New issues and PRs from new contributors are auto-closed by default. Maintainers review auto-closed issues daily. See CONTRIBUTING.md.

FactCode is a minimal terminal coding harness. Adapt FactCode to your workflows, not the other way around, without having to fork and modify FactCode internals. Extend it with TypeScript Extensions, Skills, Prompt Templates, and Themes. Put your extensions, skills, prompt templates, and themes in FactCode Packages and share them with others via npm or git.

FactCode ships with powerful defaults but skips features like sub agents and plan mode. Instead, you can ask FactCode to build what you want or install a third party FactCode package that matches your workflow.

FactCode runs in four modes: interactive, print or JSON, RPC for process integration, and an SDK for embedding in your own apps. See openclaw/openclaw for a real-world SDK integration.

Sessions

FactCode stores your coding agent sessions locally. Session data captures real development workflows and can be useful for evaluating prompts, tools, and models internally.

Table of Contents

• Quick Start
• Providers & Models
• Interactive Mode
  • Editor
  • Commands
  • Keyboard Shortcuts
  • Message Queue
• Sessions
  • Branching
  • Compaction
• Settings
• Context Files
• Customization
  • Prompt Templates
  • Skills
  • Extensions
  • Themes
  • FactCode Packages
• Programmatic Usage
• Philosophy
• CLI Reference

Quick Start

npm install -g --ignore-scripts @datamesh/factcode

--ignore-scripts disables dependency lifecycle scripts during install. FactCode does not require install scripts for normal npm installs.

This is an on-prem build with no public website, so the hosted curl | sh installer is not used; install from npm as shown above (or your internal registry).

Authenticate with an API key:

export ANTHROPIC_API_KEY=sk-ant-...
factcode

Or use your existing subscription:

factcode
/login  # Then select provider

Then just talk to FactCode. By default, FactCode gives the model four tools: read, write, edit, and bash. The model uses these to fulfill your requests. Add capabilities via skills, prompt templates, extensions, or FactCode packages.

Platform notes: Windows | Termux (Android) | tmux | Terminal setup | Shell aliases

Providers & Models

For each built-in provider, FactCode maintains a list of tool-capable models, updated with every release. Authenticate via subscription (/login) or API key, then select any model from that provider via /model (or Ctrl+L).

Subscriptions:

• Anthropic Claude Pro/Max
• OpenAI ChatGPT Plus/Pro (Codex)
• GitHub Copilot

API keys:

• Anthropic
• OpenAI
• Azure OpenAI
• DeepSeek
• Google Gemini
• Google Vertex
• Amazon Bedrock
• Mistral
• Groq
• Cerebras
• Cloudflare AI Gateway
• Cloudflare Workers AI
• xAI
• OpenRouter
• Vercel AI Gateway
• ZAI
• OpenCode Zen
• OpenCode Go
• Hugging Face
• Fireworks
• Together AI
• Kimi For Coding
• MiniMax
• Xiaomi MiMo
• Xiaomi MiMo Token Plan (China)
• Xiaomi MiMo Token Plan (Amsterdam)
• Xiaomi MiMo Token Plan (Singapore)

See docs/providers.md for detailed setup instructions.

Custom providers & models: Add providers via ~/.factcode/agent/models.json if they speak a supported API (OpenAI, Anthropic, Google). For custom APIs or OAuth, use extensions. See docs/models.md and docs/custom-provider.md.

Interactive Mode

The interface from top to bottom:

• Startup header - Shows shortcuts (/hotkeys for all), loaded AGENTS.md files, prompt templates, skills, and extensions
• Messages - Your messages, assistant responses, tool calls and results, notifications, errors, and extension UI
• Editor - Where you type; border color indicates thinking level
• Footer - Working directory, session name, total token/cache usage, cost, context usage, current model

The editor can be temporarily replaced by other UI, like built-in /settings or custom UI from extensions (e.g., a Q&A tool that lets the user answer model questions in a structured format). Extensions can also replace the editor, add widgets above/below it, a status line, custom footer, or overlays.

Editor

| Feature | How | |---------|-----| | File reference | Type @ to fuzzy-search project files | | Path completion | Tab to complete paths | | Multi-line | Shift+Enter (or Ctrl+Enter on Windows Terminal) | | Images | Ctrl+V to paste (Alt+V on Windows), or drag onto terminal | | Bash commands | !command runs and sends output to LLM, !!command runs without sending |

Standard editing keybindings for delete word, undo, etc. See docs/keybindings.md.

