| IMAGE_GENERATION_MCP_KV_STORE_URL | No | Persistent-state backend URL shared by every pvl-core subsystem that needs state. `memory://` is in-process and lost on restart; `file:///path` persists on one server; `redis://`, `dynamodb://` and `mongodb://` each need their matching extra. When unset, defaults to `file:///data/state` (the volume family Docker images mount), or to `memory://` — with a warning — on a host where that directory is not usable. |
| IMAGE_GENERATION_MCP_TOOLS_ALLOW | No | Comma-separated explicit tool names this instance exposes; every other tool is hidden from listings and cannot be invoked. Names matching no registered tool are inert. Mutually exclusive with `tools_deny`. Takes effect through `apply_tool_visibility`. |
| IMAGE_GENERATION_MCP_TOOLS_DENY | No | Comma-separated explicit tool names hidden from this instance (absent from listings, cannot be invoked). Names matching no registered tool are inert. Mutually exclusive with `tools_allow`. Takes effect through `apply_tool_visibility`. |
| IMAGE_GENERATION_MCP_SERVER_NAME | No | Rename this server instance; defaults to the project name. |
| IMAGE_GENERATION_MCP_INSTRUCTIONS | No | Replaces the default MCP instructions text sent to clients. |
| FASTMCP_LOG_LEVEL | No | Log level for FastMCP internals and app loggers (DEBUG / INFO / WARNING / ERROR / CRITICAL). The -v CLI flag overrides to DEBUG. |
| FASTMCP_ENABLE_RICH_LOGGING | No | Set false for plain or structured JSON log output. |
| IMAGE_GENERATION_MCP_A1111_HOST | No | Deprecated alias for IMAGE_GENERATION_MCP_SD_WEBUI_HOST; logs a warning when used. |
| IMAGE_GENERATION_MCP_A1111_MODEL | No | Deprecated alias for IMAGE_GENERATION_MCP_SD_WEBUI_MODEL; logs a warning when used. |
| IMAGE_GENERATION_MCP_READ_ONLY | No | When true, write-tagged tools (image generation, transforms, uploads) are hidden from clients. Set false to enable them. |
| IMAGE_GENERATION_MCP_SCRATCH_DIR | No | Directory where generated images are saved. Created automatically on first use. |
| IMAGE_GENERATION_MCP_OPENAI_API_KEY | No | OpenAI API key. Enables the OpenAI provider (gpt-image-2, gpt-image-1.5, dall-e-3) when set. Secret. |
| IMAGE_GENERATION_MCP_GOOGLE_API_KEY | No | Google API key. Enables the Gemini provider (gemini-3.1-flash-image and others) when set. Get a key at https://aistudio.google.com/apikey. Secret. |
| IMAGE_GENERATION_MCP_SD_WEBUI_HOST | No | SD WebUI base URL (such as http://localhost:7860). Enables the SD WebUI provider when set. Compatible with AUTOMATIC1111, Forge, reForge, and Forge-neo. |
| IMAGE_GENERATION_MCP_SD_WEBUI_MODEL | No | SD WebUI checkpoint name, used for model-aware preset detection (SD 1.5 / SDXL / Lightning) and checkpoint override. Unset uses the instance's current model. |
| IMAGE_GENERATION_MCP_DEFAULT_PROVIDER | No | Provider used when no keyword triggers auto-selection: auto, openai, gemini, sd_webui, or placeholder. auto picks the first configured provider. |
| IMAGE_GENERATION_MCP_TRANSFORM_CACHE_SIZE | No | Maximum number of transformed image results (resize, crop, convert) kept in memory. Set 0 to disable caching. |
| IMAGE_GENERATION_MCP_PAID_PROVIDERS | No | Comma-separated provider names that cost money; generate_image asks for confirmation (client elicitation) before using them. An empty value falls back to this default; to disable confirmation, set a value that names no provider (such as none). |
| IMAGE_GENERATION_MCP_STYLES_DIR | No | Directory for style preset files (Markdown with YAML front matter). Created automatically if it does not exist. |
| IMAGE_GENERATION_MCP_ALLOW_LOCAL_FILE_INPUT | No | Allow reading input images from local filesystem paths. Off by default: only URLs and uploads are accepted. |
| IMAGE_GENERATION_MCP_MAX_INPUT_IMAGE_BYTES | No | Maximum accepted input image size in bytes. |
| IMAGE_GENERATION_MCP_FETCH_TIMEOUT_S | No | HTTP timeout in seconds when fetching remote image URLs (fetch_image and URL inputs). |
| IMAGE_GENERATION_MCP_TRANSFER_TTL_DEFAULT_S | No | Link lifetime in seconds when the caller requests no explicit TTL. |
