mwoods79 · Oct 10, 2026 · Oct 10, 2026 · Oct 10, 2026 · Oct 10, 2026 · Oct 10, 2026
diff --git a/.agents/skills/ash-framework/SKILL.md b/.agents/skills/ash-framework/SKILL.md
@@ -24,6 +24,7 @@ metadata:
 - [query_filter](references/ash/query_filter.md)
 - [querying_data](references/ash/querying_data.md)
 - [relationships](references/ash/relationships.md)
+- [temporal](references/ash/temporal.md)
 - [testing](references/ash/testing.md)
 
 ### ash_ai

diff --git a/.agents/skills/ash-framework/references/ash/temporal.md b/.agents/skills/ash-framework/references/ash/temporal.md
@@ -0,0 +1,92 @@
+# Temporal Resources
+
+Temporal resources are experimental. A temporal resource keeps every version of a record, and each version is valid for a half-open period `[from, to)`. Every read and write happens "as of" one instant. Read the "Temporal Resources" guide before working with them.
+
+## Supported Data Layers
+
+- Only `AshPostgres.DataLayer` on PostgreSQL 18+ and `Ash.DataLayer.Ets` support temporal resources. On any other data layer, a resource that declares `temporal` won't compile.
+- Manual actions skip temporal handling entirely. If you write one, you manage periods yourself.
+
+## Defining a Temporal Resource
+
+```elixir
+temporal do
+  strategy :context
+  attribute :valid_at
+  # optional: wall-clock time each version was written
+  recorded_at :recorded_at
+end
+```
+
+- You don't have to declare the period attribute. If you leave it out, `temporal` adds an `Ash.Type.Range` over `:utc_datetime_usec` with `[from, to)` bounds.
+- If you do declare it, it must be an `Ash.Type.Range` over `:utc_datetime_usec`, `:utc_datetime` or `:datetime`, with `allow_nil? false`, an inclusive lower bound and an exclusive upper bound. Ranges over dates, naive datetimes or other types are refused at compile time.
+- **Never put the period attribute in an action's `accept`**, and never set it in a change. Its value always comes from the write's `as_of`.
+- Use `mix ash.codegen` for migrations. It generates the `PRIMARY KEY (id, valid_at WITHOUT OVERLAPS)` and installs `btree_gist`. Don't write these by hand.
+
+## Reading
+
+- To read at a point in time, use `Ash.Query.as_of/2` or pass `as_of:` anywhere `tenant:` is accepted (`Ash.read`, `Ash.get`, code interfaces, `for_read`, and so on).
+- If you leave out `as_of`, the read happens now and returns exactly one row per record. It never returns the full history.
+- Every read is a single instant. A range-valued `as_of` on a read raises `Ash.Error.Query.AsOfNotAnInstant`. Don't try to fetch several versions of a record in one query.
+- `as_of` propagates like `tenant`. Loaded relationships, calculations, aggregates and nested actions all run at the same instant, so you don't need to pass it to them again.
+- In expressions, `now()`, `ago/2` and `from_now/2` mean the query's `as_of`, not the wall clock. Write `expr(expires_at > now())`, not `^DateTime.utc_now()`. Pinning the wall clock breaks time travel.
+
+```elixir
+Ash.get!(MyApp.Subscription, 1, as_of: ~U[2026-01-15 00:00:00Z])
+
+MyApp.Subscription
+|> Ash.Query.filter(plan == "gold")
+|> Ash.Query.as_of(~U[2026-01-15 00:00:00Z])
+|> Ash.read!()
+```
+
+## Writing
+
+- A write makes something true from `as_of` onward. If you don't pass `as_of`, it uses now. One instant is pinned for the whole write, and `&DateTime.utc_now/0` defaults and `set_attribute(..., &DateTime.utc_now/0)` resolve to that same instant. Back-dated writes therefore get back-dated timestamps. Use `recorded_at` if you need the actual time a version was written.
+- **Pass `as_of` as an action option** (`for_create(:create, input, as_of: ...)`, `for_update(...)`, `for_destroy(...)`). `Ash.Changeset.as_of/2` is applied too late for cascading destroys, `manage_relationship`, and identity pre-checks.
+- A **create** opens `[as_of, ∞)`. You can't create a record if any later version of it already exists.
