Build LLM apps as explicit flowcharts, not black boxes
Most LLM frameworks hide the plumbing; this one gives you traceable, retry-aware dependency graphs for every prompt and API call.

What it does
LLMFlows is a Python framework for chaining Large Language Model calls into structured workflows. It provides thin wrappers around APIs like OpenAI, plus PromptTemplate, MessageHistory, and FlowStep classes that pass outputs between dependent steps. The library runs steps only when their inputs are ready and can execute independent branches in parallel via async flows.
The interesting bit
The whole pitch is transparency: every flowstep exposes its exact prompt, model configuration, raw API response, token count, retries, and timing. That turns the usual black-box LLM orchestration into something you can actually debug in production without guessing what hidden template generated a query.
Key highlights
- Explicit flows: Connect
FlowStepnodes into directed graphs; theFlowclass resolves dependencies and passes outputs as inputs to downstream steps. - Async execution:
AsyncFlowStepruns independent branches in parallel when their inputs are ready, cutting runtime for complex pipelines. - Built-in observability: Each step returns call metadata, raw API responses, token usage, retry counts, and timing—no hidden prompts or magic strings.
- Vector store support:
VectorStoreFlowStepintegrates with databases like Pinecone for retrieval-augmented generation inside flows. - Callback hooks: Inject functions at different stages for custom logging, tracing, or side effects.
Verdict
Best for developers who need to trace, retry, and wire together OpenAI-centric workflows with strict observability. Less compelling if you are looking for a generic, provider-agnostic orchestrator with broad third-party integrations.
Frequently asked
- What is stoyan-stoyanov/llmflows?
- Most LLM frameworks hide the plumbing; this one gives you traceable, retry-aware dependency graphs for every prompt and API call.
- Is llmflows open source?
- Yes — stoyan-stoyanov/llmflows is open source, released under the MIT license.
- What language is llmflows written in?
- stoyan-stoyanov/llmflows is primarily written in Python.
- How popular is llmflows?
- stoyan-stoyanov/llmflows has 705 stars on GitHub.
- Where can I find llmflows?
- stoyan-stoyanov/llmflows is on GitHub at https://github.com/stoyan-stoyanov/llmflows.