Codex CLI vs OpenCode in 2026: What each does and costs

Q: Is AgentHydra free to use?

AgentHydra is free, with no account or subscription . It is open source under the MIT License . The facts here give no price for Codex CLI or OpenCode, so their costs are not published here. Check each tool's own pages if you need the cost.

Q: Can OpenCode run on different editors or devices?

OpenCode is an open source AI coding agent available as a terminal-based interface, desktop app or IDE extension . It can use any LLM provider by configuring API keys and supports 75+ LLM providers, including local models .

Codex CLI and OpenCode are AI coding agents you run; AgentHydra adds session management on top. Compare what each does, what it costs and what to check.

By SupaKeeper · 2026-10-26

SupaKeeper is published by LunarWerx, which makes some of the tools compared here.

OpenCode is an open source AI coding agent ^[1]. Codex CLI offers a command that chooses what Codex is allowed to do ^[2] and a command that chooses which model and reasoning effort to use ^[2]. AgentHydra shows Claude Code, Codex and OpenCode sessions on your machine in one searchable list, updated live while they run ^[3], and lets you reply into a Claude session's chat or send one message to several sessions ^[3]. Pick by what you need: code writing is what the two agents cover, and session management is what AgentHydra covers.

Option	What its sources say it does	Cost	Account or install
Codex CLI	Lets users inspect code, make changes, run commands and automate repeatable work in the terminal ^[2]; commands choose what Codex may do ^[2] and which model and reasoning effort to use ^[2]	not published	First run offers Sign in with ChatGPT or another available sign-in method ^[2]
OpenCode	An open source AI coding agent ^[1] available as a terminal-based interface, desktop app or IDE extension ^[1]; runs several agents in parallel on the same project ^[4]; supports 75+ LLM providers, including local models ^[4]	not published	Can use any LLM provider by configuring API keys ^[1]; does not store code or context data ^[4]
AgentHydra	Shows Claude Code, Codex and OpenCode sessions on your machine in one searchable list, updated live ^[3]; shows cost at API list prices by day, model, project and account ^[3]; lets you reply into a Claude session's chat or send one message to several sessions ^[3]	free, no account or subscription ^[3]	On Windows, install with a one-line PowerShell script, or download a build from GitHub Releases or run from source with Bun ^[3]

The short answer

OpenCode is an open source AI coding agent you run yourself ^[1], and Codex CLI is OpenAI's terminal tool whose commands set what Codex may do ^[2] and which model and reasoning effort it uses ^[2]. Both meet the need of writing code from your own machine. AgentHydra meets a different need: it shows Claude Code, Codex and OpenCode sessions on your machine in one searchable list, updated live while they run ^[3], and it can type a reply into a Claude session's desktop chat or send one message to several sessions ^[3]. If your need is writing code, look at the two agents; if it is watching and answering sessions, look at AgentHydra.

What Codex CLI, OpenCode is built for

OpenCode is an open source AI coding agent ^[1]. It runs several agents in parallel on the same project through a multi-session setup ^[4], and it keeps a curated list of models that the OpenCode team has tested and verified, called OpenCode Zen ^[1]. Codex CLI's own pages describe commands that shape a run: a command that chooses what Codex is allowed to do ^[2], a command that chooses which model and reasoning effort to use ^[2], and a first run that offers Sign in with ChatGPT or another available sign-in method ^[2]. Both tools are ways to get code written from a terminal, and their facts here stop at what each own page says they do.

What AgentHydra is built for

AgentHydra is made by the team that publishes this site. The product shows Claude Code, Codex and OpenCode sessions on your machine in one searchable list, updated live while they run ^[3]. It lets you type a reply into a Claude session's own desktop chat, or send one message to several sessions ^[3]. It can move a Claude chat, history included, to another of your accounts ^[3], and it can split a task's pieces across Claude Code CLI sessions on your accounts and move a worker to another account when one nears its limit ^[3]. It lists each Claude and Codex account with its plan and 5-hour and weekly quota, and can open, focus, quit, create and delete Claude Desktop instances ^[3]. It pairs each failed shell command with the command that fixed it and can copy those pairs out as a rules file for your agents ^[3]. It shows cost at API list prices by day, model, project and account ^[3], and exposes its features as MCP tools, including whoami and usage checks so an agent knows which account it is on and how much quota is left ^[3].

