Amazon Textract

Local emulators. Real API contracts. Part of Mockingbird.

Stateful Amazon Textract emulator for the official SDK v3 client. It models synchronous and asynchronous document analysis, connected block graphs, stable pagination, idempotency, and completion notifications.

#Install

npm install -D @crvouga/mockingbird-service-textract

ESM only. Node 22+ or Bun 1.2+.

#Usage

import { AnalyzeDocumentCommand, TextractClient } from "@aws-sdk/client-textract"
import { createServer } from "@crvouga/mockingbird-service-textract/server"

// Test setup: start the emulator with a seeded document and point the SDK's endpoint at it.
const server = await createServer({
  corpora: [
    {
      bucket: "fixtures",
      name: "invoice.pdf",
      pages: 1,
      blocks: [{ id: "line-1", blockType: "LINE", page: 1, text: "Total due 42.00", confidence: 99 }],
    },
  ],
})
const textract = new TextractClient({
  endpoint: server.url,
  region: "us-east-1",
  credentials: { accessKeyId: "fixture", secretAccessKey: "fixture" },
})

// Application code: the Textract SDK calls it already makes.
const analysis = await textract.send(
  new AnalyzeDocumentCommand({
    Document: { S3Object: { Bucket: "fixtures", Name: "invoice.pdf" } },
    FeatureTypes: ["FORMS"],
  }),
)
console.log(analysis.Blocks?.map((block) => block.Text)) // [ "Total due 42.00" ]

await server.close()

Point TextractClient.endpoint at server.url with fixture SigV4 credentials. Supported operations are AnalyzeDocument, StartDocumentAnalysis, and GetDocumentAnalysis. Block records retain PAGE, LINE, WORD, KEY_VALUE_SET, TABLE, CELL, and SELECTION_ELEMENT graph fields including Geometry, Confidence, EntityTypes, Text, and Relationships.

#Controls

• GET/POST /__admin/corpora lists or seeds a block graph by S3 bucket, key, and optional version.
• GET /__admin/jobs and GET /__admin/jobs/:id inspect exact submitted jobs.
• POST /__admin/jobs/:id/transition moves a job to SUCCEEDED, PARTIAL_SUCCESS, or FAILED, with an optional statusMessage.
• Corpus fixtures choose pageSize to force deterministic page boundaries and can contain low-confidence blocks, malformed relationships, and warnings.
• Fault presets are throttled, throughput_exceeded, and unavailable.

Terminal jobs with a NotificationChannel publish an SNS-compatible Textract status body through the shared webhook hub. The shared runtime also provides reset, clock, journal, metrics, faults, and namespace isolation.

#API

• TextractAPI, TextractAPIOptions, TextractNotification: handler and notification contract.
• TextractBlock, TextractCorpus, TextractJob, TextractJobStatus: fixtures and durable state.
• createRuntime, TextractRuntime, TextractRuntimeOptions: full Mockingbird runtime and webhook hub.
• TEXTRACT_NAMESPACE, TEXTRACT_PRESETS, accessKeyCredential: constants and fault controls.
• document, operationIds, supportedOperationIds: generated OpenAPI metadata.
• createServer, TextractServerOptions, DEFAULT_PORT, serveTarget from ./server: Node HTTP adapter and CLI integration.

#Deliberately not modelled

OCR, S3 access, IAM evaluation, adapters, output delivery, production limits, billing, dashboards, and Textract operations outside the documented subset are not modelled.

Official oracle: Amazon Textract API Reference.