Sofos Code
A blazingly fast, interactive AI coding assistant powered by Claude or GPT, implemented in pure Rust, that can generate code, edit files, and search the web - all from your terminal.
Tested on macOS; supported on Linux and Windows.
Table of Contents
- Features
- Install
- Usage
- Custom Instructions
- Session History
- Available Tools
- MCP Servers
- Security
- Configuration
- Development
- Release
- Troubleshooting
- License
- Acknowledgments
- Links & Resources
Features
- Interactive TUI - Multi-turn conversations with Claude or GPT in an inline viewport at the bottom of your terminal; your emulator owns the scrollback, scrollbar, mouse wheel, and copy-paste
- Keep Typing During AI Turns - Messages queue FIFO while the model works; mid tool-loop messages steer the current turn without interrupting
- Live Status Line - Model, mode, reasoning config, and running token totals shown under the input
- Markdown Formatting - AI responses with syntax highlighting for code blocks
- Image Vision - Analyze local or web images, paste from clipboard with Ctrl+V
- Session History - Auto-save with an in-TUI resume picker (
/resumeorsofos -r) - Custom Instructions - Project and personal context files
- File Operations - Read, write, edit, list, glob, create, move, copy, delete (sandboxed; external paths via permission grants)
- Targeted Edits - Diff-based
edit_filefor precise string replacements - Ultra-Fast Editing - Optional Morph Apply integration (10,500+ tokens/sec)
- File Search - Find files by glob pattern (
**/*.rs) - Code Search - Fast regex search with ripgrep
- Web Search - Real-time info via Claude's/OpenAI's native search
- Web Fetch - Read documentation and web pages
- Bash Execution - Run tests and builds, sandboxed behind a 3-tier permission system
- MCP Integration - Connect to external tools via Model Context Protocol
- Visual Diffs - Syntax-highlighted diffs with line numbers
- Iterative Tools - Up to 200 tool calls per request
- Context Compaction - Summarizes older messages instead of dropping them
- Cost Tracking - Session token usage and cost estimates
- Safe Mode - Read-only operation mode
Install
Requirements: Anthropic API key (get one) or OpenAI API key (get one)
Optional (but highly recommended): ripgrep for code search (install), Morph API key for ultra-fast editing (get one)
Prebuilt binary
Download from GitHub Releases (macOS, Linux, Windows):
# macOS / Linux
# Windows — extract the .zip, then add the folder to your PATH
macOS: On first run, macOS may block the binary. Go to System Settings → Privacy & Security and click Allow Anyway.
With Rust
From source
&&
Important: Add .sofos/ to .gitignore (contains session history and personal settings). Keep AGENTS.md (team-wide instructions).
Usage
Quick Start
# Set your API key (choose one)
# or
# Optional: Enable ultra-fast editing
# Start Sofos
Commands
/resume- Resume previous session/clear- Clear conversation history/think [on|off]- Toggle extended thinking (shows status if no arg)/compact- Summarize older messages via the LLM to reclaim context tokens (auto-triggers at 80% usage)/s- Safe mode (read-only, prompt::)/n- Normal mode (all tools, prompt:>)/exit,/quit,/q,Ctrl+D- Exit with cost summaryESCorCtrl+C(while busy) - Interrupt AI response
Message queueing: Keep typing while the AI is working. Pressing Enter queues the message; queued messages are sent automatically once the current turn finishes. The hint line shows the queue count.
Multi-line input: Shift+Enter inserts a newline; Enter alone submits.
Scrollback: Sofos runs as an inline viewport at the bottom of your terminal — the rest of the terminal is normal scrollback, so use your terminal emulator's own scrollbar, mouse wheel, and text selection / copy-paste.
Status line: Shown below the input box. Updates live as you change state (/s, /n, /think) — model, mode (normal/safe), reasoning config (thinking: <N> tok / effort: high), and running token totals.
