SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

apigw-sqs-fifo-direct-integration

claude-code claude-opus-4-7 ✓ resolved HARNESS_ERROR ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
HARNESS_ERRORInfrastructure failure, the agent never ran properly. Not a signal about agent or task.
SubtypeClassification Failed
EvidenceClaude Code classification failed: (classifier unavailable for this trial)
Root causeCould not analyze trial with Claude Code
RecommendationReview trial manually or check authentication
Trajectory
Tool-by-tool agent trajectory
30 tool calls · 4 tool types · 38 steps
ok so we need an order-ingest pipeline on localstack. localstack is at `http://localstack:4566`, creds are already exported (`AWS_ACCESS_KEY_ID=test`, same for secret, region `us-east-1`), you've got `aws`, `python3`, `boto3`, `jq`, `zip`, `curl`. build the whole thing. a seeder (`/app/setup.sh`, already ran) has pre-created the consumer Lambda (`orders-consumer`) and its role (`orders-consumer-role`) , **both broken by design**. the handler has the wrong batch-failure response shape and isn't idempotent, and the role is missing the AWS actions it actually needs to do its job. you fix those. everything else is up to you to build from scratch: - the rest api + stage + resource + method + integration + deployment - the apigw→sqs iam role - the two fifo queues (main + dlq) with redrive - the ddb table - the event source mapping from the main queue to the pre-seeded lambda IAM policies too , every role needs whatever actions its job requires. merchants POST orders to a rest api. the api drops the order onto a fifo queue, a consumer lambda drains the queue into dynamodb, and anything that keeps failing lands in a dlq. duplicate POSTs for the same order must be no-ops at the storage layer , second POST succeeds http-wise but the stored row doesn't change. done looks like this: one `POST /dev/orders` from inside the compose network with body `{"order_id":..., "merchant_id":..., "amount":...}` and within ~30s: - http 200 back - exactly one row in the `orders` table keyed by `order_id`, carrying merchant_id and amount - nothing in the dlq - re-POST the same body → still 200, still one row, unchanged - two different order_ids under the same merchant preserve posted order in the table timestamps shape of it: - rest api, stage `dev`, resource `/orders`, method `POST`. integration is a direct aws-service call to sqs , not AWS_PROXY, not a lambda proxy. api gateway assumes a role and hands the message straight to the queue. - the queue is fifo. content-based dedup off. a separate fifo dlq is wired via redrive. - a lambda consumes the queue via an event source mapping, writes to ddb, and reports per-record failures so a single bad record doesn't retry the whole batch. - ddb table `orders`, partition key `order_id` (String). also: api gateway is two-layer , there's the CONFIGURATION (resources, methods, integration, role, mapping templates) and there's the live STAGE that clients actually hit. editing configuration in place doesn't promote anything; clients keep seeing the old behavior until you create a NEW deployment for the stage. so after every wiring change, call `apigateway create-deployment` against this rest-api targeting stage `dev` , once at the very end, once after a fix, every time. forgetting this is the single most common reason an otherwise-correct setup still looks broken. names the verifier grabs by hand, use them exactly: | thing | name | |-|-| | rest api | `orders-api` | | stage | `dev` | | resource path | `/orders` | | method | `POST` | | main queue | `orders.fifo` | | dlq | `orders-dlq.fifo` | | apigw→sqs role | `apigw-to-sqs-role` | | consumer lambda | `orders-consumer` | | consumer lambda role | `orders-consumer-role` | | ddb table | `orders` (pk `order_id` String) | python3.11 for the lambda. the lambda runs on the shared compose network so `http://localstack:4566` is reachable from inside it. localstack community 4.13.1. you have up to 60 minutes.

List app directory contents

shell
ls /app/
output
setup.sh
starter

[stdout]
setup.sh
starter

Read starter files and setup script

shell
ls /app/starter/ && cat /app/setup.sh
output
setup.sh
#!/bin/bash
[redacted: decontamination sentinel]
[redacted: decontamination sentinel]
#
# Pre-seeds the consumer Lambda + its role with a broken-by-design
# handler and incomplete IAM. The agent has to build everything else
# (queues, DDB, apigw, integration, deployment, ESM) AND fix this
# Lambda's handler + role. Without the pre-seeded Lambda, Opus 4.7
# tends to read the prose and forget the consumer path entirely.

set -euo pipefail

REGION="${AWS_DEFAULT_REGION:-us-east-1}"
ACCOUNT_ID="000000000000"

LAMBDA_FUNC="orders-consumer"
LAMBDA_ROLE="orders-consumer-role"

log() { echo "[setup] $*" >&2; }

log "waiting for localstack"
for _ in $(seq 1 80); do
  HEALTH=$(curl -sf http://localstack:4566/_localstack/health || true)
  echo "$HEALTH" | grep -qE '"lambda": "(available|running)"' \
    && echo "$HEALTH" | grep -qE '"iam": "(available|running)"' \
    && break
  sleep 2
done

log "creating Lambda consumer role (deliberately incomplete)"
TRUST=$(cat <<'JSON'
{
  "Version": "2012-10-17",
  "Statement": [
    {"Effect": "Allow", "Principal": {"Service": "lambda.amazonaws.com"}, "Action": "sts:AssumeRole"}
  ]
}
JSON
)
aws iam create-role \
  --role-name "$LAMBDA_ROLE" \
  --assume-role-policy-document "$TRUST" >/dev/null
aws iam attach-role-policy \
  --role-name "$LAMBDA_ROLE" \
  --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
# Note: no dynamodb:PutItem, no sqs perms. Agent fixes this.
ROLE_ARN=$(aws iam get-role --role-name "$LAMBDA_ROLE" --query 'Role.Arn' --output text)

log "packaging Lambda (broken-by-design inline handler)"
WORKDIR="$(mktemp -d)"
cat > "${WORKDIR}/handler.py" <<'PY'
"""Orders consumer - broken by design.

Known issues (agent must fix):
  - Not idempotent: a duplicate message will try to PutItem again,
    which will either overwrite (wrong) or fail (wrong shape).
  - Returns a per-record 'failed' list instead of the AWS-required
    batchItemFailures shape for partial-batch-failure reporting.
"""

import json
import os
import time
import boto3

_endpoint = os.environ.get("AWS_ENDPOINT_URL", "http://localstack:4566")
ddb = boto3.client("dynamodb", endpoint_url=_endpoint)

TABLE_NAME = os.environ.get("TABLE_NAME", "orders")


def _process_record(record):
    payload = json.loads(record["body"])
    order_id = payload["order_id"]
    merchant_id = payload["merchant_id"]
    amount = int(payload["amount"])

    ddb.put_item(
        TableName=TABLE_NAME,
        Item={
            "order_id": {"S": order_id},
            "merchant_id": {"S": merchant_id},
            "amount": {"N": str(amount)},
            "created_at": {"N": str(int(time.time()))},
        },
    )


def lambda_handler(event, context):
    failed = []
    for record in event.get("Records", []):
        try:
            _process_record(record)
        except Exception as e:
            print(f"[error] msgId={record.get('messageId')} {type(e).__name__}: {e}")
            failed.append({"itemIdentifier": record["messageId"]})

    return {"failed": failed}
PY
(cd "$WORKDIR" && zip -q handler.zip handler.py)

log "creating Lambda function"
aws lambda create-function \
  --function-name "$LAMBDA_FUNC" \
  --runtime python3.11 \
  --role "$ROLE_ARN" \
  --handler handler.lambda_handler \
  --timeout 30 \
  --memory-size 512 \
  --environment "Variables={AWS_ENDPOINT_URL=http://localstack:4566,TABLE_NAME=orders}" \
  --zip-file "fileb://${WORKDIR}/handler.zip" >/dev/null

for _ in $(seq 1 30); do
  STATE=$(aws lambda get-function --function-name "$LAMBDA_FUNC" \
    --query 'Configuration.State' --output text 2>/dev/null || echo "Pending")
  [ "$STATE" = "Active" ] && break
  sleep 1
done
log "Lambda $LAMBDA_FUNC ready"

log "done"

[stdout]
setup.sh
#!/bin/bash
[redacted: decontamination sentinel]
[redacted: decontamination sentinel]
#
# Pre-seeds the consumer Lambda + its role with a broken-by-design
# handler and incomplete IAM. The agent has to build everything else
# (queues, DDB, apigw, integration, deployment, ESM) AND fix this
# Lambda's handler + role. Without the pre-seeded Lambda, Opus 4.7
# tends to read the prose and forget the consumer path entirely.

set -euo pipefail

REGION="${AWS_DEFAULT_REGION:-us-east-1}"
ACCOUNT_ID="000000000000"

LAMBDA_FUNC="orders-consumer"
LAMBDA_ROLE="orders-consumer-role"

log() { echo "[setup] $*" >&2; }

log "waiting for localstack"
for _ in $(seq 1 80); do
  HEALTH=$(curl -sf http://localstack:4566/_localstack/health || true)
  echo "$HEALTH" | grep -qE '"lambda": "(available|running)"' \
    && echo "$HEALTH" | grep -qE '"iam": "(available|running)"' \
    && break
  sleep 2
done

log "creating Lambda consumer role (deliberately incomplete)"
TRUST=$(cat <<'JSON'
{
  "Version": "2012-10-17",
  "Statement": [
    {"Effect": "Allow", "Principal": {"Service": "lambda.amazonaws.com"}, "Action": "sts:AssumeRole"}
  ]
}
JSON
)
aws iam create-role \
  --role-name "$LAMBDA_ROLE" \
  --assume-role-policy-document "$TRUST" >/dev/null
aws iam attach-role-policy \
  --role-name "$LAMBDA_ROLE" \
  --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
# Note: no dynamodb:PutItem, no sqs perms. Agent fixes this.
ROLE_ARN=$(aws iam get-role --role-name "$LAMBDA_ROLE" --query 'Role.Arn' --output text)

log "packaging Lambda (broken-by-design inline handler)"
WORKDIR="$(mktemp -d)"
cat > "${WORKDIR}/handler.py" <<'PY'
"""Orders consumer - broken by design.