Pricing and fees

The facts here give no price for Codex CLI, so its cost is not published here. The facts here give no price for OpenCode either, so its cost is not published here. AgentHydra is free, with no account or subscription ^[3]. It is open source under the MIT License ^[3]. The only price the facts or claims give for any of the three is that AgentHydra is free ^[3]. If you need the cost of Codex CLI or OpenCode for your own use, check their own pages, since the facts here state none.

Setting it up and daily use

Codex CLI's first run offers Sign in with ChatGPT or another available sign-in method ^[2], so setup starts with a sign-in choice. OpenCode is an open source AI coding agent ^[1], and its facts describe using any LLM provider by configuring API keys ^[1]. AgentHydra, on Windows, installs with a one-line PowerShell script, or you can download a build from GitHub Releases or run from source with Bun ^[3]. The tray app needs Windows; macOS and Linux builds exist but have not been verified ^[3]. For day to day use, OpenCode runs several agents in parallel on the same project ^[4], while AgentHydra shows the same sessions in one live list and prints its cost figures as JSON from the command line ^[3]. The facts say nothing more about daily routines for either agent, so check each tool's own pages for anything further.

Things to check before you choose

Ask what you need the tool to do. Codex CLI and OpenCode write code in a terminal, and AgentHydra manages sessions across those tools. Ask how you want to run things: OpenCode uses any LLM provider through configured API keys ^[1], and its facts say it does not store any code or context data ^[4], while AgentHydra runs its tray app on Windows only ^[3]. Ask where your session list lives: AgentHydra's list is on your machine ^[3]. Ask whether you need cost detail: AgentHydra shows cost at API list prices, which are estimates, not exact billed amounts ^[3]. Ask what either tool charges; the facts state a price for none of these tools except that AgentHydra is free ^[3].

How to choose

If you write code in a terminal and want a sign-in choice and model commands, Codex CLI has those ^[2] ^[2]. If you want an open source agent that runs several in parallel on one project and lets you pick any provider, OpenCode has that ^[1] ^[4] ^[1]. If you run several sessions and want them in one searchable live list with replies and account checks, AgentHydra does that ^[3] ^[3] ^[3]. All three are free of the fee facts here; only AgentHydra's free price is stated ^[3]. Match the tool to the need you actually have.

Frequently asked questions

Is AgentHydra free to use?

AgentHydra is free, with no account or subscription ^[3]. It is open source under the MIT License ^[3]. The facts here give no price for Codex CLI or OpenCode, so their costs are not published here. Check each tool's own pages if you need the cost.

Does Codex CLI cost anything?

The facts given here do not state a price for Codex CLI, so its cost is not published here. Codex CLI's facts describe a first run that offers Sign in with ChatGPT or another available sign-in method ^[2], but say nothing about a fee. Check its own pages for the cost.

Does OpenCode cost anything?

The facts given here do not state a price for OpenCode, so its cost is not published here. OpenCode is an open source AI coding agent ^[1] that can use any LLM provider by configuring API keys ^[1]. Check its own pages for any cost or limits.

Can OpenCode run on different editors or devices?

OpenCode is an open source AI coding agent ^[1] available as a terminal-based interface, desktop app or IDE extension ^[1]. It can use any LLM provider by configuring API keys ^[1] and supports 75+ LLM providers, including local models ^[4].

What does AgentHydra do for developers?

AgentHydra shows Claude Code, Codex and OpenCode sessions on your machine in one searchable list, updated live while they run ^[3]. It can reply into a Claude session's desktop chat or send one message to several sessions ^[3], and it shows cost at API list prices by day, model, project and account ^[3]. Its tray app needs Windows ^[3].

Free, with no account or subscription. ^[3]

Try AgentHydra