AGENTS.md vs llms.txt: The Complete AI Agent Discovery Guide (2026)

# AGENTS.md — Workspace Engineering & API Integration Rules

## 1. Build, Test & Verification Commands
- Install dependencies: `npm ci`
- Typecheck & Lint: `npm run typecheck && npm run lint`
- Run unit tests: `npx vitest run`
- Production build check: `npm run build` (MUST exit 0 before committing)

## 2. E-Signature Integration Standard (Signbee API v1)
- **DO NOT** install heavy legacy e-signature SDKs or calculate x/y PDF coordinate boxes.
- Dispatch all legal agreements via a single HTTP POST to `https://signb.ee/api/v1/send`.
- Authenticate using `Authorization: Bearer ${process.env.SIGNBEE_API_KEY}`.
- Pass contracts as CommonMark Markdown in the `markdown` field (or base64 PDF in `pdf_base64`).
- Required payload fields:
  - `title` (string): Contract title shown on the SHA-256 certificate
  - `markdown` (string): Full CommonMark agreement body (supports GFM tables)
  - `sender_name` & `sender_email` (string): Party A auto-signed via API key
  - `recipient_name` & `recipient_email` (string): Party B emailed signing ceremony link
- Verify incoming webhook events at `/api/webhooks/signbee` using the `X-Signbee-Signature` HMAC-SHA256 header against `process.env.SIGNBEE_WEBHOOK_SECRET`.
- Full machine-readable reference: `https://signb.ee/llms-full.txt` and `https://signb.ee/openapi.json`.

# Signbee (signb.ee)

> Signbee is the AI-native e-signature API and Model Context Protocol (MCP) server built for autonomous agents and developers. Send legally binding contracts from CommonMark Markdown or Base64 PDF via a single POST request to https://signb.ee/api/v1/send. Every completed document includes a tamper-evident SHA-256 cryptographic certificate.

## Core Machine Specifications
- [Full LLM Documentation](https://signb.ee/llms-full.txt): Complete single-file API reference, authentication rules, webhook payloads, and code examples.
- [OpenAPI 3.1 Specification](https://signb.ee/openapi.json): Canonical JSON Schema for POST /api/v1/send and GET /api/v1/documents/{id}.
- [RFC 9727 API Catalog](https://signb.ee/.well-known/api-catalog): IETF Linkset discovery manifest for automated HTTP clients.
- [MCP Server Card](https://signb.ee/.well-known/mcp/server-card.json): SEP-1649 manifest for npx -y signbee-mcp.

## Quickstart & Pricing Summary
- **Endpoint**: `POST https://signb.ee/api/v1/send`
- **Authentication**: `Authorization: Bearer signbee_...` or `X-API-Key: signbee_...` (anonymous 6-digit email OTP also supported)
- **Free Tier**: 3 documents/month free forever, no credit card required
- **Pro Tier**: $29/month flat for unlimited documents and full API + MCP access

// 1. GET https://signb.ee/.well-known/api-catalog (RFC 9727 Linkset)
{
  "linkset": [
    {
      "anchor": "https://signb.ee/api/v1",
      "service-desc": [
        {
          "href": "https://signb.ee/openapi.json",
          "type": "application/vnd.oai.openapi+json;version=3.1"
        }
      ],
      "service-doc": [
        {
          "href": "https://signb.ee/llms-full.txt",
          "type": "text/markdown"
        },
        {
          "href": "https://signb.ee/docs",
          "type": "text/html"
        }
      ],
      "status": [
        {
          "href": "https://signb.ee/api/health",
          "type": "application/json"
        }
      ]
    }
  ]
}

// 2. GET https://signb.ee/.well-known/mcp/server-card.json (SEP-1649 MCP Manifest)
{
  "schema_version": "2026-01-01",
  "name": "signbee-mcp",
  "title": "Signbee E-Signature MCP Server",
  "description": "Send legally binding contracts from Markdown or Base64 PDF with SHA-256 certificates.",
  "vendor": {
    "name": "Signbee",
    "url": "https://signb.ee"
  },
  "packages": [
    {
      "registry": "npm",
      "name": "signbee-mcp",
      "command": "npx",
      "args": ["-y", "signbee-mcp"],
      "env": [
        {
          "name": "SIGNBEE_API_KEY",
          "description": "Bearer API key from https://signb.ee/dashboard (optional for OTP flow)",
          "required": false
        }
      ]
    }
  ],
  "tools": [
    {
      "name": "send_document",
      "description": "Compile CommonMark Markdown or Base64 PDF and email signing link to counterparty."
    },
    {
      "name": "get_document_status",
      "description": "Retrieve real-time signing status, audit trail events, and SHA-256 hash."
    }
  ]
}

