feat: pass shell context to forge CLI

crates/forge_main/src/cli.rs

@@ -90,6 +90,15 @@ pub struct Cli {
     /// Event to dispatch to the workflow in JSON format.
     #[arg(long, short = 'e')]
     pub event: Option<String>,
+
+    /// Shell context from the terminal environment.
+    ///
+    /// When provided by the shell plugin, this contains information about
+    /// the last command executed in the terminal and its exit code. This
+    /// helps the AI understand what the user was doing before asking for
+    /// help. Format: "command\nexit_code"
+    #[arg(long)]
+    pub shell_context: Option<String>,
 }
 
 impl Cli {

crates/forge_main/src/main.rs

@@ -120,6 +120,25 @@ mod tests {
         assert_eq!(cli_with_flags.restricted, true);
     }
 
+    #[test]
+    fn test_cli_parsing_shell_context() {
+        let cli = Cli::parse_from([
+            "forge",
+            "-p",
+            "fix it",
+            "--shell-context",
+            "rm test\n1",
+        ]);
+        assert_eq!(cli.prompt, Some("fix it".to_string()));
+        assert_eq!(cli.shell_context, Some("rm test\n1".to_string()));
+    }
+
+    #[test]
+    fn test_cli_shell_context_not_required() {
+        let cli = Cli::parse_from(["forge", "-p", "hello"]);
+        assert_eq!(cli.shell_context, None);
+    }
+
     #[test]
     fn test_commit_command_diff_field_initially_none() {
         // Test that the diff field in CommitCommandGroup starts as None

crates/forge_main/src/ui.rs

@@ -2955,6 +2955,39 @@ impl<A: API + ConsoleWriter + 'static, F: Fn() -> A + Send + Sync> UI<A, F> {
             event = event.additional_context(piped);
         }
 
+        // Add shell context from the terminal environment if provided.
+        // The shell plugin captures the last command and its exit code,
+        // passing them via --shell-context so the AI knows what happened
+        // before the user's request.
+        if let Some(ref shell_ctx) = self.cli.shell_context {
+            let mut parts = shell_ctx.splitn(2, '\n');
+            let last_command = parts.next().unwrap_or_default();
+            let exit_code = parts.next().unwrap_or_default();
+
+            if !last_command.is_empty() {
+                let context_text = if exit_code == "0" {
+                    format!(
+                        "Terminal context — the user just ran this command successfully:\n$ {}",
+                        last_command,
+                    )
+                } else {
+                    format!(
+                        "Terminal context — the user just ran this command and it failed (exit code {}):\n$ {}",
+                        exit_code,
+                        last_command,
+                    )
+                };
+
+                // If additional_context is already set (from piped input),
+                // prepend the shell context to it
+                if let Some(existing) = event.additional_context.take() {
+                    event = event.additional_context(format!("{}\n\n{}", context_text, existing));
+                } else {
+                    event = event.additional_context(context_text);
+                }
+            }
+        }
+
         // Create the chat request with the event
         let chat = ChatRequest::new(event, conversation_id);
 

shell-plugin/forge.plugin.zsh

@@ -13,6 +13,9 @@ source "${0:A:h}/lib/highlight.zsh"
 # Core utilities (includes logging)
 source "${0:A:h}/lib/helpers.zsh"
 
+# Shell context tracking (preexec/precmd hooks)
+source "${0:A:h}/lib/shell_context.zsh"
+
 # Completion widget
 source "${0:A:h}/lib/completion.zsh"
 

shell-plugin/lib/helpers.zsh

@@ -40,6 +40,10 @@ function _forge_exec_interactive() {
     cmd=($_FORGE_BIN --agent "$agent_id")
     [[ -n "$_FORGE_SESSION_MODEL" ]] && cmd+=(--model "$_FORGE_SESSION_MODEL")
     [[ -n "$_FORGE_SESSION_PROVIDER" ]] && cmd+=(--provider "$_FORGE_SESSION_PROVIDER")
+    # Pass shell context (last command + exit code) when available
+    if [[ -n "$_FORGE_LAST_COMMAND" ]]; then
+        cmd+=(--shell-context "${_FORGE_LAST_COMMAND}"$'\n'"${_FORGE_LAST_EXIT_CODE}")
+    fi
     cmd+=("$@")
     "${cmd[@]}" </dev/tty >/dev/tty
 }

shell-plugin/lib/shell_context.zsh

@@ -0,0 +1,31 @@
+#!/usr/bin/env zsh
+
+# Shell context tracking for forge plugin
+# Captures the last command and its exit code so that forge can understand
+# what the user was doing before asking for help.
+#
+# Uses ZSH's preexec/precmd hook arrays so that existing user hooks are
+# not overwritten.
+
+# Variables to store shell context
+typeset -g _FORGE_LAST_COMMAND=""
+typeset -g _FORGE_LAST_EXIT_CODE=""
+
+# preexec runs just before a command is executed.
+# We capture the command string here.
+function _forge_preexec() {
+    # $1 is the command string as typed by the user
+    _FORGE_LAST_COMMAND="$1"
+}
+
+# precmd runs just before the prompt is drawn (i.e., after the previous
+# command finishes). We capture the exit code here.
+function _forge_precmd() {
+    # $? is the exit code of the command that just finished
+    _FORGE_LAST_EXIT_CODE="$?"
+}
+
+# Register hooks using ZSH hook arrays (non-destructive)
+autoload -Uz add-zsh-hook
+add-zsh-hook preexec _forge_preexec
+add-zsh-hook precmd _forge_precmd