[Proposal setup] Proposal title

Please provide your proposal title

TxBuild: Instant Cardano API from Plutus Blueprint

[Proposal Summary] Budget Information

Enter the amount of funding you are requesting in ADA

132500

[Proposal Summary] Time

Please specify how many months you expect your project to last

6

[Proposal Summary] Translation Information

Please indicate if your proposal has been auto-translated

No

Original Language

en

[Proposal Summary] Problem Statement

What is the problem you want to solve?

Post-contract Development, Developers hit a wall: Manual indexing, CBOR decoding, complete off-chain setup needed. The gap between validator and queryable API Slows Cardano dApp development.

[Proposal Summary] Supporting Documentation

Supporting links

• https://txbuild.io/
,
• https://drive.proton.me/urls/BKYBPGRNTM#APP5wfHshjeH

[Proposal Summary] Project Dependencies

Does your project have any dependencies on other organizations, technical or otherwise?

Yes

Describe any dependencies or write 'No dependencies'

Cardano Node, Ogmios

[Proposal Summary] Project Open Source

Will your project's outputs be fully open source?

Yes

Please provide details on the intellectual property (IP) status of your project outputs, including whether they will be released as open source or retained under another licence.

Yes project will be opensourced under Apache 2.0 license

[Theme Selection] Theme

Please choose the most relevant theme and tag related to the outcomes of your proposal

UTXO

[Campaign Category] Category Questions

Describe what makes your idea innovative compared to what has been previously launched in the market (whether by you or others).

First tool to auto-generate queryable APIs directly from Plutus blueprints. No manual indexing, no custom code - just upload your blueprint and get instant UTXO queries with decoded datums

Zero-Configuration Infrastructure

Existing solutions: Developers must set up and maintain:

• Cardano node or Ogmios connection
• Database with proper schemas
• Indexing service
• API layer
• Monitoring and scaling

TxBuild innovation: All infrastructure is managed - just upload Plutus Blueprint and start querying

Impact: Reduces time-to-market from weeks to minutes

Query API Generated Automatically

• Existing solutions: After indexing data, developers still need to build REST APIs with proper filtering
• TxBuild innovation: Query endpoints are auto-generated based on datum structure
• Impact: Developers can immediately query by any field without writing API code

Real-time UTXO Subscriptions

The Innovation: WebSocket subscriptions for real-time UTXO updates with datum-level filtering.

How It Works:

• Subscribe to UTXOs matching specific datum criteria
• Receive instant notifications when matching UTXOs are created, spent, or updated
• Filter subscriptions by any datum field
• Multiple concurrent subscriptions per connection

Impact:

• Build reactive UIs without polling
• Instant user notifications
• Reduced server load (no repeated queries)
• Better UX with real-time updates

The Complete Workflow Innovation

Traditional Approach

• Build Plutus smart contract
• Design custom indexer To store Datum information
• Write CBOR decoders for Datum & Redeemers
• Build API layer (1-2 weeks)
• Deploy infrastructure (1 week)
• Maintain ongoing infra

TxBody Approach

• Build Plutus smart contract
• Upload blueprint
• Query your data

Describe what your prototype or MVP will demonstrate, and where it can be accessed.

Our MVP at txbuild.io demonstrates the complete workflow: users upload Plutus blueprints, and within minutes receive production-ready query APIs with decoded datums. The platform includes real UTXO indexing from mainnet and preprod networks, with full filtering capabilities on any datum field.

MVP Features:

• User Authentication
• Upload & Parse: Users upload their Plutus blueprint file through a simple web interface. The system immediately parses the blueprint, extracts all type definitions, and generates CBOR decoders automatically.
• Automatic Indexing: Once parsed, the platform begins indexing UTXOs from the Cardano blockchain (mainnet and preprod supported). All datum fields are decoded in real-time using the generated decoders.
• Query API: Users receive instant access to REST APIs that allow querying UTXOs by any datum field. Complex filters like datum.amount > 1000000 AND datum.status = "active" work immediately without writing any code.
• Developer Dashboard: Visual interface showing indexed UTXO counts, API usage, query performance, and project settings.
• Interactive API documentation

Self-Hosted Version:

Docker Compose and Kubernetes configurations demonstrating full deployment with Cardano node integration, PostgreSQL setup, and monitoring stack.