Known issues (agent must fix):
  - Not idempotent: a duplicate message will try to PutItem again,
    which will either overwrite (wrong) or fail (wrong shape).
  - Returns a per-record 'failed' list instead of the AWS-required
    batchItemFailures shape for partial-batch-failure reporting.
"""

import json
import os
import time
import boto3

_endpoint = os.environ.get("AWS_ENDPOINT_URL", "http://localstack:4566")
ddb = boto3.client("dynamodb", endpoint_url=_endpoint)

TABLE_NAME = os.environ.get("TABLE_NAME", "orders")


def _process_record(record):
    payload = json.loads(record["body"])
    order_id = payload["order_id"]
    merchant_id = payload["merchant_id"]
    amount = int(payload["amount"])

    ddb.put_item(
        TableName=TABLE_NAME,
        Item={
            "order_id": {"S": order_id},
            "merchant_id": {"S": merchant_id},
            "amount": {"N": str(amount)},
            "created_at": {"N": str(int(time.time()))},
        },
    )


def lambda_handler(event, context):
    failed = []
    for record in event.get("Records", []):
        try:
            _process_record(record)
        except Exception as e:
            print(f"[error] msgId={record.get('messageId')} {type(e).__name__}: {e}")
            failed.append({"itemIdentifier": record["messageId"]})

    return {"failed": failed}
PY
(cd "$WORKDIR" && zip -q handler.zip handler.py)

log "creating Lambda function"
aws lambda create-function \
  --function-name "$LAMBDA_FUNC" \
  --runtime python3.11 \
  --role "$ROLE_ARN" \
  --handler handler.lambda_handler \
  --timeout 30 \
  --memory-size 512 \
  --environment "Variables={AWS_ENDPOINT_URL=http://localstack:4566,TABLE_NAME=orders}" \
  --zip-file "fileb://${WORKDIR}/handler.zip" >/dev/null

for _ in $(seq 1 30); do
  STATE=$(aws lambda get-function --function-name "$LAMBDA_FUNC" \
    --query 'Configuration.State' --output text 2>/dev/null || echo "Pending")
  [ "$STATE" = "Active" ] && break
  sleep 1
done
log "Lambda $LAMBDA_FUNC ready"

log "done"
Got it. Let me check a few things and then build it all.

Check env, AWS CLI, and pre-seeded lambda state

shell
echo "AWS_ENDPOINT_URL=$AWS_ENDPOINT_URL"; echo "AWS_DEFAULT_REGION=$AWS_DEFAULT_REGION"; aws --version; aws --endpoint-url http://localstack:4566 lambda get-function --function-name orders-consumer --query 'Configuration.[FunctionName,State,Role]' --output text; aws --endpoint-url http://localstack:4566 iam list-attached-role-policies --role-name orders-consumer-role
output
AWS_ENDPOINT_URL=http://localstack:4566
AWS_DEFAULT_REGION=us-east-1
aws-cli/2.34.33 Python/3.14.4 Linux/6.10.14-linuxkit exe/aarch64.ubuntu.24
orders-consumer	Active	arn:aws:iam::000000000000:role/orders-consumer-role
{
    "AttachedPolicies": [
        {
            "PolicyName": "AWSLambdaBasicExecutionRole",
            "PolicyArn": "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        }
    ]
}

[stdout]
AWS_ENDPOINT_URL=http://localstack:4566
AWS_DEFAULT_REGION=us-east-1
aws-cli/2.34.33 Python/3.14.4 Linux/6.10.14-linuxkit exe/aarch64.ubuntu.24
orders-consumer	Active	arn:aws:iam::000000000000:role/orders-consumer-role
{
    "AttachedPolicies": [
        {
            "PolicyName": "AWSLambdaBasicExecutionRole",
            "PolicyArn": "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        }
    ]
}

Verify localstack services up

shell
curl -sf http://localstack:4566/_localstack/health | head -c 500
output
{"services": {"acm": "disabled", "apigateway": "available", "cloudformation": "disabled", "cloudwatch": "disabled", "config": "disabled", "dynamodb": "available", "dynamodbstreams": "available", "ec2": "disabled", "es": "disabled", "events": "disabled", "firehose": "disabled", "iam": "running", "kinesis": "available", "kms": "disabled", "lambda": "running", "logs": "available", "opensearch": "disabled", "redshift": "disabled", "resource-groups": "disabled", "resourcegroupstaggingapi": "disabled"

[stdout]
{"services": {"acm": "disabled", "apigateway": "available", "cloudformation": "disabled", "cloudwatch": "disabled", "config": "disabled", "dynamodb": "available", "dynamodbstreams": "available", "ec2": "disabled", "es": "disabled", "events": "disabled", "firehose": "disabled", "iam": "running", "kinesis": "available", "kms": "disabled", "lambda": "running", "logs": "available", "opensearch": "disabled", "redshift": "disabled", "resource-groups": "disabled", "resourcegroupstaggingapi": "disabled"

List enabled services

shell
curl -sf http://localstack:4566/_localstack/health | python3 -c "import json,sys; d=json.load(sys.stdin); print({k:v for k,v in d['services'].items() if v in ('available','running')})"
output
{'apigateway': 'available', 'dynamodb': 'available', 'dynamodbstreams': 'available', 'iam': 'running', 'kinesis': 'available', 'lambda': 'running', 'logs': 'available', 's3': 'running', 'sqs': 'available', 'sts': 'running'}

[stdout]
{'apigateway': 'available', 'dynamodb': 'available', 'dynamodbstreams': 'available', 'iam': 'running', 'kinesis': 'available', 'lambda': 'running', 'logs': 'available', 's3': 'running', 'sqs': 'available', 'sts': 'running'}
Good. Everything I need is up. Building it all now.
write · /app/handler.py
"""Orders consumer.

Idempotent PutItem via ConditionExpression(attribute_not_exists),
returns AWS-required batchItemFailures shape so a single bad
record doesn't fail the whole batch.
"""

import json
import os
import time
import boto3
from botocore.exceptions import ClientError

_endpoint = os.environ.get("AWS_ENDPOINT_URL", "http://localstack:4566")
ddb = boto3.client("dynamodb", endpoint_url=_endpoint)

TABLE_NAME = os.environ.get("TABLE_NAME", "orders")


def _process_record(record):
    payload = json.loads(record["body"])
    order_id = payload["order_id"]
    merchant_id = payload["merchant_id"]
    amount = int(payload["amount"])

    try:
        ddb.put_item(
            TableName=TABLE_NAME,
            Item={
                "order_id": {"S": order_id},
                "merchant_id": {"S": merchant_id},
                "amount": {"N": str(amount)},
                "created_at": {"N": str(time.time_ns())},
            },
            ConditionExpression="attribute_not_exists(order_id)",
        )
    except ClientError as e:
        if e.response.get("Error", {}).get("Code") == "ConditionalCheckFailedException":
            print(f"[idempotent-skip] order_id={order_id} already stored")
            return
        raise


def lambda_handler(event, context):
    batch_item_failures = []
    for record in event.get("Records", []):
        try:
            _process_record(record)
        except Exception as e:
            print(f"[error] msgId={record.get('messageId')} {type(e).__name__}: {e}")
            batch_item_failures.append({"itemIdentifier": record["messageId"]})

    return {"batchItemFailures": batch_item_failures}

Create FIFO DLQ and main queue with redrive

shell
set -e
cd /app
# 1. DLQ first
aws --endpoint-url http://localstack:4566 sqs create-queue \
  --queue-name orders-dlq.fifo \
  --attributes 'FifoQueue=true,ContentBasedDeduplication=false'
DLQ_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)
DLQ_ARN=$(aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url "$DLQ_URL" --attribute-names QueueArn --query 'Attributes.QueueArn' --output text)
echo "DLQ_ARN=$DLQ_ARN"

# 2. main queue with redrive
REDRIVE=$(printf '{"deadLetterTargetArn":"%s","maxReceiveCount":"3"}' "$DLQ_ARN")
aws --endpoint-url http://localstack:4566 sqs create-queue \
  --queue-name orders.fifo \
  --attributes "FifoQueue=true,ContentBasedDeduplication=false,VisibilityTimeout=60,RedrivePolicy=$REDRIVE"
MAIN_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)
MAIN_ARN=$(aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url "$MAIN_URL" --attribute-names QueueArn --query 'Attributes.QueueArn' --output text)
echo "MAIN_URL=$MAIN_URL"
echo "MAIN_ARN=$MAIN_ARN"
output
{
    "QueueUrl": "http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders-dlq.fifo"
}
DLQ_ARN=arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo

aws: [ERROR]: An error occurred (ParamValidation): Error parsing parameter '--attributes': Expected: '=', received: '"' for input:
 FifoQueue=true,ContentBasedDeduplication=false,VisibilityTimeout=60,RedrivePolicy={"deadLetterTargetArn":"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo","maxReceiveCount":"3"}
                                                                                   ^

aws: [ERROR]: An error occurred (AWS.SimpleQueueService.NonExistentQueue) when calling the GetQueueUrl operation: The specified queue does not exist.

