diff --git a/.github/workflows/changelog.yml b/.github/workflows/changelog.yml
new file mode 100644
index 000000000..3cb50282c
--- /dev/null
+++ b/.github/workflows/changelog.yml
@@ -0,0 +1,37 @@
+name: Changelog
+on:
+  pull_request:
+    # labeled and unlabeled re-run this workflow when the
+    # "changelog: skip" label is applied or removed. Actions cannot
+    # filter those events by label name, so the changelog check lives
+    # here rather than in ci.yml, where every label change would
+    # re-run the whole suite.
+    types: [opened, synchronize, reopened, labeled, unlabeled]
+
+permissions:
+  contents: read
+
+jobs:
+  changelog:
+    runs-on: ubuntu-latest
+    if: >-
+      ${{ !contains(github.event.pull_request.labels.*.name,
+      'changelog: skip') }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: yarn
+          cache-dependency-path: yarn.lock
+
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile
+
+      - name: Check changelogs are updated
+        run: >-
+          yarn tsx bin/check-changelog.ts
+          "origin/${{ github.base_ref || 'main' }}"
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 000000000..88fd8b26c
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,592 @@
+# Changelog
+
+This file tracks changes to the `ethdebug/format` specification: the schemas
+under `schemas/`. Those schemas ship inside the `@ethdebug/format` package,
+whose build generates its distributed copies from `schemas/`, so the spec
+version is that package's version and this file is keyed by it. Each published
+package that implements the spec (`@ethdebug/pointers`, `@ethdebug/evm`, and so
+on) has its own `CHANGELOG.md` under `packages/<name>/`; this file covers only
+the spec itself.
+
+Each entry gives a summary of what changed. Three sub-items follow:
+
+- `Schemas:` the fully qualified name(s) of the schema(s) the change touches.
+- `Producers:` what the change means for an emitter of `ethdebug/format` data (a
+  compiler such as solc or bugc).
+- `Consumers:` what the change means for a reader of `ethdebug/format` data (a
+  debugger such as soldb).
+
+Each `Producers:` and `Consumers:` sub-item starts with one of three prefixes:
+
+- `no change needed.` Nothing that was valid becomes invalid, and nothing
+  changes meaning for this party. One short reason may follow.
+- `optional:` The change adds a capability. Nothing that was valid in the
+  previous published version changes. No party is obliged to do anything. The
+  sub-item says what the party may now do.
+- `required:` Output that was valid in the previous published version no longer
+  validates, or the specification adds or changes a normative **must**, or the
+  meaning of data that was already valid changes. The sub-item names the schema keyword, or
+  quotes the specification prose, that imposes the obligation. Prose that says
+  **should** or "preferred" is never `required:`.
+
+A consumer has an obligation only where producers can now emit something that a
+conforming consumer would otherwise misread or reject, or where the meaning of
+data that was already valid changed. A consumer that does not use a new optional
+feature has no obligation.
+
+A new branch in a closed `oneOf` that a consumer must interpret to read the data
+at all (for example a new pointer expression or collection) is `required:` for
+consumers, because producers may start to emit it at any time. An addition that
+a consumer can skip without misreading anything else (for example a new kind of
+context) is `optional:`.
+
+Each impact line states the net effect for a party that moves from the previous
+published version to the version of the section. A change inside a schema that
+is new in that version obliges nobody, so its lines are `optional:` or
+`no change needed.` and describe how the new schema works. An obligation that a
+later change in the same version reverses does not appear in an impact line; the
+summary may tell the history.
+
+Each version has at most two sections. `### Added` holds a new schema, or a new
+keyword or capability. `### Changed` holds a change to something that exists.
+The sections do not signal obligations; the prefixes do.
+
+## Unreleased
+
+### Changed
+
+- A segment's `offset` is no longer limited to a value below `$wordsize`: an
+  offset at or past `$wordsize` now carries into later slots. The default
+  `length` is now `$wordsize - (offset mod $wordsize)`, which runs to the end of
+  the slot in which the segment begins and equals the earlier default for an
+  offset inside the slot. A `length` that spans slots was already defined. A new
+  segment example shows the carry, and a new pointer example collapses a long
+  storage string to one multi-slot region ([#284]).
+  - Schemas: **ethdebug/format/pointer/scheme/segment**,
+    **ethdebug/format/pointer**
+  - Producers: optional: a producer may emit an `offset` at or past `$wordsize`
+    and let it carry into later slots. Every pointer that was valid before keeps
+    its meaning.
+  - Consumers: required: find the slot and byte of an `offset` by division and
+    remainder against `$wordsize`, and compute the default `length` as
+    `$wordsize - (offset mod $wordsize)`. The `offset` description no longer
+    says that the offset "**must** begin inside the slot".
+
+- A property lookup through `$this` (for example `{ ".length": "$this" }`) must
+  not be circular: the property it reads has to be resolvable without depending
+  on the value being defined. A struct-array example that named its own region
+  the long way around now uses `$this` ([#284]).
+  - Schemas: **ethdebug/format/pointer/expression**,
+    **ethdebug/format/pointer**
+  - Producers: required: do not emit a circular property lookup through `$this`.
+    A new "must not be circular" in the description imposes this; no validator
+    catches it. A pointer that already resolves is not affected.
+  - Consumers: no change needed. The rule constrains producers only, and no
+    valid data changes meaning.
+
+- Expressions now evaluate to one of two sorts, an unbounded integer or
+  definite-width bytes, and the `$concat` and `$keccak256` operands **must** be
+  width-bearing bytes rather than bare integers. A hexadecimal literal with an
+  even number of digits is bytes of exactly the width written, a literal with an
+  odd number of digits is an integer, and widths are never inferred from
+  context; the earlier text let a literal omit leading zeroes and padded it to
+  the width of its context. No schema keyword changes, so a validator accepts
+  the same documents as before, but an expression that passes a bare integer to
+  `$concat` or `$keccak256`, as the schema's own earlier examples did, no longer
+  conforms. Those examples are corrected ([#286]).
+  - Schemas: **ethdebug/format/pointer/expression**
+  - Producers: required: give each bare-integer operand of `$concat` or
+    `$keccak256` a width first with `$wordsized` or a `$sizedN` form, and write
+    a literal that is meant as bytes with its full number of digits (a new
+    "**must** be width-bearing" in the description). No validator catches this.
+  - Consumers: required: the meaning of literals changed ("Widths are never
+    inferred from context"). Read an even-digit hexadecimal literal as bytes of
+    exactly the width written, and an odd-digit literal or a JSON number as an
+    integer. Arithmetic results are unbounded integers. The specification does
+    not say what a consumer does with a bare-integer operand.
+
+## 0.1.0-1 — 2026-09-16
+
+### Added
+
+- A character encoding is a label defined by the WHATWG Encoding Standard, and
+  an omitted optional encoding field means `utf-8`.
+  **ethdebug/format/materials/source** and
+  **ethdebug/format/type/elementary/string** both reference the new primitive
+  instead of accepting a free-form string. The label requirement is a normative
+  tightening that no validator catches: the schema is still `type: string`, so
+  a label the Standard does not define validates anyway. ([#285])
+  - Schemas: **ethdebug/format/materials/encoding**,
+    **ethdebug/format/materials/source**,
+    **ethdebug/format/type/elementary/string**
+  - Producers: required: an `encoding` value must be a label that the Standard
+    defines (a new **must** in the description); no validator catches this. The
+    canonical lowercase name (`utf-16le`, not `utf-16`) is only preferred.
+  - Consumers: optional: a consumer may pass the value straight to
+    `new TextDecoder(label)`. No validator rejects a label from outside the
+    Standard. An omitted field means `utf-8`, as it did before.
+
+- A context may list the compiler transformations that produced an instruction —
+  `inline`, `tailcall`, `fold`, `coalesce`, with an extensible identifier set
+  and repeats allowed. A transform annotates rather than replaces the semantic
+  contexts, and composes flat beside them on one context object. The
+  **ethdebug/format/program/context/function/invoke** page now describes how a
+  debugger reconstructs activations from `invoke` and `return` contexts, and
+  says that a compiler must emit the two as a bracket around a body. ([#216])
+  - Schemas: **ethdebug/format/program/context/transform**,
+    **ethdebug/format/program/context**,
+    **ethdebug/format/program/context/function/invoke**
+  - Producers: optional: the **ethdebug/format/program/context** schemas are new
+    in 0.1.0-1. A producer that emits `invoke` and `return` **must** emit them
+    as a bracket: `invoke` on the first instruction of a body, `return` on its
+    last. `transform` is optional.
+  - Consumers: optional: the schemas are new in 0.1.0-1. A consumer may ignore
+    `transform`, or use it to reconstruct inlined and tail-call activations. It
+    should keep an unfamiliar identifier as an opaque label.
+
+- An optional `activation` string pairs an invocation with the return or revert
+  that ends it. Distinct activations carry distinct values, unique within the
+  program. ([#245])
+  - Schemas: **ethdebug/format/program/context/function/invoke**,
+    **ethdebug/format/program/context/function/return**,
+    **ethdebug/format/program/context/function/revert**
+  - Producers: optional: the **ethdebug/format/program/context/function**
+    schemas are new in 0.1.0-1. A producer may put one `activation` string on an
+    `invoke` and on the `return` or `revert` that ends it, distinct for each
+    activation.
+  - Consumers: optional: the schemas are new in 0.1.0-1. Where `activation` is
+    present, a consumer that reads them may pair a call with its return or
+    revert by that value instead of by strict nesting in trace order.
+
+- Contexts mark the function-call lifecycle — an invocation of exactly one kind
+  (`jump` for an internal call, `message` for an external message call, `create`
+  for a contract creation), a successful return, or a revert — each carrying
+  optional function identity (`identifier`, `declaration`, `type`).
+  **ethdebug/format/type/specifier** names the "full type or `{ id }` reference"
+  pattern that **ethdebug/format/type/wrapper** and context variables now share.
