opendia-harness

opendia-harness is a skill for Claude Code from aeonfun/opendia. It costs 52 tokens per session (725 once invoked), scanned A, original, MIT.

A setup and troubleshooting guide for OpenDia, a bridge that connects a browser extension with Grok Build and other MCP harnesses. MCP is a standard way for an AI client to connect to external tools.

In plain words
What is it for?
Use it to install or enable OpenDia, configure its WebSocket and HTTP ports, check connection status, and diagnose disconnected extensions or timed-out tools.
Why use it?
It helps resolve installation, trust, configuration, port, connection, and timeout problems that prevent the extension and tool server from communicating.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions Claude Code.

Part of the opendia plugin — 2 skills, 1 MCP server shipped together

Good fit Use it to install or enable OpenDia, configure its WebSocket and HTTP ports, check connection status, and diagnose disconnected extensions or timed-out tools.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/aeonfun/opendia/opendia-harness
About the project

OpenDia connects web browsers such as Chrome, Arc, and Firefox to AI models. It is for people who want to use AI models through their browser, with automation and MCP support.

aeonfun/opendia · 1,920 stars · on GitHub · aeon.fun

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add aeonfun/opendia --skill opendia-harness
Clone the repo
git clone --depth 1 https://github.com/aeonfun/opendia

Made for: Claude Code.

Or install opendia, the plugin that ships this one along with the rest of its 2 skills, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for opendia-harness

README.md
[![agentmods](https://agentmods.dev/badge/skills/aeonfun/opendia/opendia-harness/github.svg)](https://agentmods.dev/skills/aeonfun/opendia/opendia-harness)
Your own site
<a href="https://agentmods.dev/skills/aeonfun/opendia/opendia-harness"><img src="https://agentmods.dev/badge/skills/aeonfun/opendia/opendia-harness/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for opendia-harness

Your own site · 80×15
<a href="https://agentmods.dev/skills/aeonfun/opendia/opendia-harness"><img src="https://agentmods.dev/badge/skills/aeonfun/opendia/opendia-harness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 725 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 4 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium MCP Rug Pull · line 39
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 49
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 64
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 66
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00052 $0.00725
Opus 5 $0.00026 $0.00362
Sonnet 5 $0.00010 $0.00145
Haiku 4.5 $0.00005 $0.00072

Measured 10d ago against content hash 94e3f2208c9d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

opendia-harness scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/opendia/skills/opendia-harness/SKILL.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

OpenDia harness setup (Grok Build)

Install plugin

grok plugin marketplace add aeonfun/opendia
grok plugin install opendia --trust

Or pin a path:

grok plugin install aeonfun/opendia#plugins/opendia --trust

Enable the plugin (/plugins or [plugins].enabled). Trust is required for the MCP server to attach.

Manual config.toml

[mcp_servers.opendia]
command = "npx"
args = ["-y", "opendia"]
enabled = true
startup_timeout_sec = 60

Optional custom ports (must match what the extension expects):

npx opendia --ws-port=5555 --http-port=5556

Default: WebSocket 5555 (extension), HTTP/SSE 5556, stdio for the AI client.

Extension checklist

  1. Install from GitHub Releases (Chrome zip or Firefox zip).
  2. Load unpacked / temporary add-on as documented in the main README.
  3. Open the extension popup — must show Connected to ws://localhost:5555 (or your chosen WS port).
  4. If disconnected: start or restart npx opendia, then reload the extension.

Doctor commands (Grok Build)

grok mcp list
grok mcp doctor opendia
grok plugin details opendia

Common failures

Symptom Likely cause Fix
MCP tools timeout Extension not connected Connect extension; confirm WS port
Tools present but actions no-op Stale socket / server restart Restart npx opendia, reload extension
Cold schemas only Extension not registered yet Wait for connect + tools/list_changed, re-list
Port conflict Another process on 5555/5556 npx opendia --port=6000 and point extension at new WS
npx slow / fails startup Cold npm download Raise startup_timeout_sec; ensure network for first install
Tunnel 401 Missing bearer token Pass Authorization: Bearer <token> (printed at startup)

Modes

  • Local (default) — stdio + loopback WS/SSE. Correct for Grok Build, Claude Code, Cursor.
  • --tunnel — ngrok public URL for ChatGPT-style remote connectors. Requires token. Not the default for local harnesses.
  • --http-host=0.0.0.0 — LAN bind; also requires token. Avoid unless intentional.

Read the full file on GitHub · 84 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 84 lines · 52 tokens per session scan A 94e3f2208c9d

Subscribe to this mod's changes

opendia-harness is a skill published in the GitHub repository aeonfun/opendia (1,920 stars, last pushed 6d ago), licensed MIT. It adds 52 tokens to every session and 725 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.