aws: [ERROR]: An error occurred (AWS.SimpleQueueService.NonExistentQueue) when calling the GetQueueAttributes operation: The specified queue does not exist.
MAIN_URL=
MAIN_ARN=

[stdout]
{
    "QueueUrl": "http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders-dlq.fifo"
}
DLQ_ARN=arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo

aws: [ERROR]: An error occurred (ParamValidation): Error parsing parameter '--attributes': Expected: '=', received: '"' for input:
 FifoQueue=true,ContentBasedDeduplication=false,VisibilityTimeout=60,RedrivePolicy={"deadLetterTargetArn":"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo","maxReceiveCount":"3"}
                                                                                   ^

aws: [ERROR]: An error occurred (AWS.SimpleQueueService.NonExistentQueue) when calling the GetQueueUrl operation: The specified queue does not exist.

aws: [ERROR]: An error occurred (AWS.SimpleQueueService.NonExistentQueue) when calling the GetQueueAttributes operation: The specified queue does not exist.
MAIN_URL=
MAIN_ARN=

Create main queue using attrs file

shell
set -e
cat > /tmp/queue-attrs.json <<JSON
{
  "FifoQueue": "true",
  "ContentBasedDeduplication": "false",
  "VisibilityTimeout": "60",
  "RedrivePolicy": "{\"deadLetterTargetArn\":\"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo\",\"maxReceiveCount\":\"3\"}"
}
JSON
aws --endpoint-url http://localstack:4566 sqs create-queue \
  --queue-name orders.fifo \
  --attributes file:///tmp/queue-attrs.json

MAIN_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)
MAIN_ARN=$(aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url "$MAIN_URL" --attribute-names QueueArn --query 'Attributes.QueueArn' --output text)
echo "MAIN_URL=$MAIN_URL"
echo "MAIN_ARN=$MAIN_ARN"
output
{
    "QueueUrl": "http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders.fifo"
}
MAIN_URL=http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders.fifo
MAIN_ARN=arn:aws:sqs:us-east-1:000000000000:orders.fifo

[stdout]
{
    "QueueUrl": "http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders.fifo"
}
MAIN_URL=http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders.fifo
MAIN_ARN=arn:aws:sqs:us-east-1:000000000000:orders.fifo
ToolSearch
{
  "query": "select:TodoWrite",
  "max_results": 1
}

, output, 
{"type": "tool_reference", "tool_name": "TodoWrite"}
  • Create FIFO queues (DLQ + main with redrive)
  • Create DDB orders table
  • Update consumer Lambda role with DDB+SQS perms and replace handler code
  • Create event source mapping with batch failure reporting
  • Create apigw-to-sqs role + REST API + /orders POST + AWS-service integration
  • Deploy to dev stage and end-to-end test (single + duplicate + ordering)

Create DDB orders table

shell
aws --endpoint-url http://localstack:4566 dynamodb create-table \
  --table-name orders \
  --attribute-definitions AttributeName=order_id,AttributeType=S \
  --key-schema AttributeName=order_id,KeyType=HASH \
  --billing-mode PAY_PER_REQUEST \
  --query 'TableDescription.[TableName,TableStatus]' --output text

for _ in $(seq 1 30); do
  STATE=$(aws --endpoint-url http://localstack:4566 dynamodb describe-table --table-name orders --query 'Table.TableStatus' --output text 2>/dev/null || echo "PENDING")
  [ "$STATE" = "ACTIVE" ] && { echo "table ACTIVE"; break; }
  sleep 1
done
output
orders	ACTIVE
table ACTIVE

[stdout]
orders	ACTIVE
table ACTIVE

Attach consumer role policy + update Lambda code

shell
set -e
# Inline policy for the consumer lambda role
cat > /tmp/consumer-policy.json <<'JSON'
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "sqs:ReceiveMessage",
        "sqs:DeleteMessage",
        "sqs:GetQueueAttributes",
        "sqs:ChangeMessageVisibility"
      ],
      "Resource": [
        "arn:aws:sqs:us-east-1:000000000000:orders.fifo",
        "arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo"
      ]
    },
    {
      "Effect": "Allow",
      "Action": [
        "dynamodb:PutItem",
        "dynamodb:GetItem",
        "dynamodb:UpdateItem",
        "dynamodb:DescribeTable"
      ],
      "Resource": "arn:aws:dynamodb:us-east-1:000000000000:table/orders"
    },
    {
      "Effect": "Allow",
      "Action": ["logs:CreateLogGroup","logs:CreateLogStream","logs:PutLogEvents"],
      "Resource": "*"
    }
  ]
}
JSON
aws iam put-role-policy \
  --role-name orders-consumer-role \
  --policy-name orders-consumer-inline \
  --policy-document file:///tmp/consumer-policy.json
echo "policy attached"

# Repackage the fixed handler
cd /app
rm -f handler.zip
zip -q handler.zip handler.py
aws --endpoint-url http://localstack:4566 lambda update-function-code \
  --function-name orders-consumer \
  --zip-file fileb:///app/handler.zip \
  --query '[FunctionName,LastUpdateStatus]' --output text

for _ in $(seq 1 30); do
  S=$(aws --endpoint-url http://localstack:4566 lambda get-function --function-name orders-consumer --query 'Configuration.LastUpdateStatus' --output text)
  [ "$S" = "Successful" ] && { echo "lambda updated"; break; }
  sleep 1
done
output
policy attached
orders-consumer	InProgress
lambda updated

[stdout]
policy attached
orders-consumer	InProgress
lambda updated

Create event source mapping with ReportBatchItemFailures

shell
set -e
# Event source mapping with partial batch failure reporting
aws --endpoint-url http://localstack:4566 lambda create-event-source-mapping \
  --function-name orders-consumer \
  --event-source-arn arn:aws:sqs:us-east-1:000000000000:orders.fifo \
  --batch-size 10 \
  --function-response-types ReportBatchItemFailures \
  --query '[UUID,State]' --output text
output
0ca437ac-ddb2-4aab-be94-befd4add3fcb	Creating

[stdout]
0ca437ac-ddb2-4aab-be94-befd4add3fcb	Creating

Wait for ESM to become Enabled

shell
UUID=$(aws --endpoint-url http://localstack:4566 lambda list-event-source-mappings --function-name orders-consumer --query 'EventSourceMappings[0].UUID' --output text)
for _ in $(seq 1 30); do
  S=$(aws --endpoint-url http://localstack:4566 lambda get-event-source-mapping --uuid "$UUID" --query 'State' --output text)
  echo "ESM state=$S"
  [ "$S" = "Enabled" ] && break
  sleep 1
done
output
ESM state=Enabled

[stdout]
ESM state=Enabled
  • Create FIFO queues (DLQ + main with redrive)
  • Create DDB orders table
  • Update consumer Lambda role with DDB+SQS perms and replace handler code
  • Create event source mapping with batch failure reporting
  • Create apigw-to-sqs role + REST API + /orders POST + AWS-service integration
  • Deploy to dev stage and end-to-end test (single + duplicate + ordering)

Create apigw-to-sqs role with SendMessage policy

shell
set -e
# 1. apigw-to-sqs role
cat > /tmp/apigw-trust.json <<'JSON'
{
  "Version": "2012-10-17",
  "Statement": [
    {"Effect":"Allow","Principal":{"Service":"apigateway.amazonaws.com"},"Action":"sts:AssumeRole"}
  ]
}
JSON
aws iam create-role \
  --role-name apigw-to-sqs-role \
  --assume-role-policy-document file:///tmp/apigw-trust.json \
  --query 'Role.Arn' --output text

cat > /tmp/apigw-policy.json <<'JSON'
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["sqs:SendMessage","sqs:GetQueueUrl","sqs:GetQueueAttributes"],
      "Resource": "arn:aws:sqs:us-east-1:000000000000:orders.fifo"
    },
    {
      "Effect": "Allow",
      "Action": ["logs:CreateLogGroup","logs:CreateLogStream","logs:PutLogEvents"],
      "Resource": "*"
    }
  ]
}
JSON
aws iam put-role-policy \
  --role-name apigw-to-sqs-role \
  --policy-name apigw-to-sqs-inline \
  --policy-document file:///tmp/apigw-policy.json
APIGW_ROLE_ARN=$(aws iam get-role --role-name apigw-to-sqs-role --query 'Role.Arn' --output text)
echo "APIGW_ROLE_ARN=$APIGW_ROLE_ARN"
output
arn:aws:iam::000000000000:role/apigw-to-sqs-role
APIGW_ROLE_ARN=arn:aws:iam::000000000000:role/apigw-to-sqs-role

[stdout]
arn:aws:iam::000000000000:role/apigw-to-sqs-role
APIGW_ROLE_ARN=arn:aws:iam::000000000000:role/apigw-to-sqs-role

Create REST API, /orders POST, AWS integration to SQS

shell
set -e
APIGW_ROLE_ARN="arn:aws:iam::000000000000:role/apigw-to-sqs-role"

# 2. REST API
API_ID=$(aws --endpoint-url http://localstack:4566 apigateway create-rest-api \
  --name orders-api \
  --query 'id' --output text)
echo "API_ID=$API_ID"

