescript/packages/runtime-ts/src/validator-runner.ts` plus `fixtures/validation-conformance/README.md`.
+
+## Global Constraints
+
+- No new vocabulary, no new validator subtype, no metamodel change. Java is not touched.
+- The Python runner adds no runtime dependency (`PyYAML` stays the only one).
+- ADR-0039: read effective values. Python `attr()` is OWN-only — use `get_meta_attr()` / `children()`. The one own read is `@dbColumnType`.
+- Rules, rule names, field labels and message text are byte-identical in both runners.
+- The behaviour change for TypeScript users goes in `CHANGELOG.md` under `[Unreleased]` (the 1.1 line).
+
+## The rules both runners implement
+
+Per field, in declaration order (effective children):
+
+1. **required** — `mustBePresent = @required | validator.required | assigned primary key with no @default`. An assigned primary key is a field of the primary identity whose `@generation` is neither `increment` nor `uuid`. Absent or null → `{rule: "required", message: "'f' is required"}`. Existing exemptions are unchanged (`partial` and absent; `@default` and absent; `storeFilled` and absent).
+2. Open-bag jsonb string, value-object recursion: unchanged.
+3. **array** (new) — on an array field, `validator.array @min/@max` bounds the element count:
+   `{rule: "array", message: "'tags' must have at least 1 items (got 0)", expected: {min: 1}, received: 0}` and `"... at most 3 items (got 4)"` with `expected: {max: 3}`. Applies to scalar arrays and value-object arrays.
+4. **type** — unchanged, plus `field.uri` / `field.inet` must be a string (`expected string`).
+5. **length** — max is strictest-wins: `min(@maxLength, validator.length @max)`. Min is the authored `validator.length @min` when one is authored (`@min: 0` opts out of the floor), else 1 for a declared-required string, else 0. Messages unchanged. Length counts UTF-16 code units in both ports.
+6. **regex** — unchanged (full match).
+7. **numeric** (new) — on `field.int|long|currency|double|float`, `validator.numeric @min/@max`, inclusive:
+   `{rule: "numeric", message: "'score' must be at least 0 (got -1)", expected: {min: 0}, received: -1}` and `"... at most 100 (got 101)"` with `expected: {max: 100}`. An int64 passed as a numeric string is compared as an integer and echoed as given.
+8. **format** (new) — unless `@lenient: true`:
+   - `field.uri`: strip leading/trailing characters ≤ U+0020; the rest must match `^[A-Za-z][A-Za-z0-9+.-]*:` with a non-empty remainder, and when the remainder starts with `//` the authority (up to the next `/`, `?` or `#`) must be non-empty. Failure: `{rule: "format", message: "'website' must be an absolute URI", expected: "uri", received: value}`.
+   - `field.inet`: must match the IPv4 or IPv6 literal patterns from `codegen-ts/src/templates/net-regex.ts`. Failure: `{rule: "format", message: "'sourceIp' must be an IPv4 or IPv6 address", expected: "inet", received: value}`.
+
+A type failure stops further checks on that value. Order of failures within one value: length max, length min, regex, numeric min, numeric max, format.
+
+## Review Focus
+
+- Python `bool` is an `int`: `True` on a numeric field must be a type failure, as in TypeScript.
+- A `1.0` bound must print as `1`, as JavaScript prints it.
+- A non-BMP character counts as 2 toward length in both ports.
+- An invalid `@pattern` yields a `regex` failure, never an exception.
+- `partial=True` with an absent assigned primary key is not a failure; a present `None` is.
+
+---
+
+### Task 1: Pin the failure list — `fixtures/validation-conformance/runtime-errors.json`
+
+- [ ] Add `runtime-errors.json`: `{ "errors": { "<case name>": [ {field, rule, message, expected?, received?} ] } }`, one entry per `expectValid: false` case in `cases.json`.
+- [ ] Document the file and the two run-time runners in the corpus `README.md`.
+
+### Task 2: TypeScript `runValidators` — corpus + new rules
+
+**Files:** modify `server/typescript/packages/runtime-ts/src/validator-runner.ts`; tests in `server/typescript/packages/runtime-ts/test/validator-runner.test.ts`; create `server/typescript/packages/integration-tests/test/validation-conformance-runtime.test.ts`; modify `scripts/ci-local.sh` (`gate_conf_ts`).
+
+- [ ] Write the corpus runner test: load `meta.json`, run each case through `runValidators`, assert `result.ok === expectValid`, and for a failing case assert `result.errors` deep-equals `runtime-errors.json`. Run it; expect the uri/inet/numeric/array/length/assigned-PK cases to fail.
