fix

codex-rs/Cargo.lock

@@ -773,6 +773,7 @@ dependencies = [
  "tokio",
  "tracing",
  "tracing-subscriber",
+ "uuid",
 ]
 
 [[package]]

codex-rs/README.md

@@ -55,6 +55,14 @@ In the transcript preview, the footer shows an `Esc edit prev` hint while editin
 
 Sometimes it is not convenient to `cd` to the directory you want Codex to use as the "working root" before running Codex. Fortunately, `codex` supports a `--cd` option so you can specify whatever folder you want. You can confirm that Codex is honoring `--cd` by double-checking the **workdir** it reports in the TUI at the start of a new session.
 
+### Resuming sessions
+
+When you use `codex resume`, provide any follow-up prompt *before* an optional session id. This keeps combinations like `codex resume --last "fix the tests"` working while still letting you resume a specific session when needed:
+
+- `codex resume --last "kick off linting"` — resume the most recent session and immediately send a new prompt.
+- `codex resume "draft release notes" d9b7b8b8-3a1f-4a4d-b0a2-4f04bb8d58df` — resume a specific session and send a follow-up prompt.
+- `codex resume d9b7b8b8-3a1f-4a4d-b0a2-4f04bb8d58df` — resume a session without sending a prompt (the CLI treats lone UUIDs as session ids).
+
 ### Shell completions
 
 Generate shell completion scripts via:

codex-rs/cli/Cargo.toml

@@ -36,6 +36,7 @@ ctor = { workspace = true }
 owo-colors = { workspace = true }
 serde_json = { workspace = true }
 supports-color = { workspace = true }
+uuid = { workspace = true }
 tokio = { workspace = true, features = [
     "io-std",
     "macros",

codex-rs/cli/src/main.rs

@@ -1,5 +1,7 @@
 use clap::CommandFactory;
 use clap::Parser;
+use clap::error::Error as ClapError;
+use clap::error::ErrorKind as ClapErrorKind;
 use clap_complete::Shell;
 use clap_complete::generate;
 use codex_arg0::arg0_dispatch_or_else;
@@ -22,6 +24,7 @@ use codex_tui::Cli as TuiCli;
 use owo_colors::OwoColorize;
 use std::path::PathBuf;
 use supports_color::Stream;
+use uuid::Uuid;
 
 mod mcp_cmd;
 
@@ -112,17 +115,17 @@ struct CompletionCommand {
 
 #[derive(Debug, Parser)]
 struct ResumeCommand {
-    /// Conversation/session id (UUID). When provided, resumes this session.
-    /// If omitted, use --last to pick the most recent recorded session.
-    #[arg(value_name = "SESSION_ID")]
-    session_id: Option<String>,
-
-    /// Continue the most recent session without showing the picker.
-    #[arg(long = "last", default_value_t = false, conflicts_with = "session_id")]
-    last: bool,
-
     #[clap(flatten)]
     config_overrides: TuiCli,
+
+    /// Continue the most recent session without showing the picker.
+    #[arg(long = "last", default_value_t = false)]
+    last: bool,
+
+    /// Conversation/session id (UUID). When provided, resumes this session.
+    /// If omitted, use --last to pick the most recent recorded session.
+    #[arg(value_name = "SESSION_ID", index = 2)]
+    session_id: Option<String>,
 }
 
 #[derive(Debug, Parser)]
@@ -286,11 +289,15 @@ async fn cli_main(codex_linux_sandbox_exe: Option<PathBuf>) -> anyhow::Result<()
         Some(Subcommand::AppServer) => {
             codex_app_server::run_main(codex_linux_sandbox_exe, root_config_overrides).await?;
         }
-        Some(Subcommand::Resume(ResumeCommand {
-            session_id,
-            last,
-            config_overrides,
-        })) => {
+        Some(Subcommand::Resume(mut resume_cmd)) => {
+            if let Err(err) = resume_cmd.normalize() {
+                err.exit();
+            }
+            let ResumeCommand {
+                config_overrides,
+                last,
+                session_id,
+            } = resume_cmd;
             interactive = finalize_resume_interactive(
                 interactive,
                 root_config_overrides.clone(),
@@ -491,14 +498,16 @@ mod tests {
             subcommand,
         } = cli;
 
