UIGraph Gateway (`uigraph-gateway`)

The gateway presigns uploads and runs the AI chat. UIGRAPH_API_URL and the STORAGE_* keys are required; the AI provider and MCP settings are only needed for the AI chat feature.

Core

Variable	Required	Default	Description
`PORT`	No	`8080`	Port inside the container (published on host `8081` in the bundled deploy).
`UIGRAPH_API_URL`	Yes	—	In-network base URL of `uigraph-api` (e.g. `http://uigraph-api:8080`).
`DEPLOYMENT_ENV`	No	`production`	`local` \| `development` \| `production`. How much detail is written to the logs. Leave at `production` for a normal deploy; the others are noisier and meant for debugging.

Object storage

Presigns uploads with the same credentials as the API; these must match the values set on UIGraph API.

Variable	Required	Default	Description
`STORAGE_ENDPOINT`	Yes	—	In-network storage endpoint (e.g. `http://minio:9000`).
`STORAGE_BUCKET`	Yes	—	Bucket name.
`STORAGE_ACCESS_KEY`	Yes	—	Access key.
`STORAGE_SECRET_KEY`	Yes	—	Secret key.
`STORAGE_PUBLIC_ENDPOINT`	No	—	Browser-reachable storage host for presigned URLs.
`STORAGE_REGION`	No	`us-east-1`	Region for the `s3` backend.
`STORAGE_FORCE_PATH_STYLE`	No	`true`	Path-style addressing. Set `false` for AWS S3.

AI provider

The model the AI chat uses. See AI Providers for the full explanation and Examples for complete configurations.

Variable	Required	Default	Description
`AI_PROVIDER_NPM`	No	`@ai-sdk/openai-compatible`	Which provider to use.
`AI_PROVIDER_API_URL`	If `AI_PROVIDER_NPM` not provided	—	Endpoint URL. Needed for the default OpenAI-compatible provider.
`AI_PROVIDER_API_KEY`	For AI chat	—	API key for the provider.
`AI_PROVIDER_MODEL`	For AI chat	—	Model to use, e.g. `gpt-4o`.
`AI_PROVIDER_TITLE_MODEL`	No	falls back to `AI_PROVIDER_MODEL`	Cheaper model used only to generate chat session titles.
`AI_PROVIDER_BEAUTIFY_MODEL`	No	falls back to `AI_PROVIDER_MODEL`	Model used only when someone tidies up an architecture diagram's layout.
`AI_PROVIDER_OPTIONS`	No	—	Extra provider settings as a single line of JSON.

MCP connection

Variable	Required	Default	Description
`UIGRAPH_MCP_URL`	For AI chat	—	Base URL of the UIGraph MCP server the chat reads architecture data from. Without it, the chat returns an `MCP_NOT_CONFIGURED` error.
`MCP_CACHE_TTL_MS`	No	`900000`	How long (ms) the gateway caches the MCP tool list. Default is 15 minutes.

Caching

The gateway remembers which organization a token belongs to, so it does not ask the API on every request.

Variable	Required	Default	Description
`REDIS_URL`	No	—	A Redis instance the gateway shares its cache through, the same one the API uses. Leave it blank and each gateway process caches in its own memory instead. Worth setting when you run more than one gateway.
`ORG_ID_CACHE_TTL_MS`	No	`86400000`	How long (ms) a token's organization is remembered. Default is 1 day.

Behaviour

Variable	Required	Default	Description
`LLM_MAX_STEP`	No	`100`	The most tool-calling steps the chat may take while answering one question.
`LLM_ATTACHMENT_IMAGE`	No	`false`	Let the chat read image attachments.
`LLM_ATTACHMENT_AUDIO`	No	`false`	Let the chat read audio attachments.
`LLM_ATTACHMENT_VIDEO`	No	`false`	Let the chat read video attachments.

UIGraph Gateway (uigraph-gateway)