OpenCode

OpenCode

OpenCode is an open-source AI coding tool. Signet integrates via a bundled plugin and AGENTS.md sync.

Files managed by Signet

File	Description
~/.config/opencode/AGENTS.md	Auto-synced from $SIGNET_WORKSPACE/AGENTS.md
~/.config/opencode/plugins/signet.mjs	Bundled plugin providing memory tools

Plugin Bundle

During signet install, the connector writes a self-contained signet.mjs file to ~/.config/opencode/plugins/ and registers ./plugins/signet.mjs in the OpenCode config so the runtime loads it consistently at startup.

The plugin is built from @signet/opencode-plugin source and bundled into a single ESM file at build time (stored as a string constant in plugin-bundle.ts). This means the plugin has no external dependencies at runtime.

The previous approach (memory.mjs in the OpenCode root directory) is considered legacy. The connector automatically migrates away from it during install by deleting the old file and scrubbing any memory.mjs references from the config’s plugin or plugins arrays.

Config File Detection

The connector writes the highest-precedence global OpenCode config file:

1. ~/.config/opencode/opencode.jsonc
2. ~/.config/opencode/opencode.json
3. ~/.config/opencode/config.json

This matches OpenCode’s load order, where opencode.jsonc is merged last. If none exist, opencode.jsonc is created. Config updates are targeted JSONC edits, so comments, trailing commas, and unrelated settings are preserved.

MCP Tools

The plugin handles lifecycle hooks; MCP provides on-demand Signet tools. A local install without an explicit daemon URL uses the packaged stdio command:

{
  "mcp": {
    "signet": {
      "type": "local",
      "command": ["signet-mcp"],
      "enabled": true
    }
  }
}

A standalone remote install with --url uses OpenCode’s remote MCP transport instead, pointing at <daemon-origin>/mcp, setting oauth: false, and adding the supplied API key as a bearer header. The key is kept in a mode-0600 managed file referenced through OpenCode’s {file:} substitution, not embedded in the config or plugin. This path does not require or create a local Signet identity workspace.

Supported hooks

Hook	Supported
session-start	yes
user-prompt-submit	yes
pre-compaction	yes
compaction-complete	yes
session-end	yes

Prerequisites

• OpenCode installed
• ~/.config/opencode/ directory exists

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