assemblix-mcp 0.3.0

MCP server for Assemblix — author, run & inspect workflows over a project API key

assemblix-mcp

MCP server for Assemblix. Author, run & inspect your project's workflows from any MCP client using a single project API key (sk_...). projectId is never needed — the key defines the project.

Get your sk_ key from the project's API keys page in the Assemblix UI.

Install

Hosted (easiest — nothing to install)

claude mcp add --transport http assemblix https://mcp.assmblx.com \
  --header "Authorization: Bearer sk_your_key"

Local via uvx (privacy / self-host)

claude mcp add assemblix \
  --env ASSEMBLIX_API_KEY=sk_your_key \
  --env ASSEMBLIX_API_URL=https://app.assmblx.com \
  -- uvx assemblix-mcp

Claude Desktop / Cursor (JSON config)

{
  "mcpServers": {
    "assemblix": {
      "command": "uvx",
      "args": ["assemblix-mcp"],
      "env": {
        "ASSEMBLIX_API_KEY": "sk_your_key",
        "ASSEMBLIX_API_URL": "https://app.assmblx.com"
      }
    }
  }
}

For the hosted server, use your client's "add custom connector → URL + header" flow.

Configuration

Env var	Default	Notes
ASSEMBLIX_API_URL	https://app.assmblx.com	Base URL of your Assemblix instance
ASSEMBLIX_API_KEY	—	Project sk_ key. Required for stdio; for hosted HTTP the Authorization header is used instead
ASSEMBLIX_MCP_TRANSPORT	stdio	stdio or http
ASSEMBLIX_MCP_HOST / ASSEMBLIX_MCP_PORT	0.0.0.0 / 8000	HTTP transport bind

Tools

Authoring: list_node_types, list_workflows, get_workflow, create_workflow, update_workflow, publish_workflow Run & inspect: run_workflow, run_workflow_and_wait, get_execution, list_executions, get_execution_detail, list_in_flight

Resources: assemblix://examples/minimal, assemblix://examples/branching (example workflow JSON), assemblix://guides/execution (how to call a workflow from your product — sync/async/streaming/sessions/voice, with curl/JS/Python examples). Prompts: author_workflow (authoring guide), integrate_workflow (integration guide).

Lifecycle: create_workflow → update_workflow(nodes, edges) → publish_workflow → run_workflow. Runs always execute the published snapshot. AGENT nodes need a provider credential configured in the Assemblix UI.

All tools operate on the single project your API key is scoped to; projectId is never a parameter.