feat(opencode): add v2 adapter with Dual Support (V1 + V2 in one pack…

…age) Add an OpenCode v2 plugin mouth alongside the existing v1 one so a single published package serves both host generations. - core.ts: host-agnostic ContextModeCore (SessionDB, capture/claim, routing islands, ctx tool handlers); memoized per platform::loadScopeDir so plugin load is idempotent. - plugin-v2.ts: setupV2 mouth — registers the 11 ctx tools under the `ctx` namespace (effective ctx_* names), routing enforcement, session/prompt capture, routing-block + resume-pointer injection on primary requests, compaction ownership (replaces the host summary with our snapshot), and a context-mode-owned destructive-tool policy (ctx_purge/ctx_upgrade refused by default; CONTEXT_MODE_ALLOW_DESTRUCTIVE=1 to enable). - plugin.ts: merged default export {id, setup, server} — V1 hosts call server(), V2 hosts call setup(); ContextModePlugin named export preserved. - index.ts: AdapterTarget (v1/v2) axis; pluginKey/oppositeKey; stale-key removal on target switch; doctor warns on a stale opposite key; detectTargetFromConfig. - detect.ts: getAdapter(platform?, pluginTarget?) threads the target. - cli.ts: --v2/--opencode2 flag + resolveUpgradeTarget (explicit -> PATH -> existing config -> v1). - configs/opencode/opencode-v2.json: v2 `plugins`-key template. - docs: honest v2 permission posture + trust boundary + upgrade path. @opencode/plugin and @opencode/schema are type-only devDependencies (import type -> erased at runtime). v1 behavior is byte-identical; the 57 v1 tests are unchanged. Full suite green (4760 passed). Live-verified against OpenCode 2.0.11: the plugin loads via the `plugins` key and 11 ctx tools register under the ctx namespace with the correct bash-permission bucket and destructive set.
nathanpride · Sep 21, 2026 · Sep 21, 2026 · Sep 21, 2026 · Sep 22, 2026 · Sep 22, 2026
commit 95859ea3140ade40782107fb0f03dd16c0f1f2f3
diff --git a/cli.bundle.mjs b/cli.bundle.mjs
diff --git a/configs/opencode/opencode-v2.json b/configs/opencode/opencode-v2.json
@@ -0,0 +1,6 @@
+{
+  "$schema": "https://opencode.ai/config.json",
+  "plugins": [
+    "context-mode"
+  ]
+}
diff --git a/docs/platform-support.md b/docs/platform-support.md
@@ -188,6 +188,64 @@ When OpenCode triggers `experimental.session.compacting` (auto on context overfl
 
