Workflow MCP server

workflow-mcp

Run Claude Code dynamic-workflow files through any agent provider — as a durable, resumable Model Context Protocol server.

workflow-mcp is a standalone runtime and MCP server that executes Claude Code dynamic workflow files — the JavaScript orchestration programs that fan out dozens or hundreds of agent calls and return a single result — without requiring Claude to run them.

The whole project hangs on one promise:

A workflow authored for workflow-mcp can be copied into

.claude/workflows/.js and run by a compatible Claude Code release

without changing the file — and a real Claude workflow file runs through this

runtime without any importer or translation step.

Everything that isn't portable — which provider executes the agents, its credentials, the durable run cache, MCP run IDs, and UI state — lives in the runtime, never inside the .js file.

Why it exists

Claude Code workflows are a strong primitive: the JavaScript owns the loops, branches, fan-out, and aggregation, while each agent() call owns the model reasoning and side effects — keeping hundreds of intermediate results out of the parent conversation. But out of the box they come with three constraints:

directory, and it does not survive as an independently controllable object.

• Claude executes every agent node. There is no seam for another provider.
• A run belongs to a Claude session. Its state lives inside that session

or resume a run.

• There is no server surface. Other tools cannot discover, launch, follow,

workflow-mcp keeps the exact same workflow file and lifts those constraints: the same .js runs through a provider-neutral engine (Codex today), every run is a durable object that survives restarts, and any MCP-capable host can drive it over a stable set of tools.

How it works

Two kinds of portability are kept deliberately separate — MCP solves the first, the provider interface solves the second:

MCP-capable host
      │  workflow_list · workflow_run · workflow_run_events · …
      ▼
WorkflowService  +  durable event store   ← the long-lived owner of runs
      ▼
Claude-compatible JavaScript runtime       ← agent/parallel/pipeline/phase/…
      ▼
provider-neutral AgentProvider
      ├─ Codex SDK  (@openai/codex-sdk)
      ├─ fake       (deterministic tests)
      └─ future providers

Shortened. The full README is on GitHub.