Commands

Type / in the editor to trigger commands. Extensions can register custom commands, skills are available as /skill:name, and prompt templates expand via /templatename.

| Command | Description | |---------|-------------| | /login, /logout | OAuth authentication | | /model | Switch models | | /scoped-models | Enable/disable models for Ctrl+P cycling | | /settings | Thinking level, theme, message delivery, transport | | /resume | Pick from previous sessions | | /new | Start a new session | | /name <name> | Set session display name | | /session | Show session info (file, ID, messages, tokens, cost) | | /tree | Jump to any point in the session and continue from there | | /fork | Create a new session from a previous user message | | /clone | Duplicate the current active branch into a new session | | /compact [prompt] | Manually compact context, optional custom instructions | | /copy | Copy last assistant message to clipboard | | /export [file] | Export session to HTML file | | /share | Upload as private GitHub gist with shareable HTML link | | /reload | Reload keybindings, extensions, skills, prompts, and context files (themes hot-reload automatically) | | /hotkeys | Show all keyboard shortcuts | | /changelog | Display version history | | /quit | Quit FactCode |

Keyboard Shortcuts

See /hotkeys for the full list. Customize via ~/.factcode/agent/keybindings.json. See docs/keybindings.md.

Commonly used:

| Key | Action | |-----|--------| | Ctrl+C | Clear editor | | Ctrl+C twice | Quit | | Escape | Cancel/abort | | Escape twice | Open /tree | | Ctrl+L | Open model selector | | Ctrl+P / Shift+Ctrl+P | Cycle scoped models forward/backward | | Shift+Tab | Cycle thinking level | | Ctrl+O | Collapse/expand tool output | | Ctrl+T | Collapse/expand thinking blocks |

Message Queue

Submit messages while the agent is working:

• Enter queues a steering message, delivered after the current assistant turn finishes executing its tool calls
• Alt+Enter queues a follow-up message, delivered only after the agent finishes all work
• Escape aborts and restores queued messages to editor
• Alt+Up retrieves queued messages back to editor

On Windows Terminal, Alt+Enter is fullscreen by default. Remap it in docs/terminal-setup.md so FactCode can receive the follow-up shortcut.

Configure delivery in settings: steeringMode and followUpMode can be "one-at-a-time" (default, waits for response) or "all" (delivers all queued at once). transport selects provider transport preference ("sse", "websocket", or "auto") for providers that support multiple transports.

Sessions

Sessions are stored as JSONL files with a tree structure. Each entry has an id and parentId, enabling in-place branching without creating new files. See docs/session-format.md for file format.

Management

Sessions auto-save to ~/.factcode/agent/sessions/ organized by working directory.

factcode -c                  # Continue most recent session
factcode -r                  # Browse and select from past sessions
factcode --no-session        # Ephemeral mode (don't save)
factcode --name "my task"    # Set session display name at startup
factcode --session <path|id> # Use specific session file or ID
factcode --fork <path|id>    # Fork specific session file or ID into a new session

Use /session in interactive mode to see the current session ID before reusing it with --session <id> or --fork <id>.

Branching

/tree - Navigate the session tree in-place. Select any previous point, continue from there, and switch between branches. All history preserved in a single file.

• Search by typing, fold/unfold and jump between branches with Ctrl+←/Ctrl+→ or Alt+←/Alt+→, page with ←/→
• Filter modes (Ctrl+O): default → no-tools → user-only → labeled-only → all
• Press Shift+L to label entries as bookmarks and Shift+T to toggle label timestamps

/fork - Create a new session file from a previous user message on the active branch. Opens a selector, copies the active path up to that point, and places the selected prompt in the editor for modification.

/clone - Duplicate the current active branch into a new session file at the current position. The new session keeps the full active-path history and opens with an empty editor.

--fork <path|id> - Fork an existing session file or partial session UUID directly from the CLI. This copies the full source session into a new session file in the current project.

Compaction

Long sessions can exhaust context windows. Compaction summarizes older messages while keeping recent ones.

Manual: /compact or /compact <custom instructions>

Automatic: Enabled by default. Triggers on context overflow (recovers and retries) or when approaching the limit (proactive). Configure via /settings or settings.json.

Compaction is lossy. The full history remains in the JSONL file; use /tree to revisit. Customize compaction behavior via extensions. See docs/compaction.md for internals.

