BLOCKCHAIN DEVELOPMENT AGREEMENT

Agreement Date: [DATE]

Agreement Number: [DEV-XXXX-XXXX]

PARTIES

CLIENT:
- Legal Name: [CLIENT NAME] (the "Client")
- Address: [ADDRESS]
- Email: [EMAIL]
- Contact Person: [NAME/TITLE]

DEVELOPER:
- Legal Name: [DEVELOPER NAME] (the "Developer")
- Address: [ADDRESS]
- Email: [EMAIL]
- Contact Person: [NAME/TITLE]

RECITALS

WHEREAS, Client desires to engage Developer to design, develop, and deliver certain blockchain-based software, smart contracts, and related services;

WHEREAS, Developer has the technical expertise and resources to perform such services;

NOW, THEREFORE, in consideration of the mutual covenants herein, the parties agree as follows:

ARTICLE 1: SCOPE OF WORK

1.1 Project Description

Developer shall design, develop, and deliver the following (the "Project"):

Project Name: [PROJECT NAME]

Project Description: [DETAILED DESCRIPTION]

Blockchain Platform: ☐ Ethereum ☐ Polygon ☐ Solana ☐ Arbitrum ☐ Other: [SPECIFY]

Development Type:
☐ Smart contracts
☐ Decentralized application (dApp) frontend
☐ Backend infrastructure
☐ Token creation
☐ NFT collection/marketplace
☐ DeFi protocol
☐ DAO infrastructure
☐ Blockchain integration
☐ Other: [SPECIFY]

1.2 Detailed Specifications

The detailed technical specifications for the Project are set forth in Exhibit A (Statement of Work).

1.3 Deliverables

Developer shall deliver the following (collectively, the "Deliverables"):

1.4 Out of Scope

The following are expressly excluded from the scope of this Agreement:

☐ Security audit (to be performed by third party)
☐ Ongoing maintenance and support (unless separately agreed)
☐ Marketing and go-to-market activities
☐ Legal and regulatory compliance advice
☐ Token economics/tokenomics design
☐ Community management
☐ Other: [SPECIFY]

ARTICLE 2: TIMELINE AND MILESTONES

2.1 Project Timeline

Project Start Date: [DATE]

Target Completion Date: [DATE]

Total Duration: [NUMBER] weeks/months

2.2 Milestones

2.3 Acceptance Process

2.3.1 Upon delivery of each Milestone, Client shall have [NUMBER] business days to review and either accept or provide written notice of deficiencies.

2.3.2 If Client identifies deficiencies, Developer shall correct them within [NUMBER] business days at no additional cost.

2.3.3 Milestone is deemed accepted if Client does not respond within the review period.

2.4 Timeline Extensions

Timeline may be extended due to:
- Scope changes approved by Client
- Client delays in providing required information or approvals
- Force majeure events
- Technical issues with third-party dependencies beyond Developer's control

ARTICLE 3: PAYMENT TERMS

3.1 Total Project Fee

Total Fee: $[AMOUNT] USD (or [AMOUNT] [CRYPTOCURRENCY])

Fee Structure:
☐ Fixed price
☐ Time and materials (capped at $[AMOUNT])
☐ Milestone-based payments (per Section 2.2)
☐ Hybrid: [DESCRIBE]

3.2 Payment Schedule

3.3 Payment Method

☐ Bank wire transfer to:
- Bank: [BANK NAME]
- Account: [ACCOUNT NUMBER]
- Routing: [ROUTING NUMBER]

☐ Cryptocurrency to:
- Currency: [ETH/USDC/BTC/OTHER]
- Wallet Address: [ADDRESS]
- Network: [NETWORK]

3.4 Additional Work

Work beyond the scope defined in Exhibit A shall be subject to a separate change order specifying scope, timeline, and fees.

Hourly Rate for Additional Work: $[RATE]/hour

3.5 Late Payment

Late payments shall accrue interest at [X]% per month. Developer may suspend work if payment is [NUMBER] days overdue.

ARTICLE 4: INTELLECTUAL PROPERTY

4.1 Work Product Ownership

4.1.1 Client Ownership:

Upon full payment, Client shall own all right, title, and interest in the following (the "Work Product"):

☐ Custom smart contracts developed specifically for Client
☐ Custom frontend code developed specifically for Client
☐ Custom backend code developed specifically for Client
☐ Documentation created for the Project
☐ Other: [SPECIFY]

4.1.2 Developer Ownership:

Developer retains all right, title, and interest in:

☐ Pre-existing tools, libraries, and frameworks
☐ General-purpose code and components
☐ Development methodologies and processes
☐ Generic smart contract patterns

4.2 License Grants

4.2.1 License to Client:

Developer grants Client a perpetual, worldwide, royalty-free license to use Developer's pre-existing tools and general-purpose components solely as necessary to operate the Deliverables.