+  The `context` description in **ethdebug/format/program/instruction** also
+  gained a sentence that tied context pointers to the machine state at that
+  instruction's trace step; [#281] later replaced it with the postcondition
+  convention. ([#154])
+  - Schemas: **ethdebug/format/program/context/function**,
+    **ethdebug/format/program/context/function/invoke**,
+    **ethdebug/format/program/context/function/return**,
+    **ethdebug/format/program/context/function/revert**,
+    **ethdebug/format/type/specifier**, **ethdebug/format/type/wrapper**,
+    **ethdebug/format/program/context**,
+    **ethdebug/format/program/context/variables**,
+    **ethdebug/format/program/instruction**
+  - Producers: optional: the **ethdebug/format/program/context/function**
+    schemas and **ethdebug/format/type/specifier** are new in 0.1.0-1. An
+    `invoke` gives exactly one of `jump`, `message` and `create`.
+    **ethdebug/format/type/wrapper** accepts the same data as at 0.1.0-0.
+  - Consumers: optional: the function contexts are new in 0.1.0-1; a consumer
+    may read them to follow calls, returns and reverts.
+    **ethdebug/format/type/wrapper** validates the same data as at 0.1.0-0.
+
+- A context may carry a `name` label, now wired into the context dispatcher; it
+  is most useful for telling `pick` alternatives apart. ([#179])
+  - Schemas: **ethdebug/format/program/context/name**,
+    **ethdebug/format/program/context**,
+    **ethdebug/format/program/context/pick**
+  - Producers: optional: **ethdebug/format/program/context/name** is new in
+    0.1.0-1. A producer that emits contexts may put a `name` string on one, for
+    example to tell `pick` alternatives apart.
+  - Consumers: no change needed. The schema is new in 0.1.0-1; a consumer that
+    reads it treats `name` as an opaque label with no format-imposed semantics.
+
+- An array type may state a fixed element `count`; omitting it means the array
+  is dynamically sized. ([#168])
+  - Schemas: **ethdebug/format/type/complex/array**
+  - Producers: required: for fixed-size arrays only. State `count`, because an
+    array type without `count` now means a dynamic array ("When omitted, the
+    array is dynamically sized"). `count` is not in `required`.
+  - Consumers: required: read a missing `count` as a dynamic array and a present
+    `count` as the fixed number of elements. The `count` description changed the
+    meaning of an array type without `count`.
+
+- A pointer may declare templates inline with a `templates`/`in` pair, and a
+  template reference may remap the region names a template produces through
+  `yields`; unmapped names pass through unchanged. ([#158])
+  - Schemas: **ethdebug/format/pointer/collection/templates**,
+    **ethdebug/format/pointer/collection/reference**,
+    **ethdebug/format/pointer**, **ethdebug/format/pointer/collection**
+  - Producers: optional: a producer may declare templates inline with
+    `templates` and `in`, which makes a pointer self-contained, and may add
+    `yields` to a template reference to reuse it without region-name collisions.
+  - Consumers: required: a consumer that resolves pointers must support both
+    forms, because a valid pointer can now contain them (a new `oneOf` branch
+    for `templates` in **ethdebug/format/pointer/collection**; a new `yields`
+    property). Templates in `templates` are available by name inside `in`.
+    `yields` renames regions; unmapped names pass through unchanged.
+
+- A `{ "$concat": [...] }` expression evaluates to the concatenation of its
+  operands' bytes, preserving each operand's byte width; an empty operand list
+  is permitted. ([#156])
+  - Schemas: **ethdebug/format/pointer/expression**
+  - Producers: optional: a producer may use `$concat` to build a byte sequence
+    from several operands, for example a storage slot key or the input to a
+    hash.
+  - Consumers: required: a consumer that resolves pointers must support
+    `$concat`, because a valid pointer can now contain it (a new `Concat` branch
+    in the schema's `oneOf`). Operands join in list order and keep their byte
+    widths; no padding is added or removed.
+
+- A `pick` lists two or more alternative contexts of which one holds, a `gather`
+  lists two or more contexts that all hold simultaneously, and `frame` names,
+  as a bare string, the compilation frame a context's facts belong to — for
+  example `"ir"` or `"source"`. ([#144])
+  - Schemas: **ethdebug/format/program/context/pick**,
+    **ethdebug/format/program/context/gather**,
+    **ethdebug/format/program/context/frame**,
+    **ethdebug/format/program/context**
+  - Producers: optional: the **ethdebug/format/program/context** schemas are new
+    in 0.1.0-1. A `pick` or `gather` list needs at least two members
+    (`minItems: 2`). `gather` is needed only where two facts use the same key.
+  - Consumers: optional: the schemas are new in 0.1.0-1. A consumer that reads
+    them reads a `pick` as alternatives of which one is true, reads all members
+    of a `gather` as true together, and may separate facts by `frame`.
+
+- One schema covers a non-negative integer given either as a JSON number or as a
+  `0x`-prefixed hex string; **ethdebug/format/materials/source-range** offsets
+  and lengths, **ethdebug/format/pointer/expression** literals, and
+  **ethdebug/format/program/instruction** offsets and operation arguments all
+  reference it. ([#126])
+  - Schemas: **ethdebug/format/data/value**,
+    **ethdebug/format/materials/source-range**,
+    **ethdebug/format/pointer/expression**,
+    **ethdebug/format/program/instruction**
+  - Producers: optional: **ethdebug/format/materials/source-range** `offset` and
+    `length` may now be `0x`-prefixed hex strings. The new
+    **ethdebug/format/program/instruction** takes either form.
+  - Consumers: required: accept `0x`-prefixed hex strings as well as JSON
+    numbers in **ethdebug/format/materials/source-range** `offset` and `length`
+    (`type: number` at 0.1.0-0; now **ethdebug/format/data/value**).
+    **ethdebug/format/program/instruction** is new in 0.1.0-1 and takes both
+    forms too.
+
+- A context may carry a human-readable `remark` string, intended primarily for
+  humans to use as an annotation and not for compilers to use directly. ([#125])
+  - Schemas: **ethdebug/format/program/context/remark**,
+    **ethdebug/format/program/context**
+  - Producers: optional: **ethdebug/format/program/context** is new in 0.1.0-1.
+    A producer that emits a context may put a `remark` string on it; a context
+    may hold only a `remark`.
+  - Consumers: optional: the schema is new in 0.1.0-1. A consumer that reads it
+    may display the `remark`. It is an annotation for humans and has no other
+    meaning.
+
+- A new **ethdebug/format/info** schema can represent all debugging information
+  of one compilation as one standalone document that holds its `compilation`,
+  its `programs`, and by-name lookup tables for `types` and `pointers`. A new
+  **ethdebug/format/info/resources** schema holds only the lookup tables (and an
+  optional `compilation`), for compilers that give the other data elsewhere in
+  their output. The same change raised the compilation `id` uniqueness
+  requirement from **should** to **must** (relaxed back to **should** by
+  [#131]). ([#123])
+  - Schemas: **ethdebug/format/info**, **ethdebug/format/info/resources**,
+    **ethdebug/format/materials/compilation**
+  - Producers: optional: **ethdebug/format/info** and
+    **ethdebug/format/info/resources** are new in 0.1.0-1. A resources object
+    gives `types` and `pointers` (`required`); an **ethdebug/format/info**
+    document also gives `compilation` and `programs`. Compilation `id`
+    uniqueness stays **should**.
+  - Consumers: optional: the schemas are new in 0.1.0-1. A consumer that reads
+    either form may look up types and pointer templates by name in `types` and
+    `pointers`; how a reference resolves against them is not specified.
+
+- A program describes one bytecode of a compilation — its `contract`, its
+  `environment` (`call` or `create`), the `context` holding before its first
+  instruction, and its `instructions`, each with an `offset`, an `operation`,
+  and a `context` carrying source-range and variable facts. ([#113])
+  - Schemas: **ethdebug/format/program**,
+    **ethdebug/format/program/instruction**,
+    **ethdebug/format/program/context**,
+    **ethdebug/format/program/context/code**,
+    **ethdebug/format/program/context/variables**,
+    **ethdebug/format/program/context/name**
+  - Producers: optional: **ethdebug/format/program** is new in 0.1.0-1. A
+    producer that emits one per bytecode gives `contract`, `environment` and
+    `instructions`, and an `offset` per instruction (`required`). For EOF
+    bytecode, `offset` **must** count from the container start. A variable
+    `type`, when given, **must** be a full type or an `{ id }` reference.
+  - Consumers: no change needed. Every schema here is new in 0.1.0-1, and no
+    schema from 0.1.0-0 references them. A consumer that reads a program finds
+    each instruction by its `offset`.
+
+- A pointer template is a pointer parameterised over the variables it lists in
+  `expect`, and a `{ "template": ... }` collection instantiates one by name.
+  ([#103])
+  - Schemas: **ethdebug/format/pointer/template**,
+    **ethdebug/format/pointer/collection/reference**,
+    **ethdebug/format/pointer/collection**
+  - Producers: optional: a producer may write a repeated pointer shape one time
+    as a template and refer to it with a `template` collection. Definitions can
+    go in **ethdebug/format/info/resources** `pointers` ([#123]) or an inline
+    `templates` collection ([#158]).
+  - Consumers: required: a consumer that resolves pointers must support the
+    `template` collection (a new `oneOf` branch in
+    **ethdebug/format/pointer/collection**): find the template by name and bind
+    its `expect` variables from the scope at the reference.
+
+- Two primitives cover a `0x`-prefixed hex string of at least one digit and a
+  non-negative JSON integer. **ethdebug/format/materials/source-range** `offset`
+  and `length`, **ethdebug/format/pointer/expression** literals, and
+  **ethdebug/format/type/elementary/bytes** `size` reference them. This tightens
+  source-range values from any number to a non-negative integer and makes the
+  non-negative limit on integer literals effective. The `bits` and `places` of
+  the elementary numeric types change from `type: number` to `type: integer`.
