# EDGAR Filing Document

**Accession Number:** 0001834032
**File Stem:** 0001213900-26-031849
**Filing Date:** 2026-3
**Character Count:** 9950
**Document Hash:** 4e43f977d9b98c6253314d94d9e0870c
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001213900-26-031849.hdr.sgml**: 20260319

**ACCESSION NUMBER**: 0001213900-26-031849

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 13

**CONFORMED PERIOD OF REPORT**: 20260318

**ITEM INFORMATION**: Entry into a Material Definitive Agreement

**ITEM INFORMATION**: Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260319

**DATE AS OF CHANGE**: 20260319

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Constellation Acquisition Corp I
- **CENTRAL INDEX KEY:** 0001834032
- **STANDARD INDUSTRIAL CLASSIFICATION:** BLANK CHECKS [6770]
- **ORGANIZATION NAME:** 05 Real Estate & Construction
- **EIN:** 000000000
- **STATE OF INCORPORATION:** E9
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39945
- **FILM NUMBER:** 26774406

**BUSINESS ADDRESS:**
- **STREET 1:** 1290 AVENUE OF THE AMERICAS
- **STREET 2:** 10TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10104
- **BUSINESS PHONE:** 212-983-1602

**MAIL ADDRESS:**
- **STREET 1:** 1290 AVENUE OF THE AMERICAS
- **STREET 2:** 10TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10104

?xml version='1.0' encoding='ASCII'?

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM 8-K**

**CURRENT REPORT**

**Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934**

Date of Report (Date of earliest event reported): **March 18, 2026**

**CONSTELLATION ACQUISITION CORP I**

(Exact name of registrant as specified in its charter)

---

| | | |
|:---|:---|:---|
| **Cayman Islands** | **001-39945** | **98-1574835** |
| (State or other jurisdiction <br> of incorporation) | (Commission File Number) | (IRS Employer <br> Identification No.) |

---

---

| | |
|:---|:---|
| **1290 Avenue of the Americas <br> 10th Floor <br> New York, NY** | **10104** |
| (Address of principal executive offices) | (Zip Code) |

---

**(212) 983-1602**

Registrant's telephone number, including area code

**Not Applicable**

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

---

| | | |
|:---|:---|:---|
| **Title of each class** | **Trading Symbol(s)** | **Name of each exchange on<br> which registered** |
| Class A ordinary shares, par value $0.0001 per share | CSTAF | OTCID Basic Market |
| Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50 | CSTWF | OTCID Basic Market |
| Units, each consisting of one Class A ordinary share and one-third of one redeemable warrant | CSTUF | OTCID Basic Market |

---

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

**Item 1.01 Entry into a Material Definitive Agreement.**

On January 29, 2024, Constellation Acquisition Corp I, a Cayman Islands exempted company (the "Company"), issued an unsecured promissory note (the "Promissory Note") in the principal amount of $1,660,000 to Constellation Sponsor LP, a Delaware limited partnership, bearing no interest and maturing once the Company closes its initial business combination. On June 5, 2025, the Company amended the promissory note, to increase the principal amount by $590,000 from $1,660,000 to $2,250,000. On March 18, 2026, the Company further amended the Promissory Note (the "Second Amendment"), to increase the principal amount by $3,000,000 from $2,250,000 to $5,250,000. Unless otherwise set forth in the Second Amendment, all other provisions of the Promissory Note remain in full force and effect.

The foregoing description of the Second Amendment is qualified in its entirety by reference to the full text of the Second Amendment, which is incorporated by reference herein and filed herewith as Exhibit 10.1.

**Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.**

The disclosure contained in Item 1.01 of this Current Report on Form 8-K is incorporated by reference in this Item 2.03.