Settings

Use /settings to modify common options, or edit JSON files directly:

| Location | Scope | |----------|-------| | ~/.factcode/agent/settings.json | Global (all projects) | | .factcode/settings.json | Project (overrides global) |

See docs/settings.md for all options.

Telemetry and update checks

This is an on-prem build with no callback to any hosted service. The upstream startup features below are disabled in this build:

• Update check: the hosted latest-version endpoint is not contacted in this build. FACTCODE_SKIP_VERSION_CHECK=1 is honored but has no effect since the check is already off.
• Install/update telemetry: no install/update ping is sent. enableInstallTelemetry in settings.json and FACTCODE_TELEMETRY=0 are honored but have no effect since telemetry is already off.

Use --offline or FACTCODE_OFFLINE=1 to disable any remaining startup network operations, including package update checks.

Context Files

FactCode loads AGENTS.md (or CLAUDE.md) at startup from:

• ~/.factcode/agent/AGENTS.md (global)
• Parent directories (walking up from cwd)
• Current directory

Use for project instructions, conventions, common commands. All matching files are concatenated.

Disable context file loading with --no-context-files (or -nc).

System Prompt

Replace the default system prompt with .factcode/SYSTEM.md (project) or ~/.factcode/agent/SYSTEM.md (global). Append without replacing via APPEND_SYSTEM.md.

Customization

Prompt Templates

Reusable prompts as Markdown files. Type /name to expand.

<!-- ~/.factcode/agent/prompts/review.md -->
Review this code for bugs, security issues, and performance problems.
Focus on: {{focus}}

Place in ~/.factcode/agent/prompts/, .factcode/prompts/, or a FactCode package to share with others. See docs/prompt-templates.md.

Skills

On-demand capability packages following the Agent Skills standard. Invoke via /skill:name or let the agent load them automatically.

<!-- ~/.factcode/agent/skills/my-skill/SKILL.md -->
# My Skill
Use this skill when the user asks about X.

## Steps
1. Do this
2. Then that

Place in ~/.factcode/agent/skills/, ~/.agents/skills/, .factcode/skills/, or .agents/skills/ (from cwd up through parent directories) or a FactCode package to share with others. See docs/skills.md.

Extensions

TypeScript modules that extend FactCode with custom tools, commands, keyboard shortcuts, event handlers, and UI components.

export default function (factcode: ExtensionAPI) {
  factcode.registerTool({ name: "deploy", ... });
  factcode.registerCommand("stats", { ... });
  factcode.on("tool_call", async (event, ctx) => { ... });
}

The default export can also be async. FactCode waits for async extension factories before startup continues, which is useful for one-time initialization such as fetching remote model lists before calling factcode.registerProvider().

What's possible:

• Custom tools (or replace built-in tools entirely)
• Sub-agents and plan mode
• Custom compaction and summarization
• Permission gates and path protection
• Custom editors and UI components
• Status lines, headers, footers
• Git checkpointing and auto-commit
• SSH and sandbox execution
• MCP server integration
• Make FactCode look like Claude Code
• Games while waiting (yes, Doom runs)
• ...anything you can dream up

Place in ~/.factcode/agent/extensions/, .factcode/extensions/, or a FactCode package to share with others. See docs/extensions.md and examples/extensions/.

Themes

Built-in: dark, light. Themes hot-reload: modify the active theme file and FactCode immediately applies changes.

Place in ~/.factcode/agent/themes/, .factcode/themes/, or a FactCode package to share with others. See docs/themes.md.

FactCode Packages

Bundle and share extensions, skills, prompts, and themes via npm or git. Find packages on npmjs.com or Discord.

Security: FactCode packages run with full system access. Extensions execute arbitrary code, and skills can instruct the model to perform any action including running executables. Review source code before installing third-party packages.

factcode install npm:@foo/factcode-tools
factcode install npm:@foo/[email protected]      # pinned version
factcode install git:github.com/user/repo
factcode install git:github.com/user/repo@v1  # tag or commit
factcode install git:[email protected]:user/repo
factcode install git:[email protected]:user/repo@v1  # tag or commit
factcode install https://github.com/user/repo
factcode install https://github.com/user/repo@v1      # tag or commit
factcode install ssh://[email protected]/user/repo
factcode install ssh://[email protected]/user/repo@v1    # tag or commit
factcode remove npm:@foo/factcode-tools
factcode uninstall npm:@foo/factcode-tools          # alias for remove
factcode list
factcode update                               # update FactCode and packages (skips pinned packages)
factcode update --extensions                  # update packages only
factcode update --self                        # update FactCode only
factcode update --self --force                # reinstall FactCode even if current
factcode update npm:@foo/factcode-tools             # update one package
factcode config                               # enable/disable extensions, skills, prompts, themes