Image Vision
Include image paths or URLs directly in your message, or paste images from clipboard:
# Paste from clipboard
# Delete a marker to remove that image
# Local images
Formats: JPEG, PNG, GIF, WebP (max 20MB local) | Clipboard: Ctrl+V pastes images on macOS, Linux, and Windows | Spaces: Wrap in quotes "path/with space.png" | Permissions: Outside workspace requires config
Cost Tracking
Exit summary shows token usage and estimated cost based on official API pricing. When the provider prompt cache served any tokens during the session, a cache read: N (M% hit) row appears under the input total, and the estimated cost reflects the cache discount (10% of base input on both providers, plus 125% for Anthropic 5-min cache writes).
CLI Options
-p, --prompt <TEXT> One-shot mode
-s, --safe-mode Start in read-only mode (native writes and bash disabled)
-r, --resume Resume a previous session
--check-connection Check API connectivity and exit
--api-key <KEY> Anthropic API key (overrides env var)
--openai-api-key <KEY> OpenAI API key (overrides env var)
--morph-api-key <KEY> Morph API key (overrides env var)
--model <MODEL> Model to use (default: claude-sonnet-4-6)
--morph-model <MODEL> Morph model (default: morph-v3-fast)
--max-tokens <N> Max response tokens (default: 32768)
-t, --enable-thinking Enable extended thinking (default: false)
--thinking-budget <N> Token budget for thinking (Claude only, default: 5120, must be < max-tokens)
-v, --verbose Verbose logging
Extended Thinking
Enable for complex reasoning tasks (disabled by default):
Note: Extended thinking works with both Claude and OpenAI models.
- Claude 4.5 / 4.6 uses a manual token budget controlled by
--thinking-budget(default5120). - Claude Opus 4.7 uses adaptive thinking — the server picks the budget based on the prompt, and sofos sends
effort: highwhen thinking is on andeffort: lowwhen off.--thinking-budgetis ignored for this model; the status line showseffort: high|lowinstead of a token count. - OpenAI (gpt-5 models) —
/think onsets high reasoning effort and/think offsets low.--thinking-budgetis ignored.
Custom Instructions
Two files are loaded at startup and appended to the system prompt:
AGENTS.md(project root, version controlled) — project context for AI agents: team-wide conventions, architecture, domain vocabulary..sofos/instructions.md(gitignored) — personal preferences that shouldn't be shared with the team.
Session History
Conversations auto-saved to .sofos/sessions/. Resume with sofos -r or /resume.
Available Tools
File Operations (accept absolute and ~/ paths with a Read or Write grant as appropriate — see Security and Configuration):
read_file- Read file contentslist_directory- List a single directory's contentsglob_files- Find files recursively by glob pattern (**/*.rs,src/**/test_*.py)write_file- Create or overwrite files (append mode for chunked writes)edit_file- Targeted string replacement edits (no API key needed)morph_edit_file- Ultra-fast code editing (requires MORPH_API_KEY)create_directory- Create a directory (and missing parents)move_file,copy_file- Move or copy files
Workspace-only file ops (absolute / ~/ paths are rejected, even with grants — destructive ops are deliberately scoped to the workspace):
delete_file,delete_directory- Delete files or directories (prompt for confirmation)
Code & Search:
search_code- Fast regex-based code search (requiresripgrep)web_search- Real-time web information via Claude's/OpenAI's native searchweb_fetch- Fetch URL content as readable text (documentation, APIs)execute_bash- Run bash commands, sandboxed through the 3-tier permission system (safe commands auto-run, destructive ones blocked, unknown ones prompt)
MCP Tools:
- Tools from configured MCP servers (prefixed with server name, e.g.,
filesystem_read_file)
Image Vision: not a tool — sofos detects image paths (JPEG, PNG, GIF, WebP, up to 20 MB local) in your user messages and loads them automatically as image content blocks. Clipboard paste (Ctrl+V) works the same way. See Image Vision under Usage.
Note: Tools can access paths outside the workspace when allowed via interactive prompt or config. Three independent scopes (Read / Write / Bash) gate this access — see Security for the full model.
Safe mode (--safe-mode or /s) restricts the native tool set to read-only operations: list_directory, read_file, glob_files, web_fetch, web_search (Anthropic + OpenAI provider-native variants), and search_code when ripgrep is available. MCP tools are not filtered by safe mode — if you've configured MCP servers with mutating tools, those remain available.