+  ([#104])
+  - Schemas: **ethdebug/format/data/hex**, **ethdebug/format/data/unsigned**,
+    **ethdebug/format/materials/source-range**,
+    **ethdebug/format/pointer/expression**,
+    **ethdebug/format/type/elementary/bytes**,
+    **ethdebug/format/type/elementary/int**,
+    **ethdebug/format/type/elementary/uint**,
+    **ethdebug/format/type/elementary/fixed**,
+    **ethdebug/format/type/elementary/ufixed**
+  - Producers: required: in **ethdebug/format/materials/source-range** `offset`
+    and `length`, and in an expression's integer literal, a JSON number must be
+    a non-negative integer (`type: integer`, `minimum: 0`). A bytes type `size`
+    (`0` is now valid) and the `places` of `fixed` and `ufixed` must be
+    integers; `bits` accepts the same values.
+  - Consumers: no change needed. Every instance that stays valid keeps its
+    meaning; the only newly valid value from this entry is a bytes type `size`
+    of `0`.
+
+### Changed
+
+- An instruction's `context` is its **postcondition** — both its semantic
+  facts and the pointers it contains resolve against the machine state after
+  that instruction has executed. The program-level `context` is the base case of
+  the chain: the precondition to instruction 0. ([#281])
+  - Schemas: **ethdebug/format/program/instruction**,
+    **ethdebug/format/program**
+  - Producers: optional: **ethdebug/format/program** is new in 0.1.0-1. A
+    producer that emits it gives each instruction a `context` that holds after
+    the instruction; the program-level `context` holds before instruction 0.
+  - Consumers: no change needed. The schema is new in 0.1.0-1; a consumer that
+    reads it applies the context of instruction _i − 1_ at step _i_, and the
+    program-level `context` before the first instruction.
+
+- An object whose property set the format fully defines rejects unknown
+  properties. **ethdebug/format/materials/compilation**'s `settings` object
+  stays open, since it holds settings in a format native to the compiler, and
+  **ethdebug/format/info/resources** stays lax when validated alone because
+  **ethdebug/format/info** composes it by `$ref`. ([#280])
+  - Schemas: **ethdebug/format/info**, **ethdebug/format/program**,
+    **ethdebug/format/program/instruction**,
+    **ethdebug/format/materials/compilation**,
+    **ethdebug/format/materials/source**,
+    **ethdebug/format/program/context/function/return**,
+    **ethdebug/format/program/context/function/revert**,
+    **ethdebug/format/pointer/collection/list**
+  - Producers: required: remove unknown keys from
+    **ethdebug/format/materials/compilation** (top level and `compiler`;
+    `settings` stays open) and **ethdebug/format/materials/source**
+    (`unevaluatedProperties: false`), and from `list` of a list collection
+    (`additionalProperties: false`). The other five schemas are new in 0.1.0-1.
+  - Consumers: no change needed. The change only narrows what producers can
+    emit.
+
+- An elementary type **must not** carry `contains`, which is what discriminates
+  it from a complex type; a `function` complex type requires `kind` and
+  `contains`; `contract`'s `library` and `interface` flags are booleans; a
+  context `name` must be non-empty; and a region requires `location`. In a
+  `function` complex type, the `parameters` wrapper and an external function's
+  `contract` wrapper each also accept an `{ id }` type reference
+  (**ethdebug/format/type/reference**) in place of an inline type, matching what
+  `returns` already allowed. ([#279])
+  - Schemas: **ethdebug/format/type/elementary**,
+    **ethdebug/format/type/complex/function**,
+    **ethdebug/format/type/elementary/contract**,
+    **ethdebug/format/program/context/name**, **ethdebug/format/pointer/region**
+  - Producers: required: these no longer validate: an elementary type with
+    `contains` (`not`), a `function` type with no `contains` (`required`), and a
+    non-boolean `library` or `interface` (`type: boolean`). A region with no
+    `location` already failed. **ethdebug/format/program/context/name** is new
+    in 0.1.0-1. The `{ id }` references are optional.
+  - Consumers: required: a consumer that reads function types must accept an
+    `{ id }` reference in the `contains.parameters` wrapper and in an external
+    function's `contains.contract` wrapper (a new `oneOf` in each), and resolve
+    it like any other type reference.
+
+- Schema examples are corrected — a struct member's field is `name`, a `list`
+  index is referenced bare rather than through `$read`, packed `uint128` members
+  are 16 bytes and not 128 — and `additionalItems`, which JSON Schema 2020-12
+  does not define, is dropped where it was inert.
+  **ethdebug/format/pointer/collection/scope**'s `define` validates its keys by
+  referencing **ethdebug/format/pointer/identifier** rather than an inline copy
+  of that pattern. The **ethdebug/format/type/definition** description now
+  states the rule that its `anyOf` enforces: at least one of `name` or
+  `location`. ([#277])
+  - Schemas: **ethdebug/format/type/base**, **ethdebug/format/type/definition**,
+    **ethdebug/format/pointer/collection/list**,
+    **ethdebug/format/pointer/collection/scope**,
+    **ethdebug/format/info/resources**,
+    **ethdebug/format/program/context/function/invoke**,
+    **ethdebug/format/program**, **ethdebug/format/info**,
+    **ethdebug/format/pointer/template**,
+    **ethdebug/format/program/context/gather**,
+    **ethdebug/format/program/context/pick**,
+    **ethdebug/format/program/context/variables**
+  - Producers: no change needed. No instance changes validity; the reworded
+    **must** states what the `anyOf` already enforced.
+  - Consumers: no change needed. The accepted shape of every valid instance is
+    unchanged.
+
+- A `name` is an optional identifier, meant to be unique within a program, that
+  today acts only as a label — the format defines no way to reference a
+  context by name, so a declared name is inert. Establishing the identifier is
+  groundwork for a future name-based `pick` selection. ([#251])
+  - Schemas: **ethdebug/format/program/context/name**
+  - Producers: optional: **ethdebug/format/program/context/name** is new in
+    0.1.0-1. A producer that emits it gives a `name` that is meant to be unique
+    within a program; that is an intent, not a **must**.
+  - Consumers: no change needed. The schema is new in 0.1.0-1; a consumer that
+    reads it treats a `name` as a label, because the format defines no reference
+    by name.
+
+- The `target` field is optional on an internal (`jump`) invocation, for the
+  cases with no meaningful target pointer — most notably the first instruction
+  of an inlined body, whose JUMP has been elided. External calls still require
+  it; a contract creation has no `target` field. ([#242])
+  - Schemas: **ethdebug/format/program/context/function/invoke**
+  - Producers: optional: **ethdebug/format/program/context/function/invoke** is
+    new in 0.1.0-1. A producer that emits it may omit `target` on an internal
+    (`jump`) invocation. An external (`message`) call requires `target`.
+  - Consumers: no change needed. The schema is new in 0.1.0-1; a consumer that
+    reads it accepts an internal (`jump`) invoke context that has no `target`.
+
+- A function return context's `data` field is optional, so a bare `return: {}`
+  is permitted where a return is known to happen but no return value is
+  observable — a void function, or a tail-call-optimized back-edge. ([#211])
+  - Schemas: **ethdebug/format/program/context/function/return**
+  - Producers: optional: **ethdebug/format/program/context/function/return** is
+    new in 0.1.0-1. A producer that emits it may omit `data` when no return
+    value is observable: a void function or a tail-call-optimized back-edge.
+  - Consumers: no change needed. The schema is new in 0.1.0-1; a consumer that
+    reads it accepts a return context that has no `data`, down to a bare
+    `return: {}`.
+
+- An id identifies a compilation resource such as a source file or a
+  compilation, and **must** be unique within the scope where it appears — source
+  ids within one compilation, for instance. Before, only
+  **ethdebug/format/materials/source** stated that requirement, and only for
+  source ids; the value stays numeric-or-string, as it already was. ([#172])
+  - Schemas: **ethdebug/format/materials/id**
+  - Producers: required: do not reuse an id within one scope. A new **must** in
+    the **ethdebug/format/materials/id** description imposes this; at 0.1.0-0
+    only source ids had that **must**. No validator catches a collision.
+  - Consumers: no change needed. A consumer may now rely on an id as a key
+    within its scope.
+
+- The array type schema carries a description of itself, of `contains`, and of
+  each of its examples. ([#170])
+  - Schemas: **ethdebug/format/type/complex/array**
+  - Producers: no change needed. The change adds only descriptions and example
+    comments.
+  - Consumers: no change needed. The set of valid array types is unchanged.
+
+- The context schema dispatches on each property with `if`/`then` clauses
+  instead of an `anyOf` over the member schemas, so a general-purpose validator
+  reports one error against the relevant member rather than a failure of the
+  whole union. The rewrite is also what made an empty context (`{}`) validate,
+  matching the relaxation [#145] had documented: every `anyOf` member required
+  its own key, so an explicit `{}` still failed until here. ([#150])
+  - Schemas: **ethdebug/format/program/context**
+  - Producers: optional: **ethdebug/format/program/context** is new in 0.1.0-1.
+    A producer that emits it may give an explicit `"context": {}`; the
+    `if`/`then` clauses accept the empty object.
+  - Consumers: no change needed. The schema is new in 0.1.0-1; a consumer that
+    reads it accepts an explicit `"context": {}` as the empty context. The
+    change in validator errors needs no action.
+
+- An instruction's `context` is optional, and omitting it is equivalent to the
+  empty context (`{}`). The program-level `context` was already optional and
+  gains the same statement. The change removed `context` from an instruction's
+  `required` and removed `minProperties: 1` from the context schema. An explicit
+  `{}` still did not validate: the context schema's `anyOf` rejected it, because
+  each of its members requires its own key, until [#150] replaced the union.
+  ([#145])
+  - Schemas: **ethdebug/format/program**,
+    **ethdebug/format/program/instruction**, **ethdebug/format/program/context**
+  - Producers: optional: **ethdebug/format/program/instruction** is new in
+    0.1.0-1. A producer that emits it may omit `context` on an instruction that
+    carries no facts; `context` is not in the `required` list.
+  - Consumers: no change needed. The schemas are new in 0.1.0-1; a consumer that
+    reads them treats a missing instruction `context` as the empty context
+    (`{}`).
