opencode-free-9router

Expose the OpenCode Zen free-tier models as one OpenAI-compatible provider for 9Router. No OpenCode account, no API key, no subscription — just a local adapter.

Free models · attested free-tier client · OpenAI-compatible · zero dependencies

English · Indonesia · Español · 日本語 · 中文

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What it is

OpenCode ships a free tier — eleven models you can use at no cost. Access is gated though: the gateway answers 403 FreeTierError: "OpenCode's free tier can only be used from within OpenCode" unless the request carries the official client's fingerprint.

opencode-free-9router reproduces that fingerprint in a tiny local adapter, so 9Router — and anything pointed at 9Router — can call these models for free.

OpenAI client ──▶ 9Router :20128/v1 ──▶ provider-node "OpenCode Free"
              ──▶ adapter :8790/v1 ──▶ opencode.ai/zen/v1  (Bearer public + attestation)

See STRUCTURE.md for the full topology, file map and data-flow diagrams.

9Router also ships its own oc/, ocz/ and opencode-go/ providers. This project is the standalone, auditable alternative: you own the adapter, see exactly what leaves your machine, and can point any OpenAI client at it with or without 9Router.

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The free models

Eleven models are verified reachable end-to-end. Two endpoint families are used.

Model	Endpoint	Context	Notes
big-pickle	chat/completions	200K	general reasoning
fledge-alpha-free	chat/completions	1M	text + image input
ling-3.1-flash-free	chat/completions	262K	fast flash
longcat-2.5-preview-free	chat/completions	1M	long context
mimo-v2.6-flash-free	chat/completions	200K	compact flash
nemotron-3-ultra-free	chat/completions	1M	large model
nemotron-3.5-lightning-free	chat/completions	262K	low latency
space-bunny-free	chat/completions	1M	512K output
step-5-preview-free	chat/completions	1M	StepFun flagship, text+image+video
muse-spark-1.2-contributor-free	responses	1M	contributor model
muse-spark-1.3-contributor-free	responses	1M	contributor model

Not currently serving (listed by the gateway, but the model itself is deprecated or unavailable upstream): exo-free (deprecated), ling-3.0-flash-fin-free (unavailable). They are excluded from the default set but remain documented.

Not proxied (different wire protocol, SystemOne): jev-1.13-free. 9Router handles it natively.

Run node src/cli.js list for the current set.

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Quick start

Requires Node.js >= 18. There is nothing to install — zero dependencies.

git clone https://github.com/0xgetz/opencode-free-9router.git
cd opencode-free-9router

# 1. start the adapter (http://127.0.0.1:8790/v1)
node src/adapter.js

# 2. in another shell, register it in 9Router (9Router must be running)
node src/connect-9router.js

That's it. In 9Router the provider OpenCode Free now lists eleven routable models.

Try a model directly

node src/cli.js ask big-pickle "Explain closures in one line"
node src/cli.js check          # live-probe every working model

Call the adapter like any OpenAI API

curl http://127.0.0.1:8790/v1/chat/completions \
  -H 'Content-Type: application/json' \
  -d '{"model":"space-bunny-free","messages":[{"role":"user","content":"hi"}]}'

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How the free-tier gate works

The gateway only serves the free models to what it believes is the OpenCode client. The adapter sends the exact attested fingerprint:

Signal	Value
User-Agent	opencode/<version> (version >= 1.17)
x-opencode-client	desktop
x-opencode-session	ses_<12 hex><14 base62> — one stable id per identity
x-opencode-request	msg_<12 hex><14 base62> — one stable id per turn
Authorization	Bearer public
stream (body)	true — non-streaming requests are rejected
tools (body)	bash, glob, grep, read — the fingerprint quartet

Session and request ids are generated locally with no network round-trip. Reusing one stable session mirrors the real client and keeps free-tier accounting per conversation instead of per request.

Everything above lives in src/opencode_free.js and is covered by node src/selftest.js.

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Project layout

opencode-free-9router/
├── src/
│   ├── opencode_free.js     # attestation, ids, request shaping, one-shot complete()
│   ├── adapter.js           # OpenAI-compatible HTTP server (:8790/v1)
│   ├── connect-9router.js   # register the provider in 9Router
│   ├── cli.js               # list / ask / check
│   └── selftest.js          # offline + --live checks
├── docs/                    # translated READMEs
├── assets/                  # logo + social preview
└── STRUCTURE.md             # topology, file map, data-flow diagrams

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Testing

npm test              # offline: 11 checks, no network
npm run test:live     # also calls every free model (slow, ~8s between calls)

The live run is deliberately paced because the free tier rate-limits bursts.

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9Router notes

connect-9router.js talks to a local 9Router at http://127.0.0.1:20128. It registers a custom openai-compatible node and an API-key connection, then prints the live model ids.

Verified against 9Router v0.5.95:

POST /api/provider-nodes  { name, prefix, baseUrl, type, apiType }   -> node
POST /api/providers       { provider, name, apiKey, baseUrl }        -> connection
GET  /v1/models                                                      -> <prefix>/<model>
POST /v1/chat/completions  (with a router API key)                   -> 200

Models appear in 9Router as ocfree/<model>. Override behaviour with:

Variable	Default	Meaning
ROUTER_URL	http://127.0.0.1:20128	9Router base URL
ADAPTER_URL	http://127.0.0.1:8790/v1	this adapter's base URL
ADAPTER_API_KEY	sk-opencode-free	key the adapter expects (and 9Router sends)
PROVIDER_NAME	OpenCode Free	node name in the 9Router dashboard
PROVIDER_PREFIX	ocfree	model id prefix used by 9Router
NINEROUTER_CLIENT	auto-detected	path to 9Router's CLI API client
NINEROUTER_CLI_TOKEN	—	fallback device token for raw HTTP mode
SKIP_CONNECTION	—	set 1 to only create the node

9Router protects these routes with a device CLI token. The connector auto-detects the installed 9Router package and reuses its own authenticated client; if it cannot, it falls back to raw HTTP with NINEROUTER_CLI_TOKEN.

The adapter also honours PORT, HOST, ADAPTER_API_KEY and QUIET.

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Legal and fair use

This project is unofficial and not affiliated with OpenCode or 9Router. It uses the free tier as the OpenCode client does. Free tiers have limits and change without notice — respect the upstream terms of service, keep request volume reasonable, and do not resell the access. Use at your own risk.

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License

MIT © 2026 0xgetz