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[!IMPORTANT] The plugin is the client half. devin-2api-lite owns the Devin protocol, catalog, quota and upstream token. Start the gateway first: without it the plugin advertises no models and cannot stream.

What it is

dsh-devin2api registers the provider route devin2api in DeepSeek Harness. It reads the catalog from GET /v1/models, streams POST /v1/chat/completions as DSH StreamChunks, and contributes a settings page, per-model switches and a quota pill to the Web UI.

• streaming text, reasoning and tool calls, with stable error codes;
• current-turn images as resized, byte-capped data URLs;
• allowlists and per-model visibility applied live.

Gateway endpoint	Caller	Credential
GET /healthz	settings panel	none
GET /v1/models	catalog, discovery	Host Bearer; browser none
GET /v1/quota	quota pill, panel	browser none
POST /v1/chat/completions	every model call	Bearer
POST /__clientlog	diagnostics	none, local

Requirements

• DeepSeek Harness 0.2.x (tested 0.2.1-rc.3); peers @deepseek-ai/dsh-llm >= 0.1.5-rc.1, @deepseek-ai/schemastery >= 3.18.0.
• Node.js ^22.19.0 || >=24.0.0.
• devin-2api-lite with /v1/quota and CORS on read-only GETs; the Host attachments service for images.

Quick start

# 1. gateway
git clone https://github.com/Green-hats/devin-2api-lite.git
cd devin-2api-lite
cp config.example.yaml config.yaml   # set devin.token
go run ./cmd/devin-2api -config config.yaml

# 2. plugin (restart the profile afterwards, then refresh the page)
dsh plugin --profile desktop add github:Green-hats/dsh-devin2api
# or: dsh plugin --profile desktop add /absolute/path/to/dsh-devin2api

# 3. sanity check
curl -s http://127.0.0.1:18089/healthz

Configure it in Settings → Models → Devin2API, or override the row in $DSH_HOME/profiles/<profile>/cordis.patch.yml:

- id: devin2api
  config:
    providers:
      devin2api:
        baseURL: http://127.0.0.1:18089/v1
        apiKeyEnv: DEVIN2API_API_KEY

Then choose Devin2API in /model.

Configuration

Everything lives under providers.devin2api:

Field	Default	Notes
displayName	Devin2API	Provider name in the selector
baseURL	http://127.0.0.1:18089/v1	Gateway root including /v1
apiKey / apiKeyEnv	'' / DEVIN2API_API_KEY	Direct key (redacted) or env var read per request
enabled	true	Mount-time gate; changing it needs a reload
models	[]	Empty = all. Non-empty allowlist of ids or { id, name }
modelVisibility	{}	Per-model switch; false hides a model
images	true	Declare image input for vision models
contextWindow / maxTokens	262144 / 128000	Limits reported to DSH (not in /v1/models)
refreshMinutes	5	Catalog cache TTL (minimum 1)
requestTimeoutMs	300000	Per-request timeout including the stream
imagePixelBudget / imageMaxBytes	4194304 / 1048576	Resize target per image
maxRequestImageBytes	20971520	Total base64 characters per request

All fields except enabled are volatile: settings writes apply live. DEVIN2API_BASE_URL is reported to the Models page as an endpoint hint.

Web UI

The real Settings → Devin2API page and the composer pill (UI copy is Chinese). Full-size settings.

• Settings → Devin2API — gateway status, daily/weekly quota, catalog switches and refresh.
• Settings → Models → Devin2API — base URL, key, images, model discovery.
• Composer pill — only for a devin2api model; 60 s poll; click to request ?fresh=1.

The browser calls /healthz, /v1/models and /v1/quota directly and sends no API key. With auth.api_key set, the catalog/panel reads fail (chat still works); read-only settings disable the switches.

Catalog and images

• The catalog is cached for refreshMinutes, refreshed in a single flight, and falls back to models; if both are empty it reports EMPTY_CATALOG.
• models is an allowlist; modelVisibility is applied after it. All-off or all-missing falls back to the full list.
• Only the current turn (last user message onward) is uploaded. Older images become [Image omitted from history].
• Images are resized per imagePixelBudget/imageMaxBytes; over maxRequestImageBytes fails with IMAGE_BUDGET.

Protocol mapping

DSH input	Gateway request
system prompt + leading/mid-history system	one or more system messages
developer	system
user / tool content	string, or text + image_url parts
assistant text / tool calls	content + tool_calls (JSON-string arguments)
tools	OpenAI function tools; deferLoading skipped
maxTokens / reasoningEffort / temperature / stop	same-named fields

Stream: reasoning_content → reasoning block, content → text, tool_calls → tool-call block, usage → usage, finish_reason → stop / tool-calls / max-tokens. [DONE] ends the stream.

Errors: AUTH, QUOTA, INVALID_REQUEST, TIMEOUT, ABORTED, TRANSPORT, SERVER, IMAGE_BUDGET, IMAGE_UNAVAILABLE, EMPTY_CATALOG, EMPTY_RESPONSE, UPSTREAM_ERROR.

Current lite fixes sampling (max_tokens, temperature, top_p, top_k) and ignores client values; the plugin still forwards temperature / stop for gateways that honor them.

Architecture

lib/index.js     host adapter, registration, discovery, settings policy
lib/protocol.js  message/tool/SSE translation
lib/catalog.js   catalog, quota, visibility, error mapping
lib/schema.js    volatile Config schema
lib/client.js    settings page, switches, quota pill

Troubleshooting

• cannot reach the gateway — curl /healthz, check baseURL; the Host must reach it too.
• AUTH — check apiKey / apiKeyEnv against lite's auth.api_key.
• Empty model selector — curl /v1/models; set models as a fallback; reload the plugin.
• Images become text — expected for history; check images, supports_images, attachments, budgets.
• Settings unavailable — the namespace needs volatile fields; check the Host log.
• Pill missing — model is not devin2api, gateway down, CORS blocked, or auth.api_key set.
• Client errors — POST /__clientlog; lite appends to $TMPDIR/dsh-devin2api-client.log.

Limitations

• No replay state; multi-turn replays visible text and tool calls only.
• One gateway per plugin instance.
• enabled requires a reload.
• The browser UI is unauthenticated; use a loopback gateway with auth.api_key unset.
• UI copy is Chinese-only.
• contextWindow / maxTokens are configured, not discovered.

Development

npm install --legacy-peer-deps   # schemastery for the schema tests
npm test                         # 30 tests
npm run check                    # node --check for lib/*.js

A test-only resolve hook maps @deepseek-ai/dsh-llm to test/fixtures/dsh-llm, so the suite runs without DSH. Banners, the architecture diagram and the UI composite are generated by python3 scripts/make-images.py (needs rsvg-convert and Pillow); docs/settings.jpg and docs/composer.png are the source screenshots. CI runs Node 22/24.

Related

• devin-2api-lite — the gateway (中文)
• DeepSeek Harness
• leookun/devin-2api — original protocol research

License

MIT © 2026 Green-hats. The Host path is tested against a live lite gateway; the UI composite uses screenshots from a live profile.