Accessible at: txbuild.io with free tier for testing and premium options for production use.

Describe realistic measures of success, ideally with on-chain metrics.

For MVP we are targetting atleast

Adoption Metrics:

• 50+ unique Plutus blueprints indexed
• 100+ registered developers
• 10,000+ API calls per Weel
• 1+ production dApps built with TxBuild

Platform Usage:

• 25,000+ UTXOs decoded and indexed

Engagement:

• 1+ self-hosted deployments
• 50+ weekly documentation views

[Your Project and Solution] Solution

Please describe your proposed solution and how it addresses the problem

The Gap Between Smart Contract and Working dApp

After deploying a Plutus validator, developers face a critical challenge: their on-chain contract is completed, but completely unusable without off-chain infrastructure. They need to:

• Index UTXOs from the blockchain
• Decode CBOR-encoded datums manually
• Parse complex Plutus Data types
• Build query APIs for their frontend
• Maintain synchronization with the chain
• Handle rollbacks and edge cases

This gap forces developers to spend 4-8 weeks building infrastructure before they can even start building their actual dApp features. Many talented developers abandon Cardano at this point because they lack the backend expertise or resources to bridge this gap.

Why This Matters

The Cardano ecosystem loses potential builders not because Plutus is hard, but because what comes after Plutus is harder. Frontend developers who can build beautiful UIs, product designers who understand user needs, and domain experts who know DeFi or gaming—all are blocked by infrastructure complexity.

Our Solution Approach - Leverage What Developers Already Have: The Blueprint

Every Plutus validator compilation produces a blueprint JSON file containing complete type definitions. This file already exists—developers just can't use it effectively.

Our insight: use the blueprint as the single source of truth to automatically generate everything needed for off-chain data access.

Why This Approach Works:

• Zero Additional Work - Developers already have blueprints from compilation
• Automatic Updates - Recompile contract → upload new blueprint → infrastructure updates
• Standard Format - CIP-57 blueprints work across all Plutus languages (Aiken, Plutarch, PlutusTx)

Who Will Our Project Engage?

• Solo Developers - Frontend devs and indie hackers who want to build on Cardano.
• Early-Stage Projects - Startups and small teams that need to launch MVPs quickly
• Established Projects - Projects wanting to reduce infrastructure maintenance burden
• Enterprise Teams - Organizations needing auditable, self-hosted indexing solutions
• Cardano Educators - Can teach complete dApp development without infrastructure complexity
• The Cardano Ecosystem - More apps launched means more activity, more users, more value

What Makes TxBuild Unique?

• Complete Automation: Upload blueprint → get production APIs. No configuration files, no manual decoder writing, no infrastructure setup. Just one JSON file.
• Universal Compatibility: Works with any Plutus language (Aiken, Plutarch, PlutusTx, OpShin) because we use the standard blueprint format.
• Zero Lock-In: Self-hosted option means you're never dependent on our service. Download, deploy, run forever on your own infrastructure.

A Cardano where any developer with a good idea can launch a production dApp in weeks, not months. Where the barrier to entry is your creativity and Plutus skills, not your DevOps expertise. Where infrastructure is invisible, and building is effortless.

TxBuild makes this vision real.

[Your Project and Solution] Impact

Please define the positive impact your project will have on the wider Cardano community

Accelerated dApp Development

• TxBuild removes 4-8 weeks of infrastructure development from every Cardano project. When 50 projects save 6 weeks each, that's 300 weeks (5.7 years) of developer time redirected from building indexers to building innovative features. Faster development means more projects reach production, iterate quicker, and bring users to Cardano sooner.

Lower Barrier to Entry

• By eliminating backend infrastructure complexity, TxBuild opens Cardano to frontend developers, solo entrepreneurs, students, and domain experts who understand DeFi or gaming but not DevOps.

Improved Developer Experience.

• TxBuild creates a smooth path from contract to working dApp with instant gratification: upload blueprint, query data in minutes.

[Your Project and Solution] Capabilities & Feasibility

What is your capability to deliver your project with high levels of trust and accountability? How do you intend to validate if your approach is feasible?

