read all AGENTS.md up to git root

codex-rs/core/src/lib.rs

@@ -43,7 +43,7 @@ mod models;
 mod openai_model_info;
 mod openai_tools;
 pub mod plan_tool;
-mod project_doc;
+pub mod project_doc;
 mod rollout;
 pub(crate) mod safety;
 pub mod seatbelt;

codex-rs/core/src/project_doc.rs

@@ -1,18 +1,19 @@
 //! Project-level documentation discovery.
 //!
-//! Project-level documentation can be stored in a file named `AGENTS.md`.
-//! Currently, we include only the contents of the first file found as follows:
+//! Project-level documentation can be stored in files named `AGENTS.md`.
+//! We include the concatenation of all files found along the path from the
+//! repository root to the current working directory as follows:
 //!
-//! 1.  Look for the doc file in the current working directory (as determined
-//!     by the `Config`).
-//! 2.  If not found, walk *upwards* until the Git repository root is reached
-//!     (detected by the presence of a `.git` directory/file), or failing that,
-//!     the filesystem root.
-//! 3.  If the Git root is encountered, look for the doc file there. If it
-//!     exists, the search stops – we do **not** walk past the Git root.
+//! 1.  Determine the Git repository root by walking upwards from the current
+//!     working directory until a `.git` directory or file is found. If no Git
+//!     root is found, only the current working directory is considered.
+//! 2.  Collect every `AGENTS.md` found from the repository root down to the
+//!     current working directory (inclusive) and concatenate their contents in
+//!     that order.
+//! 3.  We do **not** walk past the Git root.
 
 use crate::config::Config;
-use std::path::Path;
+use std::path::PathBuf;
 use tokio::io::AsyncReadExt;
 use tracing::error;
 
@@ -26,7 +27,7 @@ const PROJECT_DOC_SEPARATOR: &str = "\n\n--- project-doc ---\n\n";
 /// Combines `Config::instructions` and `AGENTS.md` (if present) into a single
 /// string of instructions.
 pub(crate) async fn get_user_instructions(config: &Config) -> Option<String> {
-    match find_project_doc(config).await {
+    match read_project_docs(config).await {
         Ok(Some(project_doc)) => match &config.user_instructions {
             Some(original_instructions) => Some(format!(
                 "{original_instructions}{PROJECT_DOC_SEPARATOR}{project_doc}"
@@ -41,95 +42,135 @@ pub(crate) async fn get_user_instructions(config: &Config) -> Option<String> {
     }
 }
 
-/// Attempt to locate and load the project documentation. Currently, the search
-/// starts from `Config::cwd`, but if we may want to consider other directories
-/// in the future, e.g., additional writable directories in the `SandboxPolicy`.
+/// Attempt to locate and load the project documentation.
 ///
-/// On success returns `Ok(Some(contents))`. If no documentation file is found
-/// the function returns `Ok(None)`. Unexpected I/O failures bubble up as
-/// `Err` so callers can decide how to handle them.
-async fn find_project_doc(config: &Config) -> std::io::Result<Option<String>> {
-    let max_bytes = config.project_doc_max_bytes;
-
-    // Attempt to load from the working directory first.
-    if let Some(doc) = load_first_candidate(&config.cwd, CANDIDATE_FILENAMES, max_bytes).await? {
-        return Ok(Some(doc));
+/// On success returns `Ok(Some(contents))` where `contents` is the
+/// concatenation of all discovered docs. If no documentation file is found the
+/// function returns `Ok(None)`. Unexpected I/O failures bubble up as `Err` so
+/// callers can decide how to handle them.
+pub async fn read_project_docs(config: &Config) -> std::io::Result<Option<String>> {
+    let max_total = config.project_doc_max_bytes;
+
+    if max_total == 0 {
+        return Ok(None);
     }
 
-    // Walk up towards the filesystem root, stopping once we encounter the Git
-    // repository root. The presence of **either** a `.git` *file* or
-    // *directory* counts.
-    let mut dir = config.cwd.clone();
-
-    // Canonicalize the path so that we do not end up in an infinite loop when
-    // `cwd` contains `..` components.
-    if let Ok(canon) = dir.canonicalize() {
-        dir = canon;
+    let paths = discover_project_doc_paths(config)?;
+    if paths.is_empty() {
+        return Ok(None);
     }
 