ROOT_ID=$(aws --endpoint-url http://localstack:4566 apigateway get-resources \
  --rest-api-id "$API_ID" \
  --query 'items[?path==`/`].id | [0]' --output text)
echo "ROOT_ID=$ROOT_ID"

# 3. /orders resource
ORDERS_ID=$(aws --endpoint-url http://localstack:4566 apigateway create-resource \
  --rest-api-id "$API_ID" \
  --parent-id "$ROOT_ID" \
  --path-part orders \
  --query 'id' --output text)
echo "ORDERS_ID=$ORDERS_ID"

# 4. POST method
aws --endpoint-url http://localstack:4566 apigateway put-method \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --authorization-type NONE \
  --query '[httpMethod,authorizationType]' --output text

# 5. Method response 200
aws --endpoint-url http://localstack:4566 apigateway put-method-response \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --status-code 200 \
  --response-models 'application/json=Empty' \
  --query 'statusCode' --output text

# 6. AWS service integration to SQS
INTEGRATION_URI="arn:aws:apigateway:us-east-1:sqs:path/000000000000/orders.fifo"
REQ_TEMPLATE='Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('"'"'$.merchant_id'"'"'))&MessageDeduplicationId=$util.urlEncode($input.path('"'"'$.order_id'"'"'))'
echo "Template: $REQ_TEMPLATE"

# Use a JSON file for request templates to keep quoting sane
python3 - <<'PY' > /tmp/req-template.json
import json
tpl = "Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('$.merchant_id'))&MessageDeduplicationId=$util.urlEncode($input.path('$.order_id'))"
print(json.dumps({"application/json": tpl}))
PY
cat /tmp/req-template.json
echo

aws --endpoint-url http://localstack:4566 apigateway put-integration \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --type AWS \
  --integration-http-method POST \
  --uri "$INTEGRATION_URI" \
  --credentials "$APIGW_ROLE_ARN" \
  --request-parameters 'integration.request.header.Content-Type=\x27application/x-www-form-urlencoded\x27' \
  --request-templates file:///tmp/req-template.json \
  --passthrough-behavior NEVER \
  --query '[type,httpMethod]' --output text

# 7. Integration response 200
python3 - <<'PY' > /tmp/resp-template.json
import json
print(json.dumps({"application/json": "{\"ok\":true}"}))
PY
aws --endpoint-url http://localstack:4566 apigateway put-integration-response \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --status-code 200 \
  --response-templates file:///tmp/resp-template.json \
  --query 'statusCode' --output text

echo "API_ID=$API_ID" > /tmp/api-id
output
API_ID=0jlo5uf4av
ROOT_ID=x5fweljvvz
ORDERS_ID=lzntkqhfss
POST	NONE
200
Template: Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('$.merchant_id'))&MessageDeduplicationId=$util.urlEncode($input.path('$.order_id'))
{"application/json": "Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('$.merchant_id'))&MessageDeduplicationId=$util.urlEncode($input.path('$.order_id'))"}

AWS	POST
200

[stdout]
API_ID=0jlo5uf4av
ROOT_ID=x5fweljvvz
ORDERS_ID=lzntkqhfss
POST	NONE
200
Template: Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('$.merchant_id'))&MessageDeduplicationId=$util.urlEncode($input.path('$.order_id'))
{"application/json": "Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('$.merchant_id'))&MessageDeduplicationId=$util.urlEncode($input.path('$.order_id'))"}

AWS	POST
200

Check integration to confirm request parameters

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
aws --endpoint-url http://localstack:4566 apigateway get-integration \
  --rest-api-id "$API_ID" \
  --resource-id $(aws --endpoint-url http://localstack:4566 apigateway get-resources --rest-api-id "$API_ID" --query 'items[?path==`/orders`].id | [0]' --output text) \
  --http-method POST
output
{
    "type": "AWS",
    "httpMethod": "POST",
    "uri": "arn:aws:apigateway:us-east-1:sqs:path/000000000000/orders.fifo",
    "credentials": "arn:aws:iam::000000000000:role/apigw-to-sqs-role",
    "requestParameters": {
        "integration.request.header.Content-Type": "\\x27application/x-www-form-urlencoded\\x27"
    },
    "requestTemplates": {
        "application/json": "Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('$.merchant_id'))&MessageDeduplicationId=$util.urlEncode($input.path('$.order_id'))"
    },
    "passthroughBehavior": "NEVER",
    "timeoutInMillis": 29000,
    "cacheNamespace": "lzntkqhfss",
    "cacheKeyParameters": [],
    "integrationResponses": {
        "200": {
            "statusCode": "200",
            "responseTemplates": {
                "application/json": "{\"ok\":true}"
            }
        }
    }
}

[stdout]
{
    "type": "AWS",
    "httpMethod": "POST",
    "uri": "arn:aws:apigateway:us-east-1:sqs:path/000000000000/orders.fifo",
    "credentials": "arn:aws:iam::000000000000:role/apigw-to-sqs-role",
    "requestParameters": {
        "integration.request.header.Content-Type": "\\x27application/x-www-form-urlencoded\\x27"
    },
    "requestTemplates": {
        "application/json": "Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('$.merchant_id'))&MessageDeduplicationId=$util.urlEncode($input.path('$.order_id'))"
    },
    "passthroughBehavior": "NEVER",
    "timeoutInMillis": 29000,
    "cacheNamespace": "lzntkqhfss",
    "cacheKeyParameters": [],
    "integrationResponses": {
        "200": {
            "statusCode": "200",
            "responseTemplates": {
                "application/json": "{\"ok\":true}"
            }
        }
    }
}

Fix Content-Type integration request parameter

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
ORDERS_ID=$(aws --endpoint-url http://localstack:4566 apigateway get-resources --rest-api-id "$API_ID" --query 'items[?path==`/orders`].id | [0]' --output text)

# Fix the Content-Type request parameter , it must be a single-quoted literal value
aws --endpoint-url http://localstack:4566 apigateway update-integration \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --patch-operations "op=replace,path=/requestParameters/integration.request.header.Content-Type,value='\''application/x-www-form-urlencoded'\''" \
  --query 'requestParameters' --output json
output
Exit code 252

aws: [ERROR]: An error occurred (ParamValidation): Error parsing parameter '--patch-operations': Expected: ',', received: 'a' for input:
 op=replace,path=/requestParameters/integration.request.header.Content-Type,value='\''application/x-www-form-urlencoded'\''
                                                                                     ^

[error] tool reported failure

Replace request param via JSON file

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
ORDERS_ID=$(aws --endpoint-url http://localstack:4566 apigateway get-resources --rest-api-id "$API_ID" --query 'items[?path==`/orders`].id | [0]' --output text)

# Use --cli-input-json from a file to avoid shell-quote hell
cat > /tmp/patch.json <<JSON
{
  "restApiId": "$API_ID",
  "resourceId": "$ORDERS_ID",
  "httpMethod": "POST",
  "patchOperations": [
    {
      "op": "replace",
      "path": "/requestParameters/integration.request.header.Content-Type",
      "value": "'application/x-www-form-urlencoded'"
    }
  ]
}
JSON
aws --endpoint-url http://localstack:4566 apigateway update-integration \
  --cli-input-json file:///tmp/patch.json \
  --query 'requestParameters' --output json
output
{
    "integration.request.header.Content-Type": "'application/x-www-form-urlencoded'"
}

[stdout]
{
    "integration.request.header.Content-Type": "'application/x-www-form-urlencoded'"
}

Create deployment for stage dev

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
# Deploy
aws --endpoint-url http://localstack:4566 apigateway create-deployment \
  --rest-api-id "$API_ID" \
  --stage-name dev \
  --query '[id,createdDate]' --output text
echo "API_ID=$API_ID"
output
1mbo0cgylf	2026-04-28T13:57:49+00:00
API_ID=0jlo5uf4av

[stdout]
1mbo0cgylf	2026-04-28T13:57:49+00:00
API_ID=0jlo5uf4av
Now let's test end-to-end.

Test single POST end-to-end

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
URL="http://localstack:4566/restapis/${API_ID}/dev/_user_request_/orders"
echo "URL=$URL"

BODY='{"order_id":"o-001","merchant_id":"m-A","amount":1234}'
echo "POST 1:"
curl -s -o /tmp/r1.txt -w "http=%{http_code}\n" -X POST -H "Content-Type: application/json" -d "$BODY" "$URL"
cat /tmp/r1.txt; echo

sleep 5
echo "DDB after 1st POST:"
aws --endpoint-url http://localstack:4566 dynamodb scan --table-name orders --output json | python3 -c "import sys,json; d=json.load(sys.stdin); print(json.dumps(d['Items'], indent=2))"
output
URL=http://localstack:4566/restapis/0jlo5uf4av/dev/_user_request_/orders
POST 1:
http=200
{"ok":true}
DDB after 1st POST:
[]

[stdout]
URL=http://localstack:4566/restapis/0jlo5uf4av/dev/_user_request_/orders
POST 1:
http=200
{"ok":true}
DDB after 1st POST:
[]

