SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

apigw-sqs-fifo-direct-integration

claude-code claude-opus-4-7 ✗ failed GOOD_FAILURE ↑ 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
GOOD_FAILUREHonest miss, the agent ran correctly but couldn't solve it. Expected for a hard task; the task is sound.
SubtypeIncomplete Execution
EvidenceTest output shows `test_stage_deployment_id_was_refreshed` failed with: `AssertionError: stage dev has only 1 deployment(s); editing an integration without calling create-deployment is the #1 silent failure mode for this task`. The test checks that multiple deployments exist (>= 2), indicating the agent created/modified configuration but did not call `apigateway create-deployment` to promote changes to the live stage. However, 18 other tests passed, including functional end-to-end tests (`test_end_to_end_post_reaches_ddb_no_dlq`, `test_end_to_end_duplicate_post_is_idempotent`, `test_end_to_end_fifo_group_ordering`), indicating the infrastructure was largely built correctly but the deployment step was omitted.
Root causeThe agent completed the task infrastructure correctly but failed to execute a specifically-emphasized step: calling `apigateway create-deployment` after modifying API Gateway configuration. The instruction states this explicitly and warns it is "the #1 silent failure mode." The agent either forgot this step or did not prioritize it.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
28 tool calls · 3 tool types · 36 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 contents of /app directory

shell
ls /app/
output
setup.sh
starter

[stdout]
setup.sh
starter

Read setup script

shell
cat /app/setup.sh
output
#!/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]
#!/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"

Inspect starter directory

shell
ls /app/starter/ 2>/dev/null && echo "---" && cat /app/starter/* 2>/dev/null | head -200
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"

Check localstack service health

shell
curl -sf http://localstack:4566/_localstack/health | jq '.services | {lambda, iam, sqs, dynamodb, apigateway}'
output
{
  "lambda": "running",
  "iam": "running",
  "sqs": "available",
  "dynamodb": "available",
  "apigateway": "available"
}

[stdout]
{
  "lambda": "running",
  "iam": "running",
  "sqs": "available",
  "dynamodb": "available",
  "apigateway": "available"
}

Inspect pre-seeded lambda and role

shell
aws --endpoint-url=http://localstack:4566 lambda get-function --function-name orders-consumer --query 'Configuration.{State:State,Role:Role,Handler:Handler,Runtime:Runtime}' && echo "---" && aws --endpoint-url=http://localstack:4566 iam list-attached-role-policies --role-name orders-consumer-role && echo "---" && aws --endpoint-url=http://localstack:4566 iam list-role-policies --role-name orders-consumer-role
output
{
    "State": "Active",
    "Role": "arn:aws:iam::000000000000:role/orders-consumer-role",
    "Handler": "handler.lambda_handler",
    "Runtime": "python3.11"
}
---
{
    "AttachedPolicies": [
        {
            "PolicyName": "AWSLambdaBasicExecutionRole",
            "PolicyArn": "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        }
    ]
}
---
{
    "PolicyNames": []
}

[stdout]
{
    "State": "Active",
    "Role": "arn:aws:iam::000000000000:role/orders-consumer-role",
    "Handler": "handler.lambda_handler",
    "Runtime": "python3.11"
}
---
{
    "AttachedPolicies": [
        {
            "PolicyName": "AWSLambdaBasicExecutionRole",
            "PolicyArn": "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        }
    ]
}
---
{
    "PolicyNames": []
}

Confirm fresh state

shell
export AWS_ENDPOINT_URL=http://localstack:4566 && echo "export AWS_ENDPOINT_URL=http://localstack:4566" >> ~/.bashrc && aws sqs list-queues; aws dynamodb list-tables; aws apigateway get-rest-apis --query 'items[].name'
output
This Bash command contains multiple operations. The following parts require approval: export AWS_ENDPOINT_URL=http://localstack:4566, echo "export AWS_ENDPOINT_URL=http://localstack:4566", aws sqs list-queues, aws dynamodb list-tables, aws apigateway get-rest-apis --query 'items[].name'

[error] tool reported failure

List existing AWS resources

shell
AWS_ENDPOINT_URL=http://localstack:4566 aws sqs list-queues 2>&1; AWS_ENDPOINT_URL=http://localstack:4566 aws dynamodb list-tables 2>&1; AWS_ENDPOINT_URL=http://localstack:4566 aws apigateway get-rest-apis --query 'items[].name' 2>&1
output
{
    "TableNames": []
}
[]

[stdout]
{
    "TableNames": []
}
[]
Building from scratch. Step 1: DDB table + both FIFO queues.

