Anvil Plugins

Plugins that help developers integrate Anvil's document automation APIs into their applications. Built for Claude Cowork, also compatible with Claude Code.

Plugins

Plugin	How it helps
anvil-document-sdk	Implement Anvil API integrations — PDF Filling, HTML-to-PDF Generation, Etch E-Sign, and Workflows — into any existing Node.js or TypeScript codebase.
dropbox-anvil-migration	Migrate existing DropboxSign/HelloSign e-signature integrations to Anvil Etch E-Sign. Discovers integration points, maps APIs, migrates templates, rewrites code, and verifies the migration.
anvil-document-templates	Create and manage Anvil document templates (Casts) at scale. Bulk-uploads a folder of PDFs as templates with Document AI field detection, applies field aliases from a CSV, and opens each new template in edit mode for review.

Installation

From Cowork

This repository is a plugin marketplace. To add it to Claude Cowork:

1. Open Claude Cowork
2. Go to Customize - in the left hand side nav bar
3. Click on Browse plugins
4. Click on the "Personal" tab
5. Click on the + button
6. Select Add marketplace from GitHub
7. Add this url as the source: anvilco/anvil-plugins
8. Install the Anvil document sdk plugin

From Claude Code Instance

/plugin marketplace add anvilco/anvil-plugins

then run

/plugin install <plugin-name>@anvil-plugins

or

/plugin install dropbox-anvil-migration@anvil-plugins

Authentication

Each plugin connects to Anvil's MCP server at mcp.useanvil.com, which supports OAuth. No API key or environment variable is needed.

The first time you use a plugin, run:

/mcp

then select the anvil server and complete the sign-in flow in your browser. Claude Code stores the credentials and reuses them in future sessions.

Headless / CI / Agent SDK

OAuth requires an interactive session to complete the browser flow. In environments without one — CI pipelines, claude -p on a machine that has never authenticated interactively, or the Claude Agent SDK — configure the server yourself with an API key instead:

1. Get your API key from Anvil's API Settings under Organization Settings > API Settings

2. Add the server with a Bearer token header:

   claude mcp add --transport http anvil https://mcp.useanvil.com \
     --header "Authorization: Bearer $ANVIL_BEARER_TOKEN"

   Agent SDK users should pass the same Authorization header in the server's headers config.

What's Inside

anvil-document-sdk

A guided implementation skill that walks developers through integrating Anvil's four core products:

• PDF Filling — Populate existing PDF templates with dynamic data via fillPDF
• HTML-to-PDF Generation — Create PDFs from HTML/CSS or structured Markdown via generatePDF
• Etch E-Sign — Send documents for electronic signature with embedded or email-based signing via createEtchPacket
• Workflows — Build multi-step document workflows with webforms and approvals via forgeSubmit

The skill includes:

• Quick Start flow for 5-minute setup verification
• Full discovery and implementation planning
• Reference files for each product with production-ready code patterns
• Bundled migration script for bulk PDF template uploads with AI-powered field detection
• Best practices for storage, webhooks, rate limiting, and security

dropbox-anvil-migration

A guided migration skill that walks developers through replacing DropboxSign (HelloSign) e-signature integrations with Anvil Etch E-Sign:

• Discovery — Scans for all DropboxSign/HelloSign SDK usage, API calls, env vars, webhooks, and database references
• API Mapping — Maps DropboxSign calls to Anvil equivalents with before/after code examples
• Template Migration — Downloads templates from DropboxSign, uploads to Anvil, generates DB migration scripts
• Code Rewriting — Replaces SDK calls, webhook handlers, embedded signing, and environment variables
• Verification — Guides end-to-end testing and cleanup of old dependencies

The skill includes:

• Complete API mapping reference (DropboxSign → Anvil)
• Feature parity analysis with workarounds for each gap
• Bundled template download script (standalone, no external deps)
• Template migration guide with database migration generation
• References the anvil-document-sdk skill for Anvil implementation patterns

anvil-document-templates

A guided skill that walks developers through creating and managing Anvil document templates (Casts) at scale:

• Bulk Template Creation — Turns a folder of PDFs into Anvil templates via the createCast mutation
• Document AI Field Detection — Auto-detects form fields on each PDF (detectBoxesAdvanced + advancedDetectFields)
• Field Aliases (data schema) — Applies your own field names, types, and descriptions from a CSV so detected fields map to your data model
• Graceful Fallback — Retries with standard detection when a plan lacks Document AI, without masking unrelated errors
• Manifest + Review — Writes a filename → castEid manifest and opens each new template in edit mode for review

The skill includes:

• A four-phase guided flow: understand the source templates, set up the environment, create the templates, then review and publish
• Bundled scripts/create-casts.ts for bulk-uploading a directory of PDFs with Document AI field detection and CSV-driven field aliases
• References the anvil-document-sdk skill for wiring published castEids into integration code

Contributing

To add a new plugin to this marketplace:

1. Create a new directory at the root with your plugin name (kebab-case)
2. Add .claude-plugin/plugin.json with the plugin manifest
3. Add your skills, commands, or other components
4. Add an entry to .claude-plugin/marketplace.json

License

MIT