diff --git a/CHANGELOG.md b/CHANGELOG.md
index da929e1..0df0c0d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,7 +8,40 @@ Tags follow `v{opencode_version}[letter]` — bare tag for the first build on a
 
 ## Unreleased
 
-_(no changes since v1.15.11c)_
+_(no changes since v1.15.12)_
+
+## v1.15.12 — 2026-05-29
+
+First container build on the genuine `opencode-ai@1.15.12` upstream release (published 2026-05-28). Also bumps pi `0.76.0` → `0.77.0`.
+
+> **Note on the `v1.15.12` git tag:** an earlier `v1.15.12` git tag existed at commit `be2a168` as a historical artifact from the 2026-05-28 versioning slip (re-cut as `v1.15.11c` once the slip was caught). The corresponding Hub `v1.15.12*` images were manually deleted at the time. Now that opencode upstream has actually released 1.15.12, the tag is being re-used at HEAD per the `v{opencode_version}[letter]` scheme — the old tag was force-overwritten locally and on origin. Commit `be2a168` and the v1.15.11c CHANGELOG block (which references the slip) remain in history.
+
+### Bumped: opencode-ai 1.15.11 → 1.15.12
+
+Notable upstream changes (from the [anomalyco/opencode v1.15.12 release](https://github.com/anomalyco/opencode/releases/tag/v1.15.12)):
+
+- **Core** — ACP integrations can send prompts/slash-commands/usage updates through `acp-next`; experimental WebSocket transport for OpenAI Responses (`OPENCODE_EXPERIMENTAL_WEBSOCKETS=true`); adaptive reasoning enabled for Anthropic Opus 4.7+.
+- **Bugfixes** — colons allowed in passwords; faster warm `acp-next` model/config switches; OpenAI WebSocket response timeouts kept active with retries before fallback; `acp-next` permission prompts handled correctly; persisted session directory used for existing-session requests; remote workspace request bodies forwarded correctly; custom base URLs supported for OpenAI WebSocket Responses.
+- **TUI** — workspace management dialog; session navigation works while prompt modes are open; thinking spinner restored; subagent retry status surfaced; opening editors from non-Git project paths fixed.
+- **Desktop** — tab-layout setting; home empty state and V2 font usage improved; tab close buttons showing reliably.
+
+### Bumped: pi 0.76.0 → 0.77.0
+
+Notable upstream changes (from pi's CHANGELOG):
+
+- **Claude Opus 4.8 support** — model metadata + adaptive-thinking coverage updated.
+- **Selective tool disablement** — `--exclude-tools` / `-xt` disables specific built-in, extension, or custom tools while keeping the rest available.
+- **Headless Codex subscription login** — `/login` can use device-code auth for ChatGPT Plus/Pro Codex subscriptions.
+- **Streaming-aware extension input** — `InputEvent.streamingBehavior` lets extensions distinguish idle prompts, mid-stream steers, and queued follow-ups.
+- **Bugfixes** — startup timing output excludes `createAgentSessionRuntime`; OpenRouter DeepSeek V4 `xhigh` reasoning preserved; SIGTERM/SIGHUP run extension `session_shutdown` cleanly; keyboard protocol negotiation ignores delayed terminal responses; Windows MSYS2 ucrt64 startup crash fixed; API-key/header config resolution treats plain strings as literals with `$ENV_VAR` interpolation; session disposal aborts in-flight work; numerous provider-specific reasoning/metadata fixes (Codex Responses replay, OpenAI/OpenRouter GPT-5.5 Pro, Kimi K2.6, Xiaomi Token Plan).
+
+### Inheritance from base
+
+No base change — `base-latest` is reused unchanged from v1.15.11c (`base-decide` short-circuits at the Hub-probe step). SSH ControlMaster on a writable socket path, gitleaks, and git-crypt continue to ride along from the base.
+
+### Workflow status
+
+This is the first opencode-version-bump publish exercising the afternoon-of-2026-05-28 workflow changes (cache-export removal + 3-attempt retry wrapper) end-to-end on a real upstream release. v1.15.11c proved the publish path mechanically; v1.15.12 is the first one with both an opencode bump and a pi bump driving fresh variant layers.
 
 ## v1.15.11c — 2026-05-28
 
diff --git a/Dockerfile.variant b/Dockerfile.variant
index 1c4e213..e55122c 100644
--- a/Dockerfile.variant
+++ b/Dockerfile.variant
@@ -36,7 +36,7 @@ ARG USER_NAME=developer
 # edit, so the cache-hit class of bug that bit pi-devbox v0.74.0..
 # v0.75.5 cannot apply here.
 ARG INSTALL_OPENCODE=true
-ARG OPENCODE_VERSION=1.15.11
+ARG OPENCODE_VERSION=1.15.12
 RUN if [ "${INSTALL_OPENCODE}" = "true" ]; then \
       NPM_CONFIG_PREFIX=/usr npm install -g opencode-ai@${OPENCODE_VERSION} && \
       opencode --version ; \