MCP Servers
Connect to external tools via MCP (Model Context Protocol). Configure in ~/.sofos/config.toml or .sofos/config.local.toml (see the example in the "Configuration" section).
Tools auto-discovered, prefixed with server name (e.g., filesystem_read_file). See examples/mcp_quickstart.md.
Popular servers: https://github.com/modelcontextprotocol/servers
Security
Sandboxing (by default):
- ✅ Full access to workspace files/directories
- ✅ External access via interactive prompts — user is asked to allow/deny, with option to remember in config
- Three separate scopes:
Read(read/list),Write(write/create/move/delete),Bash(commands with external paths) - Each scope is independently granted — Read access does not imply Write or Bash access, and vice versa
- Tools that both read and write a file on external paths (
edit_file,morph_edit_file) require bothReadandWritegrants on the path
Bash Permissions (3-Tier System):
- Allowed (auto-execute): Build tools (cargo, npm, go), read-only commands (ls, cat, grep), system info (pwd, date), git read-only commands (
status,log,diff,show,branch, …). - Forbidden (always blocked): file destruction (
rm,rmdir,touch,ln); permissions (chmod,chown,chgrp); disk / partition (dd,mkfs,fdisk,parted,mkswap,mount,umount); system control (shutdown,reboot,halt,systemctl,service); user management (useradd,usermod,passwd, …); process signals (kill,killall,pkill); privilege escalation (sudo,su); directory navigation (cd,pushd,popd); destructive git operations (git push,git reset --hard,git clean,git checkout -f,git checkout -b,git switch,git rebase,git commit, …). - Ask (prompt user):
cp,mv,mkdir,git checkout <branch>/git checkout HEAD~N/git checkout -- <path>, commands referencing paths outside the workspace, and any unknown command. Approvals can be session-scoped or remembered in config. Commands whose args wouldn't repeat —sed -n 'N,Mp',head -n N,tail -n N,grep -A/-B/-C N,awk 'NR==N'— drop the "and remember" options and show a plain Yes / No, since the exact command string won't match the next call.
Configuration
Permissions are stored in .sofos/config.local.toml (workspace-specific, gitignored) or ~/.sofos/config.toml (global, optional). Local config overrides global.
Example:
[]
= [
# Read permissions - for reading/listing files outside workspace
"Read(~/.zshrc)", # Specific file
"Read(~/.config/**)", # Recursive
"Read(/etc/hosts)", # Absolute path
# Write permissions - for writing/editing files outside workspace
"Write(/tmp/output/**)", # Allow writes to specific external dir
# Bash path permissions - for commands referencing external paths
"Bash(/var/log/**)", # Allow bash commands to access this dir
# Bash command permissions - for command execution
"Bash(custom_command)", # Specific command
"Bash(pattern:*)", # Wildcard pattern
]
= [
# Read denials
"Read(./.env)",
"Read(./.env.*)",
"Read(./secrets/**)",
# Bash denials
"Bash(dangerous_command)",
]
= [
# Only for Bash commands (prompts for approval)
"Bash(unknown_tool)",
]
[]
= "/usr/local/bin/company-mcp-server"
= ["--config", "/etc/company/mcp-config.json"]
= { = "https://internal.company.com" }
[]
= "npx"
= ["-y", "@modelcontextprotocol/server-github"]
= { = "ghp_YOUR_TOKEN" }
[]
= "https://api.example.com/mcp"
= { = "Bearer token123" }
Rules*:
- Workspace files: allowed by default unless in
denylist - Outside workspace: prompts interactively on first access, or pre-configure in
allowlist - Three scopes:
Read(path)for reading,Write(path)for writing,Bash(path)for bash access — each independent Bash(path)entries with globs (e.g.Bash(/tmp/**)) grant path access; plain entries (e.g.Bash(npm test)) grant command access- Bare