Create DDB table + FIFO queues with redrive

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

aws 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 >/dev/null

aws dynamodb wait table-exists --table-name orders
echo "ddb ready"

aws sqs create-queue --queue-name orders-dlq.fifo \
  --attributes 'FifoQueue=true,ContentBasedDeduplication=false' >/dev/null

DLQ_URL=$(aws sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)
DLQ_ARN=$(aws sqs get-queue-attributes --queue-url "$DLQ_URL" --attribute-names QueueArn --query 'Attributes.QueueArn' --output text)
echo "dlq: $DLQ_ARN"

REDRIVE=$(printf '{"deadLetterTargetArn":"%s","maxReceiveCount":"3"}' "$DLQ_ARN")
aws sqs create-queue --queue-name orders.fifo \
  --attributes "FifoQueue=true,ContentBasedDeduplication=false,RedrivePolicy=$REDRIVE,VisibilityTimeout=60" >/dev/null

MAIN_URL=$(aws sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)
MAIN_ARN=$(aws sqs get-queue-attributes --queue-url "$MAIN_URL" --attribute-names QueueArn --query 'Attributes.QueueArn' --output text)
echo "main: $MAIN_ARN"
output
ddb ready
dlq: 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,RedrivePolicy={"deadLetterTargetArn":"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo","maxReceiveCount":"3"},VisibilityTimeout=60
                                                              ^

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:

[stdout]
ddb ready
dlq: 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,RedrivePolicy={"deadLetterTargetArn":"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo","maxReceiveCount":"3"},VisibilityTimeout=60
                                                              ^

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:

Create main FIFO queue with redrive via JSON file

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

DLQ_ARN=$(aws sqs get-queue-attributes \
  --queue-url "$(aws sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)" \
  --attribute-names QueueArn --query 'Attributes.QueueArn' --output text)

cat > /tmp/main-attrs.json <<EOF
{
  "FifoQueue": "true",
  "ContentBasedDeduplication": "false",
  "VisibilityTimeout": "60",
  "RedrivePolicy": "{\"deadLetterTargetArn\":\"$DLQ_ARN\",\"maxReceiveCount\":\"3\"}"
}
EOF

aws sqs create-queue --queue-name orders.fifo --attributes file:///tmp/main-attrs.json >/dev/null
MAIN_URL=$(aws sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)
MAIN_ARN=$(aws sqs get-queue-attributes --queue-url "$MAIN_URL" --attribute-names QueueArn --query 'Attributes.QueueArn' --output text)
echo "main: $MAIN_ARN"
aws sqs get-queue-attributes --queue-url "$MAIN_URL" --attribute-names All --query 'Attributes.{Fifo:FifoQueue,Cbd:ContentBasedDeduplication,Redrive:RedrivePolicy}'
output
main: arn:aws:sqs:us-east-1:000000000000:orders.fifo
{
    "Fifo": "true",
    "Cbd": "false",
    "Redrive": "{\"deadLetterTargetArn\":\"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo\",\"maxReceiveCount\":\"3\"}"
}

[stdout]
main: arn:aws:sqs:us-east-1:000000000000:orders.fifo
{
    "Fifo": "true",
    "Cbd": "false",
    "Redrive": "{\"deadLetterTargetArn\":\"arn:aws:sqs:us-east-1:000000000000:orders-dlq.fifo\",\"maxReceiveCount\":\"3\"}"
}
ToolSearch
{
  "query": "select:TodoWrite",
  "max_results": 1
}

, output, 
{"type": "tool_reference", "tool_name": "TodoWrite"}
  • Create DDB table + FIFO queues with redrive
  • Fix consumer lambda role IAM (ddb + sqs)
  • Fix consumer lambda handler (idempotent + batchItemFailures)
  • Create event source mapping with ReportBatchItemFailures
  • Create apigw-to-sqs role + policy
  • Create REST API + resource + POST + AWS service integration
  • Deploy to dev stage
  • End-to-end verify

Add inline IAM policy for consumer lambda

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

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"
    },
    {
      "Effect": "Allow",
      "Action": [
        "dynamodb:PutItem",
        "dynamodb:GetItem",
        "dynamodb:UpdateItem",
        "dynamodb:DescribeTable"
      ],
      "Resource": "arn:aws:dynamodb:us-east-1:000000000000:table/orders"
    }
  ]
}
JSON

aws iam put-role-policy \
  --role-name orders-consumer-role \
  --policy-name orders-consumer-inline \
  --policy-document file:///tmp/consumer-policy.json

aws iam list-role-policies --role-name orders-consumer-role
output
{
    "PolicyNames": [
        "orders-consumer-inline"
    ]
}

[stdout]
{
    "PolicyNames": [
        "orders-consumer-inline"
    ]
}
Step 3: fix the lambda handler , idempotent put + correct `batchItemFailures` shape.

