thinking
Investigating binary sizes

I need to check the codex-rs repository to explain why the project's binaries
are large. The user is likely seeking specifics about the setup: are Rust builds
static, what features are enabled, and is debug information included? It could
be due to static linking, included OpenSSL, or how panic handling is set up. I
should look into the Cargo.toml file to confirm features and profiles without
needing to edit any code. Let's get started on this!

codex
I’m going to scan the workspace and Cargo manifests to see build profiles and
dependencies that impact binary size. Then I’ll summarize the main causes.

⚡  Running ls -la
  ⎿ total 6696
    drwxr-xr-x@ 39 easong  staff     1248 Aug  9 08:49 .
    drwxr-xr-x@ 29 easong  staff      928 Aug  9 08:50 ..
    -rw-r--r--@  1 easong  staff    10244 Aug  8 21:13 .DS_Store
    -rw-r--r--@  1 easong  staff      212 Aug  4 18:49 .gitignore
… +30 lines
    -rw-r--r--@  1 easong  staff     9971 Aug  8 23:07 simpler.md
    drwxr-xr-x@  6 easong  staff      192 Aug  4 22:40 target
    drwxr-xr-x@  6 easong  staff      192 Aug  7 19:20 tui
    -rw-r--r--@  1 easong  staff     8639 Aug  6 23:30 typewriter.md
    -rw-r--r--@  1 easong  staff     7673 Aug  6 21:58 wrap-plan.md
⚡  Running sed -n '1,200p' Cargo.toml
  ⎿ [workspace]
    members = [
        "ansi-escape",
        "apply-patch",
        "arg0",
… +38 lines
    codegen-units = 1

    [patch.crates-io]
    # ratatui = { path = "../../ratatui" }
    ratatui = { git = "https://github.com/nornagon/ratatui", branch =
"nornagon-v0.29.0-patch" }
Optimizing Rust Release Profile

I'm reviewing the workspace's release profile, which has settings like lto=fat,
strip=symbols, and codegen-units=1 to reduce binary size. However, it seems that
"strip = symbols" only removes symbols, not debug information. In Rust 1.73+,
both "symbols" and "debuginfo" stripping options are available. I should check
whether using these results in a smaller binary. I’ll also skim through crates
for heavy dependencies in Cargo.toml, including cli, core, exec, linux-sandbox,
tui, login, ollama, and mcp.

⚡  Running for d in ansi-escape apply-patch arg0 cli common core exec execpolicy
file-search linux-sandbox login mcp-client mcp-server mcp-types ollama tui; do
echo "--- $d/Cargo.toml"; sed -n '1,200p' $d/Cargo.toml; echo; done
  ⎿ --- ansi-escape/Cargo.toml
    [package]
    edition = "2024"
    name = "codex-ansi-escape"
    version = { workspace = true }
… +237 lines
        "process",
        "rt-multi-thread",
        "signal",
    ] }
    tracing = { version
⚡  Running sed -n '1,200p' execpolicy/Cargo.toml
  ⎿ [package]
    name = "codex-execpolicy"
    version = { workspace = true }
    edition = "2024"

… +23 lines
    serde_json = "1.0.142"
    serde_with = { version = "3", features = ["macros"] }

    [dev-dependencies]
    tempfile = "3.13.0"
⚡  Running sed -n '1,200p' file-search/Cargo.toml
  ⎿ [package]
    edition = "2024"
    name = "codex-file-search"
    version = { workspace = true }

… +11 lines
    ignore = "0.4.23"
    nucleo-matcher = "0.3.1"
    serde = { version = "1", features = ["derive"] }
    serde_json = "1.0.142"
    tokio = { version = "1", features = ["full"] }
⚡  Running sed -n '1,200p' linux-sandbox/Cargo.toml
  ⎿ [package]
    edition = "2024"
    name = "codex-linux-sandbox"
    version = { workspace = true }

… +24 lines
        "macros",
        "process",
        "rt-multi-thread",
        "signal",
    ] }
⚡  Running sed -n '1,200p' login/Cargo.toml
  ⎿ [package]
    edition = "2024"
    name = "codex-login"
    version = { workspace = true }

… +17 lines
    ] }

    [dev-dependencies]
    pretty_assertions = "1.4.1"
    tempfile = "3"
⚡  Running sed -n '1,200p' mcp-client/Cargo.toml
  ⎿ [package]
    name = "codex-mcp-client"
    version = { workspace = true }
    edition = "2024"

… +13 lines
        "process",
        "rt-multi-thread",
        "sync",
        "time",
    ] }
⚡  Running sed -n '1,200p' mcp-server/Cargo.toml
  ⎿ [package]
    edition = "2024"
    name = "codex-mcp-server"
    version = { workspace = true }

… +35 lines
    mcp_test_support = { path = "tests/common" }
    pretty_assertions = "1.4.1"
    tempfile = "3"
    tokio-test = "0.4"
    wiremock = "0.6"
⚡  Running sed -n '1,200p' mcp-types/Cargo.toml
  ⎿ [package]
    edition = "2024"
    name = "mcp-types"
    version = { workspace = true }

… +1 lines
    workspace = true

    [dependencies]
    serde = { version = "1", features = ["derive"] }
    serde_json = "1"
⚡  Running sed -n '1,200p' ollama/Cargo.toml
  ⎿ [package]
    edition = "2024"
    name = "codex-ollama"
    version = { workspace = true }

… +22 lines
    tracing = { version = "0.1.41", features = ["log"] }
    wiremock = "0.6"

