The Problem Until Now

Indie filmmakers have always had Kickstarter and its likes for the purpose of film fundraising. While this is a huge benefit to the average indie filmmaker, within the delivery of this value lies a string of operational problems that have created hidden pain points for the end users of these traditional solutions.

High Fees and Financial Drain

Traditional platforms like Kickstarter impose significant financial burdens:

• Platform fees: 5% of total funds raised

• Payment processing fees: An Additional 3-5%

• Bank fees and intermediary costs: Further reductions to actual funding received

For indie filmmakers whose daily modus operandi involves operating on tight budgets, losing 8-10% of raised funds to fees can be the difference between completing a project and falling short.

Lack of Transparency and Trust Issues

• Black box operations: Backers have no visibility into how funds are actually managed or used

• No accountability mechanisms: Once funds are released, there's limited oversight on spending

• Trust barriers: Backers must rely entirely on platform policies and creator promises without verifiable proof

Centralized Control and Censorship Risks

• Platform dependency: Creators are subject to arbitrary platform rules and policy changes

• Content restrictions: Projects can be removed or restricted based on subjective content policies

• Single point of failure: If the platform experiences issues, entire campaigns can be affected

Limited Global Accessibility

• Geographic restrictions: Many regions have limited access to traditional crowdfunding platforms. Oftentimes, the most deprived regions are countries in the Global South and blacklisted nations by Global political sanctions.

• Payment method limitations: Restricted to specific payment processors and fiat currencies.

• Regulatory barriers: Complex compliance requirements vary by jurisdiction

Building CineX for Indie Filmmakers Globally

Enter the centre stage, CineX, a decentralized platform to help independent filmmakers raise funds for their projects through cryptocurrency crowdfunding on the Stacks network.

Stacks, a relatively new way to build new and innovative applications on top of the Bitcoin blockchain, is a Bitcoin layer that makes it possible to create new business uses for Bitcoin beyond just sending and receiving money. It does this by enabling developers to create smart contracts and applications that are connected to the security and value of the Bitcoin network. This is the foundation upon which CineX is being built, enabling indie filmmakers globally to create funding campaigns for proposed film projects and connect with their audiences on-chain with NFTs that represent reward levels for different specific contribution limits.

On CineX, backers contribute in STX to any campaign that has metadata and filmmaker credentials relevant enough to convince them to support such campaign. Added to this, filmmakers provide prospective backers with verified identities and optional proof of third-party endorsements - the more the merrier kind of opportunity - to secure trust in their credentials.

In the course of building this platform to democratize the financing of film projects for filmmakers, a few challenges became imminent as we approached the different functionalities.

The Core Challenge: Handling Money Safely

In crowdfunding, you're dealing with other people's money. That means:

• Security is non-negotiable: One bug could drain all campaign funds

• Trust is everything: Backers need to know their money is safe

• Complexity grows fast as functionality grows: Campaign logic + fund management + rewards = In no time, code becomes bogus and messy

A Modular Architecture Solution

Since one big contract was a no-go area, the only logical solution was to split CineX’s business logic into separate, specialized smart contracts, each with a single responsibility. In this tutorial, I will focus on how we handled the issue of security and trust regarding the handling of money.

How They Work Together

Walking Through the Code

Step 1: Defining Clear Interfaces with Traits

Clarity traits ensure each contract knows exactly how to talk to the others. Here's the escrow trait that defines how CineX’s secure fund management works:

;; title: escrow-module-trait
;; version: 1.0.0
;; summary:  Traits  of Escrow Module for Secure Fund Management of campaign funds
;; Author: Victor Omenai 
;; Created: 2025

;; Strategic Purpose: Define the "Key Resources" component of CineX
;; This trait ensures proper and secure management of the critical resource (funds)


(define-trait escrow-trait
  (
    ;; Deposit funds to campaign
     ;; @params: 
        ;; campaign ID - uint; amount - uint
    (deposit-to-campaign (uint uint) (response bool uint))

    ;; Withdraw funds from campaign
        ;; @params: 
            ;; campaign ID - uint; amount - uint
    (withdraw-from-campaign (uint uint) (response bool uint))

    ;; Collect platform fee
        ;; @params: 
            ;; campaign ID - uint; fee amount - uint
    (collect-campaign-fee (uint uint) (response bool uint))

    ;; Get campaign balance
    ;; @params: 
        ;; campaign ID - uint
    (get-campaign-balance (uint) (response uint uint))
  )
)