Update lambda code with idempotent handler + correct shape

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

WORK=$(mktemp -d)
cat > "$WORK/handler.py" <<'PY'
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(int(time.time() * 1000))},
            },
            ConditionExpression="attribute_not_exists(order_id)",
        )
    except ClientError as e:
        if e.response["Error"]["Code"] == "ConditionalCheckFailedException":
            print(f"[idempotent-skip] order_id={order_id} already exists")
            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}
PY

(cd "$WORK" && zip -q handler.zip handler.py)

aws lambda update-function-code \
  --function-name orders-consumer \
  --zip-file "fileb://$WORK/handler.zip" >/dev/null

for _ in $(seq 1 30); do
  STATUS=$(aws lambda get-function --function-name orders-consumer --query 'Configuration.LastUpdateStatus' --output text)
  [ "$STATUS" = "Successful" ] && break
  sleep 1
done
echo "lambda update: $STATUS"
output
lambda update: Successful

[stdout]
lambda update: Successful
  • Create DDB table + FIFO queues with redrive
  • Fix consumer lambda role IAM (ddb + sqs)
  • Fix consumer lambda handler (idempotent + batchItemFailures)
  • Create event source mapping with ReportBatchItemFailures
  • Create apigw-to-sqs role + policy
  • Create REST API + resource + POST + AWS service integration
  • Deploy to dev stage
  • End-to-end verify

Create ESM with ReportBatchItemFailures

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

aws 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 \
  --enabled

sleep 2
aws lambda list-event-source-mappings --function-name orders-consumer \
  --query 'EventSourceMappings[].{State:State,UUID:UUID,FRT:FunctionResponseTypes,Source:EventSourceArn}'
output
{
    "UUID": "a5c488fc-5608-422f-9972-ab5ff03307d1",
    "BatchSize": 10,
    "MaximumBatchingWindowInSeconds": 0,
    "EventSourceArn": "arn:aws:sqs:us-east-1:000000000000:orders.fifo",
    "FunctionArn": "arn:aws:lambda:us-east-1:000000000000:function:orders-consumer",
    "LastModified": "2026-04-28T13:43:53.964616+00:00",
    "State": "Creating",
    "StateTransitionReason": "USER_INITIATED",
    "FunctionResponseTypes": [
        "ReportBatchItemFailures"
    ],
    "EventSourceMappingArn": "arn:aws:lambda:us-east-1:000000000000:event-source-mapping:a5c488fc-5608-422f-9972-ab5ff03307d1"
}
[
    {
        "State": "Enabled",
        "UUID": "a5c488fc-5608-422f-9972-ab5ff03307d1",
        "FRT": [
            "ReportBatchItemFailures"
        ],
        "Source": "arn:aws:sqs:us-east-1:000000000000:orders.fifo"
    }
]

[stdout]
{
    "UUID": "a5c488fc-5608-422f-9972-ab5ff03307d1",
    "BatchSize": 10,
    "MaximumBatchingWindowInSeconds": 0,
    "EventSourceArn": "arn:aws:sqs:us-east-1:000000000000:orders.fifo",
    "FunctionArn": "arn:aws:lambda:us-east-1:000000000000:function:orders-consumer",
    "LastModified": "2026-04-28T13:43:53.964616+00:00",
    "State": "Creating",
    "StateTransitionReason": "USER_INITIATED",
    "FunctionResponseTypes": [
        "ReportBatchItemFailures"
    ],
    "EventSourceMappingArn": "arn:aws:lambda:us-east-1:000000000000:event-source-mapping:a5c488fc-5608-422f-9972-ab5ff03307d1"
}
[
    {
        "State": "Enabled",
        "UUID": "a5c488fc-5608-422f-9972-ab5ff03307d1",
        "FRT": [
            "ReportBatchItemFailures"
        ],
        "Source": "arn:aws:sqs:us-east-1:000000000000:orders.fifo"
    }
]
  • Create DDB table + FIFO queues with redrive
  • Fix consumer lambda role IAM (ddb + sqs)
  • Fix consumer lambda handler (idempotent + batchItemFailures)
  • Create event source mapping with ReportBatchItemFailures
  • Create apigw-to-sqs role + policy
  • Create REST API + resource + POST + AWS service integration
  • Deploy to dev stage
  • End-to-end verify

Create apigw-to-sqs role with SendMessage perms

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

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 >/dev/null

cat > /tmp/apigw-policy.json <<'JSON'
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["sqs:SendMessage", "sqs:GetQueueUrl"],
      "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: $APIGW_ROLE_ARN"
output
apigw role: arn:aws:iam::000000000000:role/apigw-to-sqs-role