+- An **update** splits the version valid at `as_of`. The new values run from `as_of` to wherever that version ended. To schedule a future change, write an update with a future `as_of`, not a create.
+- A **destroy** closes the version valid at `as_of` down to `[from, as_of)`. It doesn't delete history.
+- An update or destroy with no version valid at `as_of` (because the history ended, the record hasn't started yet, or `as_of` falls in a gap) fails as a stale record. To bring back a record whose history has ended, *
8000
*create** it again rather than updating it.
+- On Postgres, concurrent writes to the same record are retried automatically, up to 25 conflicts, after which `AshPostgres.Temporal.WriteConflict` is raised. It's safe to retry. Under `REPEATABLE READ`/`SERIALIZABLE` you get a serialization failure instead, and retrying is up to you.
+
+## Changes, Validations and Preparations
+
+- Any change, validation or preparation that runs on a temporal resource must declare `temporal_safe?/1` returning `true`. Otherwise the action raises `Ash.Error.Framework.NotTemporalSafe`. The callback defaults to `false`.
+- Only declare a module temporal safe if it never reads the wall clock (use `now()` in expressions or the subject's `as_of` instead), has no side effects that assume the present, and does all of its reads and nested actions through Ash so `as_of` propagates.
+- The built-in changes, validations and preparations are temporal safe. These aren't, because they wrap arbitrary functions: `before_action`, `after_action`, `before_transaction`, `after_transaction`, and anonymous-function changes, validations and preparations. Move that logic into a module that declares `temporal_safe?/1`.
+- For third-party modules that you've verified are safe but that don't declare the callback, add them to `config :ash, :temporal_safe_modules, [...]`. The list is read at compile time.
+
+```elixir
+defmodule MyApp.Changes.Slugify do
+  use Ash.Resource.Change
+
+  @impl true
+  def temporal_safe?(_opts), do: true
+
+  @impl true
+  def change(changeset, _opts, _context) do
+    # ...
+  end
+end
+```
+
+## Relationships and Identities
+
+- To make a `belongs_to` point at another temporal resource for the matching period, declare `temporal_keys {:valid_at, :valid_at}`. On Postgres this produces a `PERIOD` foreign key.
+- `PERIOD` foreign keys only support `NO ACTION`, so `on_delete`/`on_update` referential actions are rejected at compile time. Cascade in the application instead, for example with `change cascade_destroy(:subscriptions)`.
+- Write identities as usual (`identity :unique_email, [:email]`). On a temporal resource they become "unique at every instant" (`UNIQUE (... WITHOUT OVERLAPS)`). Don't add the period attribute to an identity.
+
+## Authorization
+
+- Data and filter checks are evaluated as of the query's `as_of`. Actor attribute checks (`actor_attribute_equals`, `^actor(:field)`) use the actor struct exactly as you loaded it. Ash does not re-fetch the actor at the query's instant.
+- **Load the actor as of the same instant you query.** Otherwise you're authorizing historical data with the actor's current attributes.
+
+```elixir
+as_of = ~U[2026-01-15 00:00:00Z]
+actor = Ash.get!(MyApp.User, user_id, as_of: as_of)
+
+MyApp.Subscription
+|> Ash.Query.as_of(as_of)
+|> Ash.read!(actor: actor)
+```
diff --git a/mix.lock b/mix.lock
@@ -2,7 +2,7 @@