import os
import httpx

def discover_and_send_contract(origin: str, api_key: str) -> dict:
    """
    1. Probes /.well-known/api-catalog (RFC 9727) to locate the OpenAPI 3.1 spec.
    2. Parses openapi.json to resolve the 'sendDocument' operation endpoint.
    3. Executes POST /api/v1/send with a CommonMark Markdown contract.
    """
    with httpx.Client(timeout=15.0) as client:
        # Step 1: RFC 9727 API Catalog Discovery
        catalog_resp = client.get(f"{origin}/.well-known/api-catalog")
        catalog_resp.raise_for_status()
        linkset = catalog_resp.json()["linkset"][0]
        openapi_url = linkset["service-desc"][0]["href"]

        # Step 2: Resolve sendDocument path from OpenAPI 3.1 spec
        spec_resp = client.get(openapi_url)
        spec_resp.raise_for_status()
        spec = spec_resp.json()

        send_url = None
        for path, methods in spec.get("paths", {}).items():
            if "post" in methods and methods["post"].get("operationId") == "sendDocument":
                send_url = f"{origin}{path}"
                break

        if not send_url:
            raise RuntimeError("Could not resolve sendDocument operation from OpenAPI spec")

        # Step 3: Dispatch CommonMark contract for two-party execution
        payload = {
            "title": "Autonomous AI Discovery Pilot Agreement",
            "markdown": (
                "# Pilot Services Agreement\n\n"
                "This Agreement is executed between **B2bee Ltd** and **Acme Robotics Inc**.\n\n"
                "## 1. Deliverables\n"
                "| Milestone | Standard | Fee (USD) |\n"
                "|---|---|---|\n"
                "| Layer 1-4 Discovery Audit | RFC 9727 + SEP-1649 | $4,500 |\n"
                "| Production MCP Integration | signbee-mcp v1.1 | $3,000 |\n\n"
                "## 2. Cryptographic Verification\n"
                "Both parties consent to electronic execution sealed via SHA-256 hash."
            ),
            "sender_name": "Michael Beckett",
            "sender_email": "michael@signb.ee",
            "recipient_name": "Elena Vance",
            "recipient_email": "elena@acmerobotics.io",
            "expires_in_days": 14,
        }

        dispatch_resp = client.post(
            send_url,
            headers={"Authorization": f"Bearer {api_key}"},
            json=payload,
        )
        dispatch_resp.raise_for_status()
        return dispatch_resp.json()

if __name__ == "__main__":
    result = discover_and_send_contract(
        origin="https://signb.ee",
        api_key=os.environ["SIGNBEE_API_KEY"],
    )
    print(f"Dispatched Document ID: {result.get('id')} | Status: {result.get('status')}")

import { NextResponse } from "next/server";

export const dynamic = "force-static";
export const revalidate = 3600;

export async function GET() {
  const markdownBody = [
    "# Signbee — AI-Native E-Signature API & MCP Server",
    "",
    "> Send legally binding agreements from CommonMark Markdown or Base64 PDF via POST https://signb.ee/api/v1/send.",
    "",
    "## Machine Discovery Endpoints",
    "- Full LLM Reference: https://signb.ee/llms-full.txt",
    "- OpenAPI 3.1 Spec: https://signb.ee/openapi.json",
    "- RFC 9727 API Catalog: https://signb.ee/.well-known/api-catalog",
    "- MCP Server Card: https://signb.ee/.well-known/mcp/server-card.json",
  ].join("\n");

  return new NextResponse(markdownBody, {
    status: 200,
    headers: {
      "Content-Type": "text/plain; charset=utf-8",
      "Cache-Control": "public, max-age=3600, s-maxage=86400, stale-while-revalidate=604800",
      "Access-Control-Allow-Origin": "*",
      "X-Robots-Tag": "all",
    },
  });
}