-    while let Some(parent) = dir.parent() {
-        // `.git` can be a *file* (for worktrees or submodules) or a *dir*.
-        let git_marker = dir.join(".git");
-        let git_exists = match tokio::fs::metadata(&git_marker).await {
-            Ok(_) => true,
-            Err(e) if e.kind() == std::io::ErrorKind::NotFound => false,
-            Err(e) => return Err(e),
-        };
+    let mut remaining: u64 = max_total as u64;
+    let mut parts: Vec<String> = Vec::new();
 
-        if git_exists {
-            // We are at the repo root – attempt one final load.
-            if let Some(doc) = load_first_candidate(&dir, CANDIDATE_FILENAMES, max_bytes).await? {
-                return Ok(Some(doc));
-            }
+    for p in paths {
+        if remaining == 0 {
             break;
         }
 
-        dir = parent.to_path_buf();
-    }
-
-    Ok(None)
-}
-
-/// Attempt to load the first candidate file found in `dir`. Returns the file
-/// contents (truncated if it exceeds `max_bytes`) when successful.
-async fn load_first_candidate(
-    dir: &Path,
-    names: &[&str],
-    max_bytes: usize,
-) -> std::io::Result<Option<String>> {
-    for name in names {
-        let candidate = dir.join(name);
-
-        let file = match tokio::fs::File::open(&candidate).await {
+        let file = match tokio::fs::File::open(&p).await {
+            Ok(f) => f,
             Err(e) if e.kind() == std::io::ErrorKind::NotFound => continue,
             Err(e) => return Err(e),
-            Ok(f) => f,
         };
 
         let size = file.metadata().await?.len();
+        let mut reader = tokio::io::BufReader::new(file).take(remaining);
+        let mut data: Vec<u8> = Vec::new();
+        reader.read_to_end(&mut data).await?;
 
-        let reader = tokio::io::BufReader::new(file);
-        let mut data = Vec::with_capacity(std::cmp::min(size as usize, max_bytes));
-        let mut limited = reader.take(max_bytes as u64);
-        limited.read_to_end(&mut data).await?;
-
-        if size as usize > max_bytes {
+        if size > remaining {
             tracing::warn!(
-                "Project doc `{}` exceeds {max_bytes} bytes - truncating.",
-                candidate.display(),
+                "Project doc `{}` exceeds remaining budget ({} bytes) - truncating.",
+                p.display(),
+                remaining,
             );
         }
 
-        let contents = String::from_utf8_lossy(&data).to_string();
-        if contents.trim().is_empty() {
-            // Empty file – treat as not found.
-            continue;
+        let text = String::from_utf8_lossy(&data).to_string();
+        if !text.trim().is_empty() {
+            parts.push(text);
+            remaining = remaining.saturating_sub(data.len() as u64);
+        }
+    }
+
+    if parts.is_empty() {
+        Ok(None)
+    } else {
+        Ok(Some(parts.join("\n\n")))
+    }
+}
+
+/// Discover the list of AGENTS.md files using the same search rules as
+/// `read_project_docs`, but return the file paths instead of concatenated
+/// contents. The list is ordered from repository root to the current working
+/// directory (inclusive). Symlinks are allowed. When `project_doc_max_bytes`
+/// is zero, returns an empty list.
+pub fn discover_project_doc_paths(config: &Config) -> std::io::Result<Vec<PathBuf>> {
+    let mut dir = config.cwd.clone();
+    if let Ok(canon) = dir.canonicalize() {
+        dir = canon;
+    }
+
+    // Build chain from cwd upwards and detect git root.
+    let mut chain: Vec<PathBuf> = vec![dir.clone()];
+    let mut git_root: Option<PathBuf> = None;
+    let mut cursor = dir.clone();
+    while let Some(parent) = cursor.parent() {
+        let git_marker = cursor.join(".git");
+        let git_exists = match std::fs::metadata(&git_marker) {
+            Ok(_) => true,
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => false,
+            Err(e) => return Err(e),
+        };
+
+        if git_exists {
+            git_root = Some(cursor.clone());
+            break;
         }
 
-        return Ok(Some(contents));
+        chain.push(parent.to_path_buf());
+        cursor = parent.to_path_buf();
     }
 
