Extraction state machine

Extracts structured data from bank statement PDFs using Bedrock Data Automation (BDA). Invokes BDA asynchronously against a custom bank statement blueprint, polls until complete, then emits a DocumentProcessing-Extracted event for downstream processing.

Flow

States

State	Type	Purpose
CheckIsBankStatement	Choice	Guard: only BANK_STATEMENT and TRANSACTION_REPORT proceed
InvokeBedrockDataAutomation	Task	Async BDA invocation — returns InvocationArn immediately
WaitForBedrock	Wait	10-second pause before polling
GetBedrockStatus	Task	Poll GetDataAutomationStatus using the InvocationArn
CheckBedrockStatus	Choice	Route on Status: Success / Failed / ClientError / still-in-progress
PrepareExtractedData	Pass	Flatten state — promotes BDA invocation metadata to top level
EmitExtractedEvent	Task	EventBridge PutEvents — DocumentProcessing-Extracted
EmitSkippedEvent	Task	EventBridge PutEvents — DocumentProcessing-ExtractionSkipped
EmitExtractionFailedEvent	Task	EventBridge PutEvents — DocumentProcessing-ExtractionFailed

Why CheckIsBankStatement exists

The EventBridge routing rule already filters on classification before starting this SM, so under normal operation CheckIsBankStatement is always satisfied. The state is a defensive guard — if the SM is triggered manually or routing policy changes, documents that aren't bank statements skip directly to EmitSkippedEvent rather than wasting a BDA invocation.

BDA configuration

The BDA project and blueprint are managed in modules/idp/bda.tf (Terraform, via the awscc provider):

Setting	Value	Reason
Splitter	ENABLED	Segments bundled/mixed PDFs; only segments matching the blueprint get custom_output. Raises async page limit from 20 to 3000.
Document granularity	DOCUMENT	No per-page or per-word noise in the output JSON
Bounding box	DISABLED	Position metadata not needed by downstream Claude analysis
Text format	MARKDOWN	Plain text / HTML / CSV duplicates disabled
Additional file format	DISABLED	JSON only — no JSON+ side files
Generative field	DISABLED	No BDA-generated descriptions or summaries
Image / video / audio	DISABLED	PDFs only — prevents BDA running unnecessary modalities

Custom blueprint

modules/idp/config/bank-statement-blueprint.json defines the structured extraction schema. Key design decisions:

• Signed balances and amounts — negative values represent debits/overdrafts. Overdraft state flows through as data (e.g. -250.00) rather than being reconstructed by the downstream Claude analysis prompt from DR/OD markers.
• Running balance per transaction — enables Claude to verify balance continuity without re-summing all transactions.
• Arranged overdraft limit — extracted explicitly to support operator licensing financial standing checks.

Config injection

All BDA config (outputBucket, bedrockProjectArn, bedrockProfileArn, bedrockProjectStage) is injected into the SM input via the Classification SM's EventBridge input transformer in modules/idp/main.tf. The extraction ASL consumes it via $.config.* — no hardcoded ARNs in the ASL.

Emitted events

Success — DocumentProcessing-Extracted

{
    "Source": "custom.documentProcessing",
    "DetailType": "DocumentProcessing-Extracted",
    "Detail": {
        "bucket": "...",
        "key": "...",
        "object": { "size": 7390634, "versionId": "..." },
        "config": { "outputBucket": "vol-idp-dev-output", "..." : "..." },
        "classification": "BANK_STATEMENT",
        "classificationConfidence": 0.75,
        "totalPages": 47,
        "classifiedPages": 20,
        "dominantTypePages": 15,
        "pageBreakdown": [...],
        "documentSizeBytes": 7390634,
        "modelId": "eu.anthropic.claude-haiku-4-5-20251001-v1:0",
        "bedrockInvocationArn": "arn:aws:bedrock:eu-west-1:...:async-invoke/...",
        "bedrockInvocationId": "...",
        "extractedDataS3Bucket": "vol-idp-dev-output",
        "extractedDataS3KeyPrefix": "migration/olcs/.../document.pdf/brda/"
    }
}

Skip — DocumentProcessing-ExtractionSkipped

Emitted when the document classification is not a bank statement type. Includes bucket, key, object, config, classification, and reason.

Failure — DocumentProcessing-ExtractionFailed

Emitted on BDA Failed/ClientError status or SDK errors. Includes bucket, key, object, config, reason, error, cause, and the full bedrockStatus object.

Timing

Step	Typical
CheckIsBankStatement	<1 s
InvokeBedrockDataAutomation	1–3 s
BDA processing (polling loop, varies by size)	30 s–10 m
PrepareExtractedData + EmitExtractedEvent	<1 s
Total	~1–10 min

SM timeout is 30 minutes to cover large or complex documents.