    [dev-dependencies]
    tempfile = "3"
⚡  Running sed -n '1,200p' tui/Cargo.toml
  ⎿ [package]
    edition = "2024"
    name = "codex-tui"
    version = { workspace = true }

… +74 lines
    chrono = { version = "0.4", features = ["serde"] }
    insta = "1.43.1"
    pretty_assertions = "1"
    rand = "0.8"
    vt100 = "0.16.2"
⚡  Running sed -n '1,200p' chatgpt/Cargo.toml
  ⎿ [package]
    edition = "2024"
    name = "codex-chatgpt"
    version = { workspace = true }

… +11 lines
    serde_json = "1"
    tokio = { version = "1", features = ["full"] }

    [dev-dependencies]
    tempfile = "3"
thinking
Considering binary size impacts

I’m evaluating how binary size is influenced by various factors. There are many
binaries, such as codex and codex-exec, which include dependencies by default,
pulling in features like Tokio and hyper. For instance, reqwest includes
default features like TLS through rustls. If default features remain enabled,
it inflates the size with many additional components. I notice that for musl
targets, using vendored builds of OpenSSL could significantly increase binary
size. This is quite the intricate web of dependencies!

Analyzing musl and binary size

I’m considering the implications of building for musl with static linking.
In this case, OpenSSL might come into play through some crates, but reqwest
defaults to using rustls, although openssl-sys vendored could increase binary
size. It’s interesting to think about whether they’re targeting musl, especially
since it seems they might often be building for Mac and Linux with dynamic
linking instead.

I also realize there’s a difference between debug and release builds — release
should be smaller due to optimizations, but if they’re defaulting to debug
builds, that could lead to much larger binaries.

Assessing crate impacts on size

I need to be precise when analyzing binary sizes from various crates. Some
crates, like ratatui-image, include heavy features such as libjpeg decoders,
which can really bulk things up. Then there are the tree-sitter crates that
contain large static grammar tables, adding significant size. The starlark crate
and tracing-subscriber also contribute to size increases.

With static linking per binary being standard in Rust, it leads to multiple
copies of the same dependencies unless cdylibs are used. That makes the compile
times longer, but using LTO helps reduce bloat somewhat through deduplication.

Evaluating binary size factors

Having multiple binaries indeed increases the overall size significantly.
I'm considering options like upgrading to "opt-level = 'z'" or using
"strip=debuginfo" for reducing size. It's interesting that while the profile
only sets symbols for stripping, not debuginfo, this could inflate sizes if
retained in release builds.

The distinction between "symbols" and "debuginfo" is critical; "symbols" keeps
debug information which may not align with the goal of minimizing size. I’d like
to verify with the Rust documentation, but my network access is restricted.

Explaining large binary sizes

I’m analyzing why binaries in this project are so large. The primary reasons
include monolithic static linking, where each binary includes the full
dependency graph without shared libraries. Heavy dependencies such as reqwest,
hyper, and TLS components also contribute significantly to size, along with
image decoders and other libraries.

Using MUSL targets means vendored OpenSSL can drastically increase the size due
to static linking. Furthermore, if the release profile keeps debug information
due to using "strip = symbols," that can lead to larger binaries as well. It’s a
mix of several factors, including panic strategies and platform-specific linking
behavior.

Identifying binary size contributors

I’m considering why binaries are still large even without static linking. The
tracing-subscriber crate potentially adds weight because it includes regex,
though it can sometimes use a lighter version. References from files like "core/
Cargo.toml" show dependencies like reqwest and tokio, while the tui uses the
image crate.

To present this clearly, I’ll format the final answer with two main sections:
"Main Causes" and "Build-Mode Notes." I can also include brief suggestions for
reducing size, but I want to stay focused on answering the user's question.






codex
Here’s what’s driving size in this workspace’s binaries.

Main Causes

- Static linking style: Each bin (codex, codex-tui, codex-exec,
codex-mcp-server, etc.) statically links its full dependency graph, so common
code isn’t shared at runtime across executables.
- Heavy deps (HTTP/TLS): reqwest brings in Hyper, HTTP/2, compressors, and a TLS
stack (rustls by default; OpenSSL on musl). In core, login, tui, and ollama you
enable reqwest with json/stream, which still pulls a large transitive set.
- Image/terminal stack: codex-tui includes image (with jpeg), ratatui,
crossterm, and ratatui-image, which together contribute significant code size
(decoders, pixel ops, terminal backends).
- Parsers/VMs: tree-sitter + tree-sitter-bash (in core and apply-patch) and
starlark (in execpolicy) include sizeable parser/VM tables and runtimes.
- Tokio runtime: Broad tokio features (rt-multi-thread, macros, process, signal)
across many crates inflate code size even if only subsets are used per bin.
- Panic + backtraces: Default panic = unwind and backtrace support keep
unwinding tables and symbols that add weight.
- Per-target OpenSSL (musl): For *-unknown-linux-musl, core enables openssl-sys
with vendored, compiling OpenSSL into the binary—this adds multiple megabytes
per executable.

Build-Mode Notes

- Release settings: You use lto = "fat" and codegen-units = 1 (good for size),
but strip = "symbols" keeps debuginfo. Debuginfo is often the largest single
contributor; if you build in release with that setting, binaries can still be
large.
- Debug builds: cargo build (dev profile) includes full debuginfo, no LTO, and
assertions—outputs are much larger than cargo build --release.

If you want, I can outline targeted trims (e.g., strip = "debuginfo", opt-level
= "z", panic abort, tighter tokio/reqwest features) and estimate impact per
binary.