[stdout]
apigw role: arn:aws:iam::000000000000:role/apigw-to-sqs-role
  • Create DDB table + FIFO queues with redrive
  • Fix consumer lambda role IAM (ddb + sqs)
  • Fix consumer lambda handler (idempotent + batchItemFailures)
  • Create event source mapping with ReportBatchItemFailures
  • Create apigw-to-sqs role + policy
  • Create REST API + resource + POST + AWS service integration
  • Deploy to dev stage
  • End-to-end verify

Create REST API + /orders resource + POST method

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

API_ID=$(aws apigateway create-rest-api --name orders-api --query 'id' --output text)
echo "api id: $API_ID"

ROOT_ID=$(aws apigateway get-resources --rest-api-id "$API_ID" --query 'items[?path==`/`].id' --output text)
echo "root id: $ROOT_ID"

ORDERS_ID=$(aws apigateway create-resource --rest-api-id "$API_ID" --parent-id "$ROOT_ID" --path-part orders --query 'id' --output text)
echo "orders resource id: $ORDERS_ID"

aws apigateway put-method \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --authorization-type NONE \
  --no-api-key-required >/dev/null

# Save IDs for next steps
echo "$API_ID" > /tmp/api_id
echo "$ORDERS_ID" > /tmp/orders_id
output
api id: ygr4firkyt
root id: kd120limrx
orders resource id: iequ8zqz8o

[stdout]
api id: ygr4firkyt
root id: kd120limrx
orders resource id: iequ8zqz8o

Wire up AWS-service SQS integration with mapping templates

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

API_ID=$(cat /tmp/api_id)
ORDERS_ID=$(cat /tmp/orders_id)
APIGW_ROLE_ARN=$(aws iam get-role --role-name apigw-to-sqs-role --query 'Role.Arn' --output text)

# Mapping template - turns the JSON body into a form-encoded SQS SendMessage call
# Pulls merchant_id -> MessageGroupId, order_id -> MessageDeduplicationId
cat > /tmp/req-template.json <<'TPL'
{
  "application/json": "Action=SendMessage&MessageBody=$util.urlEncode($input.body)&MessageGroupId=$util.urlEncode($input.path('$.merchant_id'))&MessageDeduplicationId=$util.urlEncode($input.path('$.order_id'))"
}
TPL

cat > /tmp/req-params.json <<'PARM'
{
  "integration.request.header.Content-Type": "'application/x-www-form-urlencoded'"
}
PARM

aws apigateway put-integration \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --type AWS \
  --integration-http-method POST \
  --uri "arn:aws:apigateway:us-east-1:sqs:path/000000000000/orders.fifo" \
  --credentials "$APIGW_ROLE_ARN" \
  --request-parameters file:///tmp/req-params.json \
  --request-templates file:///tmp/req-template.json \
  --passthrough-behavior NEVER >/dev/null

aws apigateway put-method-response \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --status-code 200 \
  --response-models 'application/json=Empty' >/dev/null

cat > /tmp/resp-template.json <<'TPL'
{
  "application/json": "{\"status\":\"queued\"}"
}
TPL

aws apigateway put-integration-response \
  --rest-api-id "$API_ID" \
  --resource-id "$ORDERS_ID" \
  --http-method POST \
  --status-code 200 \
  --selection-pattern "" \
  --response-templates file:///tmp/resp-template.json >/dev/null

echo "integration wired"
output
integration wired

[stdout]
integration wired
  • Create DDB table + FIFO queues with redrive
  • Fix consumer lambda role IAM (ddb + sqs)
  • Fix consumer lambda handler (idempotent + batchItemFailures)
  • Create event source mapping with ReportBatchItemFailures
  • Create apigw-to-sqs role + policy
  • Create REST API + resource + POST + AWS service integration
  • Deploy to dev stage
  • End-to-end verify

Create deployment for dev stage

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

API_ID=$(cat /tmp/api_id)
aws apigateway create-deployment --rest-api-id "$API_ID" --stage-name dev --description "initial" \
  --query '{id:id,stage:stageName}'
output
{
    "id": "wycz3lb6hs",
    "stage": null
}

[stdout]
{
    "id": "wycz3lb6hs",
    "stage": null
}
Now end-to-end verification.

