Dev Tools

Using Extend via MCP

The Extend MCP (Model Context Protocol) server lets AI clients use Extend directly from chat. They can parse documents, extract structured data, classify and split files, detect and fill PDF forms, build and run workflows, manage files and webhooks, evaluate processor accuracy, and create and publish reusable resources without writing integration code.

Connect any MCP client that supports remote servers to https://mcp.extend.ai/mcp. Nothing needs to be installed; complete the OAuth sign-in when your client prompts you.

How it works

Your MCP client talks to the Extend MCP server, which calls the Extend API on your behalf. When you connect with OAuth, a browser window opens to sign in to Extend and approve access. The consent flow names the client that’s asking and lets you choose exactly which workspaces it may use and, for each workspace, whether it can act in the Test Environment, Production, or both. The connection is scoped to those choices; nothing outside them is reachable, and you can change them any time by reconnecting.

Connect from your client

Add the following to your ~/.cursor/mcp.json file (or a project’s .cursor/mcp.json), then complete the OAuth sign-in when Cursor prompts you:

1{
2  "mcpServers": {
3    "extend": {
4      "url": "https://mcp.extend.ai/mcp"
5    }
6  }
7}

Limit available tools

The server exposes every tool by default. For token-sensitive clients, append a comma-separated list of group or tool names in the tools query parameter. The available groups are extract, classify, parse, split, workflows, edit, files, webhooks, and evaluations. For example, https://mcp.extend.ai/mcp?tools=extract,files exposes the extraction and file groups.

How to use it

Once connected, talk to your agent in terms of outcomes and let it pick the tools. These are the things people most often do:

Try Extend on your own documents. Drop in a few real files and see what comes back before you build anything: parse a contract, pull fields from an invoice, classify a document, or fill a form.

“Parse this PDF and summarize the key terms.”

“Extract the vendor, invoice number, line items, and total from these invoices into a table.”

“Fill out this W-9 with our company details.”

Build a processor without leaving chat. Have the agent draft an extractor, classifier, or splitter for your document type, test it against samples, tighten the schema where it misses, and publish a version when the results look right.

“Create an extractor for utility bills, test it on these three samples, and publish it.”

Measure accuracy with an evaluation. Turn documents with known-correct answers into an evaluation set, run a processor version against it, and review where it agrees and disagrees with the ground truth.

“Build an evaluation set from these labeled invoices and measure the extractor’s accuracy.”

Check on and operate what’s already running. Inspect runs, diagnose failures, cancel or re-run documents, and manage webhooks without opening the dashboard.

“Set up a webhook so my app is notified when runs finish.”

Long-running work is handled for you: the agent starts a run, waits, and resumes checking until it finishes. Workflow runs can take minutes to hours, and that’s normal. If a workflow pauses for human review, the agent hands you a dashboard link to review and approve.

Tools

The default connection exposes the complete tool surface. You can limit product tools with the tool-selection setting described above; access and documentation tools remain available so your agent can authenticate, select the right workspace, and look up current guidance.

Access and Documentation Tools

  • List the workspaces and environments available to the connection: get_me
  • Read a specific Extend documentation page: get_documentation
  • Search the Extend documentation: search_documentation

Parsing Tools

  • Convert a PDF, image, Office document, or spreadsheet into structured markdown or raw blocks: parse_document
  • Check, list, or delete parse runs: get_parse_run, list_parse_runs, delete_parse_run
  • Parse up to 1,000 documents in one batch and check its status: run_parse_batch, get_parse_batch

Extraction Tools

  • Extract structured fields, tables, and line items with a saved extractor or an inline schema: extract_data
  • Create, update, retrieve, and list extractors: create_extractor, update_extractor, get_extractor, list_extractors
  • List and publish extractor versions: list_extractor_versions, publish_extractor_version
  • Check, list, cancel, or delete extraction runs: get_extract_run, list_extract_runs, cancel_extract_run, delete_extract_run
  • Extract from up to 1,000 documents in one batch and check its status: run_extract_batch, get_extract_batch

