// MCP TOOL REFERENCE

COMFYUI BUILDER TOOLS

60 tools from the ComfyUI Builder MCP Server, categorised by risk level.

// ALL 60 COMFYUI BUILDER TOOLS

READ 36 tools

Read check_compatibility Check if output of one node can connect to input of another (using node-compatibility.json). Read check_model_exists Check if a model exists on the ComfyUI server (in object_info model lists). Requires COMFYUI_HOST. Read check_workflow_models Check which models required by a workflow exist on the ComfyUI server. Returns ready (boolean), missing, an... Read discover_nodes_live Get all node definitions from the running ComfyUI instance (GET /object_info). Returns class names and cate... Read download_all_outputs Download all output files for a prompt into a directory. Returns list of saved paths. Requires COMFYUI_HOST. Read download_by_filename Download an output file by filename (no prompt_id needed). Uses GET /view. Use when you have filename from ... Read download_output Download a single output file to a local path. Use list_outputs to get file info. Requires COMFYUI_HOST. Read get_error_details Get full error details for a prompt (node_id, exception_type, exception_message, full traceback). Use when ... Read get_execution_progress Get real-time execution progress for a prompt (WebSocket if available, polling fallback). Returns status, c... Read get_execution_status Get execution status and outputs for a prompt. Returns status, image filenames, and view URLs. Requires COM... Read get_generation_recommendations Get recommendations for image generation: system resources (max resolution, model size, batch) and, if the ... Read get_history Get ComfyUI execution history (GET /history) without prompt_id. Returns last N prompts with prompt_id, stat... Read get_last_output Get info for the most recent prompt that has image output (skips failed prompts). Use when prompt_id was lo... Read get_model_info Get info for a model by name and type. Returns name, type, path; null if not found. Requires COMFYUI_HOST. Read get_node_info Get full node information for a ComfyUI node by its class name. Uses live ComfyUI when COMFYUI_HOST is set,... Read get_node_inputs Get detailed input definitions for a node (required and optional). Uses live ComfyUI if available, otherwis... Read get_node_outputs Get output types and names for a node. Uses live ComfyUI if available, otherwise knowledge base. Read get_system_resources Get ComfyUI station resources (GPU/VRAM/RAM) and recommendations for model size, resolution, and batch size... Read get_workflow_json Get the current workflow JSON for a dynamic workflow (for execute_workflow or save_workflow). Read get_workflow_models Extract required models from a workflow (loader nodes: CheckpointLoaderSimple, LoraLoader, VAELoader, Contr... Read list_macros List available workflow macros (built-in sub-workflows). Returns id, name, description, inputs, outputs. Read list_models List models available on the ComfyUI server (from object_info). Optionally filter by type: checkpoint, lora... Read list_node_categories List all node categories from live ComfyUI and knowledge base (merged, unique). Read list_node_types List ComfyUI node types from the knowledge base. Optionally filter by category or priority. Read list_outputs List all output files (images, gifs) for a completed prompt. Returns prompt_id, node_id, type, filename, ur... Read list_plugins List loaded plugins (from plugins/*/plugin.json) and counts of macros/templates contributed by each. Read list_queue List current ComfyUI queue (running and pending prompts). Requires COMFYUI_HOST. Read list_saved_workflows List saved workflows (names and paths) from workflows/ directory. Read list_templates List available workflow template ids (e.g. txt2img). No ComfyUI connection needed. Read load_workflow Load a saved workflow by name (from workflows/<name>.json) or by path. Returns workflow JSON for use with e... Read reload_plugins Reload plugins from plugins/*/plugin.json and refresh macro registry. Read search_nodes Search nodes by query string and optional filters (category, input_type, output_type). Searches both live C... Read suggest_nodes Suggest ComfyUI nodes for a task (search by description/use_cases) or by output type they produce. Read suggest_template_for_checkpoint Suggest workflow template (txt2img_flux or txt2img) from checkpoint filename. FLUX checkpoints (e.g. flux1-... Read validate_template_params Validate that parameter values satisfy a workflow template (required params, types). Read validate_workflow Validate a dynamic workflow: checks that all node references exist and output indices are valid.

