Free AI coding agents: what to check

“Free” can describe the client software, a temporary allowance or a local model with no hosted per-token bill. These are different costs. Compare the costs and requirements of each option below.

Separate the client from inference

Do not infer that a free service uses your code for training or that a paid one never does. Those are policy questions, not facts established by the price. Check the particular service and account settings.

What “free unlimited” can mean

Ask which resource is unlimited: use of the client, number of requests, tokens, or access to one model. A free client license says nothing about hosted inference charges. A service allowance may have rate limits, model restrictions or an expiry date. Read those conditions without assuming that every free service has the same business model or data policy.

For OpenCode, installing the client, using its TUI, and connecting a model are separate steps. The provider you connect determines the inference bill. Review Zen's free models and prices if you want its hosted offering, or configure another provider.

Option 1: a free hosted model allowance

This is convenient for trying a small task without setting up local inference. In OpenCode, connect the service with /connect, choose an available model with /models, and check whether that exact model is free for your account. A paid and a free variant can have different IDs and different terms.

The Zen guide includes the model list, free offers and spending controls. Check automatic top-ups before starting a longer session. Treat the first task as a trial: reproduce one bug or explain one function, then review the answer before granting broader tool permissions.

Option 2: a free client with your own API key

Here the software may be free, but model calls are metered. It can fit intermittent use because you can observe costs per task instead of estimating from a subscription alone. It is not automatically the cheapest arrangement for every workload.

Connect the key using the provider instructions, select a default in model settings, and inspect the provider's usage page. If routine tasks and difficult tasks use different models, keep that choice explicit in your agent configuration. Do not assume a model switch transfers an existing account allowance.

Option 3: local inference

A local model avoids a hosted per-token bill, while hardware, memory, electricity and maintenance remain real costs. The provider reference includes local-server configuration. Start by confirming that the server responds and that the chosen model can handle the tools needed by your task.

Try a single-file change first and measure memory use and response time. Context size and model requirements determine what fits your machine; there is no single RAM requirement that applies to every local model. Review network settings and MCP connections separately before describing the complete workflow as offline.

Free AI coding tools for VS Code

Cline, Continue and Copilot are candidates to investigate through their official references above; the available features, account requirements and limits differ. OpenCode can also be used through its IDE integration. Run the client inside the editor's terminal and confirm that the expected file or selection context is actually available.

Compare an editor completion task with an agent task separately. Completing a line and changing several files require different interactions. The OpenCode vs Cursor guide explains how to evaluate the editor and agent workflows without treating them as the same feature.

When a paid option makes sense

Record the cost and outcome of representative tasks before choosing a plan. Include retries, cached and uncached input, output tokens, allowances and any additional usage. Zen's worked cost example illustrates token arithmetic; use the actual rates for your provider.

For example, if a month of accepted work costs less under metered billing than the subscription you are considering, compare the convenience and limits before switching. If it costs more, check whether the subscription actually includes that model and workload.

Follow the AI coding workflow for task sizing and review. Manual corrections also have a cost, even when the model requests are free.

Start with a bounded trial

1. Choose a provider you can access and confirm its billing and data terms. If it offers free models, check their exact IDs and current limits.
2. In OpenCode, use /connect to add the provider and /models to select a model. See the provider guide.
3. Ask a small question without sensitive data and inspect the provider's usage record. Do not enable automatic top-ups merely to test the setup.
4. Try a small code change in a reviewable checkout, then run the project's tests and review the diff.
5. Record both cost and manual corrections. A lower token rate does not establish a lower cost for an accepted change.

Account-specific eligibility needs checking in the provider console.

Local inference has its own requirements

A local provider can reduce reliance on hosted inference, but it is not a universal performance or privacy guarantee. Check that your model and serving application support the tools and context required by your task. Measure latency and memory use on your own machine before committing to a workflow.

Also review other network paths: extensions, telemetry, remote MCP servers and tools can contact external systems even when model inference is local. A claim that nothing leaves the machine requires checking the complete setup.

Keep the setup reusable

Write down the chosen provider, model and spending controls so you can reproduce the trial. Keep credentials outside the repository, and record which limits come from the provider account. The guide index links the setup, comparison and workflow references for the next step.

When an allowance runs out

Identify which provider, account and model produced the limit. Switching clients does not reset a provider's quota. Review rate limits, credit expiry and any subscription rules; distinguish a temporary rate limit from an exhausted balance.

Use the connection troubleshooting guide for authentication and network failures. For a broader shortlist, see AI coding agents compared. For third-party gateways, the API setup page provides a configuration template.