+
+- A compilation's `id` is `required`. ([#138])
+  - Schemas: **ethdebug/format/materials/compilation**
+  - Producers: required: emit `id` on every compilation; `id` is now in the
+    `required` list. At 0.1.0-0 the description called `id` optional.
+  - Consumers: no change needed. A consumer may now rely on `id` as present in
+    every valid compilation.
+
+- A compilation's `id` is described as its identifier rather than as optional,
+  and its uniqueness requirement returns to **should** after [#123] had raised
+  it to **must**. The `required` list is not actually changed here; [#138] does
+  that. ([#131])
+  - Schemas: **ethdebug/format/materials/compilation**
+  - Producers: no change needed. Uniqueness of `id` is **should** at 0.1.0-0 and
+    at 0.1.0-1. The net change is that the `id` description no longer says
+    "Optional"; [#138] adds `id` to `required`.
+  - Consumers: no change needed. The uniqueness of `id` is **should** in both
+    releases, so a consumer has no new case to handle.
+
+- A variable object must carry at least one property, and must not carry
+  properties the format does not define. ([#127])
+  - Schemas: **ethdebug/format/program/context/variables**
+  - Producers: optional: **ethdebug/format/program/context/variables** is new in
+    0.1.0-1. A producer that emits it gives no empty variable object
+    (`minProperties: 1`) and no extension keys (`unevaluatedProperties: false`).
+  - Consumers: no change needed. The schema is new in 0.1.0-1, and the rule only
+    narrows what producers can emit.
+
+- The `range` field may be omitted as shorthand for a range spanning the entire
+  source contents, and is otherwise required. ([#107])
+  - Schemas: **ethdebug/format/materials/source-range**
+  - Producers: optional: a source range that spans the entire source contents
+    may omit `range`.
+  - Consumers: required: treat a source range with no `range` as offset 0
+    through the full length of the contents of the referenced source. `range` is
+    no longer in the `required` list.
+
+## 0.1.0-0 — 2024-07-04
+
+First published version of the specification.
+
+[#103]: https://github.com/ethdebug/format/pull/103
+[#104]: https://github.com/ethdebug/format/pull/104
+[#107]: https://github.com/ethdebug/format/pull/107
+[#113]: https://github.com/ethdebug/format/pull/113
+[#123]: https://github.com/ethdebug/format/pull/123
+[#125]: https://github.com/ethdebug/format/pull/125
+[#126]: https://github.com/ethdebug/format/pull/126
+[#127]: https://github.com/ethdebug/format/pull/127
+[#131]: https://github.com/ethdebug/format/pull/131
+[#138]: https://github.com/ethdebug/format/pull/138
+[#144]: https://github.com/ethdebug/format/pull/144
+[#145]: https://github.com/ethdebug/format/pull/145
+[#150]: https://github.com/ethdebug/format/pull/150
+[#154]: https://github.com/ethdebug/format/pull/154
+[#156]: https://github.com/ethdebug/format/pull/156
+[#158]: https://github.com/ethdebug/format/pull/158
+[#168]: https://github.com/ethdebug/format/pull/168
+[#170]: https://github.com/ethdebug/format/pull/170
+[#172]: https://github.com/ethdebug/format/pull/172
+[#179]: https://github.com/ethdebug/format/pull/179
+[#211]: https://github.com/ethdebug/format/pull/211
+[#216]: https://github.com/ethdebug/format/pull/216
+[#242]: https://github.com/ethdebug/format/pull/242
+[#245]: https://github.com/ethdebug/format/pull/245
+[#251]: https://github.com/ethdebug/format/pull/251
+[#277]: https://github.com/ethdebug/format/pull/277
+[#279]: https://github.com/ethdebug/format/pull/279
+[#280]: https://github.com/ethdebug/format/pull/280
+[#281]: https://github.com/ethdebug/format/pull/281
+[#284]: https://github.com/ethdebug/format/pull/284
+[#285]: https://github.com/ethdebug/format/pull/285
+[#286]: https://github.com/ethdebug/format/pull/286
diff --git a/RELEASING.md b/RELEASING.md
index fbfa02229..c5003f527 100644
--- a/RELEASING.md
+++ b/RELEASING.md
@@ -43,7 +43,53 @@ guards that run in CI live in `bin/check-tarballs.ts` and
    yarn lerna list --all --json
    ```
 
-3. Bump to an explicit version. Lerna commits the result as
+3. Update the changelogs before bumping. The root `CHANGELOG.md`
+   tracks the spec version; each public package under
+   `packages/*/CHANGELOG.md` tracks that package's own version.
+
+   See which packages the next step will move:
+
+   ```console
+   yarn lerna changed
+   ```
+
+   The bump in step 4 moves every package that command lists, plus
+   every package that depends on one of them.
+
+   For the root file, and for each package about to be bumped,
+   rename its `## Unreleased` heading to
+   `## <version> — <YYYY-MM-DD>`: that package's own new version,
+   then today's date. Leave a fresh, empty `## Unreleased` heading
+   above the section you renamed. A package that is not being bumped
+   needs no change.
+
+   When you rename `## Unreleased` in the root file, reconcile its
+   entries against the previous published version. Each `Producers:`
+   and `Consumers:` line states the net effect for a party that
+   moves from that version to the new one. If one Unreleased entry
+   reverses an obligation of another Unreleased entry, neither
+   impact line keeps that obligation; the summaries may still tell
+   the history.
+
+   A package that is bumped only because a dependency of it changed
+   has nothing under `## Unreleased`. Give it a `### Changed` entry
+   reading "Updated `@ethdebug/<dep>` to `<version>`.", so that every
+   published version has a section of its own.
+
+   Commit the renamed files on their own, right before the version
+   bump in the next step:
+
+   ```console
+   git add CHANGELOG.md packages/*/CHANGELOG.md
+   git commit -m "docs: cut changelog entries for <version>"
+   ```
+
+   Pre-flight check: in each file you touched, the only remaining
+   `## Unreleased` section is the empty one at the top. Never publish
+   with entries still sitting under `## Unreleased` in a changelog
+   for a package (or the spec) being released.
+
+4. Bump to an explicit version. Lerna commits the result as
    `Publish` and creates one tag per bumped workspace on that
    commit:
 
@@ -62,22 +108,22 @@ guards that run in CI live in `bin/check-tarballs.ts` and
    - `--no-push`: Lerna would otherwise run
      `git push --follow-tags --no-verify --atomic <remote> <branch>`
      and, when the error text mentions "atomic", silently retry
-     WITHOUT `--atomic`. The push happens by hand in step 5 instead:
+     WITHOUT `--atomic`. The push happens by hand in step 6 instead:
      no non-atomic fallback, no `--no-verify` skipping the pre-push
-     hooks, and step 4's inspection happens before anything reaches
+     hooks, and step 5's inspection happens before anything reaches
      the remote.
    - `--yes`: skips the confirmation prompt. Preview with the command
      in step 2 first; do not use `--no-git-tag-version` as a
      preview, because it still rewrites every `package.json`.
 
-4. Inspect the result before pushing:
+5. Inspect the result before pushing:
 
    ```console
    git show --stat HEAD
    git tag --points-at HEAD   # expect one tag per bumped workspace
    ```
 
-5. Push the commit and the tags in one atomic operation:
+6. Push the commit and the tags in one atomic operation:
 
    ```console
    git push --atomic origin main --follow-tags
@@ -110,7 +156,7 @@ guards that run in CI live in `bin/check-tarballs.ts` and
    git push origin :refs/tags/<tag>
    ```
 
-6. Watch the workflow and confirm the result on the registry:
+7. Watch the workflow and confirm the result on the registry:
 
    ```console
    gh run list --workflow publish.yml --limit 3
@@ -240,10 +286,12 @@ GitHub Actions the script does not pass `--provenance`.
 - `bin/check-tarballs.ts` (CI, `run-tests` job) lists the files that
   `npm pack` would put in each public package's tarball and fails if
   any file lies outside `package.json`, `README*`, `LICENSE*`,
-  `dist/src/` or `dist/bin/`, or if any `.test.` or `.tsbuildinfo`
-  file is included. It catches a wrong `files` field, test files
-  leaking into the package, and stale build output. The publish
-  script runs the same check before every publish.
+  `CHANGELOG*`, `dist/src/` or `dist/bin/`, or if any `.test.` or
+  `.tsbuildinfo` file is included. It catches a wrong `files` field,
+  test files leaking into the package, and stale build output. The
+  publish script runs the same check before every publish. npm ships
+  `package.json`, `README*` and `LICENSE*` whatever `files` says, but
+  not `CHANGELOG.md`, so every public package lists it in `files`.