Learn here about Clarity, the smart contract language of the Stacks blockchain

Step 2: Secure Fund Flow in Action

Let's trace what happens when someone backs a campaign:

;; In crowdfunding contract - handling a contribution
(define-public (contribute-to-campaign (campaign-id uint) (amount uint))
  (let
    (
        ;; Try to fetch campaign details
        (campaign (unwrap! (map-get? campaigns campaign-id) ERR-CAMPAIGN-NOT-FOUND))

        ;; Get the escrow balance from the campaign-escrow-balances map of the escrow-module contract
        (escrow-balance (unwrap! (contract-call? (var-get escrow-contract) get-campaign-balance campaign-id) ERR-ESCROW-BALANCE-NOT-FOUND))

        ;; Try to get existing contribution, or default to zero if none
        (existing-contribution (default-to 
                                  { total-contributed: u0, contributions-count: u0, last-contribution-at: u0 } 
                                    (map-get? campaign-contributions { campaign-id: campaign-id, contributor: tx-sender })))

        ;; Get current-total-raised
        (current-total-raised (get total-raised campaign))

        ;; Calculate new total-raised
        (new-total-raised (+ current-total-raised amount)) 

        ;; Get current-total-contributed funds
        (current-total-contributed (get total-contributed existing-contribution))

        ;; Get new contributions
        (new-total-contributed (+ current-total-contributed amount))

        ;; Get current contributions-count
        (current-contributions-count (get contributions-count existing-contribution ))

        ;; Calculate new count
        (new-count (+ current-contributions-count u1))

    )

      ;; Make sure campaign is active
      (asserts! (get is-active campaign) ERR-CAMPAIGN-INACTIVE)

      ;; Make sure contribution amount is high enough
      (asserts! (>= amount MINIMUM-CONTRIBUTION) ERR-INVALID-AMOUNT)

      ;; Move funds into escrow (secure temporary storage), so it does not stay inthis crowdfunding contract 
      (unwrap! (contract-call? (var-get escrow-contract) deposit-to-campaign campaign-id amount) ERR-TRANSFER-FAILED)

      ;; Increase campaign's total raised amount
      (map-set campaigns campaign-id 
        (merge 
          campaign 
            { total-raised: new-total-raised }
        )
      )
      ;; Update record of contributor
      (map-set campaign-contributions { campaign-id: campaign-id, contributor: tx-sender } {
        total-contributed: new-total-contributed,
        contributions-count: new-count,
        last-contribution-at: block-height
      })

      (ok true)
  )
)

Step 3: Controlled Fund Release

When a campaign succeeds, the escrow contract enforces strict conditions before releasing funds:

;; In escrow contract - secure withdrawal

;; Public function: Allows the campaign owner to withdraw a specified amount from escrow
(define-public (withdraw-from-campaign (campaign-id uint) (amount uint))
  (let
    (
      ;; Retrieve current balance
      (current-balance (default-to u0 (map-get? campaign-escrow-balances campaign-id)))

      ;; Fetch campaign details from the crowdfunding module
      (campaign (unwrap! (contract-call? (var-get crowdfunding-contract) get-campaign campaign-id) ERR-CAMPAIGN-NOT-FOUND))

      ;; Calculate the new balance after withdrawal
      (new-balance (- current-balance amount))

      ;; Get campaign-owner
      (owner (get owner campaign))

    )
      ;; Ensure that the caller is the campaign owner
      (asserts! (is-eq tx-sender owner) ERR-NOT-AUTHORIZED)

      ;; Ensure there are enough funds to withdraw
      (asserts! (>= current-balance amount) ERR-INSUFFICIENT-BALANCE)

      ;; Update the escrow balance
      (map-set campaign-escrow-balances campaign-id new-balance)

      ;; Transfer the withdrawn amount to the campaign owner
      (unwrap! (stx-transfer? amount (as-contract tx-sender) owner) ERR-TRANSFER-FAILED)

      (ok true)
  )
)

Why This Architecture Works

Key Takeaway✍🏾

Modular architecture isn't just good engineering practice—it's essential for financial applications. By separating concerns and using clear interfaces, CineX achieves both security and maintainability.

The next time you're building something that handles money, ask yourself: "Can I split this into focused, single-purpose contracts?" Your future self (and your users) will thank you.

What's Next?

Want to see the full CineX implementation? Check out the complete source code and explore how these modules work together in practice, including the identity verification contract for separately handling the reputation management of filmmakers, of course, with the aim to secure backers’ trust.

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