elelem

elelem is LLM, spelled out loud. It is a Go engine for talking to LLMs that doesn’t care which one: streaming, tool loops, history that fits in the context window, retries that never repeat a streamed paragraph, and typed structured responses. Swap OpenAI for Anthropic by changing one line.

It’s a library, not a framework. Run hands you the tool calls and stops; the engine drives the loop only when you ask for it with WithAutoToolCalls(). It stores nothing, picks no driver, resolves no credentials and has no config loader. You wire it, it runs requests.

go get github.com/psyb0t/elelem

driver := openai.NewDriver(openai.WithAPIKey(apiKey))
client := elelem.New(driver)

response, err := elelem.NewRequest(client).
	WithModel(elelem.Model{ID: "some-model-id", ContextSize: 200_000}).
	WithPrompt(elelem.NewPrompt().
		WithSystem("You are a concise operations assistant.").
		UserText("Summarize the current incident state.")).
	Run(ctx)

The README is the tour. This site is the reference.

Page	What’s in it
Requests	Building and running a request. Every builder method, what it sets, and what happens if you don’t set it.
Prompts	The Prompt builder (system message, history, origins), plus images, audio and documents, and which provider takes what.
Callbacks	The sixteen observation points: text, reasoning, tool calls, rounds, retries, token limits. Ordering guarantees and what an error from one does.
Tools	Tools, images in tool results, the hook lifecycle, message injection, denial, and the bounds that stop a tool loop eating your process.
MCP tools	Turning an MCP server’s tools into elelem tools, over stdio or Streamable HTTP.
History	Token budgets, transcript units, the limiting handlers, and counting.
Retries	The retry decorator, how failures get classified, and the sentinel taxonomy.
Structured output	RunInto, JSON mode, JSON schema, validation and repair.
Drivers	The shipped drivers and their options, the Driver contract, and how to write a third one without guessing.
Security	The two untrusted inputs, what the engine bounds, and what stays your job.
Logging	Where elelem logs, what each level carries, and the stable reason values.
Testing	ScriptedDriver vs MockDriver vs the conformance suite, and which one your test actually wants.
Development	Package layout, Make targets, CI, and building this site.

Generated API reference lives on pkg.go.dev; these docs cover the parts a signature can’t tell you.