OpenCode

OpenCode is an open-source terminal coding agent — also available as a desktop app and IDE extensions — driven by opencode.json. Register MirAPI once as a provider and you can pick any MirAPI model per session, paying from your existing prepaid balance.

What you need

Element	Value
Base URL	`https://api.mirapi.ai/v1`
API key	Your MirAPI key, referenced as `{env:MIRAPI_API_KEY}`
Model	`deepseek-chat` under provider `mirapi`
Protocol	OpenAI-compatible (`/v1`)

If you do not have a key yet, create one in the console at https://console.mirapi.ai. The key is shown only once, so copy it immediately.

Configure

Install OpenCode if it is not already installed:

curl -fsSL https://opencode.ai/install | bash

Other installers include npm install -g opencode-ai and brew install anomalyco/tap/opencode.

Add a provider block to opencode.json at your project root (or ~/.config/opencode/opencode.json for user-wide settings; JSONC is accepted):

{
  "provider": {
    "mirapi": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "MirAPI",
      "options": {
        "baseURL": "https://api.mirapi.ai/v1",
        "apiKey": "{env:MIRAPI_API_KEY}"
      },
      "models": {
        "deepseek-chat": {
          "name": "DeepSeek Chat"
        }
      }
    }
  }
}

Export the key in your shell:

export MIRAPI_API_KEY=sk-...

Set a default model

To skip the model picker on startup, add a top-level model key. OpenCode composes ids as provider_id/model_id, so a MirAPI model is prefixed with mirapi/:

{
  "model": "mirapi/deepseek-chat"
}

You can still override it per invocation with --model.

Verify with a message

opencode run "Reply with exactly: connected to MirAPI" --model mirapi/deepseek-chat

The reply should contain connected to MirAPI. In an interactive session, run /models and select mirapi/deepseek-chat.

How it works

OpenCode runs custom providers on the Vercel AI SDK. @ai-sdk/openai-compatible speaks the OpenAI Chat Completions protocol, so MirAPI receives POST /v1/chat/completions at https://api.mirapi.ai/v1. Responses stream as standard SSE (data: lines, ending with data: [DONE]), which the AI SDK parses for you.

Protocol variants

MirAPI serves the same models over three protocols. The provider above is OpenAI-compatible; if you prefer another SDK’s behaviour, point the AI SDK’s @ai-sdk/anthropic provider at https://api.mirapi.ai (auth x-api-key) or @ai-sdk/google at https://api.mirapi.ai (auth x-goog-api-key). Whether a given model is available on a given protocol depends on its capability flags in the catalogue.

Errors and billing

Status	Meaning	What to do
401	Key missing, invalid, or unknown	Check `{env:MIRAPI_API_KEY}` and the exported variable
403	Key valid but rejected — balance exhausted, model not whitelisted, quota reached, or IP not allowed	Resolve the cause, then retry
413	Request too large	Reduce the payload
429	Rate limited (no `Retry-After` header)	Retry with exponential backoff
500	Server error	Idempotent requests can be retried safely

Every error message ends with a request ID — include it in any support ticket.

Chat usage bills per token: input, output, and cache read, per 1M tokens. Reasoning tokens bill as output. Prompt caching is automatic on OpenAI-compatible models; confirm hits via usage.prompt_tokens_details.cached_tokens. The balance is prepaid USD and never expires — when it runs out you get 403, and the same key resumes immediately after a top-up. Reconcile spending in the console billing log or via GET /api/usage/token (summary) and GET /api/log/token (per-request detail).

Tool-specific pitfalls

@ai-sdk/openai-compatible is the right npm package for OpenAI-compatible gateways; the plain openai package also works but keeps the SDK’s default behaviours.
The model list is manual. OpenCode does not auto-discover MirAPI models; add each one you want by its exact GET /v1/models name. The vendor/ prefix is console-only and never part of the request name.
The provider prefix is mirapi/ — mirapi/deepseek-chat means the deepseek-chat model under the mirapi provider, not a model namespace.
403 with a valid key usually means the model is not whitelisted for that key or the balance is exhausted. Top up or adjust the whitelist, then retry.
Auth errors — check that {env:MIRAPI_API_KEY} matches the exported variable name exactly.
Config changes need a restart — OpenCode reads opencode.json at startup, so restart it after editing the provider block.