OpenCode (nofc fork)

Tool calling for providers without native function calling.

Fork of anomalyco/opencode — integrates @ai-sdk-tool/parser middleware so that tools work through text-based protocols (Hermes, XML) instead of the structured tools API parameter.

Install

npx opencode-ai-nofc

# or install globally
npm i -g opencode-ai-nofc

# or download pre-built binary
curl -fsSL https://github.com/okuyam2y/opencode-nofc/releases/latest/download/opencode-$(uname -s | tr A-Z a-z)-$(uname -m).tar.gz | tar xz
./opencode

# or build from source
git clone https://github.com/okuyam2y/opencode-nofc.git
cd opencode-nofc && bun install && bun turbo build

Why this fork?

Many API gateways and self-hosted inference servers (vLLM, LiteLLM, custom proxies) strip or ignore the tools parameter from OpenAI-compatible requests. Without native function calling, OpenCode's tools — read, write, bash, and others — simply don't work.

This fork solves the problem by parsing tool calls directly from model text output. The model writes <tool_call> tags in plain text, and the parser middleware converts them into standard AI SDK tool-call events.

Configuration

Add toolParser to your provider options in opencode.json:

{
  "provider": {
    "my-gateway": {
      "npm": "@ai-sdk/openai-compatible",
      "options": {
        "baseURL": "https://your-gateway/v1",
        "toolParser": "hermes-strict"
      },
      "models": {
        "your-model": {
          "name": "Your Model",
          "limit": { "context": 200000, "output": 32768 }
        }
      }
    }
  }
}

Mode	Description
hermes-strict	Recommended. Strict JSON format with explicit rules in system prompt. Most reliable.
hermes	Standard Hermes protocol. Fallback if hermes-strict causes issues.
xml	Pure XML format for models trained on XML tool calling.

What's included

Beyond the tool parser, this fork adds:

• Streaming tag filter — removes <tool_call> / <tool_response> tags leaked into visible output
• Tool call deduplication — drops duplicate tool executions within the same LLM step
• apply_patch → edit/write auto-substitution — replaces diff-based editing with line-based tools when the tool parser is active
• PDF / DOCX / XLSX text extraction and macOS Vision OCR
• Finish reason handling — converts unknown finish reasons to terminal states, with loop guardrails

Setup guide → — per-model settings, model compatibility table, and troubleshooting.

Upstream relationship

This fork tracks the upstream dev branch and is regularly rebased. Bug fixes are submitted as PRs when applicable.

• npm: opencode-ai-nofc (separate from the official opencode-ai package)
• Related: #2917 (custom tool parser request) · #1122 (vLLM + Hermes)
• License: MIT (same as upstream)

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The original OpenCode README follows below.

The open source AI coding agent.

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Installation

# YOLO
curl -fsSL https://opencode.ai/install | bash

# Package managers
npm i -g opencode-ai@latest        # or bun/pnpm/yarn
scoop install opencode             # Windows
choco install opencode             # Windows
brew install anomalyco/tap/opencode # macOS and Linux (recommended, always up to date)
brew install opencode              # macOS and Linux (official brew formula, updated less)
sudo pacman -S opencode            # Arch Linux (Stable)
paru -S opencode-bin               # Arch Linux (Latest from AUR)
mise use -g opencode               # Any OS
nix run nixpkgs#opencode           # or github:anomalyco/opencode for latest dev branch

Tip

Remove versions older than 0.1.x before installing.

Desktop App (BETA)

OpenCode is also available as a desktop application. Download directly from the releases page or opencode.ai/download.

Platform	Download
macOS (Apple Silicon)	opencode-desktop-mac-arm64.dmg
macOS (Intel)	opencode-desktop-mac-x64.dmg
Windows	opencode-desktop-windows-x64.exe
Linux	.deb, .rpm, or .AppImage

# macOS (Homebrew)
brew install --cask opencode-desktop
# Windows (Scoop)
scoop bucket add extras; scoop install extras/opencode-desktop

Installation Directory

The install script respects the following priority order for the installation path:

1. $OPENCODE_INSTALL_DIR - Custom installation directory
2. $XDG_BIN_DIR - XDG Base Directory Specification compliant path
3. $HOME/bin - Standard user binary directory (if it exists or can be created)
4. $HOME/.opencode/bin - Default fallback

# Examples
OPENCODE_INSTALL_DIR=/usr/local/bin curl -fsSL https://opencode.ai/install | bash
XDG_BIN_DIR=$HOME/.local/bin curl -fsSL https://opencode.ai/install | bash

Agents

OpenCode includes two built-in agents you can switch between with the Tab key.

• build - Default, full-access agent for development work
• plan - Read-only agent for analysis and code exploration
  • Denies file edits by default
  • Asks permission before running bash commands
  • Ideal for exploring unfamiliar codebases or planning changes

Also included is a general subagent for complex searches and multistep tasks. This is used internally and can be invoked using @general in messages.

Learn more about agents.

Documentation

For more info on how to configure OpenCode, head over to our docs.

Contributing

If you're interested in contributing to OpenCode, please read our contributing docs before submitting a pull request.

Building on OpenCode

If you are working on a project that's related to OpenCode and is using "opencode" as part of its name, for example "opencode-dashboard" or "opencode-mobile", please add a note to your README to clarify that it is not built by the OpenCode team and is not affiliated with us in any way.

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