 - `bin/smoke-tarballs.ts` (CI, `run-tests` job) packs every public
   package, installs each tarball into a throwaway consumer project
   together with the tarballs of its sibling dependencies, imports
diff --git a/bin/check-changelog.test.ts b/bin/check-changelog.test.ts
new file mode 100644
index 000000000..45659d062
--- /dev/null
+++ b/bin/check-changelog.test.ts
@@ -0,0 +1,375 @@
+import { describe, expect, it } from "vitest";
+import {
+  changelogMessage,
+  formatProblemsMessage,
+  impactLineProblems,
+  missingPackageChangelogs,
+  needsChangelog,
+  sectionProblems,
+} from "./check-changelog.js";
+
+const packagePrefixes = ["packages/format", "packages/pointers"];
+
+describe("needsChangelog", () => {
+  it("is false when nothing relevant changed", () => {
+    expect(needsChangelog(["README.md"])).toBe(false);
+  });
+
+  describe("schemas rule", () => {
+    it("is false when no schema files changed", () => {
+      expect(needsChangelog(["packages/pointers/src/read.ts"])).toBe(false);
+    });
+
+    it("is false when schemas changed alongside CHANGELOG.md", () => {
+      expect(
+        needsChangelog(["schemas/pointer.schema.yaml", "CHANGELOG.md"]),
+      ).toBe(false);
+    });
+
+    it("is true when schemas changed without CHANGELOG.md", () => {
+      expect(needsChangelog(["schemas/pointer.schema.yaml"])).toBe(true);
+    });
+
+    it("ignores paths that merely contain the word schemas", () => {
+      expect(needsChangelog(["packages/format/schemas-notes.md"])).toBe(false);
+    });
+  });
+
+  describe("per-package rule", () => {
+    it("is false when a package's src/ changed with its CHANGELOG.md", () => {
+      expect(
+        needsChangelog(
+          ["packages/pointers/src/read.ts", "packages/pointers/CHANGELOG.md"],
+          packagePrefixes,
+        ),
+      ).toBe(false);
+    });
+
+    it("is true when a package's src/ changed without its CHANGELOG.md", () => {
+      expect(
+        needsChangelog(["packages/pointers/src/read.ts"], packagePrefixes),
+      ).toBe(true);
+    });
+
+    it("is true when a package's bin/ changed without its CHANGELOG.md", () => {
+      expect(
+        needsChangelog(["packages/pointers/bin/cli.ts"], packagePrefixes),
+      ).toBe(true);
+    });
+
+    it("is true when a package.json changed without its CHANGELOG.md", () => {
+      expect(
+        needsChangelog(["packages/pointers/package.json"], packagePrefixes),
+      ).toBe(true);
+    });
+
+    it("ignores a colocated test file under src/", () => {
+      expect(
+        needsChangelog(["packages/pointers/src/read.test.ts"], packagePrefixes),
+      ).toBe(false);
+    });
+
+    it("ignores a colocated .tsx test file", () => {
+      expect(
+        needsChangelog(
+          ["packages/pointers-react/src/cursor.test.tsx"],
+          ["packages/pointers-react"],
+        ),
+      ).toBe(false);
+    });
+
+    it("ignores an examples test suite", () => {
+      expect(
+        needsChangelog(
+          ["packages/pointers/src/pointer.examples.test.ts"],
+          packagePrefixes,
+        ),
+      ).toBe(false);
+    });
+
+    it("is true when a test file accompanies a source change", () => {
+      expect(
+        needsChangelog(
+          [
+            "packages/pointers/src/read.ts",
+            "packages/pointers/src/read.test.ts",
+          ],
+          packagePrefixes,
+        ),
+      ).toBe(true);
+    });
+
+    it("is false for a package not in the public list", () => {
+      expect(
+        needsChangelog(["packages/conformance/src/index.ts"], packagePrefixes),
+      ).toBe(false);
+    });
+
+    it("is false for files outside src/, bin/, and package.json", () => {
+      expect(
+        needsChangelog(["packages/pointers/README.md"], packagePrefixes),
+      ).toBe(false);
+    });
+  });
+
+  describe("both rules at once", () => {
+    it("is true when schemas and a package both need entries", () => {
+      expect(
+        needsChangelog(
+          ["schemas/pointer.schema.yaml", "packages/pointers/src/read.ts"],
+          packagePrefixes,
+        ),
+      ).toBe(true);
+    });
+
+    it("is false when both changelogs are present", () => {
+      expect(
+        needsChangelog(
+          [
+            "schemas/pointer.schema.yaml",
+            "packages/pointers/src/read.ts",
+            "CHANGELOG.md",
+            "packages/pointers/CHANGELOG.md",
+          ],
+          packagePrefixes,
+        ),
+      ).toBe(false);
+    });
+  });
+});
+
+describe("missingPackageChangelogs", () => {
+  it("lists only the packages that were touched", () => {
+    expect(
+      missingPackageChangelogs(
+        ["packages/pointers/src/read.ts"],
+        packagePrefixes,
+      ),
+    ).toEqual(["packages/pointers/CHANGELOG.md"]);
+  });
+
+  it("lists every touched package that is missing its file", () => {
+    expect(
+      missingPackageChangelogs(
+        ["packages/pointers/src/read.ts", "packages/format/package.json"],
+        packagePrefixes,
+      ),
+    ).toEqual([
+      "packages/format/CHANGELOG.md",
+      "packages/pointers/CHANGELOG.md",
+    ]);
+  });
+
+  it("omits a package whose CHANGELOG.md is already in the diff", () => {
+    expect(
+      missingPackageChangelogs(
+        ["packages/pointers/src/read.ts", "packages/pointers/CHANGELOG.md"],
+        packagePrefixes,
+      ),
+    ).toEqual([]);
+  });
+});
+
+describe("changelogMessage", () => {
+  it("lists only the changed schema paths", () => {
+    const message = changelogMessage([
+      "schemas/pointer.schema.yaml",
+      "schemas/pointer/expression.schema.yaml",
+      "packages/pointers/src/read.ts",
+    ]);
+    expect(message).toContain("schemas/pointer.schema.yaml");
+    expect(message).toContain("schemas/pointer/expression.schema.yaml");
+    expect(message).not.toContain("packages/pointers/src/read.ts");
+  });
+
+  it("points at the Unreleased section and the skip label", () => {
+    const message = changelogMessage(["schemas/pointer.schema.yaml"]);
+    expect(message).toContain("## Unreleased");
+    expect(message).toContain("changelog: skip");
+  });
+
+  it("names the skip label for a package-only failure", () => {
+    const message = changelogMessage(
+      ["packages/pointers/src/read.ts"],
+      packagePrefixes,
+    );
+    expect(message).toContain("changelog: skip");
+  });
+
+  it("names the skip label once when both rules apply", () => {
+    const message = changelogMessage(
+      ["schemas/pointer.schema.yaml", "packages/pointers/src/read.ts"],
+      packagePrefixes,
+    );
+    expect(message.match(/changelog: skip/g)).toHaveLength(1);
+  });
+
+  it("mentions the skip label last", () => {
+    const message = changelogMessage(["schemas/pointer.schema.yaml"]);
+    expect(message.trimEnd().split("\n").at(-1)).toContain("changelog: skip");
+  });
+
+  it("is empty when nothing is missing", () => {
+    expect(changelogMessage(["README.md"], packagePrefixes)).toBe("");
+  });
+
+  it("names each missing package CHANGELOG.md", () => {
+    const message = changelogMessage(
+      ["packages/pointers/src/read.ts", "packages/format/package.json"],
+      packagePrefixes,
+    );
+    expect(message).toContain("packages/pointers/CHANGELOG.md");
+    expect(message).toContain("packages/format/CHANGELOG.md");
+  });
+
+  it("combines the schemas and package sections when both apply", () => {
+    const message = changelogMessage(
+      ["schemas/pointer.schema.yaml", "packages/pointers/src/read.ts"],
+      packagePrefixes,
+    );
+    expect(message).toContain("schemas/pointer.schema.yaml");
+    expect(message).toContain("packages/pointers/CHANGELOG.md");
+  });
+});
+
+describe("impactLineProblems", () => {
+  const entry = (producers: string, consumers: string): string =>
+    [
+      "## Unreleased",
+      "",
+      "### Changed",
+      "",
+      "- A summary of the change ([#1]).",
+      "  - Schemas: **ethdebug/format/pointer**",
+      `  - Producers: ${producers}`,
+      `  - Consumers: ${consumers}`,
+      "",
+    ].join("\n");
+
+  it("accepts the no change needed. prefix", () => {
+    expect(
+      impactLineProblems(
+        entry("no change needed.", "no change needed. One short reason."),
+      ),
+    ).toEqual([]);
+  });
+
+  it("accepts the optional: prefix", () => {
+    expect(
+      impactLineProblems(
+        entry("optional: a producer may emit it.", "optional: may read it."),
+      ),
+    ).toEqual([]);
+  });
+
+  it("accepts the required: prefix", () => {
+    expect(
+      impactLineProblems(
+        entry("required: `minimum` forbids it.", "required: must read it."),
+      ),
+    ).toEqual([]);
+  });
+
+  it("accepts a prefix on the line below a bare label", () => {
+    const text = [
+      "- A summary.",
+      "  - Producers:",
+      "    optional: a producer may emit it.",
+      "",
+    ].join("\n");
+    expect(impactLineProblems(text)).toEqual([]);
+  });
+
+  it("reports a bare imperative with its line number", () => {
+    const problems = impactLineProblems(
+      entry("emit the new field.", "no change needed."),
+    );
+    expect(problems).toHaveLength(1);
+    expect(problems[0]).toContain("line 7:");
+    expect(problems[0]).toContain('"Producers:"');
+    expect(problems[0]).toContain('"no change needed."');
+    expect(problems[0]).toContain('"optional:"');
+    expect(problems[0]).toContain('"required:"');
+  });
+
+  it("reports each offending sub-item", () => {
+    const problems = impactLineProblems(
+      entry("emit the new field.", "Required: read the new field."),
+    );
+    expect(problems).toHaveLength(2);
+    expect(problems[0]).toContain("line 7:");
+    expect(problems[1]).toContain("line 8:");
+    expect(problems[1]).toContain('"Consumers:"');
+  });
+
+  it("reports a prefix that runs into the text after it", () => {
+    expect(
+      impactLineProblems(entry("optional:emit it.", "no change needed.")),
+    ).toHaveLength(1);
+  });
+
+  it("reports a bare label with no prefix below it", () => {
+    const text = ["- A summary.", "  - Consumers:", "    read it.", ""].join(
+      "\n",
+    );