| IMAGE_GENERATION_MCP_TRANSFER_TTL_MAX_S | No | Ceiling in seconds a caller-requested link TTL is clamped to. |
| IMAGE_GENERATION_MCP_TRANSFER_GRACE_TTL_S | No | Post-success grace window in seconds: a served token's TTL shrinks to this so a stalled transfer can retry within it. |
| IMAGE_GENERATION_MCP_TRANSFER_LEASE_S | No | Crashed-handler reclaim window in seconds for an in-flight reservation. |
| IMAGE_GENERATION_MCP_TRANSFER_MAX_UPLOAD_BYTES | No | Maximum size in bytes of a single upload. |
| IMAGE_GENERATION_MCP_BASE_URL | No | Public base URL of the deployed server, e.g. `https://mcp.example.com`. Required for OIDC. Also the fallback source of the MCP Apps domain when `app_domain` is unset. |
| IMAGE_GENERATION_MCP_BEARER_TOKEN | No | Single shared bearer token; enables bearer auth unless `bearer_tokens_file` is set, which takes precedence. Secret. |
| IMAGE_GENERATION_MCP_OIDC_CONFIG_URL | No | OIDC discovery document URL, e.g. `https://auth.example.com/.well-known/openid-configuration`. |
| IMAGE_GENERATION_MCP_OIDC_CLIENT_ID | No | OIDC client identifier registered with the provider. |
| IMAGE_GENERATION_MCP_OIDC_CLIENT_SECRET | No | OIDC client secret registered with the provider. Secret. |
| IMAGE_GENERATION_MCP_OIDC_AUDIENCE | No | Expected `aud` claim; tokens issued for another audience are rejected. |
| IMAGE_GENERATION_MCP_OIDC_REQUIRED_SCOPES | No | Scopes a caller must present, space- or comma-separated. Defaults to `openid` in oidc-proxy mode. |
| IMAGE_GENERATION_MCP_OIDC_ADVERTISED_SCOPES | No | Scopes advertised to MCP clients in protected-resource metadata, space- or comma-separated. Overrides the default `openid offline_access`; `oidc_required_scopes` is always added on top. Set this when the registered client is not permitted `offline_access`, or to have clients request extra claim scopes (e.g. `groups`) without also requiring them in every token. |
| IMAGE_GENERATION_MCP_OIDC_JWT_SIGNING_KEY | No | Signing key for issued JWTs; used in oidc-proxy mode only. When unset, the key is derived deterministically from `oidc_client_secret`, so tokens survive a restart — but rotating that secret invalidates every issued token. Set this explicitly to decouple token validity from secret rotation. Generate with `openssl rand -hex 32`. Secret. |
| IMAGE_GENERATION_MCP_OIDC_VERIFY_ACCESS_TOKEN | No | Validate the access token instead of the id token. |
| IMAGE_GENERATION_MCP_KV_STORE_URL | No | Persistent-state backend URL shared by every pvl-core subsystem that needs state. `memory://` is in-process and lost on restart; `file:///path` persists on one server; `redis://`, `dynamodb://` and `mongodb://` each need their matching extra. When unset, defaults to `file:///data/state` (the volume family Docker images mount), or to `memory://` — with a warning — on a host where that directory is not usable. |
| IMAGE_GENERATION_MCP_APP_DOMAIN | No | MCP Apps iframe domain, used for CSP sandboxing. Overrides the host derived from `base_url`. |
| IMAGE_GENERATION_MCP_TOOLS_ALLOW | No | Comma-separated explicit tool names this instance exposes; every other tool is hidden from listings and cannot be invoked. Names matching no registered tool are inert. Mutually exclusive with `tools_deny`. Takes effect through `apply_tool_visibility`. |
| IMAGE_GENERATION_MCP_TOOLS_DENY | No | Comma-separated explicit tool names hidden from this instance (absent from listings, cannot be invoked). Names matching no registered tool are inert. Mutually exclusive with `tools_allow`. Takes effect through `apply_tool_visibility`. |
| IMAGE_GENERATION_MCP_AUTH_MODE | No | Explicit auth-mode override, accepting `remote` or `oidc-proxy` (case- and whitespace-insensitive). When unset the mode is auto-detected from which auth variables are set; the override exists because having all four OIDC variables set is ambiguous between those two modes. Other values are ignored with a warning. |
| IMAGE_GENERATION_MCP_BEARER_TOKENS_FILE | No | Path to a TOML file mapping bearer tokens to subjects; overrides the single-token `bearer_token` mode. |