-        let Subcommand::Resume(ResumeCommand {
-            session_id,
-            last,
-            config_overrides: resume_cli,
-        }) = subcommand.expect("resume present")
-        else {
-            unreachable!()
+        let mut resume_cmd = match subcommand.expect("resume present") {
+            Subcommand::Resume(cmd) => cmd,
+            _ => unreachable!(),
         };
+        resume_cmd.normalize().expect("normalize resume args");
+        let ResumeCommand {
+            config_overrides: resume_cli,
+            last,
+            session_id,
+        } = resume_cmd;
 
         finalize_resume_interactive(interactive, root_overrides, session_id, last, resume_cli)
     }
@@ -575,12 +584,45 @@ mod tests {
         assert_eq!(interactive.resume_session_id, None);
     }
 
+    #[test]
+    fn resume_last_accepts_follow_up_prompt() {
+        let interactive = finalize_from_args(["codex", "resume", "--last", "hi there"].as_ref());
+        assert!(interactive.resume_last);
+        assert_eq!(interactive.prompt.as_deref(), Some("hi there"));
+        assert_eq!(interactive.resume_session_id, None);
+    }
+
+    #[test]
+    fn resume_prompt_before_session_id() {
+        let interactive = finalize_from_args(
+            [
+                "codex",
+                "resume",
+                "summarize progress",
+                "123e4567-e89b-12d3-a456-426614174000",
+            ]
+            .as_ref(),
+        );
+        assert_eq!(interactive.prompt.as_deref(), Some("summarize progress"));
+        assert_eq!(
+            interactive.resume_session_id.as_deref(),
+            Some("123e4567-e89b-12d3-a456-426614174000"),
+        );
+        assert!(!interactive.resume_last);
+        assert!(!interactive.resume_picker);
+    }
+
     #[test]
     fn resume_picker_logic_with_session_id() {
-        let interactive = finalize_from_args(["codex", "resume", "1234"].as_ref());
+        let interactive = finalize_from_args(
+            ["codex", "resume", "123e4567-e89b-12d3-a456-426614174000"].as_ref(),
+        );
         assert!(!interactive.resume_picker);
         assert!(!interactive.resume_last);
-        assert_eq!(interactive.resume_session_id.as_deref(), Some("1234"));
+        assert_eq!(
+            interactive.resume_session_id.as_deref(),
+            Some("123e4567-e89b-12d3-a456-426614174000")
+        );
     }
 
     #[test]
@@ -589,7 +631,7 @@ mod tests {
             [
                 "codex",
                 "resume",
-                "sid",
+                "123e4567-e89b-12d3-a456-426614174000",
                 "--oss",
                 "--full-auto",
                 "--search",
@@ -637,7 +679,10 @@ mod tests {
         assert!(has_a && has_b);
         assert!(!interactive.resume_picker);
         assert!(!interactive.resume_last);
-        assert_eq!(interactive.resume_session_id.as_deref(), Some("sid"));
+        assert_eq!(
+            interactive.resume_session_id.as_deref(),
+            Some("123e4567-e89b-12d3-a456-426614174000")
+        );
     }
 