Packages install to ~/.factcode/agent/git/ (git) or ~/.factcode/agent/npm/ (npm). Use -l for project-local installs (.factcode/git/, .factcode/npm/). Git @ref values are pinned tags or commits; pinned packages are skipped by factcode update, so use factcode install git:host/user/repo@new-ref to move an existing package to a new ref. Git packages install dependencies with npm install --omit=dev by default, so runtime deps must be listed under dependencies; when npmCommand is configured, git packages use plain install for compatibility with wrappers. If you use a Node version manager and want package installs to reuse a stable npm context, set npmCommand in settings.json, for example ["mise", "exec", "node@20", "--", "npm"].

Create a package by adding a factcode key to package.json:

{
  "name": "my-factcode-package",
  "keywords": ["factcode-package"],
  "factcode": {
    "extensions": ["./extensions"],
    "skills": ["./skills"],
    "prompts": ["./prompts"],
    "themes": ["./themes"]
  }
}

Without a factcode manifest, FactCode auto-discovers from conventional directories (extensions/, skills/, prompts/, themes/).

See docs/packages.md.

Programmatic Usage

SDK

import { AuthStorage, createAgentSession, ModelRegistry, SessionManager } from "@datamesh/factcode";

const authStorage = AuthStorage.create();
const modelRegistry = ModelRegistry.create(authStorage);
const { session } = await createAgentSession({
  sessionManager: SessionManager.inMemory(),
  authStorage,
  modelRegistry,
});

await session.prompt("What files are in the current directory?");

For advanced multi-session runtime replacement, use createAgentSessionRuntime() and AgentSessionRuntime.

See docs/sdk.md and examples/sdk/.

RPC Mode

For non-Node.js integrations, use RPC mode over stdin/stdout:

factcode --mode rpc

RPC mode uses strict LF-delimited JSONL framing. Clients must split records on \n only. Do not use generic line readers like Node readline, which also split on Unicode separators inside JSON payloads.

See docs/rpc.md for the protocol.

Philosophy

FactCode is aggressively extensible so it doesn't have to dictate your workflow. Features that other tools bake in can be built with extensions, skills, or installed from third-party FactCode packages. This keeps the core minimal while letting you shape FactCode to fit how you work.

MCP, by default. FactCode ships a bundled MCP client and preinstalls the FactVerse MCP server out of the box. You can also build CLI tools with READMEs (see Skills) instead of MCP where that's simpler.

No sub-agents. There's many ways to do this. Spawn FactCode instances via tmux, or build your own with extensions, or install a package that does it your way.

No permission popups. Run in a container, or build your own confirmation flow with extensions inline with your environment and security requirements.

No plan mode. Write plans to files, or build it with extensions, or install a package.

No built-in to-dos. They confuse models. Use a TODO.md file, or build your own with extensions.

No background bash. Use tmux. Full observability, direct interaction.

CLI Reference

factcode [options] [@files...] [messages...]

Package Commands

factcode install <source> [-l]     # Install package, -l for project-local
factcode remove <source> [-l]      # Remove package
factcode uninstall <source> [-l]   # Alias for remove
factcode update [source|self|factcode]   # Update FactCode and packages (skips pinned packages)
factcode update --extensions       # Update packages only
factcode update --self             # Update FactCode only
factcode update --self --force     # Reinstall FactCode even if current
factcode update --extension <src>  # Update one package
factcode list                      # List installed packages
factcode config                    # Enable/disable package resources

Modes

| Flag | Description | |------|-------------| | (default) | Interactive mode | | -p, --print | Print response and exit | | --mode json | Output all events as JSON lines (see docs/json.md) | | --mode rpc | RPC mode for process integration (see docs/rpc.md) | | --export <in> [out] | Export session to HTML |

In print mode, FactCode also reads piped stdin and merges it into the initial prompt:

cat README.md | factcode -p "Summarize this text"

Model Options

| Option | Description | |--------|-------------| | --provider <name> | Provider (anthropic, openai, google, etc.) | | --model <pattern> | Model pattern or ID (supports provider/id and optional :<thinking>) | | --api-key <key> | API key (overrides env vars) | | --thinking <level> | off, minimal, low, medium, high, xhigh | | --models <patterns> | Comma-separated patterns for Ctrl+P cycling | | --list-models [search] | List available models |