First POST + verify state

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

API_ID=$(cat /tmp/api_id)
URL="http://localstack:4566/restapis/$API_ID/dev/_user_request_/orders"
echo "URL: $URL"

BODY='{"order_id":"o-1001","merchant_id":"m-42","amount":1500}'
echo "POST 1: $BODY"
curl -s -o /tmp/resp1.txt -w "HTTP %{http_code}\n" -X POST -H "Content-Type: application/json" --data "$BODY" "$URL"
cat /tmp/resp1.txt; echo

sleep 6

echo "--- ddb scan ---"
aws dynamodb scan --table-name orders --query 'Items'

echo "--- main queue depth ---"
aws sqs get-queue-attributes --queue-url "$(aws sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)" \
  --attribute-names ApproximateNumberOfMessages ApproximateNumberOfMessagesNotVisible

echo "--- dlq depth ---"
aws sqs get-queue-attributes --queue-url "$(aws sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)" \
  --attribute-names ApproximateNumberOfMessages ApproximateNumberOfMessagesNotVisible
output
URL: http://localstack:4566/restapis/ygr4firkyt/dev/_user_request_/orders
POST 1: {"order_id":"o-1001","merchant_id":"m-42","amount":1500}
HTTP 200
{"status":"queued"}
--- ddb scan ---
[
    {
        "created_at": {
            "N": "1777383906548"
        },
        "amount": {
            "N": "1500"
        },
        "merchant_id": {
            "S": "m-42"
        },
        "order_id": {
            "S": "o-1001"
        }
    }
]
--- main queue depth ---
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0",
        "ApproximateNumberOfMessagesNotVisible": "0"
    }
}
--- dlq depth ---
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0",
        "ApproximateNumberOfMessagesNotVisible": "0"
    }
}

[stdout]
URL: http://localstack:4566/restapis/ygr4firkyt/dev/_user_request_/orders
POST 1: {"order_id":"o-1001","merchant_id":"m-42","amount":1500}
HTTP 200
{"status":"queued"}
--- ddb scan ---
[
    {
        "created_at": {
            "N": "1777383906548"
        },
        "amount": {
            "N": "1500"
        },
        "merchant_id": {
            "S": "m-42"
        },
        "order_id": {
            "S": "o-1001"
        }
    }
]
--- main queue depth ---
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0",
        "ApproximateNumberOfMessagesNotVisible": "0"
    }
}
--- dlq depth ---
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0",
        "ApproximateNumberOfMessagesNotVisible": "0"
    }
}
First POST works. Now duplicate test + ordering test.

Test duplicate POST is idempotent

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

API_ID=$(cat /tmp/api_id)
URL="http://localstack:4566/restapis/$API_ID/dev/_user_request_/orders"

# Capture original created_at
ORIG_TS=$(aws dynamodb get-item --table-name orders --key '{"order_id":{"S":"o-1001"}}' --query 'Item.created_at.N' --output text)
echo "original ts: $ORIG_TS"

echo "POST 2 (duplicate)"
BODY='{"order_id":"o-1001","merchant_id":"m-42","amount":1500}'
curl -s -o /tmp/resp2.txt -w "HTTP %{http_code}\n" -X POST -H "Content-Type: application/json" --data "$BODY" "$URL"
cat /tmp/resp2.txt; echo

sleep 6

ROWS=$(aws dynamodb scan --table-name orders --select COUNT --query 'Count')
echo "row count after dup: $ROWS"
NEW_TS=$(aws dynamodb get-item --table-name orders --key '{"order_id":{"S":"o-1001"}}' --query 'Item.created_at.N' --output text)
echo "new ts: $NEW_TS  (must equal original: $ORIG_TS)"

echo "--- dlq depth ---"
aws sqs get-queue-attributes --queue-url "$(aws sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)" \
  --attribute-names ApproximateNumberOfMessages
output
original ts: 1777383906548
POST 2 (duplicate)
HTTP 200
{"status":"queued"}
row count after dup: 1
new ts: 1777383906548  (must equal original: 1777383906548)
--- dlq depth ---
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0"
    }
}

[stdout]
original ts: 1777383906548
POST 2 (duplicate)
HTTP 200
{"status":"queued"}
row count after dup: 1
new ts: 1777383906548  (must equal original: 1777383906548)
--- dlq depth ---
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0"
    }
}
Duplicate is a no-op. Now ordering test with two distinct order_ids in the same merchant.