   "absinthe": {:hex, :absinthe, "1.12.0", "fe69ee9940e47a6a80ab506f2c1def96964ab52e7f52fe2cd642d0f574967931", [:mix], [{:dataloader, "~> 1.0.0 or ~> 2.0", [hex: :dataloader, repo: "hexpm", optional: true]}, {:decimal, "~> 2.0 or ~> 3.0", [hex: :decimal, repo: "hexpm", optional: true]}, {:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}, {:opentelemetry_process_propagator, "~> 0.2.1 or ~> 0.3", [hex: :opentelemetry_process_propagator, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "b0672939fa75c24b6286c784edc01bec1bedfbe58885acdda5d097c7053b03c6"},
   "absinthe_phoenix": {:hex, :absinthe_phoenix, "2.0.5", "1fdcfc59db241b1d5e45e4c8c9db162277e64ec5728e0fd6958a3fa491a05b82", [:mix], [{:absinthe, "~> 1.5", [hex: :absinthe, repo: "hexpm", optional: false]}, {:absinthe_plug, "~> 1.5", [hex: :absinthe_plug, repo: "hexpm", optional: false]}, {:decimal, "~> 1.0 or ~> 2.0 or ~> 3.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:phoenix, "~> 1.5", [hex: :phoenix, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.13 or ~> 3.0 or ~> 4.0", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 2.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}], "hexpm", "086c6d4a1c32f7444713130d204c87b1b006169f5159026b73f02f7d38ccd05c"},
   "absinthe_plug": {:hex, :absinthe_plug, "1.5.10", "c9e207235aaa8a086a5db6801a9bebaea035f7b5a2703cb98d962646ef70c76f", [:mix], [{:absinthe, "~> 1.7", [hex: :absinthe, repo: "hexpm", optional: false]}, {:plug, "~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm", "489ac1951c8e4128571141c60a0669a720619bc161f801a8c6be8cfaf7ab0979"},
-  "ash": {:hex, :ash, "3.34.4", "b799d852dca874b4afbe3bfa3477099e23b58830250fa6144c48ef7f58cf67d0", [:mix], [{:crux, ">= 0.1.2 and < 1.0.0-0", [hex: :crux, repo: "hexpm", optional: false]}, {:decimal, "~> 2.0 or ~> 3.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:ecto, "~> 3.14", [hex: :ecto, repo: "hexpm", optional: false]}, {:ets, "~> 0.8", [hex: :ets, repo: "hexpm", optional: false]}, {:igniter, ">= 0.6.29 and < 1.0.0-0", [hex: :igniter, repo: "hexpm", optional: true]}, {:jason, ">= 1.0.0", [hex: :jason, repo: "hexpm", optional: false]}, {:picosat_elixir, "~> 0.2", [hex: :picosat_elixir, repo: "hexpm", optional: true]}, {:plug, ">= 0.0.0", [hex: :plug, repo: "hexpm", optional: true]}, {:reactor, "~> 1.0", [hex: :reactor, repo: "hexpm", optional: false]}, {:simple_sat, ">= 0.1.1 and < 1.0.0-0", [hex: :simple_sat, repo: "hexpm", optional: true]}, {:spark, ">= 2.7.6 and < 3.0.0-0", [hex: :spark, repo: "hexpm", optional: false]}, {:splode, "~> 0.3", [hex: :splode, repo: "hexpm", optional: false]}, {:stream_data, "~> 1.0", [hex: :stream_data, repo: "hexpm", optional: false]}, {:telemetry, "~> 1.1", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "bb82f7e412fce03b50abbe87a260ce956d1f67bc97d0544f011fa0d1882f07e4"},
+  "ash": {:hex, :ash, "3.34.6", "70ce402edbe6930570ce930661859b3be514dfd34700f8432c565e526ba9a990", [:mix], [{:crux, ">= 0.1.2 and < 1.0.0-0", [hex: :crux, repo: "hexpm", optional: false]}, {:decimal, "~> 2.0 or ~> 3.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:ecto, "~> 3.14", [hex: :ecto, repo: "hexpm", optional: false]}, {:ets, "~> 0.8", [hex: :ets, repo: "hexpm", optional: false]}, {:igniter, ">= 0.6.29 and < 1.0.0-0", [hex: :igniter, repo: "hexpm", optional: true]}, {:jason, ">= 1.0.0", [hex: :jason, repo: "hexpm", optional: false]}, {:picosat_elixir, "~> 0.2", [hex: :picosat_elixir, repo: "hexpm", optional: true]}, {:plug, ">= 0.0.0", [hex: :plug, repo: "hexpm", optional: true]}, {:reactor, "~> 1.0", [hex: :reactor, repo: "hexpm", optional: false]}, {:simple_sat, ">= 0.1.1 and < 1.0.0-0", [hex: :simple_sat, repo: "hexpm", optional: true]}, {:spark, ">= 2.7.6 and < 3.0.0-0", [hex: :spark, repo: "hexpm", optional: false]}, {:splode, "~> 0.3", [hex: :splode, repo: "hexpm", optional: false]}, {:stream_data, "~> 1.0", [hex: :stream_data, repo: "hexpm", optional: false]}, {:telemetry, "~> 1.1", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "1109afed2bcf1f405aa035013d016a1ca88dab485ba2fb0c0885e7e7e9c6ae0f"},