Check queue depth and lambda logs

shell
MAIN_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)
DLQ_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)
echo "MAIN attrs:"
aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url "$MAIN_URL" --attribute-names All --query 'Attributes.{visible:ApproximateNumberOfMessages,inflight:ApproximateNumberOfMessagesNotVisible}'
echo "DLQ attrs:"
aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url "$DLQ_URL" --attribute-names All --query 'Attributes.{visible:ApproximateNumberOfMessages,inflight:ApproximateNumberOfMessagesNotVisible}'

echo "---"
echo "Recent lambda logs:"
LG=$(aws --endpoint-url http://localstack:4566 logs describe-log-groups --log-group-name-prefix /aws/lambda/orders-consumer --query 'logGroups[0].logGroupName' --output text 2>/dev/null || echo "")
echo "logGroup=$LG"
if [ -n "$LG" ] && [ "$LG" != "None" ]; then
  STREAM=$(aws --endpoint-url http://localstack:4566 logs describe-log-streams --log-group-name "$LG" --order-by LastEventTime --descending --max-items 1 --query 'logStreams[0].logStreamName' --output text 2>/dev/null || echo "")
  echo "stream=$STREAM"
  if [ -n "$STREAM" ] && [ "$STREAM" != "None" ]; then
    aws --endpoint-url http://localstack:4566 logs get-log-events --log-group-name "$LG" --log-stream-name "$STREAM" --limit 50 --query 'events[*].message' --output text
  fi
fi
output
MAIN attrs:
{
    "visible": "0",
    "inflight": "0"
}
DLQ attrs:
{
    "visible": "0",
    "inflight": "0"
}
---
Recent lambda logs:
logGroup=/aws/lambda/orders-consumer
stream=2026/04/28/[$LATEST]9342329b73028c527bb880f153b40e5d
START RequestId: 225ce8f0-47f6-47c2-a574-320010e473d9 Version: $LATEST
	END RequestId: 225ce8f0-47f6-47c2-a574-320010e473d9
	REPORT RequestId: 225ce8f0-47f6-47c2-a574-320010e473d9	Duration: 172.22 ms	Billed Duration: 173 ms	Memory Size: 512 MB	Max Memory Used: 512 MB

[stdout]
MAIN attrs:
{
    "visible": "0",
    "inflight": "0"
}
DLQ attrs:
{
    "visible": "0",
    "inflight": "0"
}
---
Recent lambda logs:
logGroup=/aws/lambda/orders-consumer
stream=2026/04/28/[$LATEST]9342329b73028c527bb880f153b40e5d
START RequestId: 225ce8f0-47f6-47c2-a574-320010e473d9 Version: $LATEST
	END RequestId: 225ce8f0-47f6-47c2-a574-320010e473d9
	REPORT RequestId: 225ce8f0-47f6-47c2-a574-320010e473d9	Duration: 172.22 ms	Billed Duration: 173 ms	Memory Size: 512 MB	Max Memory Used: 512 MB

Send a second POST + send a direct SQS message to isolate apigw vs lambda

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
URL="http://localstack:4566/restapis/${API_ID}/dev/_user_request_/orders"
BODY='{"order_id":"o-002","merchant_id":"m-A","amount":4242}'
echo "POST:"
curl -s -o /tmp/r2.txt -w "http=%{http_code}\n" -X POST -H "Content-Type: application/json" -d "$BODY" "$URL"
cat /tmp/r2.txt; echo
sleep 3

# Check what's in the queue immediately by peeking via receive (don't delete though)
MAIN_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)
echo "Sending probe message directly to bypass apigw and verify lambda end:"
aws --endpoint-url http://localstack:4566 sqs send-message \
  --queue-url "$MAIN_URL" \
  --message-body '{"order_id":"probe-1","merchant_id":"m-Z","amount":9}' \
  --message-group-id "m-Z" \
  --message-deduplication-id "probe-1" \
  --query 'MessageId' --output text
sleep 5
aws --endpoint-url http://localstack:4566 dynamodb scan --table-name orders --output json | python3 -c "import sys,json; d=json.load(sys.stdin); print(json.dumps(d['Items'], indent=2)); print('count:',d['Count'])"
output
POST:
http=200
{"ok":true}
Sending probe message directly to bypass apigw and verify lambda end:
7a78763b-d532-4d15-9512-0f68b0092812
[
  {
    "created_at": {
      "N": "1777384691631513592"
    },
    "amount": {
      "N": "1234"
    },
    "merchant_id": {
      "S": "m-A"
    },
    "order_id": {
      "S": "o-001"
    }
  },
  {
    "created_at": {
      "N": "1777384717746868382"
    },
    "amount": {
      "N": "9"
    },
    "merchant_id": {
      "S": "m-Z"
    },
    "order_id": {
      "S": "probe-1"
    }
  },
  {
    "created_at": {
      "N": "1777384716359185382"
    },
    "amount": {
      "N": "4242"
    },
    "merchant_id": {
      "S": "m-A"
    },
    "order_id": {
      "S": "o-002"
    }
  }
]
count: 3

[stdout]
POST:
http=200
{"ok":true}
Sending probe message directly to bypass apigw and verify lambda end:
7a78763b-d532-4d15-9512-0f68b0092812
[
  {
    "created_at": {
      "N": "1777384691631513592"
    },
    "amount": {
      "N": "1234"
    },
    "merchant_id": {
      "S": "m-A"
    },
    "order_id": {
      "S": "o-001"
    }
  },
  {
    "created_at": {
      "N": "1777384717746868382"
    },
    "amount": {
      "N": "9"
    },
    "merchant_id": {
      "S": "m-Z"
    },
    "order_id": {
      "S": "probe-1"
    }
  },
  {
    "created_at": {
      "N": "1777384716359185382"
    },
    "amount": {
      "N": "4242"
    },
    "merchant_id": {
      "S": "m-A"
    },
    "order_id": {
      "S": "o-002"
    }
  }
]
count: 3
Items did land , the first POST just took longer than my initial 5s wait. Now let me verify duplicate-noop, ordering, and DLQ-empty.

Verify duplicate-noop and DLQ empty

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
URL="http://localstack:4566/restapis/${API_ID}/dev/_user_request_/orders"

# 1. Duplicate POST: same body should still 200 and not change the row
echo "=== duplicate POST (o-001, same merchant/amount) ==="
ORIG=$(aws --endpoint-url http://localstack:4566 dynamodb get-item --table-name orders --key '{"order_id":{"S":"o-001"}}' --output json)
echo "before: $ORIG"
curl -s -o /tmp/dup.txt -w "http=%{http_code}\n" -X POST -H "Content-Type: application/json" \
  -d '{"order_id":"o-001","merchant_id":"m-A","amount":1234}' "$URL"
cat /tmp/dup.txt; echo
sleep 6
AFTER=$(aws --endpoint-url http://localstack:4566 dynamodb get-item --table-name orders --key '{"order_id":{"S":"o-001"}}' --output json)
echo "after:  $AFTER"
if [ "$ORIG" = "$AFTER" ]; then echo "OK: row unchanged after duplicate POST"; else echo "FAIL: row mutated!"; fi

echo
echo "=== Different body for same order_id (must STILL be a no-op) ==="
curl -s -o /tmp/dup2.txt -w "http=%{http_code}\n" -X POST -H "Content-Type: application/json" \
  -d '{"order_id":"o-001","merchant_id":"m-DIFFERENT","amount":99999}' "$URL"
cat /tmp/dup2.txt; echo
sleep 6
AFTER2=$(aws --endpoint-url http://localstack:4566 dynamodb get-item --table-name orders --key '{"order_id":{"S":"o-001"}}' --output json)
echo "after2: $AFTER2"
if [ "$ORIG" = "$AFTER2" ]; then echo "OK: row still unchanged after differing body for same order_id"; else echo "FAIL: row mutated by replay with different body"; fi

echo
echo "=== Items count ==="
aws --endpoint-url http://localstack:4566 dynamodb scan --table-name orders --select COUNT --query 'Count' --output text

echo
echo "=== DLQ depth ==="
DLQ_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)
aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url "$DLQ_URL" \
  --attribute-names ApproximateNumberOfMessages ApproximateNumberOfMessagesNotVisible --query 'Attributes' --output json
output
=== duplicate POST (o-001, same merchant/amount) ===
before: {
    "Item": {
        "created_at": {
            "N": "1777384691631513592"
        },
        "amount": {
            "N": "1234"
        },
        "merchant_id": {
            "S": "m-A"
        },
        "order_id": {
            "S": "o-001"
        }
    }
}
http=200
{"ok":true}
after:  {
    "Item": {
        "created_at": {
            "N": "1777384691631513592"
        },
        "amount": {
            "N": "1234"
        },
        "merchant_id": {
            "S": "m-A"
        },
        "order_id": {
            "S": "o-001"
        }
    }
}
OK: row unchanged after duplicate POST

=== Different body for same order_id (must STILL be a no-op) ===
http=200
{"ok":true}
after2: {
    "Item": {
        "created_at": {
            "N": "1777384691631513592"
        },
        "amount": {
            "N": "1234"
        },
        "merchant_id": {
            "S": "m-A"
        },
        "order_id": {
            "S": "o-001"
        }
    }
}
OK: row still unchanged after differing body for same order_id

=== Items count ===
3

=== DLQ depth ===
{
    "ApproximateNumberOfMessages": "0",
    "ApproximateNumberOfMessagesNotVisible": "0"
}

[stdout]
=== duplicate POST (o-001, same merchant/amount) ===
before: {
    "Item": {
        "created_at": {
            "N": "1777384691631513592"
        },
        "amount": {
            "N": "1234"
        },
        "merchant_id": {
            "S": "m-A"
        },
        "order_id": {
            "S": "o-001"
        }
    }
}
http=200
{"ok":true}
after:  {
    "Item": {
        "created_at": {
            "N": "1777384691631513592"
        },
        "amount": {
            "N": "1234"
        },
        "merchant_id": {
            "S": "m-A"
        },
        "order_id": {
            "S": "o-001"
        }
    }
}
OK: row unchanged after duplicate POST