4.2.2 License to Developer:

Client grants Developer a perpetual, worldwide, royalty-free license to use generic portions of the Work Product for other projects, excluding Client's confidential business logic and proprietary features.

4.3 Open Source Components

4.3.1 The Project may incorporate open source software subject to their respective licenses. A list of open source components is provided in Exhibit B.

4.3.2 Developer shall ensure compliance with all open source license obligations.

4.3.3 Client acknowledges that certain open source licenses (e.g., GPL, LGPL) may have implications for the licensing of the Work Product.

4.4 Third-Party Components

Developer may incorporate third-party libraries and SDKs. Developer shall:
- Identify all third-party components
- Ensure Client has necessary rights to use them
- Provide license information

4.5 Assignment

Upon final payment, Developer hereby assigns to Client all right, title, and interest in the Work Product, and agrees to execute any documents necessary to effectuate such assignment.

ARTICLE 5: DEVELOPMENT STANDARDS

5.1 Coding Standards

Developer shall develop the Project in accordance with:

☐ Industry best practices for blockchain development
☐ Solidity style guide (for Ethereum-based projects)
☐ Client's coding standards (if provided)
☐ Secure coding practices per OWASP and similar guidelines

5.2 Smart Contract Standards

For smart contracts, Developer shall:

☐ Follow established design patterns (e.g., OpenZeppelin standards)
☐ Implement proper access control mechanisms
☐ Include emergency pause/circuit breaker functionality
☐ Implement upgrade mechanisms (if required): ☐ Proxy pattern ☐ Diamond pattern ☐ Non-upgradeable
☐ Emit appropriate events for all state changes
☐ Include comprehensive NatSpec documentation
☐ Optimize for gas efficiency

5.3 Testing Requirements

Developer shall provide:

☐ Unit tests with [X]% code coverage minimum
☐ Integration tests
☐ Testnet deployment and testing
☐ Test documentation
☐ Gas usage reports

Testing Framework: [HARDHAT/FOUNDRY/OTHER]

5.4 Documentation

Developer shall provide:

☐ Technical architecture documentation
☐ Smart contract documentation (NatSpec)
☐ API documentation
☐ Deployment instructions
☐ User guide/README
☐ Code comments

5.5 Version Control

All code shall be maintained in:

Repository: [GITHUB/GITLAB/BITBUCKET]
Repository URL: [URL]
Access: ☐ Private (Client access only) ☐ Public ☐ To be determined

ARTICLE 6: SECURITY

6.1 Security Practices

Developer shall implement security best practices, including:

☐ Secure key management during development
☐ Access control for development environments
☐ Code review before deployment
☐ Protection against common vulnerabilities (reentrancy, overflow, etc.)
☐ Principle of least privilege

6.2 Security Audit

6.2.1 A third-party security audit is:

☐ Included: Developer shall engage [AUDIT FIRM] at Developer's expense
☐ Client's Responsibility: Client shall arrange and pay for audit
☐ Not Required: Parties agree no third-party audit is needed

6.2.2 If audit is performed, Developer shall:
- Cooperate with auditors
- Address critical and high-severity findings before deployment
- Provide remediation report

6.3 Bug Bounty

☐ Not applicable
☐ Client shall establish bug bounty program
☐ Developer shall assist in establishing bug bounty program

6.4 Security Incidents

Developer shall immediately notify Client of any security incident affecting the Project or Client's data.

ARTICLE 7: DEPLOYMENT

7.1 Deployment Responsibility

7.1.1 Deployment shall be performed by:

☐ Developer
☐ Client
☐ Joint deployment

7.1.2 Deployment environments:

7.2 Deployment Support

Developer shall provide deployment support including:

☐ Deployment scripts and automation
☐ Configuration documentation
☐ Verification/Etherscan publication
☐ Initial configuration and setup
☐ Post-deployment monitoring (for [NUMBER] days)

7.3 Contract Verification

Developer shall verify all smart contracts on:
☐ Etherscan (or applicable block explorer)
☐ Sourcify
☐ Other: [SPECIFY]

7.4 Keys and Access

7.4.1 Deployment keys/admin keys shall be:

☐ Generated and controlled by Client
☐ Generated by Developer and transferred to Client
☐ Multi-signature: [X] of [Y] configuration

7.4.2 Developer shall NOT retain admin access to production contracts after deployment, unless specifically authorized.

ARTICLE 8: WARRANTIES

8.1 Developer Warranties

Developer warrants that:

(a) The Deliverables will substantially conform to the specifications in Exhibit A;

(b) The Deliverables will be free from material defects for [NUMBER] days after acceptance (the "Warranty Period");

(c) Developer has the right to grant the intellectual property rights herein;

(d) The Work Product will not infringe any third-party intellectual property rights;

(e) Development will be performed in a professional and workmanlike manner;

(f) Developer will comply with applicable laws.

