For a DeepSeek V4.1 Flash OpenCode setup, install OpenCode, type /connect, pick OpenCode Zen (or DeepSeek with your own API key), then choose DeepSeek V4.1 Flash in /models. Through Zen, OpenCode lists a deepseek-v4.1-flash-free model that's free for a limited time, so you can run a full coding agent on it without paying per token.
📺 Watch: Run DeepSeek V4.1 Flash Completely Free inside OpenCode!
🔥 Get the Agent OS as a free bonus: AI Profit Boardroom members get the full Agent OS zip, prompt libraries, daily tutorials and weekly live coaching calls. → Get inside
That's exactly what I showed in my 23 October video, "Run DeepSeek V4.1 Flash Completely Free inside OpenCode!" This is the written version: setup, the workflows I'd run, how to wire it into subagents, and the limits you should know before you lean on it.
Why the DeepSeek V4.1 Flash OpenCode combo works
OpenCode is an open-source coding agent that runs in your terminal. It reads your project, edits files, runs commands and can hand jobs to subagents. On its own it's just the harness. The model is the brain.
DeepSeek V4.1 Flash is a strong brain for that job. DeepSeek's current build, V4.1-Flash-1017, came out on 17 October 2026, and its model card scores it 42.3 on Terminal-Bench 4.0 and 77.0 on DeepSWE v1.1. It has a 1M-token context window and open weights under MIT. I break the model down properly in my DeepSeek V4.1 Flash explainer.
Put them together and you get an agent that can work through a real codebase for free while the Zen offer lasts.
If you'd rather follow a full masterclass, the DeepSeek + OpenCode walkthrough and my Agent OS are inside the AI Profit Boardroom ($69/mo), along with a 30-day AI agent roadmap, daily tutorials as new tools drop and four coaching calls a week. Over 3,400 members.
Step 1: Install OpenCode
The quickest way, per the OpenCode docs, is the install script:
curl -fsSL https://opencode.ai/install | bash
Prefer a package manager? Any of these work:
- npm install -g opencode-ai
- bun install -g opencode-ai
- brew install anomalyco/tap/opencode
One catch on Mac. The docs say plain brew install opencode now installs OpenCode 2, while the tap gives you OpenCode 1. Both use the same opencode command, so pick one and don't install both under the default name. On Windows, the docs recommend WSL, with Chocolatey, Scoop and npm as other options.
Then go to your project and start it:
cd /path/to/project
opencode
📺 Watch: OpenCode + DeepSeek V4 Flash Trick Changes Everything! (FREE!)
Step 2: Connect DeepSeek V4.1 Flash in OpenCode
You've got two ways in. Pick the free one first.
Route A: OpenCode Zen (free model)
- Inside OpenCode, type /connect and select OpenCode Zen.
- Go to opencode.ai/auth, sign in and copy your API key.
- Paste the key into OpenCode.
- Type /models and pick DeepSeek V4.1 Flash Free.
Zen lists the model as deepseek-v4.1-flash-free, "free for a limited time". OpenCode says its provider follows a zero-retention policy and doesn't train on your data. When you reference Zen models in config, the format is opencode/ followed by the model ID, so this one is opencode/deepseek-v4.1-flash-free. Zen also has a paid deepseek-v4.1-flash at $0.30 input and $1.20 output per million tokens.
Route B: Your own DeepSeek API key
- Create a key in the DeepSeek platform console.
- In OpenCode, type /connect and search for DeepSeek.
- Paste the key.
- Type /models and pick the DeepSeek Flash model.
On DeepSeek's own API, the name deepseek-flash serves V4.1-Flash-1017. OpenCode stores credentials in ~/.local/share/opencode/auth.json, and opencode auth list shows what's connected.
This route costs money but it's yours, with no "limited time" tag on it.
📺 Watch: Hermes + DeepSeek V4 Flash is WILD (FREE)
Step 3: Set up the project
Before you ask for anything, type /init. OpenCode reads the project and writes an AGENTS.md file in the root. Commit it to Git. That file is how the agent remembers your structure and coding patterns between sessions.
Then learn three controls:
- Tab flips between Plan and Build. Plan can't change files, it only tells you how it would do the job. Build makes the changes.
- @ fuzzy-searches files, so you can point the model at exactly what matters.