Session Options

| Option | Description | |--------|-------------| | -c, --continue | Continue most recent session | | -r, --resume | Browse and select session | | --session <path\|id> | Use specific session file or partial UUID | | --fork <path\|id> | Fork specific session file or partial UUID into a new session | | --session-dir <dir> | Custom session storage directory | | --no-session | Ephemeral mode (don't save) | | --name <name>, -n <name> | Set session display name at startup |

Tool Options

| Option | Description | |--------|-------------| | --tools <list>, -t <list> | Allowlist specific tool names across built-in, extension, and custom tools | | --exclude-tools <list>, -xt <list> | Disable specific tool names across built-in, extension, and custom tools | | --no-builtin-tools, -nbt | Disable built-in tools by default but keep extension/custom tools enabled | | --no-tools, -nt | Disable all tools by default |

Available built-in tools: read, bash, edit, write, grep, find, ls

Resource Options

| Option | Description | |--------|-------------| | -e, --extension <source> | Load extension from path, npm, or git (repeatable) | | --no-extensions | Disable extension discovery | | --skill <path> | Load skill (repeatable) | | --no-skills | Disable skill discovery | | --prompt-template <path> | Load prompt template (repeatable) | | --no-prompt-templates | Disable prompt template discovery | | --theme <path> | Load theme (repeatable) | | --no-themes | Disable theme discovery | | --no-context-files, -nc | Disable AGENTS.md and CLAUDE.md context file discovery |

Combine --no-* with explicit flags to load exactly what you need, ignoring settings.json (e.g., --no-extensions -e ./my-ext.ts).

Other Options

| Option | Description | |--------|-------------| | --system-prompt <text> | Replace default prompt (context files and skills still appended) | | --append-system-prompt <text> | Append to system prompt | | --verbose | Force verbose startup | | -h, --help | Show help | | -v, --version | Show version |

File Arguments

Prefix files with @ to include in the message:

factcode @prompt.md "Answer this"
factcode -p @screenshot.png "What's in this image?"
factcode @code.ts @test.ts "Review these files"

Examples

# Interactive with initial prompt
factcode "List all .ts files in src/"

# Non-interactive
factcode -p "Summarize this codebase"

# Non-interactive with piped stdin
cat README.md | factcode -p "Summarize this text"

# Named one-shot session
factcode --name "release audit" -p "Audit this repository"

# Different model
factcode --provider openai --model gpt-4o "Help me refactor"

# Model with provider prefix (no --provider needed)
factcode --model openai/gpt-4o "Help me refactor"

# Model with thinking level shorthand
factcode --model sonnet:high "Solve this complex problem"

# Limit model cycling
factcode --models "claude-*,gpt-4o"

# Read-only mode
factcode --tools read,grep,find,ls -p "Review the code"

# Disable one extension or built-in tool while keeping the rest available
factcode --exclude-tools ask_question

# High thinking level
factcode --thinking high "Solve this complex problem"

Environment Variables

| Variable | Description | |----------|-------------| | FACTCODE_CODING_AGENT_DIR | Override config directory (default: ~/.factcode/agent) | | FACTCODE_CODING_AGENT_SESSION_DIR | Override session storage directory (overridden by --session-dir) | | FACTCODE_PACKAGE_DIR | Override package directory (useful for Nix/Guix where store paths tokenize poorly) | | FACTCODE_OFFLINE | Disable startup network operations, including update checks, package update checks, and install/update telemetry | | FACTCODE_SKIP_VERSION_CHECK | Skip the FactCode version update check at startup. No effect in this on-prem build, where the hosted latest-version request is already disabled | | FACTCODE_TELEMETRY | Override install/update telemetry. Use 1/true/yes to enable or 0/false/no to disable. This does not disable update checks | | FACTCODE_CACHE_RETENTION | Set to long for extended prompt cache (Anthropic: 1h, OpenAI: 24h) | | VISUAL, EDITOR | External editor for Ctrl+G |

Contributing & Development

See CONTRIBUTING.md for guidelines and docs/development.md for setup, forking, and debugging.

License

Proprietary — © 2026 DataMesh PTE. LTD. All rights reserved. See LICENSE.

FactCode incorporates third-party open-source components, each under its own license; see THIRD-PARTY-NOTICES.md.

See Also

• @datamesh/factcode-ai: Core LLM toolkit
• @datamesh/factcode-agent-core: Agent framework
• @datamesh/factcode-tui: Terminal UI components