chore(internal): bump IR to 67.2.0 for SseStreamChunk.resumable (#15812)

PR #15795 added an optional `resumable` field to `SseStreamChunk` in
`ir-types-latest/definition/http.yml` but did not bump the IR version,
so no new `@fern-fern/ir-sdk` package was published. Bump VERSION
67.1.0 -> 67.2.0 and append a corresponding CHANGELOG entry so the
field becomes visible to downstream consumers.

Also document the per-PR IR-version-bump requirement in
packages/ir-sdk/CLAUDE.md (Adding New IR Features step 4 + revised
Version Release Process) and the root CLAUDE.md (Feature Addition
Workflow), so this is not missed in future feature PRs.

Author: patrickthornton

CLAUDE.md

@@ -189,12 +189,17 @@ Multi-stage process: API Schema → IR Updates → Generator Updates → Release
 **Stages**:
 1. **API Schema**: Update `/fern/apis/<definition>/` → Run generator command (check `generators.yml` in each API folder)
 2. **IR Updates**: Modify `/packages/ir-sdk/fern/apis/ir-types-latest/definition/` → `pnpm ir:generate`
-3. **Versioning**: Update `CHANGELOG.md`, `VERSION`, and `/packages/cli/cli/versions.yml`
-4. **Compile**: `pnpm compile` and fix breaking changes (common: `switch` statements need new cases)
-5. **Generator Updates**: One PR for CLI/IR updates (merge first), then separate PR(s) for generator changes
-6. **IR Migrations**: Update `/packages/cli/generation/ir-migrations/` for backward compatibility
-
-**Key Points**: Multiple PRs required, automatic publishing via `versions.yml`, generators use published (not workspace) IR versions
+3. **IR Versioning (REQUIRED for any change to `ir-types-latest`)**:
+   - Bump `packages/ir-sdk/fern/apis/ir-types-latest/VERSION` (minor for additive/optional fields, patch for non-schema, major only as a separate batched PR)
+   - Add an entry to `packages/ir-sdk/fern/apis/ir-types-latest/changelog/CHANGELOG.md` (hand-edited; no `changes/unreleased/` for IR)
+   - Do **not** edit `packages/cli/cli/versions.yml` `irVersion` for minor/patch — that field tracks the IR major and only changes during major bumps
+   - See `packages/ir-sdk/CLAUDE.md` for the full checklist
+4. **CLI Versioning**: Add a CLI changelog entry under `packages/cli/cli/changes/unreleased/` (drives CLI semver only — see `packages/cli/CLAUDE.md`)
+5. **Compile**: `pnpm compile` and fix breaking changes (common: `switch` statements need new cases)
+6. **Generator Updates**: One PR for CLI/IR updates (merge first), then separate PR(s) for generator changes
+7. **IR Migrations**: Only required for major IR bumps — add under `/packages/cli/generation/ir-migrations/`
+
+**Key Points**: Multiple PRs required, automatic publishing via `versions.yml`, generators use published (not workspace) IR versions. Forgetting to bump `ir-types-latest/VERSION` means no new `@fern-fern/ir-sdk` is published and the new field is invisible to downstream consumers.
 
 ### Other Core Workflows
 

packages/cli/cli/changes/unreleased/bump-ir-to-67-2-0-for-sse-stream-chunk-resumable.yml

@@ -0,0 +1,8 @@
+# yaml-language-server: $schema=../../../../../fern-changes-yml.schema.json
+
+- summary: |
+    Bump IR to 67.2.0 to publish the optional `resumable` field added to
+    `SseStreamChunk` in PR #15795. Without the IR version bump, no new
+    `@fern-fern/ir-sdk` minor was published and the field stayed invisible
+    to downstream consumers.
+  type: chore

packages/ir-sdk/CLAUDE.md

@@ -112,27 +112,47 @@ pnpm generate
 - Update switch statements for new union cases
 - Test generator compatibility
 