8.2 Warranty Remedies

During the Warranty Period, Developer shall correct any material defects at no additional charge.

8.3 Disclaimer

EXCEPT AS EXPRESSLY PROVIDED HEREIN, DEVELOPER DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

8.4 Smart Contract Disclaimer

CLIENT ACKNOWLEDGES THAT SMART CONTRACTS ARE EXPERIMENTAL TECHNOLOGY. DESPITE DEVELOPER'S BEST EFFORTS, SMART CONTRACTS MAY CONTAIN BUGS OR VULNERABILITIES. DEVELOPER DOES NOT WARRANT THAT SMART CONTRACTS WILL BE ERROR-FREE OR SECURE.

ARTICLE 9: LIMITATION OF LIABILITY

9.1 Limitation

EXCEPT FOR BREACHES OF CONFIDENTIALITY, INTELLECTUAL PROPERTY INFRINGEMENT, OR GROSS NEGLIGENCE/WILLFUL MISCONDUCT:

(a) Neither party shall be liable for indirect, incidental, special, consequential, or punitive damages;

(b) Developer's total aggregate liability shall not exceed the total fees paid under this Agreement.

9.2 No Liability for Third-Party Issues

Developer shall not be liable for:
- Blockchain network failures or congestion
- Oracle or third-party service failures
- Market volatility or economic losses
- User error or misuse
- Exploits using attack vectors not known at time of development

9.3 Essential Basis

The limitations in this Article are an essential basis of the bargain between the parties.

ARTICLE 10: CONFIDENTIALITY

10.1 Confidential Information

Each party agrees to maintain the confidentiality of the other's Confidential Information, including:
- Technical specifications and architecture
- Business plans and strategies
- Proprietary code and algorithms
- Financial information
- User data

10.2 Exceptions

Confidential Information does not include information that:
- Is or becomes publicly available
- Was known before disclosure
- Is independently developed
- Is disclosed with permission

10.3 Duration

Confidentiality obligations survive termination for [NUMBER] years.

ARTICLE 11: TERM AND TERMINATION

11.1 Term

This Agreement begins on the Agreement Date and continues until completion of the Project or earlier termination.

11.2 Termination for Convenience

Either party may terminate with [NUMBER] days written notice. Upon termination:
- Client pays for work completed
- Developer delivers all completed work
- Developer returns Client materials

11.3 Termination for Cause

Either party may terminate immediately upon:
- Material breach uncured for [NUMBER] days after notice
- Insolvency or bankruptcy
- Failure to make payments for [NUMBER] days

11.4 Effect of Termination

Upon termination:
- All granted licenses continue for paid-for work
- Confidentiality obligations survive
- Accrued payment obligations remain

ARTICLE 12: GENERAL PROVISIONS

12.1 Independent Contractor

Developer is an independent contractor. Nothing creates an employment, partnership, or agency relationship.

12.2 Governing Law

This Agreement shall be governed by the laws of [STATE/JURISDICTION].

12.3 Dispute Resolution

☐ Arbitration: Binding arbitration under [AAA/JAMS] rules in [LOCATION]
☐ Litigation: Courts of [JURISDICTION]

12.4 Entire Agreement

This Agreement, including Exhibits, constitutes the entire agreement between the parties.

12.5 Amendments

Amendments must be in writing signed by both parties.

12.6 Assignment

Neither party may assign without the other's consent, except Developer may use subcontractors with Client's approval.

12.7 Severability

If any provision is invalid, the remaining provisions continue in effect.

12.8 Notices

Notices shall be sent to the addresses above.

12.9 Force Majeure

Neither party is liable for delays caused by circumstances beyond reasonable control.

12.10 Counterparts

This Agreement may be executed electronically in counterparts.

SIGNATURES

CLIENT:

Signature: _________________________________

Name: [NAME]

Title: [TITLE]

Date: [DATE]

DEVELOPER:

Signature: _________________________________

Name: [NAME]

Title: [TITLE]

Date: [DATE]

EXHIBIT A: STATEMENT OF WORK

A.1 Technical Specifications

[DETAILED TECHNICAL SPECIFICATIONS]

A.2 Functional Requirements

[DETAILED FUNCTIONAL REQUIREMENTS]

A.3 Architecture Diagram

[ATTACH OR REFERENCE]

A.4 User Stories/Use Cases

[DETAILED USER STORIES]

EXHIBIT B: OPEN SOURCE COMPONENTS

EXHIBIT C: CHANGE ORDER TEMPLATE

Change Order Number: [NUMBER]

Date: [DATE]

Description of Change:
[DESCRIPTION]

Impact on Timeline: [DAYS/WEEKS]

Impact on Cost: $[AMOUNT]

Approvals:

Client: _________________ Date: _______

Developer: _________________ Date: _______

This template is provided for informational purposes only and should be reviewed and customized by qualified legal counsel familiar with software development agreements and blockchain technology.