Verify order is preserved across two posts within same merchant

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

API_ID=$(cat /tmp/api_id)
URL="http://localstack:4566/restapis/$API_ID/dev/_user_request_/orders"

curl -s -o /dev/null -w "HTTP %{http_code} A\n" -X POST -H "Content-Type: application/json" \
  --data '{"order_id":"o-2001","merchant_id":"m-99","amount":100}' "$URL"
sleep 1
curl -s -o /dev/null -w "HTTP %{http_code} B\n" -X POST -H "Content-Type: application/json" \
  --data '{"order_id":"o-2002","merchant_id":"m-99","amount":200}' "$URL"

sleep 6

aws dynamodb scan --table-name orders \
  --filter-expression 'merchant_id = :m' \
  --expression-attribute-values '{":m":{"S":"m-99"}}' \
  --query 'Items[].{order_id:order_id.S,created_at:created_at.N,amount:amount.N}'
output
HTTP 200 A
HTTP 200 B
[]

[stdout]
HTTP 200 A
HTTP 200 B
[]

Investigate missing rows

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

sleep 5
echo "--- full table scan ---"
aws dynamodb scan --table-name orders --query 'Items[].{order_id:order_id.S,merchant_id:merchant_id.S,created_at:created_at.N,amount:amount.N}'

echo "--- queue depth ---"
aws sqs get-queue-attributes \
  --queue-url "$(aws sqs get-queue-url --queue-name orders.fifo --query QueueUrl --output text)" \
  --attribute-names ApproximateNumberOfMessages ApproximateNumberOfMessagesNotVisible

echo "--- lambda logs ---"
LG=$(aws logs describe-log-groups --log-group-name-prefix /aws/lambda/orders-consumer --query 'logGroups[0].logGroupName' --output text)
aws logs tail "$LG" --since 1m 2>/dev/null | tail -40
output
--- full table scan ---
[
    {
        "order_id": "o-1001",
        "merchant_id": "m-42",
        "created_at": "1777383906548",
        "amount": "1500"
    },
    {
        "order_id": "o-2002",
        "merchant_id": "m-99",
        "created_at": "1777383953702",
        "amount": "200"
    },
    {
        "order_id": "o-2001",
        "merchant_id": "m-99",
        "created_at": "1777383953666",
        "amount": "100"
    }
]
--- queue depth ---
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0",
        "ApproximateNumberOfMessagesNotVisible": "0"
    }
}
--- lambda logs ---
2026-04-28T13:45:06.780000+00:00 2026/04/28/[$LATEST]c1d536198ae1b4db36466fa8367999a2 START RequestId: c7159d21-83cf-4955-a3b7-09dfc6ab2852 Version: $LATEST
2026-04-28T13:45:06.780000+00:00 2026/04/28/[$LATEST]c1d536198ae1b4db36466fa8367999a2 END RequestId: c7159d21-83cf-4955-a3b7-09dfc6ab2852
2026-04-28T13:45:06.780000+00:00 2026/04/28/[$LATEST]c1d536198ae1b4db36466fa8367999a2 REPORT RequestId: c7159d21-83cf-4955-a3b7-09dfc6ab2852	Duration: 233.93 ms	Billed Duration: 234 ms	Memory Size: 512 MB	Max Memory Used: 512 MB
2026-04-28T13:45:53.716000+00:00 2026/04/28/[$LATEST]1c6ebbf7259e0bbe5e81b5f9a5253fe1 START RequestId: bcd5fd7a-8789-470b-982b-cbdc48d85f44 Version: $LATEST
2026-04-28T13:45:53.716000+00:00 2026/04/28/[$LATEST]1c6ebbf7259e0bbe5e81b5f9a5253fe1 END RequestId: bcd5fd7a-8789-470b-982b-cbdc48d85f44
2026-04-28T13:45:53.716000+00:00 2026/04/28/[$LATEST]1c6ebbf7259e0bbe5e81b5f9a5253fe1 REPORT RequestId: bcd5fd7a-8789-470b-982b-cbdc48d85f44	Duration: 52.51 ms	Billed Duration: 53 ms	Memory Size: 512 MB	Max Memory Used: 512 MB

[stdout]
--- full table scan ---
[
    {
        "order_id": "o-1001",
        "merchant_id": "m-42",
        "created_at": "1777383906548",
        "amount": "1500"
    },
    {
        "order_id": "o-2002",
        "merchant_id": "m-99",
        "created_at": "1777383953702",
        "amount": "200"
    },
    {
        "order_id": "o-2001",
        "merchant_id": "m-99",
        "created_at": "1777383953666",
        "amount": "100"
    }
]
--- queue depth ---
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0",
        "ApproximateNumberOfMessagesNotVisible": "0"
    }
}
--- lambda logs ---
2026-04-28T13:45:06.780000+00:00 2026/04/28/[$LATEST]c1d536198ae1b4db36466fa8367999a2 START RequestId: c7159d21-83cf-4955-a3b7-09dfc6ab2852 Version: $LATEST
2026-04-28T13:45:06.780000+00:00 2026/04/28/[$LATEST]c1d536198ae1b4db36466fa8367999a2 END RequestId: c7159d21-83cf-4955-a3b7-09dfc6ab2852
2026-04-28T13:45:06.780000+00:00 2026/04/28/[$LATEST]c1d536198ae1b4db36466fa8367999a2 REPORT RequestId: c7159d21-83cf-4955-a3b7-09dfc6ab2852	Duration: 233.93 ms	Billed Duration: 234 ms	Memory Size: 512 MB	Max Memory Used: 512 MB
2026-04-28T13:45:53.716000+00:00 2026/04/28/[$LATEST]1c6ebbf7259e0bbe5e81b5f9a5253fe1 START RequestId: bcd5fd7a-8789-470b-982b-cbdc48d85f44 Version: $LATEST
2026-04-28T13:45:53.716000+00:00 2026/04/28/[$LATEST]1c6ebbf7259e0bbe5e81b5f9a5253fe1 END RequestId: bcd5fd7a-8789-470b-982b-cbdc48d85f44
2026-04-28T13:45:53.716000+00:00 2026/04/28/[$LATEST]1c6ebbf7259e0bbe5e81b5f9a5253fe1 REPORT RequestId: bcd5fd7a-8789-470b-982b-cbdc48d85f44	Duration: 52.51 ms	Billed Duration: 53 ms	Memory Size: 512 MB	Max Memory Used: 512 MB
All criteria pass. Final verification of named resources:

Final resource verification

shell
set -euo pipefail
export AWS_ENDPOINT_URL=http://localstack:4566

echo "=== rest api ==="
aws apigateway get-rest-apis --query 'items[].{name:name,id:id}'

echo "=== stage ==="
API_ID=$(cat /tmp/api_id)
aws apigateway get-stages --rest-api-id "$API_ID" --query 'item[].{stage:stageName,deployment:deploymentId}'

echo "=== queues ==="
aws sqs list-queues --query 'QueueUrls'

echo "=== ddb table ==="
aws dynamodb describe-table --table-name orders --query 'Table.{Name:TableName,KS:KeySchema,Status:TableStatus}'

echo "=== iam roles ==="
aws iam list-roles --query 'Roles[?RoleName==`apigw-to-sqs-role` || RoleName==`orders-consumer-role`].RoleName'

echo "=== consumer role policies ==="
aws iam list-role-policies --role-name orders-consumer-role
aws iam list-attached-role-policies --role-name orders-consumer-role --query 'AttachedPolicies[].PolicyName'

echo "=== ESM ==="
aws lambda list-event-source-mappings --function-name orders-consumer --query 'EventSourceMappings[].{State:State,FRT:FunctionResponseTypes,Source:EventSourceArn}'

echo "=== final dlq ==="
aws sqs get-queue-attributes --queue-url "$(aws sqs get-queue-url --queue-name orders-dlq.fifo --query QueueUrl --output text)" --attribute-names ApproximateNumberOfMessages
output
=== rest api ===
[
    {
        "name": "orders-api",
        "id": "ygr4firkyt"
    }
]
=== stage ===
[
    {
        "stage": "dev",
        "deployment": "wycz3lb6hs"
    }
]
=== queues ===
[
    "http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders-dlq.fifo",
    "http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders.fifo"
]
=== ddb table ===
{
    "Name": "orders",
    "KS": [
        {
            "AttributeName": "order_id",
            "KeyType": "HASH"
        }
    ],
    "Status": "ACTIVE"
}
=== iam roles ===
[
    "orders-consumer-role",
    "apigw-to-sqs-role"
]
=== consumer role policies ===
{
    "PolicyNames": [
        "orders-consumer-inline"
    ]
}
[
    "AWSLambdaBasicExecutionRole"
]
=== ESM ===
[
    {
        "State": "Enabled",
        "FRT": [
            "ReportBatchItemFailures"
        ],
        "Source": "arn:aws:sqs:us-east-1:000000000000:orders.fifo"
    }
]
=== final dlq ===
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0"
    }
}

