Codigest

Hand an LLM your failing command, the code it points at and your changes, in one paste.

한국어

The idea

A test fails and you ask an LLM for help. You copy the error, then the test, then the file you changed, and the model still asks for one more file.

Codigest does the copying. You need two commands:

cdg cap -- pytest     runs your command and remembers its output
cdg pack              finds the files that output mentions, adds what you changed,
                      and copies all of it to your clipboard

Then you paste. That is the whole tool for most days; everything below either sets it up, explains it, or is optional.

Install

Codigest is a command-line tool. Install it with uv, which also fetches the Python version it needs (3.15) without touching your projects:

winget install --id astral-sh.uv                  # Windows (skip if you have uv)
curl -LsSf https://astral.sh/uv/install.sh | sh   # macOS/Linux

uv tool install codigest
uv tool update-shell                              # then restart your terminal

The command is codigest, or cdg for short. If the install fails with a syntax error on lazy import, run uv self update and try again.

Your first pack

Go to a project with a failing test. No setup is needed.

1. Run the test through cdg cap. Put -- before your command. The output looks exactly as it would without cdg cap; Codigest just keeps a copy.

cdg cap -- pytest -q        # or npm test, cargo test, go test ./..., make

2. Run cdg pack. It tells you what it picked and why:

$ cdg pack
Packed ~370 / 30,000 tokens
  failed   pytest -q (exit 1, just now)
  changes  uncommitted changes (git)
  + test_prices.py  line 5 in failing output
  + prices.py       changed
📋 Copied pack to clipboard

Read it as: the failing command, your uncommitted Git changes, test_prices.py because the error points at its line 5, and prices.py because you edited it.

3. Paste into the chat and say what you want. You can also put the request in the pack: cdg pack -m "fix the discount calculation".

<context_pack project="project">
<terminal_history>
<command index="1" command="pytest -q" exit_code="1" cwd="~/project" duration="1.5s" at="2026-10-17T01:58:14+09:00">
<output>
F                                                                      [100%]
================================= FAILURES ==================================
_____________________________ test_ten_percent ______________________________

    def test_ten_percent():
&gt;       assert apply_discount(200, 10) == 180
E       assert -1800 == 180
E        +  where -1800 = apply_discount(200, 10)

test_prices.py:5: AssertionError
========================== short test summary info ==========================
FAILED test_prices.py::test_ten_percent - assert -1800 == 180
1 failed in 0.11s
</output>
</command>
</terminal_history>
<changes source="uncommitted changes (git)">
diff --git a/prices.py b/prices.py
index 3d691df..428752a 100644
--- a/prices.py
+++ b/prices.py
@@ -1,2 +1,2 @@
 def apply_discount(price, percent):
-    return price * (1 - percent / 100)
+    return price * (1 - percent)
</changes>
<file path="test_prices.py" reason="line 5 in failing output">
1: from prices import apply_discount
2: 
3: 
4: def test_ten_percent():
5:     assert apply_discount(200, 10) == 180
</file>
<file path="prices.py" reason="changed">
1: def apply_discount(price, percent):
2:     return price * (1 - percent)
</file>
</context_pack>

Two optional upgrades

Once the basic loop works, each of these removes one manual step.

Stop typing cdg cap. Hook your shell once and every command is captured automatically:

cdg term install            # cdg term uninstall to undo

Stop pasting. Connect your coding agent over MCP and it fetches the pack itself:

claude mcp add --scope user codigest -- cdg mcp      # Claude Code

Other clients (Cursor, VS Code, Claude Desktop): add a stdio server with command cdg and args ["mcp"]. Details for both are in the reference.

How pack decides

When a file you expected is missing, or one you didn't expect is there, this is the order pack fills its token budget (default 30,000):

1. Files you name: cdg pack src/prices.py.
2. Files named in the output of the last failed command run in this project in the past hour: File "x.py", line 7 (Python), x.py:7 (pytest, ruff, gcc, rustc, eslint), x.ts(7,3) (tsc). Once the same command passes again, that failure is no longer used. A file that is only named in the output, not changed by you, comes as an excerpt: ten lines around each place the output points at, marked with a lines="40-60" attribute. Short files come whole.
3. Files you changed: uncommitted and untracked files in Git, or changes since cdg mark if you set a baseline (see below).
4. Tests that import a changed file (test_*.py, *_test.py, *.test.ts, *.spec.js, ...).
5. Project files imported by the files from steps 1, 3 and 4: Python imports, and relative imports in JS/TS (./x, ./x.js for x.ts, ./dir for dir/index.ts).

The failed command and the diff are always included. .env, *.pem, *.key and SSH keys never are. Tokens are estimated at four characters each, so the budget is approximate.

cdg pack -b 8000            # smaller budget
cdg pack -s > context.xml   # print instead of copying

Other things you can hand an LLM

pack covers the failing-test case. These cover the rest, grouped by what you want to do.

