buildathena-sdk

Python SDK for building blocks and workflows on the Athena Labs ML orchestration platform. Athena Labs makes ML workflows reproducible, observable, interruptible, and composable through a DAG execution engine with an AI agent that can build, run, monitor, and fix pipelines.

Alpha software — APIs may change between releases. Pin your version in production.

Installation

ATHENA_VERSION="$(athena --version | awk '{print $2}')"
pip install "buildathena-sdk==${ATHENA_VERSION}"

Requires Python 3.11+.

Quick Start

Define a block, read resolved config from ctx.config, emit metrics and progress, and register an explicit artifact when you want a durable named asset:

from athena import BlockContext, ConfigRef, block

@block(
    name="TrainModel",
    outputs=["checkpoint"],
    config=ConfigRef(search_path="conf", config_name="train"),
)
async def train_model(ctx: BlockContext) -> dict:
    epochs = int(ctx.config.get("epochs", 100))
    learning_rate = float(ctx.config.get("learning_rate", 1e-3))

    for epoch in range(epochs):
        loss = train_epoch(lr=learning_rate)
        await ctx.emit_metric("loss", loss, step=epoch)
        await ctx.emit_progress(epoch + 1, epochs)
        await ctx.check_pause()  # cooperative pause point

    checkpoint = await ctx.artifacts.register(
        "model.pt",
        name="checkpoint",
        format="pickle",
        mime_type="application/octet-stream",
        tags=["training", "final"],
    )
    return {"checkpoint": checkpoint.as_ref()}

Portable resource requests may include CPU, system memory, /dev/shm shared memory, ephemeral local storage, and accelerator requirements. memory is the total container RAM reservation/limit. shared_memory is only the /dev/shm mount-size ceiling: it may be used without memory or be larger than memory, and it does not create an additional physical RAM pool. When memory is omitted, RAM remains unreserved.

from athena import BlockEnvironment, ResourceSpec

environment = BlockEnvironment(
    backends=["docker", "kubernetes"],
    resources=ResourceSpec(
        cpu="2",
        memory="4Gi",
        shared_memory="8Gi",
        ephemeral_storage="16Gi",
    ),
)

Docker supports shared_memory and intentionally does not match requests that contain ephemeral_storage. Kubernetes supports both.

Consuming Inputs

Block inputs come from the Python signature after ctx. Athena hydrates those arguments from upstream outputs before invoking the block:

@block(name="Evaluate", outputs=["report"])
async def evaluate(ctx: BlockContext, checkpoint) -> dict:
    checkpoint_ref = checkpoint
    checkpoint_path = await ctx.artifacts.resolve(checkpoint_ref)
    model = load_model(checkpoint_path)
    score = run_eval(model)
    await ctx.emit_metric("accuracy", score)
    return {"report": {"accuracy": score}}

Credentials

Declare required secrets in the @block decorator and access them at runtime via ctx.secrets. Credentials are encrypted at rest and injected only during execution:

@block(name="FetchData", outputs=["dataset"], secrets=["API_KEY"])
async def fetch_data(ctx: BlockContext) -> dict:
    key = ctx.secrets["API_KEY"]
    data = await download(api_key=key)
    return {"dataset": data}

Declare outputs on the decorator and return a mapping with exactly those keys.

Cooperative Pause

Call check_pause() inside long-running loops to let Athena Labs pause the block between iterations without losing progress:

for epoch in range(epochs):
    train_step()
    await ctx.check_pause()  # yields control if a pause was requested

BlockContext API

Method / Accessor	Description
`ctx.secrets["KEY"]`	Access declared secrets
`await ctx.emit_metric(name, value, step=, labels=)`	Emit one scalar metric
`await ctx.emit_metrics({"loss": loss, "accuracy": acc}, step=, labels=)`	Emit multiple scalar metrics
`await ctx.emit_progress(current, total, message=)`	Emit progress (current/total)
`await ctx.emit_log(message, level=, source=)`	Emit a structured log event
`await ctx.check_pause()`	Cooperative pause checkpoint
`await ctx.artifacts.register(source=None, local_path=, format=, mime_type=, name=, tags=, metadata=)`	Create a durable artifact
`artifact.as_ref()` / `artifact.as_data()`	Choose pointer or hydrated downstream delivery
`await ctx.artifacts.resolve(ref)`	Resolve any Athena-readable artifact to a local path
`await ctx.artifacts.load(ref)`	Load and deserialize a formatted artifact
`ctx.athena`	Attempt-scoped Repo, Session, Chat, Workflow, and Run resources