WRITE 12 tools

Write add_node Add a node to a dynamic workflow. Returns the new node id (e.g. Write apply_template Apply parameter values to a workflow template. Returns workflow JSON ready to execute or save. Use create_t... Write connect_nodes Connect an output of one node to an input of another in a dynamic workflow. Write create_template Create a parameterized workflow template from a workflow and parameter definitions. Returns template JSON f... Write create_workflow Create a new empty workflow context. Returns workflow_id to use with add_node, connect_nodes, get_workflow_... Write insert_macro Insert a macro (sub-workflow) into a dynamic workflow. Connects macro input ports to existing nodes. Return... Write install_custom_node Install one or more custom nodes via ComfyUI-Manager cm-cli (e.g. ComfyUI-Blip, WAS-Node-Suite). Requires C... Write install_model Download and install a model (checkpoint, LoRA, VAE, etc.) by URL. Requires COMFYUI_PATH. Uses comfy-cli if... Write prepare_image_for_workflow Fetch the first output image from a completed prompt and upload it to ComfyUI input folder. Returns the fil... Write save_workflow Save a workflow JSON to file (workflows/<name>.json). Returns path. Use after build_workflow to persist for... Write set_node_input Set a literal input on a node in a dynamic workflow (overwrites existing value or link). Write sync_nodes_to_knowledge Sync node definitions from running ComfyUI to the knowledge base. Adds only nodes that are not already in b...

DESTRUCTIVE 4 tools

Destructive clear_queue Clear ComfyUI queue: remove all pending and stop/clear running. Requires COMFYUI_HOST. Destructive delete_queue_items Remove specific items from ComfyUI queue by prompt_id. Use list_queue to get prompt_ids. Requires COMFYUI_H... Destructive interrupt_execution Stop the currently running workflow on ComfyUI. Optionally pass prompt_id to interrupt only that prompt. If... Destructive remove_node Remove a node from a dynamic workflow. Does not fix references (validation will report dangling refs).

EXECUTE 7 tools

Execute build_workflow Build a ComfyUI workflow from a template and parameters. Returns workflow JSON ready to execute or save. Fo... Execute execute_batch Execute multiple workflows in batch. Submits each workflow and waits for completion (polling). Optional con... Execute execute_chain Execute a chain of workflows in sequence. Each step runs after the previous completes. Use inputFrom and ou... Execute execute_workflow Submit a ComfyUI workflow to run. Returns prompt_id. Use get_execution_status(prompt_id) to check result. R... Execute execute_workflow_stream Execute workflow with streaming real-time progress updates. Requires WebSocket support. Returns result and ... Execute execute_workflow_sync Submit a ComfyUI workflow and wait until execution completes with real-time progress (WebSocket if availabl... Execute reload_comfyui Restart ComfyUI so that newly installed custom nodes are loaded, then optionally sync them to the knowledge...

FINANCIAL 1 tools

Financial finalize_workflow Get the workflow JSON for a dynamic workflow (same as get_workflow_json). Use with execute_workflow or save...

// RUNNING THIS SERVER

The managed route: connect ComfyUI Builder through the PolicyLayer gateway — every tool call above is checked against your policy before it runs, with a full audit log.

DIRECT INSTALL (UNMANAGED) npx -y mcp-comfy-ui-builder

// FAQ

How many tools does the ComfyUI Builder MCP server have? +

The ComfyUI Builder MCP server exposes 60 tools across 5 categories: Read, Write, Destructive, Execute, Financial.

How do I enforce policies on ComfyUI Builder tools? +

Route the ComfyUI Builder server through the PolicyLayer gateway. Define allow, deny, or approval rules per tool in the dashboard — they are enforced on every call before it reaches the server.

What risk categories do ComfyUI Builder tools fall into? +

ComfyUI Builder tools are categorised as Read (36), Write (12), Destructive (4), Execute (7), Financial (1). Each category has a recommended default policy.

Let agents act without letting them run wild.

Route your MCP servers through PolicyLayer and every tool call is checked against your policy before it runs — allow, deny, or require approval. Per-identity grants. Full audit log. Live in minutes.

SECURE YOUR MCP →

Free to start. No card required.

4,600+ MCP servers and 31,000+ tools scanned and risk-classified.