     #[test]
@@ -656,3 +701,45 @@ mod tests {
         assert_eq!(interactive.resume_session_id, None);
     }
 }
+
+impl ResumeCommand {
+    fn normalize(&mut self) -> Result<(), ClapError> {
+        if self.last {
+            if let Some(value) = self.session_id.take() {
+                if Self::looks_like_session_id(&value) {
+                    return Err(ClapError::raw(
+                        ClapErrorKind::ArgumentConflict,
+                        "The argument '--last' cannot be used with '[SESSION_ID]'",
+                    ));
+                }
+                if let Some(existing) = &mut self.config_overrides.prompt {
+                    if !existing.is_empty() {
+                        existing.push(' ');
+                    }
+                    existing.push_str(&value);
+                } else {
+                    self.config_overrides.prompt = Some(value);
+                }
+            }
+            return Ok(());
+        }
+
+        if self.session_id.is_some() {
+            return Ok(());
+        }
+
+        if let Some(prompt) = self.config_overrides.prompt.take() {
+            if Self::looks_like_session_id(&prompt) {
+                self.session_id = Some(prompt);
+            } else {
+                self.config_overrides.prompt = Some(prompt);
+            }
+        }
+
+        Ok(())
+    }
+
+    fn looks_like_session_id(value: &str) -> bool {
+        Uuid::parse_str(value).is_ok()
+    }
+}

codex-rs/exec/Cargo.toml

@@ -30,6 +30,7 @@ codex-protocol = { workspace = true }
 owo-colors = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
+uuid = { workspace = true }
 shlex = { workspace = true }
 tokio = { workspace = true, features = [
     "io-std",

codex-rs/exec/src/cli.rs

@@ -1,7 +1,10 @@
 use clap::Parser;
 use clap::ValueEnum;
+use clap::error::Error as ClapError;
+use clap::error::ErrorKind as ClapErrorKind;
 use codex_common::CliConfigOverrides;
 use std::path::PathBuf;
+use uuid::Uuid;
 
 #[derive(Parser, Debug)]
 #[command(version)]
@@ -100,18 +103,59 @@ pub enum Command {
 
 #[derive(Parser, Debug)]
 pub struct ResumeArgs {
-    /// Conversation/session id (UUID). When provided, resumes this session.
-    /// If omitted, use --last to pick the most recent recorded session.
-    #[arg(value_name = "SESSION_ID")]
-    pub session_id: Option<String>,
+    /// Prompt to send after resuming the session. If `-` is used, read from stdin.
+    #[arg(value_name = "PROMPT", index = 1)]
+    pub prompt: Option<String>,
 
     /// Resume the most recent recorded session (newest) without specifying an id.
-    #[arg(long = "last", default_value_t = false, conflicts_with = "session_id")]
+    #[arg(long = "last", default_value_t = false)]
     pub last: bool,
 
-    /// Prompt to send after resuming the session. If `-` is used, read from stdin.
-    #[arg(value_name = "PROMPT")]
-    pub prompt: Option<String>,
+    /// Conversation/session id (UUID). When provided, resumes this session.
+    /// If omitted, use --last to pick the most recent recorded session.
+    #[arg(value_name = "SESSION_ID", index = 2)]
+    pub session_id: Option<String>,
+}
+
+impl ResumeArgs {
+    pub fn normalize(&mut self) -> Result<(), ClapError> {
+        if self.last {
+            if let Some(value) = self.session_id.take() {
+                if Self::looks_like_session_id(&value) {
+                    return Err(ClapError::raw(
+                        ClapErrorKind::ArgumentConflict,
+                        "The argument '--last' cannot be used with '[SESSION_ID]'",
+                    ));
+                }
+                if let Some(existing) = &mut self.prompt {
+                    if !existing.is_empty() {
+                        existing.push(' ');
+                    }
+                    existing.push_str(&value);
+                } else {
+                    self.prompt = Some(value);
+                }
+            }
+            return Ok(());
+        }
+
+        if self.session_id.is_some() {
+            return Ok(());
+        }
+
+        if let Some(value) = self.prompt.take() {
+            if Self::looks_like_session_id(&value) {
+                self.session_id = Some(value);
+            } else {
+                self.prompt = Some(value);
+            }
+        }
+        Ok(())
+    }
+
+    fn looks_like_session_id(value: &str) -> bool {
+        Uuid::parse_str(value).is_ok()
+    }
 }
 
 #[derive(Debug, Clone, Copy, Default, PartialEq, Eq, ValueEnum)]

codex-rs/exec/src/lib.rs

@@ -61,18 +61,24 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
         json: json_mode,
         experimental_json,
         sandbox_mode: sandbox_mode_cli_arg,
-        prompt,
+        prompt: parent_prompt,
         output_schema: output_schema_path,
         include_plan_tool,
         config_overrides,
     } = cli;
 