Block-Scoped Athena Client

Athena injects the canonical Repo, Session, and private Chat client into an executing block. Chat collections paginate transparently, sending returns after durable acceptance, and receipt waits target only the submitted turn:

repo = await ctx.athena.repos.get("https://github.com/acme/training.git")
session = await ctx.athena.sessions.create(
    title="Candidate search",
    repos=[repo.at("candidate", new_branch=True)],
)

proposal_branch = session.repos[0].branch_name
chat = await session.chats.create()
receipt = await chat.send(
    f"""Athena prepared `{proposal_branch}` as a fresh proposal branch seeded from the
exact current head of `candidate`. Work directly in the prepared branch. After the
edit, use athena_attachment_git first with action `commit` and a concise message,
then with action `publish` and no message.""",
)
turn = await receipt.wait(timeout=None)

async for existing_chat in session.chats.list():
    print(existing_chat.id)

async for item in chat.items():
    consume(item)

async for item in turn.items():
    consume_turn_item(item)

title is optional. If it is omitted, the server assigns a stable friendly title such as quiet-snail-cafe; the generated title is returned on the Session object and in browser projections. Titles are trimmed and limited to 255 characters.

Block code does not author runtime call keys or application idempotency keys. Invoke a Block or nested Workflow directly with child(...); there is no separate .call(...) authoring path. Session, Chat, and independent Workflow.run() operations likewise derive their internal replay identity. Ordinary mutations use a stable logical call slot; a response to a pending Chat request uses that exact request's identity. Keep construction order deterministic so the same source slot continues to represent the same logical operation after a controller retry. Browser-generated user intents and transport-level request keys are separate internal boundaries, not block SDK arguments.

repo.at(parent, new_branch=True) creates a fresh proposal branch from the exact current head of parent; the returned attachment reports the generated branch name. Work directly in that prepared branch. Agent-authored changes are committed with a message and then published without a message; reconciliation is only for a published remote head that changed after preparation.

chat.items() and turn.items() expose only the typed, durable, user-visible transcript projection. They are not live watches or raw event/trace access. Canonical values decode to ordinary Python primitives where lossless; inline bytes, opaque blobs, encoded values, and artifacts remain explicit InlineBytes, BlobRef, EncodedValue, and ArtifactRef wrappers rather than generated Protobuf messages or implicitly fetched bulk data.

Config System

Athena Labs supports YAML configuration with composition, inheritance, and variable substitution:

# base.yaml
training:
  epochs: 100
  optimizer: adam

# experiment.yaml
$extends: base.yaml
training:
  epochs: 200
  learning_rate: ${LR:-1e-3}

See the full config docs for $include, $extends, and ${ref} substitution.

Documentation

Getting Started — installation and first workflow
SDK Reference — decorators, config, and discovery
BlockContext API — full method reference
Features — gates, inspectors, caching, and more
knowledge-base/current/architecture/sdk.md — internal architecture and implementation reference

License

Release files for buildathena-sdk 0.4.2

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Built distribution (wheel)

Table of built distributions (wheels) for buildathena-sdk 0.4.2
File	Interpreter	ABI	Platform	Reset
buildathena_sdk-0.4.2-py3-none-any.whl 230.1 kB Aug 18, 2026	Python 3	none	any	Details

Release files / buildathena_sdk-0.4.2-py3-none-any.whl

Download URL	buildathena_sdk-0.4.2-py3-none-any.whl
Size	230.1 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`462acb8ccf8361d9c46321092ec1588f9efde71fdd55413f6863f29ad41e9408`
BLAKE2b-256 checksum How to use checksums	`3b526fc31bc8a0f43f67c5a5dc1df6fb29926b0c7b728f0835ddbe09614625a5`
Upload date	Aug 18, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`uv/0.8.0`