dpl.configure()

dpl.configure() is called at module level in routes.py to configure the AWS Lambda function that deployless generates for that feature. Every parameter maps directly to a property on the AWS::Serverless::Function resource in the generated template.yaml.

It is a no-op at runtime: when your Flask app starts normally, this call does nothing. Only the deployless compiler reads it.

Full parameter reference

import deployless as dpl

dpl.configure(
    # ── Basic ──
    memory=512,                  # int — MB (128–10240). Overrides globals.memory
    timeout=30,                  # int — Seconds (1–900). Overrides globals.timeout
    description="My feature",   # str — Description visible in CloudFormation

    # ── Environment ──
    env={"FLAG": "true"},        # dict — Additional env vars for this Lambda
    layers=["arn:aws:lambda:..."],# list — Lambda Layer ARNs

    # ── IAM ──
    policies=[
        "AmazonDynamoDBReadOnlyAccess",          # Managed policy by name
        {"DynamoDBCrudPolicy": {"TableName": dpl.Ref(my_table)}},  # SAM policy
        {"Version": "2012-10-17", "Statement": [...]},            # Inline policy
    ],

    # ── Resources (permission overrides only) ──
    # Resources are auto-detected. Use resources= ONLY to override
    # the default "crud" permission level:
    resources={
        "uploads_bucket": (uploads_bucket, "read"),
        "jobs_queue":     (jobs_queue, "send"),
    },

    # ── Architecture ──
    architectures=["arm64"],     # ["x86_64"] or ["arm64"] (Graviton, ~20% cheaper)
    tracing=True,                # Enables AWS X-Ray distributed tracing

    # ── Concurrency ──
    reserved_concurrency=10,     # int >= 0 — Max simultaneous executions
                                 #   0 = full throttle (useful for temporarily disabling)
    provisioned_concurrency=3,   # int >= 1 — Pre-warmed instances (eliminates cold starts)
                                 #   Implies AutoPublishAlias: live in the template

    # ── Temporary storage ──
    ephemeral_storage=1024,      # int — /tmp size in MB (512–10240, default 512)

    # ── Reliability ──
    dlq=True,                    # Creates an SQS Dead Letter Queue for
                                 #   failed asynchronous invocations

    # ── Observability ──
    log_retention=30,            # int — Retention days in CloudWatch (overrides global)
)

Example

app/features/user/routes.py

from flask import Blueprint
import deployless as dpl

# Resource auto-detected → DynamoDBCrudPolicy auto-generated
users_table = dpl.DynamoDB(
    "users-table",
    pk="tenant_id",
    sk="user_id",
    gsi=[{"name": "EmailIndex", "pk": "email"}],
    ttl_attribute="expires_at",
    deletion_policy="Retain",
)

dpl.configure(
    memory=512,
    timeout=30,
    description="User Management API",
    architectures=["arm64"],
    dlq=True,
    log_retention=30,
)

user_bp = Blueprint("user_bp", __name__, url_prefix="/users")

@user_bp.route("", methods=["GET"])
def list_users():
    ...

dpl.Ref() and dpl.GetAtt()

Use dpl.Ref(resource) to get the logical ID of a resource (generates {"Ref": "LogicalId"}), and dpl.GetAtt(resource, attr) to get a specific attribute (generates {"Fn::GetAtt": ["LogicalId", "Attr"]}).

They are typically used in policies= for non-standard permissions:

tabla = dpl.DynamoDB("users-table")
bucket = dpl.S3("uploads")

dpl.configure(
    resources={"users": tabla, "uploads": bucket},
    policies=[
        {
            "Version": "2012-10-17",
            "Statement": [
                {
                    "Effect": "Allow",
                    "Action": ["dynamodb:Query"],
                    "Resource": {
                        "Fn::Sub": "${%s.Arn}/index/EmailIndex" % dpl.Ref(tabla)
                    },
                },
            ]
        }
    ],
)

Both dpl.Ref() and dpl.GetAtt() accept a resource object or a string with the CloudFormation logical ID.