Classification Tools

  • Classify a document with a saved classifier or an inline set of document types: classify_document
  • Create, update, retrieve, and list classifiers: create_classifier, update_classifier, get_classifier, list_classifiers
  • List and publish classifier versions: list_classifier_versions, publish_classifier_version
  • Check, list, cancel, or delete classification runs: get_classify_run, list_classify_runs, cancel_classify_run, delete_classify_run
  • Classify up to 1,000 documents in one batch and check its status: run_classify_batch, get_classify_batch

Splitting Tools

  • Split a multi-document file into page ranges with a saved splitter or an inline configuration: split_document
  • Create, update, retrieve, and list splitters: create_splitter, update_splitter, get_splitter, list_splitters
  • List and publish splitter versions: list_splitter_versions, publish_splitter_version
  • Check, list, cancel, or delete split runs: get_split_run, list_split_runs, cancel_split_run, delete_split_run
  • Split up to 1,000 documents in one batch and check its status: run_split_batch, get_split_batch

PDF Editing Tools

  • Detect fillable fields in a PDF and generate an edit schema: detect_form_fields
  • Fill a PDF from an edit schema and field values: edit_pdf
  • Check or delete PDF edit runs: get_edit_run, delete_edit_run
  • Check a form detection run: get_form_detection_run

Workflow Tools

  • Run a deployed or draft workflow: run_workflow
  • Create, update, retrieve, and list workflows: create_workflow, update_workflow, get_workflow, list_workflows
  • List workflow versions and deploy a version: list_workflow_versions, deploy_workflow_version
  • Check, list, cancel, or delete workflow runs: get_workflow_run, list_workflow_runs, cancel_workflow_run, delete_workflow_run
  • Run a workflow on up to 1,000 inputs in one batch: run_workflow_batch

File Tools

  • Request a browser upload and retrieve the uploaded files: request_file_upload, get_file_upload
  • Retrieve file metadata and a temporary download URL, list files, or delete a file: get_file, list_files, delete_file

Webhook Tools

  • Create, list, update, or delete webhook endpoints: create_webhook_endpoint, list_webhook_endpoints, update_webhook_endpoint, delete_webhook_endpoint
  • Create, list, update, or delete webhook subscriptions: create_webhook_subscription, list_webhook_subscriptions, update_webhook_subscription, delete_webhook_subscription

Evaluation Tools

  • Create and list evaluation sets: create_evaluation_set, list_evaluation_sets
  • Add, list, update, or delete ground-truth evaluation items: add_evaluation_items, list_evaluation_items, update_evaluation_item, delete_evaluation_item
  • Run an evaluation and check its results: run_evaluation, get_evaluation_run

Each tool includes instructions for choosing inputs, handling asynchronous work, and recovering from errors.

Workspaces and environments

Every operation targets a specific workspace and environment. The agent must state both on every call, so nothing runs somewhere you didn’t intend. TEST is the isolated Test Environment (great for trying things out); PRODUCTION is live data. Resources are separate between the two: an extractor created in Test doesn’t exist in Production.

OAuth connections can span multiple workspaces, with Test/Production chosen per workspace on the consent screen. To change access later, edit or re-approve the connection from your client; disconnecting and reconnecting re-runs consent.

Uploading files from chat

Chat clients like Claude and ChatGPT don’t expose your local files to remote servers. When you ask the agent to process a file that’s only on your computer, it requests an upload link: you open the link, sign in to the Extend dashboard, drop your files, and click Done. The agent then picks the resulting files up and continues. The page shows who requested the upload and which workspace and environment the files will land in. Links expire after 15 minutes, and only members of the target workspace can use them.

If a document is already at a public URL, no upload link is needed.

Troubleshooting

Reconnect the server in your client to re-run the OAuth sign-in. Most clients have a reconnect or re-authenticate action on the server’s settings entry; disconnecting and re-adding also works.

It’s usually targeting the wrong place: resources are separated per workspace and per Test/Production environment. Ask the agent to check its granted workspaces and environments (the get_me tool) and to target where the resource actually lives.

Tool errors are structured: they tell the agent what was wrong, link to the relevant documentation page, and include a request ID. If the agent can’t resolve an error, ask it for the request ID and message, and include them when contacting support@extend.ai.

MCP is the best fit for chat and tool-calling clients. For agents writing durable integration code, use an SDK; for one-off shell-driven jobs, the CLI. See the Agent Quickstart for how to equip a coding agent.