+    expect(impactLineProblems(text)).toEqual([
+      expect.stringContaining("line 2:"),
+    ]);
+  });
+
+  it("ignores the intro bullets that describe the sub-items", () => {
+    const text = [
+      "# Changelog",
+      "",
+      "- `Schemas:` the schema(s) the change touches.",
+      "- `Producers:` what the change means for an emitter of data (a",
+      "  compiler such as solc or bugc).",
+      "- `Consumers:` what the change means for a reader.",
+      "",
+      "Each `Producers:` and `Consumers:` sub-item starts with a prefix:",
+      "",
+      "- `no change needed.` Nothing changes.",
+      "",
+    ].join("\n");
+    expect(impactLineProblems(text)).toEqual([]);
+  });
+
+  it("accepts a file with no entries", () => {
+    expect(impactLineProblems("# Changelog\n\n## Unreleased\n")).toEqual([]);
+    expect(impactLineProblems("")).toEqual([]);
+  });
+});
+
+describe("formatProblemsMessage", () => {
+  it("is empty when there are no problems", () => {
+    expect(formatProblemsMessage([])).toBe("");
+  });
+
+  it("names the file and lists each problem", () => {
+    const message = formatProblemsMessage(["line 7: first", "line 9: second"]);
+    expect(message).toContain("CHANGELOG.md");
+    expect(message).toContain("  line 7: first");
+    expect(message).toContain("  line 9: second");
+  });
+});
+
+describe("sectionProblems", () => {
+  it("accepts Added and Changed sections", () => {
+    const text = "## Unreleased\n\n### Added\n\n### Changed\n";
+    expect(sectionProblems(text)).toEqual([]);
+  });
+
+  it("rejects any other section with its line number", () => {
+    const text = "## Unreleased\n\n### Breaking\n";
+    const problems = sectionProblems(text);
+    expect(problems).toHaveLength(1);
+    expect(problems[0]).toContain("line 3");
+    expect(problems[0]).toContain('"### Added"');
+    expect(problems[0]).toContain('"### Changed"');
+  });
+
+  it("ignores version headings and deeper headings", () => {
+    expect(sectionProblems("# Changelog\n\n## 0.1.0-1\n")).toEqual([]);
+    expect(sectionProblems("#### Breaking\n")).toEqual([]);
+  });
+});
diff --git a/bin/check-changelog.ts b/bin/check-changelog.ts
new file mode 100644
index 000000000..6df4554ef
--- /dev/null
+++ b/bin/check-changelog.ts
@@ -0,0 +1,219 @@
+import { execFileSync } from "node:child_process";
+import { readFileSync } from "node:fs";
+import { join, relative } from "node:path";
+import { fileURLToPath, pathToFileURL } from "node:url";
+import { readWorkspaces } from "./publish-tagged.js";
+
+const defaultBase = "origin/main";
+
+function touchesSchemas(changedPaths: string[]): boolean {
+  return changedPaths.some((path) => path.startsWith("schemas/"));
+}
+
+// colocated test files carry no consumer-visible change, and this also
+// covers the *.examples.test.ts suites
+const testFile = /\.test\.tsx?$/;
+
+function touchesPackage(changedPaths: string[], prefix: string): boolean {
+  return changedPaths.some(
+    (path) =>
+      !testFile.test(path) &&
+      (path.startsWith(`${prefix}/src/`) ||
+        path.startsWith(`${prefix}/bin/`) ||
+        path === `${prefix}/package.json`),
+  );
+}
+
+export function missingPackageChangelogs(
+  changedPaths: string[],
+  packagePrefixes: string[],
+): string[] {
+  const changed = new Set(changedPaths);
+  return packagePrefixes
+    .filter((prefix) => touchesPackage(changedPaths, prefix))
+    .map((prefix) => `${prefix}/CHANGELOG.md`)
+    .filter((path) => !changed.has(path));
+}
+
+export function needsChangelog(
+  changedPaths: string[],
+  packagePrefixes: string[] = [],
+): boolean {
+  const schemasViolation =
+    touchesSchemas(changedPaths) && !changedPaths.includes("CHANGELOG.md");
+  return (
+    schemasViolation ||
+    missingPackageChangelogs(changedPaths, packagePrefixes).length > 0
+  );
+}
+
+export function changelogMessage(
+  changedPaths: string[],
+  packagePrefixes: string[] = [],
+): string {
+  const lines: string[] = [];
+
+  if (touchesSchemas(changedPaths) && !changedPaths.includes("CHANGELOG.md")) {
+    const schemaPaths = changedPaths.filter((path) =>
+      path.startsWith("schemas/"),
+    );
+    lines.push(
+      "This PR changes schema files without updating CHANGELOG.md:",
+      ...schemaPaths.map((path) => `  ${path}`),
+      "",
+      'Add an entry under "## Unreleased" in CHANGELOG.md.',
+    );
+  }
+
+  const missing = missingPackageChangelogs(changedPaths, packagePrefixes);
+  if (missing.length > 0) {
+    if (lines.length > 0) {
+      lines.push("");
+    }
+    lines.push(
+      "This PR changes package files without updating the matching",
+      "package CHANGELOG.md:",
+      ...missing.map((path) => `  ${path}`),
+      "",
+      'Add an entry under "## Unreleased" in each file listed above.',
+    );
+  }
+
+  if (lines.length > 0) {
+    lines.push(
+      "",
+      'Apply the "changelog: skip" label to this PR if no entry is needed.',
+    );
+  }
+
+  return lines.join("\n");
+}
+
+const impactPrefixes = ["no change needed.", "optional:", "required:"];
+
+// a real sub-item is indented two spaces and has a bare label; the intro
+// bullets that describe the sub-items start at column 0 with a code span
+const impactLabel = /^ {2}- (Producers|Consumers):(.*)$/;
+
+function startsWithImpactPrefix(text: string): boolean {
+  return impactPrefixes.some(
+    (prefix) =>
+      text.startsWith(prefix) &&
+      (text.length === prefix.length || /\s/.test(text[prefix.length])),
+  );
+}
+
+export function impactLineProblems(text: string): string[] {
+  const lines = text.split("\n");
+  const allowed = impactPrefixes.map((prefix) => `"${prefix}"`).join(", ");
+  return lines.flatMap((line, index) => {
+    const match = impactLabel.exec(line);
+    if (!match) {
+      return [];
+    }
+    const [, label, rest] = match;
+    // the text starts on the label line after one space, or, when the
+    // label stands alone, on the continuation line below it
+    const conforms =
+      rest.trim().length > 0
+        ? rest.startsWith(" ") && startsWithImpactPrefix(rest.slice(1))
+        : startsWithImpactPrefix((lines[index + 1] ?? "").trimStart());
+    return conforms
+      ? []
+      : [`line ${index + 1}: "${label}:" must start with one of: ${allowed}`];
+  });
+}
+
+const sectionNames = ["Added", "Changed"];
+
+// the prefixes carry the obligations, so a section only says whether a
+// change adds something new or alters something that exists
+export function sectionProblems(text: string): string[] {
+  const allowed = sectionNames.map((name) => `"### ${name}"`).join(", ");
+  return text.split("\n").flatMap((line, index) => {
+    if (!line.startsWith("### ")) {
+      return [];
+    }
+    return sectionNames.includes(line.slice(4).trim())
+      ? []
+      : [`line ${index + 1}: section heading must be one of: ${allowed}`];
+  });
+}
+
+export function formatProblemsMessage(problems: string[]): string {
+  if (problems.length === 0) {
+    return "";
+  }
+  return [
+    "CHANGELOG.md does not follow the entry format:",
+    ...problems.map((problem) => `  ${problem}`),
+  ].join("\n");
+}
+
+function resolvesToCommit(root: string, ref: string): boolean {
+  try {
+    execFileSync(
+      "git",
+      ["rev-parse", "--verify", "--quiet", `${ref}^{commit}`],
+      {
+        cwd: root,
+        stdio: "ignore",
+      },
+    );
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+function changedPaths(root: string, base: string): string[] {
+  const stdout = execFileSync(
+    "git",
+    ["diff", "--name-only", `${base}...HEAD`],
+    { cwd: root, encoding: "utf8" },
+  );
+  return stdout
+    .split("\n")
+    .map((line) => line.trim())
+    .filter((line) => line.length > 0);
+}
+
+function publicPackagePrefixes(root: string): string[] {
+  return readWorkspaces(root)
+    .filter((workspace) => !workspace.private)
+    .map((workspace) => relative(root, workspace.dir));
+}
+
+export function main(argv: string[]): number {
+  const base = argv[0] ?? defaultBase;
+  const root = fileURLToPath(new URL("..", import.meta.url));
+  if (!resolvesToCommit(root, base)) {
+    console.error(
+      `check-changelog: cannot resolve the base ref "${base}"; fetch it` +
+        " first, or name one that exists.",
+    );
+    return 1;
+  }
+  const paths = changedPaths(root, base);
+  const packagePrefixes = publicPackagePrefixes(root);
+  // the format lint runs on every diff, not only on schema changes
+  const changelog = readFileSync(join(root, "CHANGELOG.md"), "utf8");
+  const problems = [
+    ...impactLineProblems(changelog),
+    ...sectionProblems(changelog),
+  ];
+  const messages = [
+    changelogMessage(paths, packagePrefixes),
+    formatProblemsMessage(problems),
+  ].filter((message) => message.length > 0);
+  if (messages.length > 0) {
+    console.error(messages.join("\n\n"));
+    return 1;
+  }
+  console.log("changelog: ok");
+  return 0;
+}
+
+if (import.meta.url === pathToFileURL(process.argv[1]).href) {
+  process.exit(main(process.argv.slice(2)));
+}
diff --git a/bin/packlist.test.ts b/bin/packlist.test.ts
index beeeab145..be0aa10bf 100644
--- a/bin/packlist.test.ts
+++ b/bin/packlist.test.ts
@@ -8,6 +8,7 @@ describe("checkPackList", () => {
         "package.json",
         "README.md",
         "LICENSE",
+        "CHANGELOG.md",
         "dist/src/index.js",
         "dist/src/a/b.d.ts",
         "dist/bin/bugc.js",
diff --git a/bin/packlist.ts b/bin/packlist.ts
index 74fdc31ba..fc0d89587 100644
--- a/bin/packlist.ts
+++ b/bin/packlist.ts
@@ -4,6 +4,7 @@ const allowed = [
   /^package\.json$/,
   /^README[^/]*$/,
   /^LICENSE[^/]*$/,
+  /^CHANGELOG[^/]*$/,
   /^dist\/src\//,
   /^dist\/bin\//,
 ];
diff --git a/packages/bugc-react/CHANGELOG.md b/packages/bugc-react/CHANGELOG.md
new file mode 100644
index 000000000..3dbc80ae2
--- /dev/null
+++ b/packages/bugc-react/CHANGELOG.md
@@ -0,0 +1,20 @@
+# Changelog
+
+This file tracks changes to the `@ethdebug/bugc-react` npm package,
+React components for visualizing BUG compiler output. Changes to the
+specification itself are tracked in the root
+[`CHANGELOG.md`](../../CHANGELOG.md).