[stdout]
=== rest api ===
[
    {
        "name": "orders-api",
        "id": "ygr4firkyt"
    }
]
=== stage ===
[
    {
        "stage": "dev",
        "deployment": "wycz3lb6hs"
    }
]
=== queues ===
[
    "http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders-dlq.fifo",
    "http://sqs.us-east-1.localhost.localstack.cloud:4566/000000000000/orders.fifo"
]
=== ddb table ===
{
    "Name": "orders",
    "KS": [
        {
            "AttributeName": "order_id",
            "KeyType": "HASH"
        }
    ],
    "Status": "ACTIVE"
}
=== iam roles ===
[
    "orders-consumer-role",
    "apigw-to-sqs-role"
]
=== consumer role policies ===
{
    "PolicyNames": [
        "orders-consumer-inline"
    ]
}
[
    "AWSLambdaBasicExecutionRole"
]
=== ESM ===
[
    {
        "State": "Enabled",
        "FRT": [
            "ReportBatchItemFailures"
        ],
        "Source": "arn:aws:sqs:us-east-1:000000000000:orders.fifo"
    }
]
=== final dlq ===
{
    "Attributes": {
        "ApproximateNumberOfMessages": "0"
    }
}
  • Create DDB table + FIFO queues with redrive
  • Fix consumer lambda role IAM (ddb + sqs)
  • Fix consumer lambda handler (idempotent + batchItemFailures)
  • Create event source mapping with ReportBatchItemFailures
  • Create apigw-to-sqs role + policy
  • Create REST API + resource + POST + AWS service integration
  • Deploy to dev stage
  • End-to-end verify
Pipeline is fully built and verified. Summary: **Built from scratch** - DDB `orders` (PK `order_id` String, PAY_PER_REQUEST) - `orders-dlq.fifo` (FIFO, content-based dedup off) - `orders.fifo` (FIFO, redrive→DLQ maxReceiveCount=3, visibility 60s) - `apigw-to-sqs-role` with inline `sqs:SendMessage` on the main queue - REST API `orders-api` → `/orders` → POST → AWS-service integration to SQS, mapping template form-encodes `Action=SendMessage` with `MessageGroupId=$.merchant_id` and `MessageDeduplicationId=$.order_id` - Method/integration response templates returning `{"status":"queued"}` - Stage `dev` deployment - Event source mapping `orders.fifo` → `orders-consumer` with `FunctionResponseTypes=ReportBatchItemFailures` **Fixed on the pre-seeded resources** - `orders-consumer-role`: added inline policy granting `sqs:ReceiveMessage/DeleteMessage/GetQueueAttributes/ChangeMessageVisibility` on the main queue and `dynamodb:PutItem/GetItem/UpdateItem/DescribeTable` on `orders` - Handler: rewrote to (a) return `{"batchItemFailures":[...]}` (the AWS-required shape) and (b) use a conditional `attribute_not_exists(order_id)` PutItem so duplicates become silent no-ops without surfacing as failures **Verified behavior** - POST `o-1001/m-42/1500` → HTTP 200, exactly 1 row - Duplicate POST → HTTP 200, row count unchanged, `created_at` unchanged - POST `o-2001` then `o-2002` for `m-99` → both rows present, `created_at(o-2001) < created_at(o-2002)` (order preserved within merchant via shared MessageGroupId) - DLQ depth: 0 throughout
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/zes5b8KMWVt-Sqs_gKDvw/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 FAILED  [ 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%]

=================================== FAILURES ===================================
____________________ test_stage_deployment_id_was_refreshed ____________________

apigw = <botocore.client.APIGateway object at 0xffff8b1256a0>

    def test_stage_deployment_id_was_refreshed(apigw):
        """Stage redeployed after edit."""
        api_id = _find_api(apigw)
        stage = apigw.get_stage(restApiId=api_id, stageName=STAGE_NAME)
        current_dep_id = stage.get("deploymentId")
        assert current_dep_id, f"stage {STAGE_NAME} has no deploymentId"
        deployments = sorted(
            apigw.get_deployments(restApiId=api_id).get("items", []),
            key=lambda d: d.get("createdDate") or "",
        )
>       assert len(deployments) >= 2, (
            f"stage {STAGE_NAME} has only {len(deployments)} deployment(s); "
            f"editing an integration without calling create-deployment is "
            f"the #1 silent failure mode for this task , API Gateway keeps "
            f"serving the old snapshot. Deployments: {deployments!r}"
        )
E       AssertionError: stage dev has only 1 deployment(s); editing an integration without calling create-deployment is the #1 silent failure mode for this task , API Gateway keeps serving the old snapshot. Deployments: [{'id': 'wycz3lb6hs', 'description': 'initial', 'createdDate': datetime.datetime(2026, 4, 28, 13, 44, 55, tzinfo=tzlocal())}]
E       assert 1 >= 2
E        +  where 1 = len([{'createdDate': datetime.datetime(2026, 4, 28, 13, 44, 55, tzinfo=tzlocal()), 'description': 'initial', 'id': 'wycz3lb6hs'}])

/tests/test_outputs.py:350: AssertionError
=============================== warnings summary ===============================
test_outputs.py: 69 warnings
  /root/.cache/uv/archive-v0/zes5b8KMWVt-Sqs_gKDvw/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_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
FAILED ../tests/test_outputs.py::test_stage_deployment_id_was_refreshed - Ass...
================== 1 failed, 18 passed, 69 warnings in 30.39s ==================

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_fd33edaac30b47a4. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_fd33edaac30b47a4 · verifier authoritative; classifier explanatory.