openai/codex · error · MemoriesBackendError

line_offset must be a 1-indexed line number

Error message

line_offset must be a 1-indexed line number

What it means

Thrown by the memories read path (codex-rs/ext/memories/src/local/read.rs:16-18) when ReadMemoryRequest.line_offset is 0. Memory files are addressed with 1-indexed lines, where line 1 is the first line, so 0 is never a valid start and the request is rejected before any filesystem access. The tool-level schema (codex-rs/ext/memories/src/tools/read.rs:29) already declares schemars range(min = 1) and defaults to 1, so this variant is reached mainly by code calling the MemoriesBackend trait directly.

Source

Thrown at codex-rs/ext/memories/src/backend.rs:149

    pub content: String,
    pub matched_queries: Vec<String>,
}

#[derive(Debug, thiserror::Error)]
pub enum MemoriesBackendError {
    #[error("filename '{filename}' {reason}")]
    InvalidFilename { filename: String, reason: String },
    #[error("ad-hoc note must not be empty")]
    EmptyAdHocNote,
    #[error("ad-hoc note '{filename}' already exists")]
    AdHocNoteAlreadyExists { filename: String },
    #[error("path '{path}' {reason}")]
    InvalidPath { path: String, reason: String },
    #[error("cursor '{cursor}' {reason}")]
    InvalidCursor { cursor: String, reason: String },
    #[error("path '{path}' was not found")]
    NotFound { path: String },
    #[error("line_offset must be a 1-indexed line number")]
    InvalidLineOffset,
    #[error("max_lines must be a positive integer")]
    InvalidMaxLines,
    #[error("line_offset exceeds file length")]
    LineOffsetExceedsFileLength,
    #[error("path '{path}' is not a file")]
    NotFile { path: String },
    #[error("queries must not be empty or contain empty strings")]
    EmptyQuery,
    #[error("all_within_lines.line_count must be a positive integer")]
    InvalidMatchWindow,
    #[error("I/O error while reading memories: {0}")]
    Io(#[from] std::io::Error),
}

impl MemoriesBackendError {
    pub fn invalid_filename(filename: impl Into<String>, reason: impl Into<String>) -> Self {
        Self::InvalidFilename {

View on GitHub (pinned to 339751715c)

Solutions

1. Pass line_offset >= 1 (the first line of the file is 1).
2. Translate 0-based indexes with line_offset = index + 1.
3. Default the value to 1 at your boundary, mirroring tools/read.rs (unwrap_or(1)).
4. Keep a schemars range(min = 1) constraint on any JSON argument so invalid values fail schema validation with a clearer message.

Example fix

// before
let resp = backend.read(ReadMemoryRequest {
    path,
    line_offset: cursor_index, // 0-based index from the editor
    max_lines: Some(200),
    max_tokens: 0,
}).await?;

// after
let resp = backend.read(ReadMemoryRequest {
    path,
    line_offset: cursor_index + 1, // convert 0-based index to 1-indexed line
    max_lines: Some(200),
    max_tokens: 0,
}).await?;

// Rust - validate before calling MemoriesBackend::read
fn valid_line_offset(offset: usize) -> bool {
    offset >= 1 // lines are 1-indexed
}

// convert a 0-based index safely at the boundary
let line_offset = raw_index.saturating_add(1).max(1);

match backend.read(request).await {
    Ok(response) => { /* ... */ }
    Err(MemoriesBackendError::InvalidLineOffset) => {
        // caller bug: 0 was passed; correct to 1 and retry once
    }
    Err(other) => return Err(other),
}

When it happens

Trigger: Calling backend.read with ReadMemoryRequest { line_offset: 0, .. }; a usize field that defaulted to 0; feeding a 0-based index from an editor, cursor, or grep-style output straight into line_offset; a custom ToolExecutor that parses args without the ReadArgs schema constraint.

Common situations: Porting editor or grep-style code that numbers lines from 0; tests constructing ReadMemoryRequest by hand; a UI passing its 0-based selection start; refactors that renamed an index field into line_offset without adding 1.

Related errors

• filename '{filename}' {reason}
• ad-hoc note must not be empty
• path '{path}' {reason}
• max_lines must be a positive integer
• path '{path}' is not a file

AI-assisted analysis of openai/codex@339751715c (2026-08-25). Data as JSON: /api/errors/0d893a9270195df0. Report an issue: GitHub.