+
+## Unreleased
+
+### Changed
+
+- `yarn watch` now copies stylesheet changes into `dist/` on every
+  edit instead of only at startup. Development-only, no effect on
+  the published package ([#299]).
+
+## 0.1.0-1 — 2026-09-16
+
+First publication.
+
+[#299]: https://github.com/ethdebug/format/pull/299
diff --git a/packages/bugc-react/package.json b/packages/bugc-react/package.json
index 35c5225f1..25ed9c913 100644
--- a/packages/bugc-react/package.json
+++ b/packages/bugc-react/package.json
@@ -13,7 +13,8 @@
   "license": "MIT",
   "files": [
     "dist",
-    "!dist/**/*.tsbuildinfo"
+    "!dist/**/*.tsbuildinfo",
+    "CHANGELOG.md"
   ],
   "engines": {
     "node": ">=20"
diff --git a/packages/bugc/CHANGELOG.md b/packages/bugc/CHANGELOG.md
new file mode 100644
index 000000000..efeebdc54
--- /dev/null
+++ b/packages/bugc/CHANGELOG.md
@@ -0,0 +1,25 @@
+# Changelog
+
+This file tracks changes to the `@ethdebug/bugc` npm package, the
+BUG language compiler with `ethdebug/format` debug information
+support. Changes to the specification itself are tracked in the root
+[`CHANGELOG.md`](../../CHANGELOG.md).
+
+## Unreleased
+
+### Changed
+
+- The pointer expressions that compute a mapping or array-element slot
+  now word-size their `$keccak256` operand, as the two-sorted
+  expression semantics require. Emitted debug information does not
+  change: nothing reaches that code path yet ([#286]).
+- Normalized the `bin` path in `package.json` to the form npm
+  expects, silencing an auto-correction warning at publish time
+  ([#298]).
+
+## 0.1.0-1 — 2026-09-16
+
+First publication.
+
+[#286]: https://github.com/ethdebug/format/pull/286
+[#298]: https://github.com/ethdebug/format/pull/298
diff --git a/packages/bugc/package.json b/packages/bugc/package.json
index c491c62ef..18753d677 100644
--- a/packages/bugc/package.json
+++ b/packages/bugc/package.json
@@ -17,7 +17,8 @@
   },
   "files": [
     "dist",
-    "!dist/**/*.tsbuildinfo"
+    "!dist/**/*.tsbuildinfo",
+    "CHANGELOG.md"
   ],
   "engines": {
     "node": ">=20"
diff --git a/packages/evm/CHANGELOG.md b/packages/evm/CHANGELOG.md
new file mode 100644
index 000000000..bb99f6fc1
--- /dev/null
+++ b/packages/evm/CHANGELOG.md
@@ -0,0 +1,12 @@
+# Changelog
+
+This file tracks changes to the `@ethdebug/evm` npm package (EVM
+execution and state access for `ethdebug/format`). Changes to the
+specification itself are tracked in the root
+[`CHANGELOG.md`](../../CHANGELOG.md).
+
+## Unreleased
+
+## 0.1.0-1 — 2026-09-16
+
+First publication.
diff --git a/packages/evm/package.json b/packages/evm/package.json
index 540777384..e7ead3d5b 100644
--- a/packages/evm/package.json
+++ b/packages/evm/package.json
@@ -13,7 +13,8 @@
   "license": "MIT",
   "files": [
     "dist",
-    "!dist/**/*.tsbuildinfo"
+    "!dist/**/*.tsbuildinfo",
+    "CHANGELOG.md"
   ],
   "engines": {
     "node": ">=20"
diff --git a/packages/format/CHANGELOG.md b/packages/format/CHANGELOG.md
new file mode 100644
index 000000000..b96cb1dc8
--- /dev/null
+++ b/packages/format/CHANGELOG.md
@@ -0,0 +1,106 @@
+# Changelog
+
+This file tracks changes to the `@ethdebug/format` npm package (the schemas
+distributed for programmatic use). Changes to the specification itself are
+tracked in the root [`CHANGELOG.md`](../../CHANGELOG.md).
+
+## Unreleased
+
+## 0.1.0-1 — 2026-09-16
+
+### Added
+
+- The entry point exports TypeScript types and guards for the spec's data model:
+  the `Program`, `Pointer`, `Type`, `Materials` and `Data` namespaces, their
+  `isProgram`, `isPointer`, `isType`, `isSource`, `isValue` and sibling guards,
+  and the `mayHaveClass` and `hasKind` helpers. `0.1.0-0` exported only
+  `describeSchema`, `referencesId`, `referencesYaml`, `schemas`, `schemaIds` and
+  the `Schema` type. ([`59a5c38`])
+- `Program.Context` covers the whole context vocabulary, each member with its
+  own guard: `pick` ([`74c7d5f`]), `frame` ([`fc976ed`]), `gather`
+  ([`e469502`]), the function-call contexts `invoke`, `return` and `revert`
+  ([#154]), `name` ([#246]) and `transform` ([#216]).
+- The function-call context types carry an optional `activation` identifier that
+  correlates an invocation with its return or revert ([#245]), and treat
+  `invoke.target` ([#242]) and `return.data` ([#211]) as optional.
+- The guards use `Array.isArray` instead of `instanceof Array`, so arrays from
+  another realm pass ([#231]). `Pointer.isIdentifier` matches the identifier
+  schema's pattern, and `Type.Elementary.isContract` carries and validates the
+  `library` and `interface` flags and rejects a type that sets both ([#276]).
+- `describeSchema` accepts a schema id as a plain string, so
+  `describeSchema({ schema: "schema:ethdebug/format/program" })` works where
+  `0.1.0-0` required `{ schema: { id } }`. `referencesId` narrows a string as
+  well as an `{ id }` object, and a `SchemaId` type is exported. ([`e523e09`],
+  [`f87f678`])
+- The tarball includes `LICENSE` and `README.md`, and the manifest gives a full
+  `repository` entry with `directory: packages/format` ([#293]).
+
+### Changed
+
+- The bundled schemas are those of spec version `0.1.0-1`; see the root
+  `CHANGELOG.md`. `schemaIds` grows from 47 ids to 72, adding the
+  **ethdebug/format/program** family (including every `program/context/*` schema
+  and **ethdebug/format/program/instruction**), **ethdebug/format/info** and
+  **ethdebug/format/info/resources**, **ethdebug/format/data/value**,
+  **ethdebug/format/data/unsigned**, **ethdebug/format/data/hex**,
+  **ethdebug/format/type/specifier**, **ethdebug/format/materials/encoding**,
+  **ethdebug/format/pointer/template** and the
+  **ethdebug/format/pointer/collection/reference** and
+  **ethdebug/format/pointer/collection/templates** schemas. No schema id was
+  removed.
+- `describeSchema` parses schema YAML with merge keys enabled, so the `<<:`
+  anchor merges that the schemas use resolve into the returned `schema` and
+  `rootSchema` objects instead of surviving as a literal `<<` property
+  ([`0ef2f37`]).
+- The `SchemaInfo` that `describeSchema` returns omits `pointer` entirely when
+  no pointer was requested, where `0.1.0-0` always set the property, to
+  `undefined` if need be ([`f87f678`]).
+- The tarball no longer contains declaration maps (`*.d.ts.map`), so editors
+  step into the shipped `.d.ts` files rather than the original sources ([#293]).
+- Build and dependency housekeeping with no effect on the published API:
+  Prettier and ESLint passes, the move to Vitest, TypeScript project references,
+  `json-schema-typed` pinned to `8.0.1` and `yaml` raised to `^2.8.2` ([#293]).
+
+### Breaking
+
+- The package is an ES module: the manifest sets `"type": "module"` and `dist`
+  holds `import`/`export` statements, where `0.1.0-0` shipped CommonJS with
+  `require` calls. `require("@ethdebug/format")` now works only on Node versions
+  that support `require(esm)` (Node 20.19 and later); on earlier Node, and in a
+  CommonJS-only bundler pipeline, consumers have to switch to `import`.
+  ([`a5a7d6c`])
+- The shipped declarations import the package's own `#`-prefixed specifiers
+  (`#describe`, `#schemas`, `#types`), so TypeScript resolves the types only
+  under `moduleResolution` `node16`, `nodenext` or `bundler`. A project on the
+  legacy `node10` resolution gets "Cannot find module '#describe'" and no
+  exported members. ([`21e532e`], [#293])
+- The manifest declares `engines: { node: ">=20" }`, which `0.1.0-0` did not
+  ([#293]).
+- The layout under `dist` changed, which breaks deep imports:
+  `dist/src/schemas.js` is now `dist/src/schemas/index.js`, `dist/yamls.js` is
+  now `dist/src/schemas/yamls.js` ([`10ab103`]), and the `dist/src/bundle.js`
+  module with its `bundleSchemas` function is gone ([`59a5c38`]).
+
+## 0.1.0-0 — 2024-07-04
+
+First publication.