+- [ ] Add unit tests for rules 1, 3, 5, 7, 8 and the Review Focus lines that apply to TypeScript. Run; expect failures.
+- [ ] Implement the rules. Run both test files; expect green. Run `bun test` in `runtime-ts` and `bun run --filter '*' typecheck`.
+- [ ] Commit.
+
+### Task 3: Python `run_validators`
+
+**Files:** create `server/python/src/metaobjects/runtime/validator_runner.py`; modify `server/python/src/metaobjects/runtime/__init__.py` and `object_manager.py` (`ObjectManager.validate`); tests `server/python/tests/runtime/test_validator_runner.py` and `server/python/tests/runtime/test_validation_conformance_runtime.py`.
+
+**Interfaces:**
+
+```python
+@dataclass(frozen=True)
+class ValidationFailure:
+    field: str
+    rule: str
+    message: str
+    expected: object = None
+    received: object = None
+    def to_dict(self) -> dict[str, object]: ...   # omits expected/received when None
+
+@dataclass(frozen=True)
+class ValidationResult:
+    ok: bool
+    errors: tuple[ValidationFailure, ...] = ()
+
+def run_validators(entity: MetaData, data: Mapping[str, object], *,
+                   partial: bool = False, store_filled: Sequence[str] = ()) -> ValidationResult: ...
+
+class ObjectManager:
+    def validate(self, entity_name: str, data: Mapping[str, object]) -> ValidationResult: ...
+```
+
+- [ ] Write the corpus runner test (same assertions as Task 2, `to_dict()` compared with `runtime-errors.json`) and the unit tests, porting `validator-runner.test.ts` case for case plus the Review Focus lines. Run; expect import failure.
+- [ ] Implement. Run `uv run pytest tests/runtime -q`, `uv run mypy`, `uv run ruff check`; expect green.
+- [ ] Commit.
+
+### Task 4: Docs and changelog
+
+- [ ] `docs/ports/python.md`: document `run_validators` and `ObjectManager.validate`.
+- [ ] `docs/CONFORMANCE.md`: correct the corpus case count and note the two run-time runners.
+- [ ] `CHANGELOG.md` `[Unreleased]`: Added (Python runner), Changed (TypeScript `runValidators` now enforces numeric, array, uri/inet format, assigned-PK presence, strictest-wins max length, authored `@min` over the floor — a behaviour change).
+- [ ] Commit.
+
+### Task 5: Verify
+
+- [ ] `scripts/ci-local.sh` (full) green; one independent review of the branch; fix findings.
diff --git a/fixtures/validation-conformance/README.md b/fixtures/validation-conformance/README.md
@@ -15,6 +15,7 @@ meta.json    # `Account` (package acme::auth) exercising each constraint once,
              #   plus `Ledger` — an ASSIGNED primary key (see below)
 cases.json   # [{ name, entity?, payload, expectValid }] — single-source boolean verdicts
              #   `entity` is optional and defaults to `Account`
+runtime-errors.json  # the exact failure list per rejected case — run-time runners only (below)
 README.md
 ```
 
@@ -151,6 +152,27 @@ So the rule is:
 Python fuses both (Pydantic construct-or-`ValidationError`); the Java/Kotlin/C#
 runners wrap the bind step so a native-parse failure maps to `valid=false`.
 
+## Run-time runners (TypeScript and Python)
+
+Two ports also ship a metadata-driven **run-time** runner that needs no generated code:
+TypeScript `runValidators` (`@metaobjectsdev/runtime-ts`) and Python `run_validators`
+(`metaobjects.runtime`). Both run every case here and assert the same boolean verdict.
+
+`runtime-errors.json` goes further for these two: for each rejected case it pins the
+exact failure list — `{ field, rule, message, expected?, received? }` — and both runners
+assert it by deep equality. That is what holds them to identical structure and message
+text, which a boolean verdict cannot. It applies to the run-time runners only; the
+generated artifacts report in their own native error shapes and stay on the boolean
+verdict.
+
+The run-time rule for `field.uri` is an explicit pattern (a scheme, a non-empty
+remainder, and a non-empty authority after `//`), not a platform URL parser, so the two
+runners agree outside the pinned probe set too. It can therefore differ from the
+generated Zod `.url()` in the unpinned gray zone above.
+
+Runners: `server/typescript/packages/integration-tests/test/validation-conformance-runtime.test.ts`
+and `server/python/tests/runtime/test_validation_conformance_runtime.py`.
+
 ## CI gate
 
 All five port runners assert byte-identical boolean verdicts across all five