DeepSeek in OpenCode: Provider Setup and Coding Acceptance Checklist

The documented direct route for DeepSeek in OpenCode is to connect the DeepSeek provider, enter its API credential in the client and select the model. Begin with that built-in flow before copying a custom-provider configuration from an older tutorial.

This guide reviews the official setup documentation as of October 2, 2026. It does not claim a completed authenticated model call or repository benchmark. The verification steps below distinguish a saved connection from a working coding session and a working session from an accepted code change.

Check the client version before changing configuration

DeepSeek's OpenCode integration guide recommends OpenCode version 1.18.30 or later for its documented flow. Inspect the installed version first:

opencode --version

If an older client does not show the expected provider or model, follow the official update instructions for your installation method. Record the version in the setup notes so later troubleshooting starts from the client actually in use.

Configuration examples must match that client generation. The current OpenCode v2 provider documentation uses a providers map with package and settings fields for custom routes. Do not mix a v2 example with an older client's schema or treat one field spelling as correct for every release.

Connect the built-in DeepSeek route

Launch the client from the intended project directory:

opencode

Inside OpenCode, run /connect, choose DeepSeek and supply the credential through the client's credential input. Then open /models and select the DeepSeek model available in that catalog. The DeepSeek integration guide currently illustrates DeepSeek-V4-Flash; your selected catalog entry and account access should agree.

A completed connection step means the client has received credentials. It does not prove that a request succeeded or that the selected model supports the coding behavior you need. Check the active provider and model before starting a meaningful task.

Keep direct DeepSeek access separate from OpenCode Go or another gateway. A similarly named model can be served through a different account and billing route. Write down which provider owns the credential and which service receives the request so invoice and failure investigation remain clear.

Use custom configuration only for a specific reason

A company gateway or a non-catalog endpoint may need custom provider configuration. In that case, copy the structure from documentation for the installed client version, then set the real endpoint and the provider's exact model ID.

For OpenCode v2, the provider ID used in the configuration and the model ID sent upstream can differ. The current documentation provides modelID for that mapping. A label displayed in the model picker is not evidence that the same string is a valid upstream model identifier.

Use the endpoint and credential belonging to the same access route. Replacing a native endpoint with a marketplace URL while leaving the native credential in place is not a valid integration. Keep secrets out of source-controlled project files; use the documented connection or environment mechanism for that route.

The OpenCode tool hub provides broader discovery. This page focuses on direct setup and acceptance, rather than implying that every OpenCode feature works with every compatible provider.

Run a minimal session before granting a larger task

Start with a small question that requires reading one known file in a disposable repository. Check that the client accesses the intended file and that the response refers to actual content. Then ask for one limited edit with a visible expected result.

Inspect the diff before running the project's meaningful checks. A model can produce a plausible explanation while editing the wrong file or omitting a required case. The relevant evidence is the repository change and its behavior, not only the assistant's summary.

Keep the pilot task small enough to diagnose. A request to refactor an entire application mixes provider setup, agent behavior and implementation quality into one failure. A limited fixture separates those concerns and shows whether file reading, editing and command execution work together.

Diagnose errors by the stage that failed

An authentication error points first to the selected account and credential. A missing model points to the catalog, client version or model ID. A transport timeout points to the route and request lifecycle. A failed code test is an implementation outcome, not automatically an API compatibility error.

Record the selected provider, model, client version and sanitized error. Avoid storing credentials or private source content in a public troubleshooting report. If a request might have reached the provider before timing out, inspect usage and session state before repeatedly retrying it.

Check reasoning and tool behavior separately when the selected model exposes multiple modes. A text-only response does not establish that a multi-step agent task will use tools correctly. Evaluate the actual tool sequence needed by the product and preserve its trace in the pilot record.

Accept code by repository behavior and total task cost

Use a small acceptance set containing a straightforward edit, a bug with a regression case and a task that requires reading several files. Fix the starting commit and instructions for each task. Compare completed changes against the same acceptance criteria when evaluating alternative models.

Track model usage, retries, correction time and project checks. A low token rate does not determine the total cost of a successful coding task. Likewise, a green build alone does not prove that the requested behavior is correct if the relevant case was never exercised.

Expand the rollout only after the direct route works and the pilot changes meet their requirements. For model-selection context, read the Chinese Claude alternatives guide. Keep setup evidence, model capability and accepted application behavior as separate findings.

FAQ

Do I need custom JSON to connect DeepSeek?

The official guide provides a built-in provider flow. Use /connect and model selection first; custom configuration is for routes that actually require it.

Why does a model shown in a tutorial not appear?

Check the installed client version, selected provider and account route. Catalog availability and upstream model IDs can change; inspect the current official integration instructions.

Does a successful response prove coding compatibility?

It proves only that the request produced a response. Verify file access, tool use, the resulting diff and the repository behavior needed by your application.