 ---
 
+### OpenCode v2 (Dual Support)
+
+**Status:** Fully supported (v2 adapter, shipped in the same npm package as v1)
+
+context-mode ships **one package that serves both OpenCode V1 and V2 hosts**. The package's default export carries both entrypoints: V1 hosts call `server()`, V2 hosts call `setup()`. Nothing else changes for existing V1 users — the V1 mouth is byte-identical.
+
+**Config key (V2):** the `plugins` array (plural), not the V1 `plugin` array.
+
+```json
+{
+  "$schema": "https://opencode.ai/config.json",
+  "plugins": ["context-mode"]
+}
+```
+
+Entries may be a bare string or a `{ "package": "...", "options": { ... } }` object. Template: `configs/opencode/opencode-v2.json`.
+
+**Hook mapping (V1 → V2):**
+
+| V1 hook | V2 hook |
+| --- | --- |
+| `tool` (register) | `ctx.tool.transform` (add) |
+| `tool.execute.before` / `.after` | `ctx.tool.hook("execute.before" / "execute.after")` |
+| `chat.message` | `ctx.session.hook("prompt")` |
+| `experimental.session.compacting` | `ctx.session.hook("compaction")` |
+| `experimental.chat.system.transform` | `ctx.session.hook("context")` |
+
+**Tool namespace:** tools register under the `ctx` namespace. The host computes the effective name as `${namespace.replaceAll(".","_")}_${sanitize(name)}`, so a bare `execute` becomes `ctx_execute` — the same names V1 users see.
+
+**Compaction ownership:** on `ctx.session.hook("compaction")`, context-mode replaces the host's model-generated summary with its own snapshot (`ev.result = { summary }`), skipping the extra model call. The guard only fires when the snapshot is non-empty. The host retains the recent tail (≤ `compaction.keep.tokens`, ~15k) — the old `autoBlock` lever is dropped.
+
+**Routing block + resume pointer:** injected into `ev.system` in the `context` hook. The `context` hook fires only for `kind="primary"` requests, so it never pollutes the compaction-summary path. A quorum guard (`systemHasRoutingInstructions`) keeps the block from being added twice.
+
+**Permission posture (honest — read this):**
+
+V2's plugin-tool permission model is **coarser than V1's per-call hooks**. Be aware of what context-mode does and does not provide on V2:
+
+- The host creates **no per-call permission request** for plugin tools. There is **no host `ask`** for `ctx_*` calls.
+- **No granular-bash parity** and **no external-directory scoping** for sandboxed ctx tools — the sandbox runs with the plugin process's own filesystem/network reach, not a host-mediated grant.
+- The **only** host-side lever is a blanket deny: a `permission` rule of `resource:"*"` + `effect:"deny"` (`whollyDisabled`) removes the tool entirely.
+- context-mode's single in-plugin lever is `permission: "bash"` on `ctx_execute` / `ctx_execute_file` / `ctx_batch_execute`, which routes those through the host's bash permission bucket.
+- **Trust boundary is plugin installation, not per-call.** Installing `context-mode` trusts it to run code in-process. Do not install it in a tree you do not trust.
+
+**Destructive-tool policy (V2 only):** `ctx_purge` and `ctx_upgrade` are **refused by default**. They throw a context-mode-attributed error (`disabled by context-mode policy … not a host permission denial`). Set `CONTEXT_MODE_ALLOW_DESTRUCTIVE=1` (or `true`/`yes`) to enable them. The CLI (`context-mode upgrade`) remains the supported upgrade/purge path.
+
+**Upgrade / key migration:** `context-mode upgrade` resolves the target in this order:
+1. explicit `--v2` / `--opencode2` flag → V2
+2. `opencode2` binary on `PATH` → V2
+3. existing `plugins` key in config → V2
+4. existing `plugin` key in config → V1
+5. default → V1
+
+When switching targets, the installer writes the correct key and **removes the stale opposite key** (a leftover `plugin` alongside `plugins` would double-register). A pure-V1 config is left byte-identical. `context-mode doctor` warns when a stale opposite-generation key is present.
+
+**Not yet on V2:** usage/token capture (V2's `session.usage.updated` / `step.ended` shape differs from V1's `message.updated` parser) is deferred — it is out of scope for the v2 adapter change.
+
+---
+
 ### Codex CLI
 
 **Status:** Supported (MCP active, hooks require `[features].hooks = true`)

diff --git a/package.json b/package.json
@@ -111,6 +111,8 @@
     "zod": "^3.25.0"
   },
   "devDependencies": {
+    "@opencode/plugin": "^2.0.12",
+    "@opencode/schema": "^2.0.12",
     "@types/better-sqlite3": "^7.6.13",
     "@types/node": "^22.19.11",
     "@types/turndown": "^5.0.5",

diff --git a/server.bundle.mjs b/server.bundle.mjs
diff --git a/src/adapters/detect.ts b/src/adapters/detect.ts
@@ -634,7 +634,10 @@ export function detectPlatform(clientInfo?: { name: string; version?: string }):
  * Get the adapter instance for a given platform.
  * Lazily imports platform-specific adapter modules.
  */
-export async function getAdapter(platform?: PlatformId): Promise<HookAdapter> {
+export async function getAdapter(
+  platform?: PlatformId,
+  pluginTarget?: import("./opencode/index.js").AdapterTarget,
+): Promise<HookAdapter> {
   const ?? detectPlatform().platform;
 
   switch (target) {
@@ -651,7 +654,7 @@ export async function getAdapter(platform?: PlatformId): Promise<HookAdapter> {
     case "kilo":
     case "opencode": {
       const { OpenCodeAdapter } = await import("./opencode/index.js");
-      return new OpenCodeAdapter(target);
+      return new OpenCodeAdapter(target, pluginTarget ?? "v1");
     }
 
     case "openclaw": {