Add iai-mcp-session-init plugin for automatic memory loading in OpenCode

README.md

@@ -133,15 +133,21 @@ Use the absolute path. `~` and `$HOME` won't expand here.
 
 For Claude Desktop (untested), edit `~/Library/Application Support/Claude/claude_desktop_config.json`.
 
-### Install the OpenCode plugin
+### Install the OpenCode plugins
 
-This is the OpenCode equivalent of the Claude Code Stop hook. It listens for idle sessions and writes a deferred-capture JSONL file for the daemon to drain.
+**Capture plugin** — listens for idle sessions and writes a deferred-capture JSONL file for the daemon to drain.
 
 ```bash
 mkdir -p ~/.config/opencode/plugins
 cp deploy/opencode/iai-mcp-capture.js ~/.config/opencode/plugins/
 ```
 
+**Session-init plugin** — automatically loads session background memory on every new session. The model calls `memory_session_context` before responding, so it has your identity, topic cluster, and rich club context from turn one.
+
+```bash
+cp deploy/opencode/iai-mcp-session-init.js ~/.config/opencode/plugins/
+```
+
 Make sure `@opencode-ai/plugin` is installed:
 
 ```bash
@@ -149,12 +155,27 @@ cd ~/.config/opencode
 npm install @opencode-ai/plugin
 ```
 
-### Connect OpenCode
+Register both plugins in `~/.config/opencode/config.json`:
-
-Add the MCP server to `~/.config/opencode/config.json`:
 
 ```json
 {
+  "plugin": [
+    "~/.config/opencode/plugins/iai-mcp-capture.js",
+    "~/.config/opencode/plugins/iai-mcp-session-init.js"
+  ]
+}
+```
+
+### Connect OpenCode
+
+Add the MCP server and plugins to `~/.config/opencode/config.json`:
+
+```json
+{
+  "plugin": [
+    "~/.config/opencode/plugins/iai-mcp-capture.js",
+    "~/.config/opencode/plugins/iai-mcp-session-init.js"
+  ],
   "mcp": {
     "iai-mcp": {
       "type": "local",
@@ -165,7 +186,7 @@ Add the MCP server to `~/.config/opencode/config.json`:
 }
 ```
 
-Use the absolute path to `mcp-wrapper/dist/index.js`. The plugin file (`iai-mcp-capture.js`) must already be in `~/.config/opencode/plugins/`.
+Use the absolute path to `mcp-wrapper/dist/index.js`. Both plugin files must already be in `~/.config/opencode/plugins/`.
 
 ### Verify
 
@@ -362,7 +383,7 @@ Limitations worth knowing about:
 
 Claude Code is the primary host, validated in daily use.
 
-OpenCode is supported via the `iai-mcp-capture.js` plugin (see Install the OpenCode plugin above) and MCP server config in `~/.config/opencode/config.json`.
+OpenCode is supported via the `iai-mcp-capture.js` and `iai-mcp-session-init.js` plugins (see Install the OpenCode plugins above) and MCP server config in `~/.config/opencode/config.json`.
 
 Claude Desktop should work (uses `claude_desktop_config.json` instead of `~/.claude.json`) but hasn't been tested end to end.
 

deploy/opencode/iai-mcp-session-init.js

@@ -0,0 +1,40 @@
+/**
+ * iai-mcp session-init plugin for OpenCode.
+ *
+ * Sets the system prompt via chat.message hook's UserMessage.system field.
+ * This reaches the main agent and triggers memory_session_context on every session.
+ */
+
+export const IaiMcpSessionInit = async ({
+  client,
+  project,
+  directory,
+  worktree,
+  experimental_workspace,
+  serverUrl,
+  $,
+}) => {
+  const injectedSessions = new Set();
+
+  return {
+    event: async ({ event }) => {
+      if (event.type !== "session.updated") return;
+      const sid = event.properties?.info?.id;
+      if (!sid || injectedSessions.has(sid)) return;
+      injectedSessions.add(sid);
+    },
+
+    "chat.message": async (input, output) => {
+      const sid = input.sessionID;
+      if (!sid || !injectedSessions.has(sid)) return;
+      if (injectedSessions.has(`done-${sid}`)) return;
+
+      if (output.message) {
+        output.message.system =
+          "MANDATORY: Call `memory_session_context` (no arguments) BEFORE answering any user query.";
+      }
+
+      injectedSessions.add(`done-${sid}`);
+    },
+  };
+};