=== Different body for same order_id (must STILL be a no-op) ===
http=200
{"ok":true}
after2: {
    "Item": {
        "created_at": {
            "N": "1777384691631513592"
        },
        "amount": {
            "N": "1234"
        },
        "merchant_id": {
            "S": "m-A"
        },
        "order_id": {
            "S": "o-001"
        }
    }
}
OK: row still unchanged after differing body for same order_id

=== Items count ===
3

=== DLQ depth ===
{
    "ApproximateNumberOfMessages": "0",
    "ApproximateNumberOfMessagesNotVisible": "0"
}

Ordering test: same merchant, two order_ids

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
URL="http://localstack:4566/restapis/${API_ID}/dev/_user_request_/orders"
# Wipe table for clean ordering test
aws --endpoint-url http://localstack:4566 dynamodb delete-table --table-name orders --query 'TableDescription.TableName' --output text
for _ in $(seq 1 20); do
  S=$(aws --endpoint-url http://localstack:4566 dynamodb describe-table --table-name orders --query 'Table.TableStatus' --output text 2>/dev/null || echo "GONE")
  [ "$S" = "GONE" ] && break
  sleep 1
done
aws --endpoint-url http://localstack:4566 dynamodb create-table \
  --table-name orders \
  --attribute-definitions AttributeName=order_id,AttributeType=S \
  --key-schema AttributeName=order_id,KeyType=HASH \
  --billing-mode PAY_PER_REQUEST --query 'TableDescription.TableStatus' --output text

for _ in $(seq 1 20); do
  S=$(aws --endpoint-url http://localstack:4566 dynamodb describe-table --table-name orders --query 'Table.TableStatus' --output text 2>/dev/null || echo "PENDING")
  [ "$S" = "ACTIVE" ] && break
  sleep 1
done

echo "=== ordering: two distinct order_ids same merchant, posted in sequence ==="
curl -s -o /dev/null -w "p1=%{http_code}\n" -X POST -H "Content-Type: application/json" \
  -d '{"order_id":"ord-A","merchant_id":"merchA","amount":10}' "$URL"
curl -s -o /dev/null -w "p2=%{http_code}\n" -X POST -H "Content-Type: application/json" \
  -d '{"order_id":"ord-B","merchant_id":"merchA","amount":20}' "$URL"
sleep 8

aws --endpoint-url http://localstack:4566 dynamodb scan --table-name orders --output json | python3 -c "
import sys,json
d = json.load(sys.stdin)
items = d['Items']
print('count:', d['Count'])
for it in items:
    print(it['order_id']['S'], 'created_at=', it['created_at']['N'])
a = next(i for i in items if i['order_id']['S']=='ord-A')
b = next(i for i in items if i['order_id']['S']=='ord-B')
ta = int(a['created_at']['N']); tb = int(b['created_at']['N'])
print('ord-A ts=', ta)
print('ord-B ts=', tb)
print('order preserved (A<B)?', ta < tb)
"
output
Exit code 1
orders
ACTIVE
=== ordering: two distinct order_ids same merchant, posted in sequence ===
p1=200
p2=200
Traceback (most recent call last):
  File "<string>", line 8, in <module>
StopIteration
count: 0

[error] tool reported failure

Diagnose ordering test result

shell
MAIN_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)
DLQ_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)
echo "MAIN: $(aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url $MAIN_URL --attribute-names ApproximateNumberOfMessages ApproximateNumberOfMessagesNotVisible --query Attributes --output json)"
echo "DLQ:  $(aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url $DLQ_URL --attribute-names ApproximateNumberOfMessages ApproximateNumberOfMessagesNotVisible --query Attributes --output json)"

LG=/aws/lambda/orders-consumer
STREAMS=$(aws --endpoint-url http://localstack:4566 logs describe-log-streams --log-group-name $LG --order-by LastEventTime --descending --max-items 3 --query 'logStreams[*].logStreamName' --output text)
for s in $STREAMS; do
  echo "--- stream $s ---"
  aws --endpoint-url http://localstack:4566 logs get-log-events --log-group-name $LG --log-stream-name "$s" --limit 30 --query 'events[*].message' --output text | tail -30
done

echo "=== Wait + scan ==="
sleep 10
aws --endpoint-url http://localstack:4566 dynamodb scan --table-name orders --select COUNT --query 'Count' --output text
aws --endpoint-url http://localstack:4566 dynamodb scan --table-name orders --output json | python3 -c "import sys,json; d=json.load(sys.stdin); [print(i['order_id']['S'],'ts=',i['created_at']['N']) for i in d['Items']]"
output
MAIN: {
    "ApproximateNumberOfMessages": "0",
    "ApproximateNumberOfMessagesNotVisible": "0"
}
DLQ:  {
    "ApproximateNumberOfMessages": "0",
    "ApproximateNumberOfMessagesNotVisible": "0"
}
--- stream 2026/04/28/[$LATEST]61376175aea3656d9fb7c9fea0bb5f0f ---
START RequestId: e65bef76-4289-4918-a814-d222a2bf7ed8 Version: $LATEST
	END RequestId: e65bef76-4289-4918-a814-d222a2bf7ed8
	REPORT RequestId: e65bef76-4289-4918-a814-d222a2bf7ed8	Duration: 78.22 ms	Billed Duration: 79 ms	Memory Size: 512 MB	Max Memory Used: 512 MB	

--- stream 2026/04/28/[$LATEST]f1b919b2e25019815ad0f8a9aa987a50 ---
START RequestId: f7317bfd-3622-45ce-a07b-29ad9198cd64 Version: $LATEST
	END RequestId: f7317bfd-3622-45ce-a07b-29ad9198cd64
	REPORT RequestId: f7317bfd-3622-45ce-a07b-29ad9198cd64	Duration: 44.11 ms	Billed Duration: 45 ms	Memory Size: 512 MB	Max Memory Used: 512 MB	

--- stream 2026/04/28/[$LATEST]58a040d98de112b7df73d63e8ee97080 ---
START RequestId: 76ed38f1-4b89-4aa8-bd87-c3290cef165e Version: $LATEST
	END RequestId: 76ed38f1-4b89-4aa8-bd87-c3290cef165e
	REPORT RequestId: 76ed38f1-4b89-4aa8-bd87-c3290cef165e	Duration: 56.67 ms	Billed Duration: 57 ms	Memory Size: 512 MB	Max Memory Used: 512 MB	

--- stream None ---

aws: [ERROR]: An error occurred (ResourceNotFoundException) when calling the GetLogEvents operation: The specified log stream does not exist.
=== Wait + scan ===
2
ord-A ts= 1777384771654450088
ord-B ts= 1777384771709401504

[stdout]
MAIN: {
    "ApproximateNumberOfMessages": "0",
    "ApproximateNumberOfMessagesNotVisible": "0"
}
DLQ:  {
    "ApproximateNumberOfMessages": "0",
    "ApproximateNumberOfMessagesNotVisible": "0"
}
--- stream 2026/04/28/[$LATEST]61376175aea3656d9fb7c9fea0bb5f0f ---
START RequestId: e65bef76-4289-4918-a814-d222a2bf7ed8 Version: $LATEST
	END RequestId: e65bef76-4289-4918-a814-d222a2bf7ed8
	REPORT RequestId: e65bef76-4289-4918-a814-d222a2bf7ed8	Duration: 78.22 ms	Billed Duration: 79 ms	Memory Size: 512 MB	Max Memory Used: 512 MB	

--- stream 2026/04/28/[$LATEST]f1b919b2e25019815ad0f8a9aa987a50 ---
START RequestId: f7317bfd-3622-45ce-a07b-29ad9198cd64 Version: $LATEST
	END RequestId: f7317bfd-3622-45ce-a07b-29ad9198cd64
	REPORT RequestId: f7317bfd-3622-45ce-a07b-29ad9198cd64	Duration: 44.11 ms	Billed Duration: 45 ms	Memory Size: 512 MB	Max Memory Used: 512 MB	

--- stream 2026/04/28/[$LATEST]58a040d98de112b7df73d63e8ee97080 ---
START RequestId: 76ed38f1-4b89-4aa8-bd87-c3290cef165e Version: $LATEST
	END RequestId: 76ed38f1-4b89-4aa8-bd87-c3290cef165e
	REPORT RequestId: 76ed38f1-4b89-4aa8-bd87-c3290cef165e	Duration: 56.67 ms	Billed Duration: 57 ms	Memory Size: 512 MB	Max Memory Used: 512 MB	

--- stream None ---

aws: [ERROR]: An error occurred (ResourceNotFoundException) when calling the GetLogEvents operation: The specified log stream does not exist.
=== Wait + scan ===
2
ord-A ts= 1777384771654450088
ord-B ts= 1777384771709401504
Ordering preserved (A=1777384771654450088 < B=1777384771709401504). Now full final verification with a clean snapshot.

