hdls Sign
hdls Sign is a headless, MCP-native e-signature backend. It manages envelopes, signers, and signatures, operated entirely through named tools your AI assistant calls. It stands in for tools like DocuSign eSignature, Dropbox Sign — same job, no UI to run.
💬 Just ask
"Create an envelope for Acme, then show me my envelopes."
You don't call these tools yourself — just tell your assistant in plain English. Everything below is the reference for when you (or your assistant) want the exact details.
How Sign is organized
The headline entity is the envelope — start there, then attach the rest to it. Records connect by reference: a document links to an envelope; a signer links to an envelope; a field links to a document and a signer. The event table is an append-only timeline — every change and note lands there and is never edited or deleted.
| Entity | Purpose | Relates to |
|---|---|---|
envelope | A package of documents routed to signers for e-signature. | — |
document | A document/file contained in an envelope, with integrity hash and storage pointer. | envelope |
signer | A recipient/signer on an envelope with routing order and signing status. | envelope |
field | A field (signature, initial, date, text…) placed on a document page and assigned to a signer. | document, signer |
event | Append-only immutable audit trail (certificate of completion): every action with IP/user-agent. | envelope, signer |
Common workflows
Each line is one real sequence of tool calls — your assistant chains them for you.
- Set up an envelope end to end:
create_envelope→add_signer - Move an envelope through its lifecycle:
create_envelope→send_for_signature
Tools
Call these at https://hdls.ai/api/mcp/esign. Required fields you must supply; optional fields refine the call. You never pass tenant_id — it is stamped server-side.
Create
| Tool | What it does | Required | Optional |
|---|---|---|---|
create_envelope | Create a new envelope. | title | message, status, routing, sender, sent_at, completed_at |
Update & advance
| Tool | What it does | Required | Optional |
|---|---|---|---|
add_signer | Add a signer. | envelope_id, name, email | role, routing_order, status, access_token, signed_at, data |
send_for_signature | Send the envelope for signature. | id | — |
void_envelope | Void the envelope. | id | — |
Find & read
| Tool | What it does | Required | Optional |
|---|---|---|---|
search_envelopes | Search envelopes by free-text and/or column filters (tenant-scoped, paginated). | — | search, filters, limit, orderBy |
Field lists come from the product's live schema and are embedded in each tool's own description — read the tool description for the exact, current fields.
Field reference
Every field you can set on each record. Custom fields you add live alongside these in data.
envelope
| Field | Type | Required | Notes |
|---|---|---|---|
title | text | Yes | Display name. |
message | text | ||
status | text | Lifecycle state. | |
routing | text | ||
sender | text | ||
sent_at | timestamp | ||
completed_at | timestamp | ||
expires_at | timestamp | ||
data | json | Free-form JSON — custom fields live here. |
document
| Field | Type | Required | Notes |
|---|---|---|---|
envelope_id | id | Yes | Links to an envelope. |
name | text | Yes | Display name. |
storage_ref | text | ||
content_type | text | ||
page_count | number | ||
sha256 | text | ||
position | number | ||
data | json | Free-form JSON — custom fields live here. |
signer
| Field | Type | Required | Notes |
|---|---|---|---|
envelope_id | id | Yes | Links to an envelope. |
name | text | Yes | Display name. |
email | text | Yes | |
role | text | ||
routing_order | number | ||
status | text | Lifecycle state. | |
access_token | text | ||
signed_at | timestamp | ||
data | json | Free-form JSON — custom fields live here. |
field
| Field | Type | Required | Notes |
|---|---|---|---|
document_id | id | Yes | Links to a document. |
signer_id | id | Yes | Links to a signer. |
field_type | text | ||
page | number | ||
x | numeric(8,2) | ||
y | numeric(8,2) | ||
required | true / false | ||
value | text | ||
data | json | Free-form JSON — custom fields live here. |
Tailor it with custom fields
Add fields without a schema change. add_custom_field defines one, list_custom_fields shows what's defined, and promote_custom_field (admin) shares a personal field with the whole workspace. The value lives in each row's data (JSON) and is set and read through the normal record tools. See Products, tools & custom fields for the full model.
Roles & safety
- Tenant isolation is automatic. Your credential is pinned to one workspace; you never pass
tenant_id, and you can only ever see your own data (enforced by Postgres row-level security). - Role-gated. Permissions run
reader < member < admin < owner. Installing a product and promoting a custom field workspace-wide need admin/owner. - History is append-only. The
eventtimeline is never edited or deleted — it's your audit trail.
Connect
On the concierge (https://hdls.ai/api/mcp), run install_product({ slug: "esign" }) (admin/owner) to enable it for your workspace, then add https://hdls.ai/api/mcp/esign as a connector in your assistant — see Connect your assistant.
A worked example
The literal call your assistant makes when you ask it to create the headline record:
Tool: create_envelope
Arguments: {
"title": "NDA — Acme & Northwind"
}