"Bash"inallowauto-allows every command except those in the built-in forbidden set (rm,chmod,sudo, …); bare"Bash"indenyauto-rejects every bash command. Deny wins when both lists carry the blanket entry. Structural safety (>redirection,<<,git push, parent traversal, external-path prompts) still applies under blanket-allow. - Glob patterns supported:
*(single level),**(recursive) - Tilde expansion:
~→$HOMEon Unix,%USERPROFILE%on Windows askonly works for Bash commands
* These rules do not restrict MCP server command paths
Development
RUST_LOG=debug
Structure:
src/
├── main.rs # Entry point
├── cli.rs # CLI argument parsing
├── clipboard.rs # Clipboard image paste (Ctrl+V)
├── error.rs # Error types
├── error_ext.rs # Error extensions
├── config.rs # Configuration
│
├── api/ # API clients
│ ├── anthropic.rs # Claude API client (+ streaming)
│ ├── openai.rs # OpenAI API client
│ ├── morph.rs # Morph Apply API client
│ ├── types.rs # Message types and serialization
│ └── utils.rs # Retries, error handling
│
├── mcp/ # MCP (Model Context Protocol)
│ ├── config.rs # Server configuration loading
│ ├── protocol.rs # Protocol types (JSON-RPC)
│ ├── client.rs # Client implementations (stdio, HTTP)
│ └── manager.rs # Server connection management
│
├── repl/ # REPL components
│ ├── mod.rs # Core Repl state and process_message
│ ├── conversation.rs # Message history and compaction
│ ├── request_builder.rs # API request construction
│ ├── response_handler.rs # Response and tool iteration
│ └── tui/ # Ratatui front end
│ ├── mod.rs # Event loop and wiring
│ ├── app.rs # UI state (log, input, queue, picker)
│ ├── ui.rs # Rendering
│ ├── event.rs # Job / UiEvent channel payloads
│ ├── worker.rs # Background thread that owns the Repl
│ ├── output.rs # Stdout/stderr capture via dup2
│ ├── inline_terminal.rs # Custom ratatui Terminal (resize-safe)
│ ├── inline_tui.rs # Frame driver and history log
│ ├── scrollback.rs # DECSTBM-based insert-above-viewport
│ └── sgr.rs # SGR escape helpers
│
├── session/ # Session management
│ ├── history.rs # Session persistence
│ ├── state.rs # Runtime session state
│ └── selector.rs # Session selection TUI
│
├── tools/ # Tool implementations
│ ├── filesystem.rs # File operations (read, write, edit, chunked append)
│ ├── bashexec.rs # Bash execution + confirmation gate
│ ├── codesearch.rs # Code search (ripgrep)
│ ├── image.rs # Image detection + loading for message content
│ ├── permissions.rs # 3-tier permission system
│ ├── tool_name.rs # Type-safe tool name enum
│ ├── types.rs # Tool definitions for the API
│ ├── utils.rs # Confirmations, truncation, HTML-to-text
│ └── tests.rs # Tool integration tests
│
├── ui/ # UI components
│ ├── mod.rs # UI utilities, markdown renderer
│ ├── syntax.rs # Syntax highlighting
│ └── diff.rs # Syntax-highlighted diffs with line numbers
│
└── commands/ # Built-in commands
└── builtin.rs # Command implementations
See AGENTS.md for detailed conventions.
Release
This project uses cargo-release for automated versioning and publishing.
Quick commands:
# Preview the release
# Execute the release
# Release specific version
The release workflow automatically:
- Bumps version in
Cargo.toml - Runs tests and formatting checks
- Updates
CHANGELOG.md - Publishes to crates.io
- Creates release commit and Git tag
- Pushes to remote repository
For detailed instructions, see RELEASE.md.
Troubleshooting
- API errors: Check connection and API key
- Path errors: Use relative paths for workspace; external paths prompt interactively or can be pre-allowed with
Read/Write/Bashentries in config - Build errors:
rustup update && cargo clean && cargo build - Images with spaces: Wrap path in quotes
License
MIT License
Acknowledgments
Built with Rust and powered by Anthropic's Claude or OpenAI's GPT. Morph Apply integration for fast edits.
Links & Resources
Disclaimer: Sofos Code may make mistakes. Always review generated code before use.