Recall an earlier command

Every captured command stays available, not only the last failure:

cdg term              # last command and its output
cdg term -n 3         # last 3
cdg term -f           # last failed one
cdg term --here -n 3  # last 3 run in this project

See what changed since a point

Set a baseline before you start, then ask for everything since:

cdg mark              # e.g. before a refactor
# ... work ...
cdg diff              # text diff since the mark
cdg semdiff           # Python only: which functions and classes changed

A baseline is a private copy kept in .codigest/; your Git history is not touched. Once you set one, pack also uses it instead of git diff.

Give the whole project, or its shape

cdg scan              # every file, as one block (asks first above 30k tokens)
cdg scan src/app.py -r  # one file plus the local files it imports
cdg digest            # Python signatures and docstrings only, much smaller
cdg tree              # just the file tree

Reference

• All commands
• Terminal capture
• MCP tools
• Configuration
• Privacy and safety
• How it works
• Development

All commands

Every command that produces context copies it to the clipboard. -s / --stdout prints it instead, --no-copy skips the clipboard, and -m / --message adds an instruction.

More options: scan -l adds line numbers, scan -a ignores the config filters, scan -y skips the confirmation (CI). -r / --resolve on scan, diff, semdiff and digest also pulls in local files imported by the targets. cdg <command> --help lists everything.

Terminal capture

cdg cap streams the command's output live and records the command line, combined stdout/stderr, exit code and working directory. Captures from all projects share one store on your machine, so cap and term work in any directory.

cdg cap "npm run build | tail -20"  # quote pipelines
cdg term -i 2         # only the command from 2 runs ago
cdg term path         # where captures are stored (override with CODIGEST_HOME)
cdg term clear        # delete all captures

Commands not run through cap are read from the native shell history (PowerShell, bash, zsh, fish), without their output.

Automatic capture

cdg term install edits your PowerShell profile, ~/.bashrc and ~/.zshrc for whichever of these shells is installed; choose with --shell powershell|bash|zsh|all. On Windows, Git Bash counts as bash. Commands still run in your current session (cd, variables and functions work normally) and appear in your history as typed. Editors, pagers, REPLs and ssh are skipped.

• Skip one command: start the line with a space.
• Skip more programs: $env:CODIGEST_CAP_SKIP = '^\s*(myrepl|mytui)\b' (bash/zsh: export CODIGEST_CAP_SKIP='^(myrepl|mytui)( |$)', an extended regex).
• Disable for a session: $env:CODIGEST_NOCAP = 1 (bash/zsh: export CODIGEST_NOCAP=1).
• Remove the hooks: cdg term uninstall.

Limitations:

• Captured programs write to a pipe, not a TTY, so some lose colors or progress bars.
• In bash (4+) and zsh, multi-line commands (loops typed over several lines, heredocs), background jobs (cmd &) and lines using ! history expansion are not captured; they run normally. In bash, neither are lines that start with a subshell ( ... ).
• In bash the hook uses the DEBUG trap and keeps one set before the first prompt (starship, bash-preexec); a DEBUG trap set later replaces it.

MCP tools

The tools return the same text the CLI prints. None of them moves the baseline, and paths outside the project the server was started in are refused.

Configuration

cdg init writes .codigest/config.toml. The [filter] section controls which files every command considers:

[filter]
# Only these extensions (omit to include every non-ignored file)
extensions = [".py", ".ts", ".rs", ".md", ".json"]

# Extra exclusions, in .gitignore syntax (.gitignore itself is always honored)
exclude_patterns = [
    "*.lock",
    "tests/data/",
    "legacy_code/"
]

.git/, .codigest/, virtual environments, node_modules/ and __pycache__/ are always skipped.

Privacy and safety

• Secrets in captures. Known secret shapes (API keys, tokens, password=..., private keys, URL credentials) are masked before a capture is written to disk. Output of credential commands (env, printenv, gh auth token, aws configure, ...) is never stored. This catches common formats, not every possible secret.
• Secret files. pack never includes .env*, *.pem, *.key, *.p12, *.pfx or SSH private keys, and lists them as omitted instead.
• Your project. No command changes your source files. Commands that save output, and the baseline, live only inside .codigest/, which init adds to .gitignore. pack without a baseline creates nothing at all.
• Where captures live. cdg term path shows the file. On macOS and Linux it is readable only by you. cdg term clear deletes it.
• Nothing leaves your machine. Codigest makes no network requests. Context goes where you paste it, or to the MCP client you connected.

How it works

• Baseline. A Git repository at .codigest/anchor/.shadow_git, separate from your project's repository. The directory is not named .git so editors don't mistake it for yours. mark and init commit the current state to it; diff, semdiff, status and pack compare the working tree against it.
• Captures. One newline-delimited JSON file holds the last 200 commands; each output is capped at 64 KB, keeping the head and tail.
• Output. File contents are XML-escaped inside <file> blocks, written flush-left so no stray indentation reaches the prompt.
• MCP. The server is a small JSON-RPC loop over stdio. Each tool runs the regular CLI with -s --no-copy, so an agent sees exactly what you would paste.

Development

git clone https://github.com/NaNIsaac/codigest
cd codigest
uv run cdg --help              # run from the checkout
uv run --with pytest pytest -q # tests

The demo GIF is rendered from recorded output by docs/demo/make_gif.py; its docstring explains how to record a new one.

License

MIT. See LICENSE.