Initial public release v0.0.1.alpha2

opencode-rails — production-grade Rails integration for OpenCode.

Rails companion to opencode-ruby. ActiveRecord-aware session lifecycle
(idempotent ensure!/recreate!/abort! with row-level locks), a Turn
orchestrator driving the Reply state machine and recovering from
session-not-found, an artifact pipeline backed by ActiveStorage,
sandbox seeding, and tool-display value objects for Turbo Stream
broadcasts. Drop into any Rails 7.1+ app that wants production-grade
OpenCode streaming without rolling boilerplate.

What this version ships:
  - Opencode::Session (AR-coupled lifecycle, row-level locks)
  - Opencode::Turn (Reply state machine, session-not-found recovery)
  - Opencode::Exchange (one turn = one request/response unit)
  - Opencode::Impostor (deterministic mock for tests)
  - Opencode::Sandbox / SandboxFile (per-session FS scratch space)
  - Opencode::Transform (host-rendered artifact pipeline)
  - Opencode::Artifact / MessageArtifacts (ActiveStorage-backed)
  - Opencode::UploadedFilesPrompt (system-prompt builder)
  - Opencode::ToolDisplay (Turbo Stream value objects)
  - Opencode::ErrorReporter (pluggable adapter — Honeybadger/Sentry/etc.)
  - examples/rails_integration.rb — canonical wiring blueprint

53 smoke tests. CI on Ruby 3.2/3.3/3.4.

Ruby >= 3.2. Runtime deps: opencode-ruby = 0.0.1.alpha2,
activerecord/activestorage/activesupport >= 7.1, < 9.0.

See CHANGELOG.md for the alpha1 -> alpha2 delta.

CHANGELOG.md

@@ -0,0 +1,50 @@
+# Changelog
+
+## 0.0.1.alpha2 — 2026-05-20
+
+### Changed
+
+- `Opencode::Exchange` now emits `opencode.apply_patch.artifacts_dropped`
+  via the new `Opencode::Instrumentation.notify` fire-and-forget API
+  (introduced in opencode-ruby v0.0.1.alpha2) instead of
+  `.instrument(name, payload) { }` with an empty block. Cleaner read
+  at the call site; identical semantics on the wire (same event name,
+  same payload).
+
+### Bumped
+
+- Runtime dependency `opencode-ruby` pinned to `= 0.0.1.alpha2` (was
+  `= 0.0.1.alpha1`). Versions stay in lockstep during alpha.
+
+## 0.0.1.alpha1 — 2026-05-20
+
+Initial public alpha. Extracted from a production Rails app where these objects shipped as in-tree library code before being carved out into a standalone gem.
+
+**Includes:**
+
+- `Opencode::Session` — AR-coupled, row-level-locked session lifecycle (`ensure!`, `recreate!`, `abort!`)
+- `Opencode::Turn` — orchestrator covering send → stream → recover → finalize, with CAS-safe message terminal-state transitions
+- `Opencode::Exchange` — domain object over a turn's message array; emits `opencode.apply_patch.artifacts_dropped` when post-write file content is unavailable
+- `Opencode::Artifact` — value-object (filename + content + content_type + trust metadata), idempotent attach
+- `Opencode::MessageArtifacts` — ActiveStorage-aware artifact attachment pipeline with transform support
+- `Opencode::Sandbox` — disk-backed sandbox reader, returns `Artifact` list
+- `Opencode::SandboxFile` — single-file value object (pathname → bytes/content-type)
+- `Opencode::Transform` — base class for content-rewriting transforms
+- `Opencode::Impostor` — ActiveStorage download/upload round-trip helper
+- `Opencode::UploadedFilesPrompt` — user-prompt prefix builder listing uploaded files, sandbox-path inverted (injection-based, no `Opencode::Permissions` reference)
+- `Opencode::ToolDisplay` — view-model for tool-call hashes (Turbo Stream-friendly)
+- `Opencode::ErrorReporter` — pluggable adapter mirroring the `Opencode::Instrumentation` pattern
+
+**Runtime dependencies:**
+
+- `opencode-ruby ~> 0.0.1.alpha1` (wire client + Reply state machine)
+- `activerecord >= 7.1, < 9.0`
+- `activestorage >= 7.1, < 9.0`
+- `activesupport >= 7.1, < 9.0`
+
+**Known limitations (alpha):**
+
+- Apply-patch tool's post-write file content is not extracted (wire-format limitation in OpenCode v1.15+); affected files surface via the `opencode.apply_patch.artifacts_dropped` instrumentation event. Future work: optional sandbox-read fallback path.
+- Smoke tests only inside the gem. Behavioral coverage currently lives in the host app that produced this code. A standalone gem-side test suite using Combustion is open work.
+- No generator (`rails g opencode:install`) yet.
+- No Rails Engine integration — `require "opencode-rails"` is sufficient.