- /undo and /redo roll changes back and forward.
Always start in Plan. Read the plan. Then Tab into Build. That one habit saves you more mess than any prompt trick.
Agent workflows to run on it
Here's where a free, fast model earns its keep. These are the jobs I'd give it first.
- Build a small app from a brief. Plan a landing page or internal tool, approve it, let Build write it. DeepSeek trained 1017 with reinforcement learning for end-to-end project work, from games to 3D modeling.
- Refactor a messy folder. Point it at files with @, ask for a plan, then let it clean up.
- Write and fix tests. Ask it to add tests, run them in the terminal and fix what fails.
- Explain an unfamiliar codebase. With 1M tokens of context, it can hold a lot of the project at once.
- Automate the boring scripts. Data cleanup, file renames, scrapers, report generators.
If you want to know which of these would actually pay off in your business, book a free AI strategy session.
Subagents: build a smarter system
This is the part most people skip, and it's the part that makes OpenCode feel like a team.
OpenCode has two kinds of agents. Primary agents are the ones you talk to: Build and Plan. Subagents are helpers the primary agent calls for specific jobs. Two come built in: General for multi-step tasks and Explore for read-only codebase search. You can call one by name, like @general find every place we call the payments API, or let the primary agent call it when the task fits.
Make your own with opencode agent create, or drop a Markdown file into .opencode/agents/ in your project (or ~/.config/opencode/agents/ for every project). The file name becomes the agent name. A simple reviewer that runs on the free DeepSeek model looks like this:
---
description: Reviews code for bugs and style
mode: subagent
model: opencode/deepseek-v4.1-flash-free
permission:
edit: deny
bash: deny
---
Run opencode agent list to check it loaded.
The key rule from the docs: if a subagent has no model set, it uses the model of the primary agent that called it. So you can run your main agent on a frontier model and pin the cheap, repetitive subagents to DeepSeek V4.1 Flash. Or flip it and run everything on DeepSeek, then pull in a bigger model only for the hard calls.
That's the same idea I use with Hermes inside my Agent OS every day, a profile per model and each job routed to the right one. My Agent OS guide shows the full layout.
Limits to know
Free is great. Here's what to keep in mind.
| Limit | What it means for you |
|---|---|
| Free for a limited time | Zen doesn't promise the free model stays free. Have Route B ready. |
| Free models need OpenCode | Zen says free-tier chat models only work inside OpenCode, not other clients. |
| Not top of every benchmark | Per DeepSeek's card, Opus 5 still leads on Terminal-Bench 4.0 (51.8 vs 42.3) and HLE. |
| Peak pricing on your own key | DeepSeek charges double at peak, 01:00 to 04:00 and 06:00 to 10:00 UTC on weekdays. |
| Agents can still break things | Use Plan first, restrict subagent permissions and keep /undo handy. |
Want to hide the free models altogether? Set OPENCODE_DISABLE_FREE_MODELS=1. And benchmarks are DeepSeek's numbers. I test models on my own work in Goldie Bench, and that's what you should do too: one real task from your week, run it, compare.
Prefer DeepSeek's own agent? See my DeepSeek V4 Flash harness guide. And if you want another free model to rotate in, my GLM 5.3 Flash OpenCode setup works the same way through Zen.
Stuck on where agents fit in your workflow? Grab a free AI strategy session.
FAQ
Is DeepSeek V4.1 Flash free in OpenCode?
Yes, for now. OpenCode Zen lists deepseek-v4.1-flash-free as free for a limited time. Connect Zen with /connect and select it in /models.
Do I need a DeepSeek API key?
Not for the free Zen model. You sign in at opencode.ai/auth and use your Zen key. You only need a DeepSeek key for Route B.
Can I use DeepSeek V4.1 Flash for subagents only?
Yes. Set model: opencode/deepseek-v4.1-flash-free in the subagent's Markdown file. Subagents without a model inherit the primary agent's model.
Does my code get used for training?
OpenCode says the DeepSeek V4.1 Flash Free provider follows a zero-retention policy and doesn't use your data for training.
Want the full DeepSeek + OpenCode masterclass and the Agent OS? Join the AI Profit Boardroom, or book a free AI strategy session. Install it today and get DeepSeek V4.1 Flash running in OpenCode.