   "ash_ai": {:hex, :ash_ai, "1.1.1", "f8e10dec47a9177f62488f64b611ae29eccb7cdc1e073525a5b1a00c074030a6", [:mix], [{:ash, ">= 3.33.6 and < 4.0.0-0", [hex: :ash, repo: "hexpm", optional: false]}, {:ash_authentication, "~> 4.8 or ~> 5.0-rc", [hex: :ash_authentication, repo: "hexpm", optional: true]}, {:ash_json_api, ">= 1.4.27 and < 2.0.0-0", [hex: :ash_json_api, repo: "hexpm", optional: false]}, {:ash_oban, "~> 0.5", [hex: :ash_oban, repo: "hexpm", optional: true]}, {:ash_phoenix, "~> 2.0", [hex: :ash_phoenix, repo: "hexpm", optional: true]}, {:ash_postgres, "~> 2.5", [hex: :ash_postgres, repo: "hexpm", optional: true]}, {:igniter, "~> 0.5", [hex: :igniter, repo: "hexpm", optional: true]}, {:open_api_spex, "~> 3.0", [hex: :open_api_spex, repo: "hexpm", optional: false]}, {:phx_new, "~> 1.7", [hex: :phx_new, repo: "hexpm", optional: true]}, {:plug, "~> 1.17", [hex: :plug, repo: "hexpm", optional: true]}, {:req_llm, "~> 1.24", [hex: :req_llm, repo: "hexpm", optional: true]}], "hexpm", "a6faf5187e6828f02a2f3a65cbfd645fbf3e56f6f16e8bc66e943c119939d25f"},
   "ash_archival": {:hex, :ash_archival, "2.0.3", "40590162ece428c097e98da8c5b8c7cb073b6af72fd1acf7ba5b36f3d731df4d", [:mix], [{:ash, ">= 3.0.5 and < 4.0.0-0", [hex: :ash, repo: "hexpm", optional: false]}], "hexpm", "33f3f3006aef7e4271573c85db4e9422b5e1b0d7cfb110f52732d5004cafa62a"},
   "ash_authentication": {:hex, :ash_authentication, "4.15.0", "e68d30e8bfc3c73bccd2e1bbf0dd15913a27951334dc5558e634b6f46a788ee9", [:mix], [{:argon2_elixir, "~> 4.0", [hex: :argon2_elixir, repo: "hexpm", optional: true]}, {:ash, "~> 3.7", [hex: :ash, repo: "hexpm", optional: false]}, {:ash_postgres, ">= 2.6.8 and < 3.0.0-0", [hex: :ash_postgres, repo: "hexpm", optional: true]}, {:assent, "> 0.2.0 and < 0.3.0", [hex: :assent, repo: "hexpm", optional: false]}, {:bcrypt_elixir, "~> 3.0", [hex: :bcrypt_elixir, repo: "hexpm", optional: false]}, {:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: false]}, {:finch, "~> 0.19", [hex: :finch, repo: "hexpm", optional: false]}, {:igniter, "~> 0.4", [hex: :igniter, repo: "hexpm", optional: true]}, {:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: false]}, {:joken, "~> 2.5", [hex: :joken, repo: "hexpm", optional: false]}, {:plug, "~> 1.13", [hex: :plug, repo: "hexpm", optional: false]}, {:spark, "~> 2.0", [hex: :spark, repo: "hexpm", optional: false]}, {:splode, "~> 0.2", [hex: :splode, repo: "hexpm", optional: false]}], "hexpm", "3919317e97465d369292a7aa430836efe42b636d5467ab7196200bd25df6c2d7"},

diff --git a/test/huddlz/communities/huddl/recurrence_helper_test.exs b/test/huddlz/communities/huddl/recurrence_helper_test.exs
@@ -80,7 +80,7 @@ defmodule Huddlz.Communities.Huddl.RecurrenceHelperTest do
       expected_second = Date.add(source_date, 14)
       expected_third = Date.add(source_date, 21)
 
-      assert dates == Enum.sort([expected_first, expected_second, expected_third])
+      assert dates == Enum.sort([expected_first, expected_second, expected_third], Date)
     end
 
     test "generates no huddlz when repeat_until is before next occurrence", ctx do