-    Ok(None)
+    let search_dirs: Vec<PathBuf> = if let Some(root) = git_root {
+        let mut dirs: Vec<PathBuf> = Vec::new();
+        let mut saw_root = false;
+        for p in chain.iter().rev() {
+            if !saw_root {
+                if p == &root {
+                    saw_root = true;
+                } else {
+                    continue;
+                }
+            }
+            dirs.push(p.clone());
+        }
+        dirs
+    } else {
+        vec![config.cwd.clone()]
+    };
+
+    let mut found: Vec<PathBuf> = Vec::new();
+    for d in search_dirs {
+        for name in CANDIDATE_FILENAMES {
+            let candidate = d.join(name);
+            match std::fs::symlink_metadata(&candidate) {
+                Ok(md) => {
+                    let ft = md.file_type();
+                    // Allow regular files and symlinks; opening will later fail for dangling links.
+                    if ft.is_file() || ft.is_symlink() {
+                        found.push(candidate);
+                        break;
+                    }
+                }
+                Err(e) if e.kind() == std::io::ErrorKind::NotFound => continue,
+                Err(e) => return Err(e),
+            }
+        }
+    }
+
+    Ok(found)
 }
 
 #[cfg(test)]
@@ -278,4 +319,32 @@ mod tests {
 
         assert_eq!(res, Some(INSTRUCTIONS.to_string()));
     }
+
+    /// When both the repository root and the working directory contain
+    /// AGENTS.md files, their contents are concatenated from root to cwd.
+    #[tokio::test]
+    async fn concatenates_root_and_cwd_docs() {
+        let repo = tempfile::tempdir().expect("tempdir");
+
+        // Simulate a git repository.
+        std::fs::write(
+            repo.path().join(".git"),
+            "gitdir: /path/to/actual/git/dir\n",
+        )
+        .unwrap();
+
+        // Repo root doc.
+        fs::write(repo.path().join("AGENTS.md"), "root doc").unwrap();
+
+        // Nested working directory with its own doc.
+        let nested = repo.path().join("workspace/crate_a");
+        std::fs::create_dir_all(&nested).unwrap();
+        fs::write(nested.join("AGENTS.md"), "crate doc").unwrap();
+
+        let mut cfg = make_config(&repo, 4096, None);
+        cfg.cwd = nested;
+
+        let res = get_user_instructions(&cfg).await.expect("doc expected");
+        assert_eq!(res, "root doc\n\ncrate doc");
+    }
 }

codex-rs/tui/src/history_cell.rs

@@ -11,6 +11,7 @@ use codex_core::config::Config;
 use codex_core::plan_tool::PlanItemArg;
 use codex_core::plan_tool::StepStatus;
 use codex_core::plan_tool::UpdatePlanArgs;
+use codex_core::project_doc::discover_project_doc_paths;
 use codex_core::protocol::FileChange;
 use codex_core::protocol::McpInvocation;
 use codex_core::protocol::SandboxPolicy;
@@ -538,6 +539,54 @@ pub(crate) fn new_status_output(
         sandbox_name.into(),
     ]));
 
+    // AGENTS.md files discovered via core's project_doc logic
+    let agents_list = {
+        match discover_project_doc_paths(config) {
+            Ok(paths) => {
+                let mut rels: Vec<String> = Vec::new();
+                for p in paths {
+                    let display = if let Some(parent) = p.parent() {
+                        if parent == config.cwd {
+                            "AGENTS.md".to_string()
+                        } else {
+                            let mut cur = config.cwd.as_path();
+                            let mut ups = 0usize;
+                            let mut reached = false;
+                            while let Some(c) = cur.parent() {
+                                if cur == parent {
+                                    reached = true;
+                                    break;
+                                }
+                                cur = c;
+                                ups += 1;
+                            }
+                            if reached {
+                                format!("{}AGENTS.md", "../".repeat(ups))
+                            } else if let Ok(stripped) = p.strip_prefix(&config.cwd) {
+                                stripped.display().to_string()
+                            } else {
+                                p.display().to_string()
+                            }
+                        }
+                    } else {
+                        p.display().to_string()
+                    };
+                    rels.push(display);
+                }
+                rels
+            }
+            Err(_) => Vec::new(),
+        }
+    };
+    if agents_list.is_empty() {
+        lines.push(Line::from("  • AGENTS files: (none)"));
+    } else {
+        lines.push(Line::from(vec![
+            "  • AGENTS files: ".into(),
+            agents_list.join(", ").into(),
+        ]));
+    }
+
     lines.push(Line::from(""));
 
     // 👤 Account (only if ChatGPT tokens exist), shown under the first block