diff --git a/README.md b/README.md
index d935b5b..fdfdfc0 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,7 @@ Add plugin with tokens to `~/.config/opencode/opencode.json`:
 | `SLACK_BOT_TOKEN` | — | Required. Bot token (`xoxb-...`) |
 | `SLACK_APP_TOKEN` | — | Required. App-level token (`xapp-...`) |
 | `DEFAULT_DIRECTORY` | serve directory | Default workspace for new sessions |
+| `DEFAULT_AGENT` | — | Agent name to use for prompts in Slack threads. Reads plugin option first, then `SLACK_DEFAULT_AGENT` env var. Can be overridden per-message with `@<agent>` or per-thread with `!agent`; cleared by `!agent reset`. Useful when the global opencode default agent has an identity you don't want exposed in Slack (e.g., a chat-facing persona) |
 | `ALLOWED_USERS` | — | Comma-separated Slack user IDs or emails. If unset, everyone can use the bot |
 | `ATTACH_TIMEOUT_SEC` | 600 | Timeout (seconds) for `!attach bg_xxx` polling. Reads plugin option first, then env var fallback. Invalid/non-positive values fall back to 600 |
 
diff --git a/dist/plugin.js b/dist/plugin.js
index ea55873..23e8937 100644
--- a/dist/plugin.js
+++ b/dist/plugin.js
@@ -13566,6 +13566,8 @@ var pluginModule = {
     }
     pluginClient = input.client;
     defaultDirectory = expandTilde(options?.DEFAULT_DIRECTORY || process.env.SLACK_DEFAULT_DIRECTORY || input.directory);
+    agentOverride = options?.DEFAULT_AGENT || process.env.SLACK_DEFAULT_AGENT || null;
+    if (agentOverride) log(`default agent: ${agentOverride}`);
     attachBgTimeoutMs = resolveAttachTimeoutMs(options?.ATTACH_TIMEOUT_SEC);
     log(`attach timeout set to ${attachBgTimeoutMs}ms`);
     sessionsPath = join(input.directory, "slack-sessions.json");
diff --git a/src/plugin.ts b/src/plugin.ts
index bda0677..71933cf 100644
--- a/src/plugin.ts
+++ b/src/plugin.ts
@@ -1302,6 +1302,8 @@ const pluginModule: PluginModule = {
 
     pluginClient = input.client;
     defaultDirectory = expandTilde((options?.DEFAULT_DIRECTORY as string) || process.env.SLACK_DEFAULT_DIRECTORY || input.directory);
+    agentOverride = (options?.DEFAULT_AGENT as string) || process.env.SLACK_DEFAULT_AGENT || null;
+    if (agentOverride) log(`default agent: ${agentOverride}`);
     attachBgTimeoutMs = resolveAttachTimeoutMs(options?.ATTACH_TIMEOUT_SEC);
     log(`attach timeout set to ${attachBgTimeoutMs}ms`);
     sessionsPath = join(input.directory, "slack-sessions.json");