-### 4. Add Migrations (if breaking)
+### 4. Bump the IR version (REQUIRED)
+**Every PR that modifies `ir-types-latest/definition/` must bump the IR version, otherwise no new IR package is published and consumers can't pick up the change.**
+
+The IR carries its own semver in `packages/ir-sdk/fern/apis/ir-types-latest/VERSION` (currently `MAJOR.MINOR.PATCH`, e.g. `67.2.0`). Pick the bump based on the change:
+
+- **Minor bump** (`67.1.0` → `67.2.0`): additive, backward-compatible changes — new optional fields, new union variants on forward-compatible enums, additive type declarations. This is the common case.
+- **Patch bump** (`67.1.0` → `67.1.1`): non-schema fixes (doc-string edits, comment-only changes, internal refactors that don't alter the public type surface).
+- **Major bump** (`67.x.x` → `68.0.0`): breaking changes — required-field additions, field removals/renames, type changes, removed enum values. **Major bumps are batched and done as a separate "Update IR to N+1" PR**, not per-feature; they require freezing the previous latest into `ir-types-vN/`, adding a `vN+1-to-vN` migration under `packages/cli/generation/ir-migrations/`, and re-aliasing `IrVersions.ts`.
+
+**Per-PR checklist for additive IR changes:**
+
+1. Edit `packages/ir-sdk/fern/apis/ir-types-latest/definition/<file>.yml`.
+2. Run `pnpm ir:generate` from the repo root to regenerate `packages/ir-sdk/src/sdk/...` artifacts.
+3. **Bump `packages/ir-sdk/fern/apis/ir-types-latest/VERSION`** (minor for additive, patch for non-schema).
+4. **Add an entry to `packages/ir-sdk/fern/apis/ir-types-latest/changelog/CHANGELOG.md`** describing the new field/feature, dated today, under a new `## [vMAJ.MIN.PATCH] - YYYY-MM-DD` heading at the top.
+5. Run `pnpm --filter @fern-api/ir-sdk compile` to confirm the workspace types still build.
+6. Do **not** edit `packages/cli/cli/versions.yml`'s `irVersion` — that field tracks the IR *major* and is only updated during major-version bumps.
+7. Do **not** edit `generators.yml` coordinates (`irV66`, `fern_fern_ir_v66`) — those reference the published external IR major and are stable across minor bumps.
+
+The IR changelog is **hand-edited**, not driven by a `changes/unreleased/` directory like the CLI.
+
+### 5. Add Migrations (only on major bump)
 ```bash
-# Add migration in CLI package
+# Required only when freezing latest into a new numbered version
 vim packages/cli/generation/ir-migrations/src/migrations/
 ```
 
 ## Version Release Process
 
-### 1. Prepare Release
-- Ensure `ir-types-latest` is stable
-- Update `CHANGELOG.md` with changes
-- Update `VERSION` file
-
-### 2. Create New Version
-- Copy `ir-types-latest` to `ir-types-v{n+1}`
-- Update `packages/cli/cli/versions.yml`
-
-### 3. Test Compatibility
-- Run full test suite (`pnpm test:ete`)
-- Test seed across all generators
-- Validate migration logic
+### Per-PR (minor / patch) — see "Adding New IR Features" above
+- Bump `packages/ir-sdk/fern/apis/ir-types-latest/VERSION`
+- Append entry to `packages/ir-sdk/fern/apis/ir-types-latest/changelog/CHANGELOG.md`
+- Release automation publishes a new `@fern-fern/ir-sdk` minor on merge to main
+
+### Major-version bump (batched, separate PR)
+1. Freeze current `ir-types-latest` contents into `packages/ir-sdk/fern/apis/ir-types-v{N}/`
+2. Set `ir-types-latest/VERSION` to `{N+1}.0.0`
+3. Add `packages/cli/generation/ir-migrations/src/migrations/v{N+1}-to-v{N}/` with backward migration logic
+4. Re-alias `packages/cli/generation/ir-migrations/src/ir-versions/IrVersions.ts` so `V{N+1} = @fern-api/ir-sdk` and add a frozen `@fern-fern/ir-v{N}-sdk` import
+5. Update `packages/cli/cli/versions.yml` `irVersion: {N}` → `{N+1}` for the next CLI release
+6. Run full test suite (`pnpm test:ete`) and seed across all generators
 
 ## Best Practices
 

packages/ir-sdk/fern/apis/ir-types-latest/VERSION

@@ -1 +1 @@
-67.1.0
+67.2.0

packages/ir-sdk/fern/apis/ir-types-latest/changelog/CHANGELOG.md

@@ -5,6 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [v67.2.0] - 2026-05-08
+
+- Feature: Add optional `resumable` field to `SseStreamChunk`. When `true`, signals
+  to generators that the SSE endpoint supports auto-reconnection via standard SSE
+  primitives (`Last-Event-ID` request header and `retry:` directive). Populated from
+  the new `x-fern-streaming.resumable` OpenAPI extension (inheritable from the
+  document root) and the `resumable` field on Fern Definition `response-stream`
+  blocks. Defaults to `false`; non-resumable JSON streaming endpoints always emit
+  `false` since they have no `Last-Event-ID` semantics.
+
 ## [v67.1.0] - 2026-05-01
 
 - Feature: Add optional `defaultValue` field to `HttpHeader`, `QueryParameter`,