Sonny: a guess at your next message, for Tab to take

client/src/config.rs

@@ -18,6 +18,7 @@
 //! task_effort = "high"          # each new task's
 //! lead_profile = "my-lead"     # the role a new lead starts in, not lead
 //! task_profile = "worker"       # what every other agent is told, not task
+//! suggest = false               # no guess at the next message, on by default
 //!
 //! [sonny.mcp_servers.linear]    # an MCP server Sonny's agents reach
 //! url = "https://mcp.linear.app/mcp"
@@ -70,7 +71,7 @@ pub struct Judge {
 }
 
 /// What Sonny starts its agents with.
-#[derive(Clone, Debug, Default, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Sonny {
     pub lead_effort: Option<String>,
     pub task_effort: Option<String>,
@@ -81,6 +82,22 @@ pub struct Sonny {
     pub task_profile: Option<String>,
     /// The MCP servers Sonny's agents reach, by name.
     pub mcp_servers: BTreeMap<String, McpServer>,
+    /// Whether a copy of the agent guesses the person's next message after
+    /// a turn they started, shown in the empty composer for Tab to take.
+    pub suggest: bool,
+}
+
+impl Default for Sonny {
+    fn default() -> Self {
+        Sonny {
+            lead_effort: None,
+            task_effort: None,
+            lead_profile: None,
+            task_profile: None,
+            mcp_servers: BTreeMap::new(),
+            suggest: true,
+        }
+    }
 }
 
 /// An MCP server, under Codex's key names for `[mcp_servers.NAME]`: a
@@ -289,7 +306,13 @@ fn parse(text: &str) -> Result<Config, String> {
             .ok_or_else(|| format!("unknown key {name}"))?;
         let keys: &[&str] = match name.as_str() {
             "judge" => &["model", "effort"],
-            "sonny" => &["lead_effort", "task_effort", "lead_profile", "task_profile"],
+            "sonny" => &[
+                "lead_effort",
+                "task_effort",
+                "lead_profile",
+                "task_profile",
+                "suggest",
+            ],
             _ => return Err(format!("unknown table [{name}]")),
         };
         for (key, value) in section {
@@ -306,6 +329,12 @@ fn parse(text: &str) -> Result<Config, String> {
             if !keys.contains(&key.as_str()) {
                 return Err(format!("unknown key {name}.{key}"));
             }
+            if key == "suggest" {
+                config.sonny.suggest = value
+                    .as_bool()
+                    .ok_or_else(|| format!("{name}.{key} must be true or false"))?;
+                continue;
+            }
             let value = string(&format!("{name}.{key}"), value)?;
             // The daemon judges models and levels when the agents are made.
             *match (name.as_str(), key.as_str()) {
@@ -477,6 +506,12 @@ mod tests {
             parse("[sonny]\nlead_profile = \"my-lead\"\ntask_profile = \"worker\"").unwrap();
         assert_eq!(roles.sonny.lead_profile.as_deref(), Some("my-lead"));
         assert_eq!(roles.sonny.task_profile.as_deref(), Some("worker"));
+        assert!(config.sonny.suggest);
+        assert!(!parse("[sonny]\nsuggest = false").unwrap().sonny.suggest);
+        assert_eq!(
+            parse("[sonny]\nsuggest = \"no\"").unwrap_err(),
+            "sonny.suggest must be true or false"
+        );
         let off = parse("web_search = \"disabled\"").unwrap();
         assert_eq!(off.web_search, WebSearch::Disabled);
         assert!(!config.hide_senders);

sonny/README.md

@@ -138,6 +138,7 @@ at its model's own effort (`AGENT_EFFORT` when its model is
 | Each new task's model | (the lead's) | `threads_model` |
 | Each new task's effort | `[sonny] task_effort` | `threads_effort` |
 | The approver's and lookout's judge | `[judge] model`, `effort` | |
+| A guess at your next message | `[sonny] suggest` (true, the default, or false) | |
 
 `start_task` applies them in code, so the lead's prompt says nothing about
 effort; the lead names a `model` or `effort` only for one the person asks
@@ -259,6 +260,27 @@ out, Ctrl-W, Ctrl-U or Ctrl-K cut it for Ctrl-Y, and Esc lets go of it.
 
 ![A selection in the composer](../docs/sonny/composer-selection.png)
 
+After a turn you started from this window ends well, a copy of the agent
+guesses what you will type next, as Claude Code's prompt suggestions and
+Codex's composer predictions do, and the empty composer shows it dim for
+Tab to take. Tab puts it in the composer to edit or send; it never sends
+itself. The copy is forked where the turn ended, with the agent's tools and
+model so its prompt cache is warm, but allowed no call; it is asked for 2 to
+12 words in your style, or nothing when the next step is not obvious, and is
+deleted once it answers. That is one small model call per turn of yours
+(a steer counts for the turn it joins): none follows a turn the lead, the
+lookout or another window started, one that failed or was stopped, or one
+that ended on a question, so watching a task costs nothing.
+`[sonny] suggest = false` turns it off. Typing hides the guess, a new turn
+drops it, and Tab does what it does otherwise while none shows. Every Sonny
+has it, so a side chat or a task opened in the pane does too.
+
+![The guess, dim in the empty composer after a reply](../docs/sonny/suggest-shown.png)
+
+![Tab took it into the composer, unsent](../docs/sonny/suggest-taken.png)
+
+![The same in a side chat in the pane](../docs/sonny/suggest-side.png)
+
 Pictures go with a message: Ctrl-V takes the one on the clipboard, as in
 Codex and Claude Code (terminals paste only text), and an image file
 dropped on the terminal, or its path pasted, is attached rather than typed.