**Item 9.01. Exhibits.**

**(d) Exhibits**

---

| | |
|:---|:---|
| **Exhibit No.** | **Exhibit** |
| 10.1 | [Second Amendment to the Promissory Note, dated March 18, 2026, between Constellation Acquisition Corp I and Constellation Sponsor LP.](ea028250701ex10-1.htm) |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document). |

---

**SIGNATURES**

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

---

| | | |
|:---|:---|:---|
|  | **CONSTELLATION ACQUISITION CORP I** | **CONSTELLATION ACQUISITION CORP I** |
| Dated: March 19, 2026 | By: | */s/ Chandra R. Patel* |
|  |  | Chandra R. Patel |
|  |  | Chief Executive Officer |

---

## Exhibit 10.1

**Exhibit 10.1**

**SECOND AMENDMENT TO PROMISSORY NOTE**

THIS SECOND AMENDMENT TO THE PROMISSORY NOTE dated the 18th day of March, 2026 (this "**Second Amendment**") is made by and between Constellation Acquisition Corp I, a Cayman Islands exempted company (the "**Maker**"), and Constellation Sponsor LP, a Delaware limited partnership, or its registered assigns or successors in interest (the "**Payee**"). All capitalized terms not defined in this Second Amendment will have the meanings given to them in the Note (as defined below).

**<u>RECITALS</u>**

**WHEREAS**, the Maker executed that certain Promissory Note, dated as of January 30, 2024, in the original principal amount of up to $1,660,000 (the "**Note**"); and

**WHEREAS**, the Note was amended by that certain Amendment to the Promissory Note, dated as of June 5, 2025, to increase the principal amount of the Note by $590,000 from $1,660,00 to $2,250,000; and

**WHEREAS**, the Maker and Payee desire to enter into this Second Amendment pursuant to the terms of the original Note, as set forth below; and

**WHEREAS**, any amendment hereto or waiver of any provision hereof may be made with, and only with, the written consent of the Maker and the Payee.

**NOW, THEREFORE**, in consideration of these premises, the mutual covenants contained in this Second Amendment and other good and valuable consideration, the receipt and sufficiency of which are acknowledged, the parties agree as follows:

**<u>AGREEMENT</u>**

1. <u>Amendment to the Note</u>:

1.1 The Total Principal Amount of the Note is increased by $3,000,000
from $2,250,000 to $5,250,000.

1.2 <u>Section 3</u> of the Note is hereby amended and restated
in its entirety to read as follows:

"3. <u>Drawdown Requests</u>. Maker and Payee agree that, in addition to the Initial Principal Amount, Maker may request an additional aggregate amount of up to $5,195,000, which may be drawn down from time to time until the Maker consummates a Business Combination (each a "**Drawdown Request**"). Payee shall fund each Drawdown Request no later than three (3) business days after receipt of a Drawdown Request. Once an amount is drawn down under this Note, it shall not be available for future Drawdown Requests even if prepaid. No fees, payments or other amounts shall be due to Payee in connection with, or as a result of, any Drawdown Request by the Maker."

2. <u>No Other Amendments</u>. Except as specifically set forth herein, all other provisions of the Note shall remain in full force and effect.

3. <u>Counterparts</u>. This Second Amendment may be executed in two or more counterparts, and by different parties in separate counterparts, with the same effect as if all parties hereto had signed the same document, but all of which together will constitute one and the same instrument. Copies of executed counterparts of this Second Amendment transmitted by electronic transmission (including by email or in .pdf format) or facsimile as well as electronically or digitally executed counterparts (such as DocuSign) will have the same legal effect as original signatures and will be considered original executed counterparts of this Second Amendment.

[*Signature Page Follows*]

IN WITNESS WHEREOF, the Maker and Payee, intending to be legally bound hereby, have caused this Second Amendment to the Note to be duly executed as of the day and year first written above.

---

| | |
|:---|:---|
| **Constellation Acquisition Corp I** | **Constellation Acquisition Corp I** |
| By: | */s/ Chandra R. Patel* |
| Name: | Chandra R. Patel |
| Title: | Chief Executive Officer |

---

Agreed and Acknowledged:

**Constellation Sponsor LP**<br> a Delaware limited partnership

By: Antarctica Endurance Manager, LLC, its<br> general partner

---

| | |
|:---|:---|
| By: | */s/ Chandra R. Patel* |
| Name: | Chandra R. Patel |
| Title: | Manager |

---