     // Determine the prompt source (parent or subcommand) and read from stdin if needed.
-    let prompt_arg = match &command {
+    let mut command = command;
+    let prompt_arg = match &mut command {
         // Allow prompt before the subcommand by falling back to the parent-level prompt
         // when the Resume subcommand did not provide its own prompt.
-        Some(ExecCommand::Resume(args)) => args.prompt.clone().or(prompt),
-        None => prompt,
+        Some(ExecCommand::Resume(args)) => {
+            if let Err(err) = args.normalize() {
+                err.exit();
+            }
+            args.prompt.clone().or_else(|| parent_prompt.clone())
+        }
+        None => parent_prompt,
     };
 
     let prompt = match prompt_arg {

codex-rs/exec/tests/suite/resume.rs

@@ -130,6 +130,62 @@ fn exec_resume_last_appends_to_existing_file() -> anyhow::Result<()> {
     Ok(())
 }
 
+#[test]
+fn exec_resume_last_accepts_prompt_after_flag() -> anyhow::Result<()> {
+    let home = TempDir::new()?;
+    let fixture = std::path::Path::new(env!("CARGO_MANIFEST_DIR"))
+        .join("tests/fixtures/cli_responses_fixture.sse");
+
+    let marker = format!("resume-last-flag-{}", Uuid::new_v4());
+    let prompt = format!("echo {marker}");
+
+    Command::cargo_bin("codex-exec")
+        .context("should find binary for codex-exec")?
+        .env("CODEX_HOME", home.path())
+        .env("OPENAI_API_KEY", "dummy")
+        .env("CODEX_RS_SSE_FIXTURE", &fixture)
+        .env("OPENAI_BASE_URL", "http://unused.local")
+        .arg("--skip-git-repo-check")
+        .arg("-C")
+        .arg(env!("CARGO_MANIFEST_DIR"))
+        .arg(&prompt)
+        .assert()
+        .success();
+
+    let sessions_dir = home.path().join("sessions");
+    let path = find_session_file_containing_marker(&sessions_dir, &marker)
+        .expect("no session file found after first run");
+
+    let marker2 = format!("resume-last-flag-2-{}", Uuid::new_v4());
+    let prompt2 = format!("echo {marker2}");
+
+    Command::cargo_bin("codex-exec")
+        .context("should find binary for codex-exec")?
+        .env("CODEX_HOME", home.path())
+        .env("OPENAI_API_KEY", "dummy")
+        .env("CODEX_RS_SSE_FIXTURE", &fixture)
+        .env("OPENAI_BASE_URL", "http://unused.local")
+        .arg("--skip-git-repo-check")
+        .arg("-C")
+        .arg(env!("CARGO_MANIFEST_DIR"))
+        .arg("resume")
+        .arg("--last")
+        .arg(&prompt2)
+        .assert()
+        .success();
+
+    let resumed_path = find_session_file_containing_marker(&sessions_dir, &marker2)
+        .expect("no resumed session file containing marker2");
+    assert_eq!(
+        resumed_path, path,
+        "resume --last should reuse the existing file",
+    );
+    let content = std::fs::read_to_string(&resumed_path)?;
+    assert!(content.contains(&marker));
+    assert!(content.contains(&marker2));
+    Ok(())
+}
+
 #[test]
 fn exec_resume_by_id_appends_to_existing_file() -> anyhow::Result<()> {
     let home = TempDir::new()?;

codex-rs/tui/src/cli.rs

@@ -7,7 +7,7 @@ use std::path::PathBuf;
 #[command(version)]
 pub struct Cli {
     /// Optional user prompt to start the session.
-    #[arg(value_name = "PROMPT")]
+    #[arg(value_name = "PROMPT", index = 1)]
     pub prompt: Option<String>,
 
     /// Optional image(s) to attach to the initial prompt.