| IMAGE_GENERATION_MCP_BEARER_DEFAULT_SUBJECT | No | Subject assigned to the single-token bearer mode; ignored when `bearer_tokens_file` is set, since mapped mode carries per-token subjects. |
| IMAGE_GENERATION_MCP_SERVER_NAME | No | Rename this server instance; defaults to the project name. |
| IMAGE_GENERATION_MCP_INSTRUCTIONS | No | Replaces the default MCP instructions text sent to clients. |
| IMAGE_GENERATION_MCP_HTTP_PATH | No | Mount path for the MCP endpoint. |
| PUID | No | Run the server process as this UID; the container entrypoint chowns writable paths to match. |
| PGID | No | Run the server process as this GID; pair with PUID to match the owner of a mounted volume. |
| FASTMCP_LOG_LEVEL | No | Log level for FastMCP internals and app loggers (DEBUG / INFO / WARNING / ERROR / CRITICAL). The -v CLI flag overrides to DEBUG. |
| FASTMCP_ENABLE_RICH_LOGGING | No | Set false for plain or structured JSON log output. |
| IMAGE_GENERATION_MCP_A1111_HOST | No | Deprecated alias for IMAGE_GENERATION_MCP_SD_WEBUI_HOST; logs a warning when used. |
| IMAGE_GENERATION_MCP_A1111_MODEL | No | Deprecated alias for IMAGE_GENERATION_MCP_SD_WEBUI_MODEL; logs a warning when used. |
| IMAGE_GENERATION_MCP_READ_ONLY | No | When true, write-tagged tools (image generation, transforms, uploads) are hidden from clients. Set false to enable them. |
| IMAGE_GENERATION_MCP_SCRATCH_DIR | No | Directory where generated images are saved. Created automatically on first use. |
| IMAGE_GENERATION_MCP_OPENAI_API_KEY | No | OpenAI API key. Enables the OpenAI provider (gpt-image-2, gpt-image-1.5, dall-e-3) when set. Secret. |
| IMAGE_GENERATION_MCP_GOOGLE_API_KEY | No | Google API key. Enables the Gemini provider (gemini-3.1-flash-image and others) when set. Get a key at https://aistudio.google.com/apikey. Secret. |
| IMAGE_GENERATION_MCP_SD_WEBUI_HOST | No | SD WebUI base URL (such as http://localhost:7860). Enables the SD WebUI provider when set. Compatible with AUTOMATIC1111, Forge, reForge, and Forge-neo. |
| IMAGE_GENERATION_MCP_SD_WEBUI_MODEL | No | SD WebUI checkpoint name, used for model-aware preset detection (SD 1.5 / SDXL / Lightning) and checkpoint override. Unset uses the instance's current model. |
| IMAGE_GENERATION_MCP_DEFAULT_PROVIDER | No | Provider used when no keyword triggers auto-selection: auto, openai, gemini, sd_webui, or placeholder. auto picks the first configured provider. |
| IMAGE_GENERATION_MCP_TRANSFORM_CACHE_SIZE | No | Maximum number of transformed image results (resize, crop, convert) kept in memory. Set 0 to disable caching. |
| IMAGE_GENERATION_MCP_PAID_PROVIDERS | No | Comma-separated provider names that cost money; generate_image asks for confirmation (client elicitation) before using them. An empty value falls back to this default; to disable confirmation, set a value that names no provider (such as none). |
| IMAGE_GENERATION_MCP_STYLES_DIR | No | Directory for style preset files (Markdown with YAML front matter). Created automatically if it does not exist. |
| IMAGE_GENERATION_MCP_ALLOW_LOCAL_FILE_INPUT | No | Allow reading input images from local filesystem paths. Off by default: only URLs and uploads are accepted. |
| IMAGE_GENERATION_MCP_MAX_INPUT_IMAGE_BYTES | No | Maximum accepted input image size in bytes. |
| IMAGE_GENERATION_MCP_FETCH_TIMEOUT_S | No | HTTP timeout in seconds when fetching remote image URLs (fetch_image and URL inputs). |
| IMAGE_GENERATION_MCP_TRANSFER_TTL_DEFAULT_S | No | Link lifetime in seconds when the caller requests no explicit TTL. |
| IMAGE_GENERATION_MCP_TRANSFER_TTL_MAX_S | No | Ceiling in seconds a caller-requested link TTL is clamped to. |
| IMAGE_GENERATION_MCP_TRANSFER_GRACE_TTL_S | No | Post-success grace window in seconds: a served token's TTL shrinks to this so a stalled transfer can retry within it. |
| IMAGE_GENERATION_MCP_TRANSFER_LEASE_S | No | Crashed-handler reclaim window in seconds for an in-flight reservation. |
| IMAGE_GENERATION_MCP_TRANSFER_MAX_UPLOAD_BYTES | No | Maximum size in bytes of a single upload. |