+
+[#154]: https://github.com/ethdebug/format/pull/154
+[#211]: https://github.com/ethdebug/format/pull/211
+[#216]: https://github.com/ethdebug/format/pull/216
+[#231]: https://github.com/ethdebug/format/pull/231
+[#242]: https://github.com/ethdebug/format/pull/242
+[#245]: https://github.com/ethdebug/format/pull/245
+[#246]: https://github.com/ethdebug/format/pull/246
+[#276]: https://github.com/ethdebug/format/pull/276
+[#293]: https://github.com/ethdebug/format/pull/293
+[`0ef2f37`]: https://github.com/ethdebug/format/commit/0ef2f37
+[`10ab103`]: https://github.com/ethdebug/format/commit/10ab103
+[`21e532e`]: https://github.com/ethdebug/format/commit/21e532e
+[`59a5c38`]: https://github.com/ethdebug/format/commit/59a5c38
+[`74c7d5f`]: https://github.com/ethdebug/format/commit/74c7d5f
+[`a5a7d6c`]: https://github.com/ethdebug/format/commit/a5a7d6c
+[`e469502`]: https://github.com/ethdebug/format/commit/e469502
+[`e523e09`]: https://github.com/ethdebug/format/commit/e523e09
+[`f87f678`]: https://github.com/ethdebug/format/commit/f87f678
+[`fc976ed`]: https://github.com/ethdebug/format/commit/fc976ed
diff --git a/packages/format/package.json b/packages/format/package.json
index 3867b2232..1e4cc87ac 100644
--- a/packages/format/package.json
+++ b/packages/format/package.json
@@ -12,7 +12,8 @@
   "license": "MIT",
   "files": [
     "dist",
-    "!dist/**/*.tsbuildinfo"
+    "!dist/**/*.tsbuildinfo",
+    "CHANGELOG.md"
   ],
   "engines": {
     "node": ">=20"
diff --git a/packages/pointers-react/CHANGELOG.md b/packages/pointers-react/CHANGELOG.md
new file mode 100644
index 000000000..a74a5b09d
--- /dev/null
+++ b/packages/pointers-react/CHANGELOG.md
@@ -0,0 +1,24 @@
+# Changelog
+
+This file tracks changes to the `@ethdebug/pointers-react` npm
+package, React components for visualizing `ethdebug/format` pointer
+resolution. Changes to the specification itself are tracked in the
+root [`CHANGELOG.md`](../../CHANGELOG.md).
+
+## Unreleased
+
+### Changed
+
+- Fixed the documented CSS import paths in comments; the stylesheets
+  ship under `dist/src/components/`, and `variables.css` must be
+  imported first ([#298]).
+- `yarn watch` now copies stylesheet changes into `dist/` on every
+  edit instead of only at startup. Development-only, no effect on
+  the published package ([#299]).
+
+## 0.1.0-1 — 2026-09-16
+
+First publication.
+
+[#298]: https://github.com/ethdebug/format/pull/298
+[#299]: https://github.com/ethdebug/format/pull/299
diff --git a/packages/pointers-react/package.json b/packages/pointers-react/package.json
index 0bbfde890..2bb890652 100644
--- a/packages/pointers-react/package.json
+++ b/packages/pointers-react/package.json
@@ -13,7 +13,8 @@
   "license": "MIT",
   "files": [
     "dist",
-    "!dist/**/*.tsbuildinfo"
+    "!dist/**/*.tsbuildinfo",
+    "CHANGELOG.md"
   ],
   "engines": {
     "node": ">=20"
diff --git a/packages/pointers/CHANGELOG.md b/packages/pointers/CHANGELOG.md
new file mode 100644
index 000000000..8f30000c0
--- /dev/null
+++ b/packages/pointers/CHANGELOG.md
@@ -0,0 +1,87 @@
+# Changelog
+
+This file tracks changes to the `@ethdebug/pointers` npm package, the reference
+implementation of `ethdebug/format` pointers. Changes to the specification
+itself are tracked in the root [`CHANGELOG.md`](../../CHANGELOG.md).
+
+## Unreleased
+
+### Changed
+
+- `dereference` resolves a region whose segment `offset` carries past the end of
+  a slot and whose `length` spans the slots that follow, instead of reading
+  within the starting slot only ([#284]).
+- A pointer that passes a bare integer to `$concat` or `$keccak256` now throws,
+  naming the operand, where it used to hash the wrong preimage: a literal took
+  its minimal byte width, so a bare slot number hashed as fewer than 32 bytes.
+  Word-size the operand with `$wordsized` or a `$sizedN` form. ([#286])
+
+## 0.1.0-1 — 2026-09-16
+
+### Added
+
+- `dereference` resolves pointer templates. `DereferenceOptions` takes a
+  `templates` map, and the dereferencer handles a template reference collection
+  (`{ template, yields }`) and an inline `{ templates }` collection, reporting
+  an unknown template name or a missing expected variable as a thrown error.
+  ([`29df1e1`], [`1a8a752`], [`4e9d0ac`])
+- A template reference's `yields` mapping renames the regions the template
+  produces, so `Cursor.Regions.named` and `Cursor.Regions.lookup` find them
+  under the caller's names ([`1a8a752`]).
+- Expression evaluation supports the `$concat` operator, concatenating its
+  operands' bytes ([`3866cec`]).
+- The tarball includes `LICENSE`, the manifest gives a full `repository` entry
+  with `directory: packages/pointers`, and the `README.md` states the supported
+  TypeScript resolution modes ([#293]).
+
+### Changed
+
+- `@ethdebug/format` is a runtime dependency (`^0.1.0-1`), where `0.1.0-0`
+  listed it only as a devDependency. The shipped `evaluate` and dereference
+  modules import the `Pointer` guards from it, so the package no longer installs
+  usefully on its own. ([#293])
+- `Data` registers its custom inspect hook with
+  `Symbol.for("nodejs.util.inspect.custom")` rather than a top-level
+  `await import("util")`, so the module loads in environments without top-level
+  await and without Node's `util` ([`0697233`]).
+- The tarball holds only `dist`, the manifest, `README.md` and `LICENSE`.
+  `0.1.0-0` also shipped the TypeScript sources under `src`, every test and
+  integration test (compiled and as source), the `test` helpers,
+  `bin/run-example.ts`, `tsconfig.json`, `typings.d.ts`, `jest.config.cjs` and
+  the declaration maps. ([#293])
+- Build and dependency housekeeping with no effect on the published API:
+  Prettier and ESLint passes, the move from Jest to Vitest, TypeScript project
+  references, type-only imports, and upgrades to `ethereum-cryptography`
+  `^2.2.1` and the dev toolchain ([#293]).
+
+### Breaking
+
+- `Pointer` and `isPointer` are no longer exported. The entry point now exports
+  `dereference`, `Data`, and the `DereferenceOptions`, `Cursor` and `Machine`
+  types only; the pointer type and its guard live in `@ethdebug/format`.
+  ([`59a5c38`])
+- The shipped declarations import the package's own `#`-prefixed specifiers
+  (`#cursor`, `#data`, `#dereference`, `#machine`), so TypeScript resolves the
+  types only under `moduleResolution` `node16`, `nodenext` or `bundler`. A
+  project on the legacy `node10` resolution gets "Cannot find module
+  '#dereference'" and no exported members. ([`21e532e`], [#293])
+- The manifest declares `engines: { node: ">=20" }`, which `0.1.0-0` did not
+  ([#293]).
+- Deep imports into the shipped tree break: `dist/src/pointer.js`,
+  `dist/src/test-cases.js`, `dist/bin/run-example.js` and everything under
+  `dist/test` are gone ([`59a5c38`], [#293]).
+
+## 0.1.0-0 — 2024-07-04
+
+First publication.
+
+[#284]: https://github.com/ethdebug/format/pull/284
+[#286]: https://github.com/ethdebug/format/pull/286
+[#293]: https://github.com/ethdebug/format/pull/293
+[`0697233`]: https://github.com/ethdebug/format/commit/0697233
+[`1a8a752`]: https://github.com/ethdebug/format/commit/1a8a752
+[`21e532e`]: https://github.com/ethdebug/format/commit/21e532e
+[`29df1e1`]: https://github.com/ethdebug/format/commit/29df1e1
+[`3866cec`]: https://github.com/ethdebug/format/commit/3866cec
+[`4e9d0ac`]: https://github.com/ethdebug/format/commit/4e9d0ac
+[`59a5c38`]: https://github.com/ethdebug/format/commit/59a5c38
diff --git a/packages/pointers/package.json b/packages/pointers/package.json
index 8cebbbf4d..30dd0652e 100644
--- a/packages/pointers/package.json
+++ b/packages/pointers/package.json
@@ -12,7 +12,8 @@
   "license": "MIT",
   "files": [
     "dist",
-    "!dist/**/*.tsbuildinfo"
+    "!dist/**/*.tsbuildinfo",
+    "CHANGELOG.md"
   ],
   "engines": {
     "node": ">=20"
diff --git a/packages/programs-react/CHANGELOG.md b/packages/programs-react/CHANGELOG.md
new file mode 100644
index 000000000..8433c6d09
--- /dev/null
+++ b/packages/programs-react/CHANGELOG.md
@@ -0,0 +1,23 @@
+# Changelog
+
+This file tracks changes to the `@ethdebug/programs-react` npm
+package, React components for visualizing `ethdebug/format` program
+annotations. Changes to the specification itself are tracked in the
+root [`CHANGELOG.md`](../../CHANGELOG.md).
+
+## Unreleased
+
+### Changed
+
+- Fixed the documented CSS import paths in comments; the stylesheets
+  ship under `dist/src/components/` ([#298]).
+- `yarn watch` now copies stylesheet changes into `dist/` on every
+  edit instead of only at startup. Development-only, no effect on
+  the published package ([#299]).
+
+## 0.1.0-1 — 2026-09-16
+
+First publication.
+
+[#298]: https://github.com/ethdebug/format/pull/298
+[#299]: https://github.com/ethdebug/format/pull/299
diff --git a/packages/programs-react/package.json b/packages/programs-react/package.json
index aa2e0b14d..c1786c05e 100644
--- a/packages/programs-react/package.json
+++ b/packages/programs-react/package.json
@@ -13,7 +13,8 @@
   "license": "MIT",
   "files": [
     "dist",
-    "!dist/**/*.tsbuildinfo"
+    "!dist/**/*.tsbuildinfo",
+    "CHANGELOG.md"
   ],
   "engines": {
     "node": ">=20"
diff --git a/packages/web/spec/changelog.mdx b/packages/web/spec/changelog.mdx
new file mode 100644
index 000000000..cea320f7a
--- /dev/null
+++ b/packages/web/spec/changelog.mdx
@@ -0,0 +1,9 @@
+---
+title: Changelog
+hide_title: true
+sidebar_position: 6
+---
+
+import Changelog from "../../../CHANGELOG.md";
+
+<Changelog />