arachna 1.5.0

Context collector for AI — gathers project files into token-limited chunks

arachna

Context collector for AI — gathers project files into token-limited chunks.

What is arachna

arachna is a command-line tool that collects your project's source code and documentation into files ready to be sent to an AI. It understands tokens (not lines) and splits output smartly so nothing gets cut in the middle.

Why arachna

• Token-aware splitting: other tools split by lines, arachna splits by tokens
• Zero dependencies: just Python stdlib
• Uniformly packed parts: all output chunks are filled densely to the token limit
• Multiple presets: 17 language and engine presets out of the box
• Smart defaults: arachna --init detects your project in seconds

Install

pip install arachna

Quick start

cd your-project
arachna --init
arachna --all

Creates arachna_context/ folder with .md files ready for AI.

Commands

arachna --init              interactive setup
arachna --init --defaults   auto-detect everything
arachna --init --preset X   use specific preset
arachna --all               collect all profiles
arachna --profile code      collect one profile
arachna --all --dry-run     preview without writing
arachna --clean             remove collected files
arachna --list              show profiles
arachna --validate          check config for errors
arachna --doctor            run full diagnostic
arachna --install-hook      install git post-commit hook

Options

Option	Description
--output-dir path	where to write (default: arachna_context/)
--verbose	show skipped files
--compress	remove blank lines and trailing spaces
--incremental	only files changed since last run
--format xml,json	markdown (default), xml, or json
--merge	append to existing output instead of replacing
--dry-run	preview without writing files
--force	force overwrite with --install-hook

Safety

Commands in .arachna.json (pre_commands, post_commands, command) are validated before execution. Unknown or dangerous commands are blocked by default. Use --dry-run to preview what will be executed before running.

Doctor

arachna --doctor runs a full diagnostic of your configuration — validates all profiles, checks that directories and files exist, and verifies .gitignore integration. Use it when something doesn't work as expected.

Git hooks

arachna --install-hook installs a post-commit hook that automatically runs arachna after each commit. Configure the command in .arachna.json:

{
  "hook": {
    "post-commit": "arachna --all --incremental"
  }
}

Configuration (.arachna.json)

arachna uses profiles to define what and how to collect.

Example for a Python project:

{
  "project_name": "MyProject",
  "profiles": {
    "code": {
      "split_mode": "by_file",
      "directories": ["src", "app"],
      "patterns": ["*.py"],
      "files": ["pyproject.toml", "requirements.txt"],
      "pre_commands": ["tree src app"],
      "max_tokens": 16000
    },
    "tests": {
      "split_mode": "by_file",
      "directories": ["tests"],
      "patterns": ["*.py"],
      "max_tokens": 16000
    },
    "docs": {
      "split_mode": "by_file",
      "files": ["README.md", "TODO.md", "CHANGELOG.md"],
      "max_tokens": 16000
    },
    "git": {
      "split_mode": "by_marker",
      "split_marker": "\n=== COMMIT:",
      "command": "git log --reverse --format='=== COMMIT: %h ===%nTITLE: %s%n%nMESSAGE:%n%b%n'",
      "max_tokens": 16000
    }
  }
}

Split modes

• by_file: code and docs, each file stays intact (default)
• by_paragraph: logs, splits on blank lines
• by_marker: git history, splits on custom marker
• single: everything in one file, truncates if too big

All config fields

• split_mode: by_file, by_paragraph, by_marker, or single
• split_marker: string for by_marker mode
• directories: folders to scan
• patterns: glob patterns like ["*.py"]
• files: specific files to include
• exclude_patterns: glob patterns to skip
• pre_commands: shell commands before collection
• post_commands: shell commands after collection
• command: use command output instead of files
• max_tokens: token limit per output file
• section_format: markdown, xml, or json
• compress: enable safe whitespace compression (blank lines, trailing spaces). Does not modify indentation.
• include_binary: include binaries as base64 (true/false)
• binary_extensions: whitelist like [".png"]
• binary_max_mb: max binary file size in MB

Output

Files go to arachna_context/ (configurable):

arachna_context/
  .arachna_manifest.json
  chat-manifest.md          # summary of all files
  chat-code.md
  chat-tests.md
  chat-docs.md
  chat-git.md

When content exceeds max_tokens, files are numbered: chat-code_1.md, chat-code_2.md...

Manifest and cleanup

Every created file is tracked in .arachna_manifest.json. Running --all again removes old files automatically. With --profile, only that profile's files are cleaned.

Incremental mode

With --incremental, arachna skips files unchanged since last run. Uses .arachna_cache.json.

Tokenizer

arachna uses a conservative estimate: 4 characters = 1 token. This works for any model with a 20-30% safety margin.

Built-in (default)

No dependencies. Always works. Set max_tokens below your model's context window:

• 8192 window → max_tokens: 6000
• 32768 window → max_tokens: 24000

Custom tokenizer

Add to your .arachna.json:

  "tokenizer": "my_module:count_tokens"

Your module must export count_tokens(text) -> int. Example:

# my_tok.py
def count_tokens(text: str) -> int:
    return max(1, len(text) // 4)  # your logic here

Cloud models

For exact token counts with cloud APIs, install tiktoken:

pip install tiktoken

  "tokenizer": "tiktoken:cl100k_base"    # GPT-4, DeepSeek
  "tokenizer": "tiktoken:o200k_base"     # GPT-4o

Local models

For exact token counts with HuggingFace tokenizers, install transformers:

pip install transformers

  "tokenizer": "transformers:Qwen/Qwen2.5-7B-Instruct"
  "tokenizer": "transformers:mistralai/Mistral-7B-Instruct-v0.3"
  "tokenizer": "transformers:google/gemma-7b"

Note: transformers is a heavy dependency (gigabytes). Use only if you need exact counts. For most local models, the built-in estimate with safety margin is sufficient.

Supported project types

arachna --init auto-detects 17 project types:

Languages

• Python: src/, app/, lib/, pkg/, scripts/, *.py, pyproject.toml
• JavaScript/TypeScript: src/, app/, lib/, *.js, *.ts, package.json
• C/C++: src/, include/, *.c, *.cpp, *.h, CMakeLists.txt
• C#: *.cs, *.csproj, *.sln
• Swift: Sources/, *.swift, Package.swift
• Kotlin/Java: src/, *.kt, *.java, build.gradle, pom.xml
• Ruby: lib/, app/, *.rb, Gemfile
• PHP: src/, app/, public/, *.php, composer.json

Engines

• Godot: *.gd, *.tscn, *.tres, project.godot
• Unity: Assets/, *.cs, *.unity, *.prefab
• Unreal Engine: Source/, Content/, *.cpp, *.h, *.cs, *.uproject, *.uplugin

Infrastructure

• Docker: Dockerfile, docker-compose.yml
• Terraform: *.tf, *.tfvars

Service (always available)

• tests: tests/, test/
• docs: docs/, README.md, TODO.md, CHANGELOG.md, Makefile
• config: pyproject.toml, package.json, go.mod, Cargo.toml, requirements.txt
• git: git log --reverse with commit history

Custom presets

Create presets.json in your project root to add or override presets:

{
  "my_game": {
    "dirs": ["game"],
    "patterns": ["*.lua"],
    "max_tokens": 8000,
    "split_mode": "by_file",
    "detect": ["game"]
  }
}

Use with: arachna --init --preset my_game

Links

• GitHub Repository
• Issue Tracker
• Changelog

License

GNU Affero General Public License v3.0 (AGPL-3.0) See LICENSE for full text.