Full end-to-end verification

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
URL="http://localstack:4566/restapis/${API_ID}/dev/_user_request_/orders"

echo "=== FINAL VERIFICATION ==="
echo
echo "Wipe table for clean test:"
aws --endpoint-url http://localstack:4566 dynamodb delete-table --table-name orders --query 'TableDescription.TableName' --output text
for _ in $(seq 1 20); do
  S=$(aws --endpoint-url http://localstack:4566 dynamodb describe-table --table-name orders --query 'Table.TableStatus' --output text 2>/dev/null || echo "GONE")
  [ "$S" = "GONE" ] && break
  sleep 1
done
aws --endpoint-url http://localstack:4566 dynamodb create-table \
  --table-name orders \
  --attribute-definitions AttributeName=order_id,AttributeType=S \
  --key-schema AttributeName=order_id,KeyType=HASH \
  --billing-mode PAY_PER_REQUEST --query 'TableDescription.TableStatus' --output text
for _ in $(seq 1 20); do
  S=$(aws --endpoint-url http://localstack:4566 dynamodb describe-table --table-name orders --query 'Table.TableStatus' --output text 2>/dev/null || echo "PENDING")
  [ "$S" = "ACTIVE" ] && break
  sleep 1
done
echo
echo "Test 1: single POST"
curl -s -o /tmp/t1.txt -w "  http=%{http_code}\n" -X POST -H "Content-Type: application/json" \
  -d '{"order_id":"X-1","merchant_id":"M-1","amount":500}' "$URL"
echo "  body: $(cat /tmp/t1.txt)"
sleep 8
aws --endpoint-url http://localstack:4566 dynamodb get-item --table-name orders --key '{"order_id":{"S":"X-1"}}' --output json | python3 -c "import sys,json;d=json.load(sys.stdin); print('  row:',d.get('Item'))"

echo
echo "Test 2: duplicate POST same body -> still 200, no change"
BEFORE=$(aws --endpoint-url http://localstack:4566 dynamodb get-item --table-name orders --key '{"order_id":{"S":"X-1"}}' --output json)
curl -s -o /tmp/t2.txt -w "  http=%{http_code}\n" -X POST -H "Content-Type: application/json" \
  -d '{"order_id":"X-1","merchant_id":"M-1","amount":500}' "$URL"
echo "  body: $(cat /tmp/t2.txt)"
sleep 8
AFTER=$(aws --endpoint-url http://localstack:4566 dynamodb get-item --table-name orders --key '{"order_id":{"S":"X-1"}}' --output json)
[ "$BEFORE" = "$AFTER" ] && echo "  OK: row unchanged" || echo "  FAIL"
COUNT=$(aws --endpoint-url http://localstack:4566 dynamodb scan --table-name orders --select COUNT --query 'Count' --output text)
echo "  total rows: $COUNT (expected 1)"

echo
echo "Test 3: ordering for same merchant"
curl -s -o /dev/null -w "  p1=%{http_code}\n" -X POST -H "Content-Type: application/json" \
  -d '{"order_id":"Y-A","merchant_id":"M-2","amount":1}' "$URL"
curl -s -o /dev/null -w "  p2=%{http_code}\n" -X POST -H "Content-Type: application/json" \
  -d '{"order_id":"Y-B","merchant_id":"M-2","amount":2}' "$URL"
sleep 10
aws --endpoint-url http://localstack:4566 dynamodb scan --table-name orders --output json | python3 -c "
import sys,json
d=json.load(sys.stdin)
items={i['order_id']['S']:i for i in d['Items']}
ya=int(items['Y-A']['created_at']['N']); yb=int(items['Y-B']['created_at']['N'])
print(f'  Y-A ts={ya}'); print(f'  Y-B ts={yb}')
print('  ORDER OK' if ya<yb else '  ORDER FAIL')
"

echo
echo "Test 4: DLQ depth (must be 0)"
DLQ_URL=$(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)
aws --endpoint-url http://localstack:4566 sqs get-queue-attributes --queue-url "$DLQ_URL" \
  --attribute-names ApproximateNumberOfMessages ApproximateNumberOfMessagesNotVisible \
  --query 'Attributes' --output json
output
=== FINAL VERIFICATION ===

Wipe table for clean test:
orders
ACTIVE

Test 1: single POST
  http=200
  body: {"ok":true}
  row: {'created_at': {'N': '1777384819268511763'}, 'amount': {'N': '500'}, 'merchant_id': {'S': 'M-1'}, 'order_id': {'S': 'X-1'}}

Test 2: duplicate POST same body -> still 200, no change
  http=200
  body: {"ok":true}
  OK: row unchanged
  total rows: 1 (expected 1)

Test 3: ordering for same merchant
  p1=200
  p2=200
  Y-A ts=1777384843431035885
  Y-B ts=1777384843476100802
  ORDER OK

Test 4: DLQ depth (must be 0)
{
    "ApproximateNumberOfMessages": "0",
    "ApproximateNumberOfMessagesNotVisible": "0"
}

[stdout]
=== FINAL VERIFICATION ===

Wipe table for clean test:
orders
ACTIVE

Test 1: single POST
  http=200
  body: {"ok":true}
  row: {'created_at': {'N': '1777384819268511763'}, 'amount': {'N': '500'}, 'merchant_id': {'S': 'M-1'}, 'order_id': {'S': 'X-1'}}

Test 2: duplicate POST same body -> still 200, no change
  http=200
  body: {"ok":true}
  OK: row unchanged
  total rows: 1 (expected 1)

Test 3: ordering for same merchant
  p1=200
  p2=200
  Y-A ts=1777384843431035885
  Y-B ts=1777384843476100802
  ORDER OK

Test 4: DLQ depth (must be 0)
{
    "ApproximateNumberOfMessages": "0",
    "ApproximateNumberOfMessagesNotVisible": "0"
}
All four pass. Let me confirm everything's wired up by name and re-deploy a final time to flush state.

Final deployment + inventory of every resource by name

shell
API_ID=$(cat /tmp/api-id | cut -d= -f2)
# Final deployment to make sure latest config is live
aws --endpoint-url http://localstack:4566 apigateway create-deployment \
  --rest-api-id "$API_ID" --stage-name dev \
  --query 'id' --output text
echo
echo "=== INVENTORY ==="
echo "REST API:"
aws --endpoint-url http://localstack:4566 apigateway get-rest-apis --query 'items[?name==`orders-api`].{name:name,id:id}' --output table

echo "Stage:"
aws --endpoint-url http://localstack:4566 apigateway get-stage --rest-api-id "$API_ID" --stage-name dev --query '{stage:stageName,deployment:deploymentId}' --output table

echo "Resource /orders + POST:"
ORDERS_ID=$(aws --endpoint-url http://localstack:4566 apigateway get-resources --rest-api-id "$API_ID" --query 'items[?path==`/orders`].id|[0]' --output text)
aws --endpoint-url http://localstack:4566 apigateway get-method --rest-api-id "$API_ID" --resource-id "$ORDERS_ID" --http-method POST --query '{httpMethod:httpMethod,integrationType:methodIntegration.type,uri:methodIntegration.uri,credentials:methodIntegration.credentials}' --output table

echo "Queues:"
aws --endpoint-url http://localstack:4566 sqs list-queues --output text
echo "Main queue redrive:"
aws --endpoint-url http://localstack:4566 sqs get-queue-attributes \
  --queue-url $(aws --endpoint-url http://localstack:4566 sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text) \
  --attribute-names FifoQueue ContentBasedDeduplication RedrivePolicy --query 'Attributes' --output json

echo "DDB table:"
aws --endpoint-url http://localstack:4566 dynamodb describe-table --table-name orders \
  --query 'Table.{name:TableName,status:TableStatus,keys:KeySchema,attrs:AttributeDefinitions}' --output json

echo "ESM:"
aws --endpoint-url http://localstack:4566 lambda list-event-source-mappings \
  --function-name orders-consumer \
  --query 'EventSourceMappings[*].{state:State,src:EventSourceArn,fn:FunctionArn,resp:FunctionResponseTypes}' --output json

echo "Roles:"
aws iam list-role-policies --role-name orders-consumer-role
aws iam list-role-policies --role-name apigw-to-sqs-role
output
sb5zgldngb

=== INVENTORY ===
REST API:
------------------------------
|         GetRestApis        |
+-------------+--------------+
|     id      |    name      |
+-------------+--------------+
|  0jlo5uf4av |  orders-api  |
+-------------+--------------+
Stage:
-------------------------
|       GetStage        |
+-------------+---------+
| deployment  |  stage  |
+-------------+---------+
|  sb5zgldngb |  dev    |
+-------------+---------+
Resource /orders + POST:
---------------------------------------------------------------------------------------
|                                      GetMethod                                      |
+-----------------+-------------------------------------------------------------------+
|  credentials    |  arn:aws:iam::000000000000:role/apigw-to-sqs-role                 |
|  httpMethod     |  POST                                                             |
|  integrationType|  AWS                                                              |
|  uri            |  arn:aws:apigateway:us-east-1:sqs:path/000000000000/orders.fifo   |
+-----------------+-------------------------------------------------------------------+
Queues:
QUEUEURLS	http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders-dlq.fifo
QUEUEURLS	http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders.fifo
Main queue redrive:
{
    "FifoQueue": "true",
    "ContentBasedDeduplication": "false",
    "RedrivePolicy": "{\"deadLetterTargetArn\":\"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo\",\"maxReceiveCount\":\"3\"}"
}
DDB table:
{
    "name": "orders",
    "status": "ACTIVE",
    "keys": [
        {
            "AttributeName": "order_id",
            "KeyType": "HASH"
        }
    ],
    "attrs": [
        {
            "AttributeName": "order_id",
            "AttributeType": "S"
        }
    ]
}
ESM:
[
    {
        "state": "Enabled",
        "src": "arn:aws:sqs:us-east-1:000000000000:orders.fifo",
        "fn": "arn:aws:lambda:us-east-1:000000000000:function:orders-consumer",
        "resp": [
            "ReportBatchItemFailures"
        ]
    }
]
Roles:
{
    "PolicyNames": [
        "orders-consumer-inline"
    ]
}
{
    "PolicyNames": [
        "apigw-to-sqs-inline"
    ]
}

