OpenCode 2.0 background service and the Codex daemon: what a resident coding agent changes and how to turn it off

The OpenCode 2.0 background service is one per-user server that every OpenCode client connects to, and it keeps running after you close the terminal. It owns your sessions, permissions and tool execution. OpenCode made it the default with the 2.0 upgrade that Anomaly announced on 12 October 2026. Codex CLI did the same in version 0.157.0 on 25 September, and the issue asking OpenAI to make it opt-in reached 606 points on Hacker News by 15 October. Both can be turned off: opencode --standalone or opencode service set disabled true for OpenCode, daemon_auto_start = false or --no-daemon for Codex.

What is the OpenCode 2.0 background service?

The OpenCode 2.0 background service is a local HTTP server that the first OpenCode client starts and every later client reuses: the terminal UI, the web UI, the desktop app and scripts. The docs say it "owns sessions, configuration, integrations, permissions, and tool execution". Your terminal window becomes one client among several, and closing it disconnects that client without stopping the work.

OpenCode had a client and server from the start, but only power users ran the server on purpose. In 2.0, in Anomaly's words, "this server now automatically runs as a single background process on your machine". The 2.0.0 package appeared on npm on 11 September. The announcement and the opencode upgrade --major path from 1.x came a month later, and 2.0.29 was current on 14 October.

The details, from the web docs and troubleshooting page:

• It listens on localhost only, on port 49374 (45278 on Windows), behind a generated password.
• It registers itself in ~/.local/state/opencode/service.json, and keeps its sessions in ~/.local/share/opencode/opencode.db.
• Its docs describe no login item and its source has no launchd or systemd code, so it starts the first time a client needs it, not at boot.
• It does not update itself by default: the update setting defaults to "notify", and an installed update waits for a manual restart (config docs).

One Service.ensure() call, every client on the same sessions

Any program can attach to the service the same way OpenCode's own apps do. Service.ensure() from @opencode/client returns the running service, starting one if needed and replacing one from another version. This example, condensed from the announcement, starts a session from a script, and the session then shows up in the terminal and web UIs:

import { OpenCode } from "@opencode/client"
import { Service } from "@opencode/client/service"
const endpoint = await Service.ensure()
const client = OpenCode.make({ baseUrl: endpoint.url, headers: Service.headers(endpoint) })
const session = await client.session.create({ location: { directory: process.cwd() } })
await client.session.prompt({ sessionID: session.id, text: "Review the current changes" })

opencode pair prints one-time links, valid for five minutes, that sign a browser or phone in to the same server. opencode pair --remote exposes it to the internet through a tunnel, after a confirmation prompt.

Codex CLI's daemon also updates itself every hour

Codex CLI's daemon works the same way and adds an updater. OpenAI added daemon_auto_start as an opt-in experiment on 17 September (#46117), turned it on by default five days later (#47179) and shipped it in 0.157.0. It is still on by default in 0.162.1, released on 9 October and the current stable version on 15 October.

An OpenAI engineer explained the change on 30 September: agents now start and manage other sessions, so all terminal sessions "remote" to one background app server, which "gives them all a unified view of which threads are actively running". The daemon's README adds what issue #48195 complained about:

• It runs detached, tracked by a pidfile, until you stop it or reboot. There is no launchd or systemd unit.
• Its updater checks five minutes after start and then hourly, downloads new releases and restarts the server, so active or queued work "may be interrupted" after a 60-second grace period.
• It keeps the environment of whichever session started it: "per-client environment isolation is not provided".
• It copies its own binaries, about 374 MB per release on the reporter's machine, into ~/.codex/packages/app-server-daemon/, separate from the copy your package manager installed.

As of 15 October, no OpenAI employee had replied on #48195. A fix that prunes old daemon releases was merged on 14 October and is not in a stable release yet.

A resident service buys shared sessions and background work

A resident agent service lets work continue when no window is open, and lets several clients see the same sessions. In OpenCode 2.0 that means background subagents and shell commands (Ctrl+B moves running work there), the web UI and desktop app on the same session, and scheduled scripts that find the service without configuration. For Codex, OpenAI names "background work that continues after the CLI exits" and the codex agents command center, which does not run with --no-daemon.

I found no startup benchmark from either vendor. The one number I found is from the maintainer of a permissions wrapper for OpenCode, who measured 2 to 4 seconds per service boot when running OpenCode with --standalone. Their conclusion: the daemon's advantages "are almost entirely multi-client and always-on features", and for one terminal session per start, "almost none of them apply".