[stdout]
sb5zgldngb

=== INVENTORY ===
REST API:
------------------------------
|         GetRestApis        |
+-------------+--------------+
|     id      |    name      |
+-------------+--------------+
|  0jlo5uf4av |  orders-api  |
+-------------+--------------+
Stage:
-------------------------
|       GetStage        |
+-------------+---------+
| deployment  |  stage  |
+-------------+---------+
|  sb5zgldngb |  dev    |
+-------------+---------+
Resource /orders + POST:
---------------------------------------------------------------------------------------
|                                      GetMethod                                      |
+-----------------+-------------------------------------------------------------------+
|  credentials    |  arn:aws:iam::000000000000:role/apigw-to-sqs-role                 |
|  httpMethod     |  POST                                                             |
|  integrationType|  AWS                                                              |
|  uri            |  arn:aws:apigateway:us-east-1:sqs:path/000000000000/orders.fifo   |
+-----------------+-------------------------------------------------------------------+
Queues:
QUEUEURLS	http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders-dlq.fifo
QUEUEURLS	http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders.fifo
Main queue redrive:
{
    "FifoQueue": "true",
    "ContentBasedDeduplication": "false",
    "RedrivePolicy": "{\"deadLetterTargetArn\":\"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo\",\"maxReceiveCount\":\"3\"}"
}
DDB table:
{
    "name": "orders",
    "status": "ACTIVE",
    "keys": [
        {
            "AttributeName": "order_id",
            "KeyType": "HASH"
        }
    ],
    "attrs": [
        {
            "AttributeName": "order_id",
            "AttributeType": "S"
        }
    ]
}
ESM:
[
    {
        "state": "Enabled",
        "src": "arn:aws:sqs:us-east-1:000000000000:orders.fifo",
        "fn": "arn:aws:lambda:us-east-1:000000000000:function:orders-consumer",
        "resp": [
            "ReportBatchItemFailures"
        ]
    }
]
Roles:
{
    "PolicyNames": [
        "orders-consumer-inline"
    ]
}
{
    "PolicyNames": [
        "apigw-to-sqs-inline"
    ]
}
  • Create FIFO queues (DLQ + main with redrive)
  • Create DDB orders table
  • Update consumer Lambda role with DDB+SQS perms and replace handler code
  • Create event source mapping with batch failure reporting
  • Create apigw-to-sqs role + REST API + /orders POST + AWS-service integration
  • Deploy to dev stage and end-to-end test (single + duplicate + ordering)
All built and verified. Pipeline is live: - **Lambda fix** (`/app/handler.py`): switched return shape to `{"batchItemFailures": [...]}`; idempotent via `PutItem` with `ConditionExpression="attribute_not_exists(order_id)"` (catching `ConditionalCheckFailedException` → silent skip). Bumped `created_at` to `time.time_ns()` so two messages within the same second still order correctly. - **`orders-consumer-role`**: added inline policy granting `sqs:ReceiveMessage/DeleteMessage/GetQueueAttributes/ChangeMessageVisibility` on both queues, `dynamodb:PutItem`/`GetItem`/`UpdateItem`/`DescribeTable` on `orders`, plus logs. - **Queues**: `orders-dlq.fifo` (FIFO, no content dedup), then `orders.fifo` (FIFO, no content dedup, `RedrivePolicy` → DLQ with `maxReceiveCount=3`, 60s visibility). - **DDB**: `orders` table, PK `order_id` (S), PAY_PER_REQUEST. - **Event source mapping**: `orders.fifo` → `orders-consumer`, batch size 10, `FunctionResponseTypes=[ReportBatchItemFailures]`. - **`apigw-to-sqs-role`**: trusts `apigateway.amazonaws.com`, inline policy with `sqs:SendMessage` on `orders.fifo`. - **REST API `orders-api`**: resource `/orders`, method `POST` (auth NONE), AWS-service integration to `arn:aws:apigateway:us-east-1:sqs:path/000000000000/orders.fifo`, `IntegrationHttpMethod=POST`, credentials = apigw role, `Content-Type: 'application/x-www-form-urlencoded'` header, `passthroughBehavior=NEVER`. Mapping template builds `Action=SendMessage&MessageBody=<urlEncoded body>&MessageGroupId=<merchant_id>&MessageDeduplicationId=<order_id>`. Method+integration response 200 → `{"ok":true}`. - **Deployment**: `dev` stage, redeployed at the end. Verification (last clean run): - `POST /dev/orders` → 200, `{"ok":true}`, row appears within ~8s. - Duplicate POST → 200, row unchanged, count stays 1. - Two distinct order_ids same merchant → both rows present, `created_at` strictly increasing. - DLQ depth: 0/0.
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
============================= test session starts ==============================
platform linux -- Python 3.12.3, pytest-8.4.1, pluggy-1.6.0 -- /root/.cache/uv/archive-v0/FDwakNtoShlX1KGLT3q6r/bin/python
cachedir: .pytest_cache
rootdir: /tests
plugins: json-ctrf-0.3.5
collecting ... collected 19 items

../tests/test_outputs.py::test_localstack_reachable PASSED               [  5%]
../tests/test_outputs.py::test_main_fifo_queue_exists PASSED             [ 10%]
../tests/test_outputs.py::test_dlq_fifo_queue_exists PASSED              [ 15%]
../tests/test_outputs.py::test_ddb_table_exists PASSED                   [ 21%]
../tests/test_outputs.py::test_lambda_and_esm_exist PASSED               [ 26%]
../tests/test_outputs.py::test_rest_api_exists_with_post_orders PASSED   [ 31%]
../tests/test_outputs.py::test_integration_uri_targets_fifo_queue PASSED [ 36%]
../tests/test_outputs.py::test_integration_credentials_role_is_set PASSED [ 42%]
../tests/test_outputs.py::test_integration_sets_content_type_header PASSED [ 47%]
../tests/test_outputs.py::test_integration_request_template_uses_full_body PASSED [ 52%]
../tests/test_outputs.py::test_integration_request_template_has_message_group_id PASSED [ 57%]
../tests/test_outputs.py::test_integration_request_template_has_dedup_id PASSED [ 63%]
../tests/test_outputs.py::test_integration_template_identifiers_are_request_derived PASSED [ 68%]
../tests/test_outputs.py::test_stage_deployment_id_was_refreshed PASSED  [ 73%]
../tests/test_outputs.py::test_event_source_mapping_declares_report_batch_item_failures PASSED [ 78%]
../tests/test_outputs.py::test_lambda_handler_idempotency_and_response_shape PASSED [ 84%]
../tests/test_outputs.py::test_end_to_end_post_reaches_ddb_no_dlq PASSED [ 89%]
../tests/test_outputs.py::test_end_to_end_fifo_group_ordering PASSED     [ 94%]
../tests/test_outputs.py::test_end_to_end_duplicate_post_is_idempotent PASSED [100%]

=============================== warnings summary ===============================
test_outputs.py: 65 warnings
  /root/.cache/uv/archive-v0/FDwakNtoShlX1KGLT3q6r/lib/python3.12/site-packages/botocore/auth.py:424: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
    datetime_now = datetime.datetime.utcnow()

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
==================================== PASSES ====================================
=========================== short test summary info ============================
PASSED ../tests/test_outputs.py::test_localstack_reachable
PASSED ../tests/test_outputs.py::test_main_fifo_queue_exists
PASSED ../tests/test_outputs.py::test_dlq_fifo_queue_exists
PASSED ../tests/test_outputs.py::test_ddb_table_exists
PASSED ../tests/test_outputs.py::test_lambda_and_esm_exist
PASSED ../tests/test_outputs.py::test_rest_api_exists_with_post_orders
PASSED ../tests/test_outputs.py::test_integration_uri_targets_fifo_queue
PASSED ../tests/test_outputs.py::test_integration_credentials_role_is_set
PASSED ../tests/test_outputs.py::test_integration_sets_content_type_header
PASSED ../tests/test_outputs.py::test_integration_request_template_uses_full_body
PASSED ../tests/test_outputs.py::test_integration_request_template_has_message_group_id
PASSED ../tests/test_outputs.py::test_integration_request_template_has_dedup_id
PASSED ../tests/test_outputs.py::test_integration_template_identifiers_are_request_derived
PASSED ../tests/test_outputs.py::test_stage_deployment_id_was_refreshed
PASSED ../tests/test_outputs.py::test_event_source_mapping_declares_report_batch_item_failures
PASSED ../tests/test_outputs.py::test_lambda_handler_idempotency_and_response_shape
PASSED ../tests/test_outputs.py::test_end_to_end_post_reaches_ddb_no_dlq
PASSED ../tests/test_outputs.py::test_end_to_end_fifo_group_ordering
PASSED ../tests/test_outputs.py::test_end_to_end_duplicate_post_is_idempotent
======================= 19 passed, 65 warnings in 22.45s =======================

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_cd90a99a39134a9a. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_cd90a99a39134a9a · verifier authoritative; classifier explanatory.