Our Team's Proven Cardano Expertise

Piyush Thapa - Project Lead & Core Developer

brings deep, hands-on experience across the Cardano development stack:

Senior Cardano Developer Experience:

• Iagon - Senior Cardano Developer working on decentralized storage infrastructure
• Nuvola - Senior Cardano Developer building blockchain solutions
• Direct experience with production Cardano systems, smart contract integration, and off-chain infrastructure at scale

Creator of Sutra SDK: https://sutra.txbody.io/

• https://github.com/txbody-org/sutra-cardano
• Built Cardano's first comprehensive Elixir SDK for off-chain transaction building
• Parsing complex Cardano data structures using Elixir
• Working with CBOR encoding/decoding
• Transaction construction and signing flows

Technical Feasibility Validation

Already Proven Components:

1. Blueprint Parsing

• Blueprints follow CIP-57 standard with well-defined JSON structure
• Similar to parsing Plutus Data structures (proven in Sutra SDK)
• Test cases from real Aiken and Plutarch projects available
• Validation: Parse 3+ existing blueprints from popular projects before Milestone 1 completion

2. CBOR Datum Decoding

• Raw CBOR is decoded using Sutra SDK
• Decoding patterns proven in transaction building work
• Plutus Data structure is documented and standardized

3. Cardano Node Integration

• Ogmios and Dolos protocols are production-ready
• Validation: Test sync on devnet with multiple chain rollback scenarios

Our Commitment

We commit to:

• Transparent development with regular updates
• Quality code with comprehensive testing and documentation
• Milestone accountability with clear evidence of completion
• Long-term maintenance beyond initial funding period

[Milestones] Project Milestones

Milestone Title

Foundation & Parser

Milestone Outputs

• Plutus blueprint parser supporting all CIP-57 datum and redeemer types.
• Complete database schema design with documentation.
• JSON to SQL query translation module enabling datum field filtering with support for nested fields and comparison operators.

Acceptance Criteria

• Parser successfully extracts and validates types from 10+ different Plutus blueprints including complex nested structures.
• Database schema supports all datum types with proper indexing.
• Query module translates nested datum field queries to SQL.

Evidence of Completion

• Blueprint Parsing demonstration video showcasing datum and redeemer are parsed & decoded properly
• Query module demonstration video showing translation of complex datum queries to SQL statements

Delivery Month

1

Cost

30000

Progress

20 %

Milestone Title

Blockchain Integration

Milestone Outputs

• Cardano node event integration module connecting via Ogmios / Dolos protocols.
• Real-time UTXO synchronization system tracking validator addresses.
• Automatic datum decoding engine using parsed blueprint types with decoded data stored in PostgreSQL database.

Acceptance Criteria

• System successfully connects to Cardano node and subscribes to block events.
• Indexes minimum 100+ UTXOs with correctly decoded datums.
• Handles chain rollbacks
• Initialise existing Utxos for validator

Evidence of Completion

• Working indexer demonstration video showing real-time synchronization with Cardano network.
• Database export showing decoded UTXOs with proper datum fields.

Delivery Month

1

Cost

40000

Progress

50 %

Milestone Title

Application UI & Deployment

Milestone Outputs

• User authentication system with registration, login, and API key management.
• Project management features for organizing multiple validators.
• Blueprint upload interface with drag-drop support and validation.
• Apply Params for parameterized contracts
• Project dashboard displaying UTXO counts and statistics.
• deploy application with preprod network

Acceptance Criteria

• Users can register accounts, login securely, and generate API keys for their projects.
• Blueprint upload validates JSON structure and displays parsed types preview.
• Dashboard shows real-time project statistics
• web application accessable through preprod.txbuild.io

Evidence of Completion

• Live application deployed at dev.txbuild.io accessible to public users.
• Video walkthrough demonstrating user registration, blueprint upload, and dashboard features.
• preprod.txbuild.io is live and user can start uploading blueprint

Delivery Month

2

Cost

40000

Progress

70 %

Milestone Title

REST API & OpenAPI Integration

Milestone Outputs

• REST API endpoints for querying UTXOs with decoded datum filtering.
• Support for comparison operators, nested field access, pagination, and sorting.
• Complete OpenAPI specification auto-generated from endpoint definitions. Interactive API documentation with live query testing.

Acceptance Criteria

• API endpoints support filtering UTXOs by any datum field including nested structures.
• OpenAPI spec accurately documents all endpoints, parameters, and response schemas.
• Interactive docs allow testing queries directly in browser.

Evidence of Completion

• Published API documentation URL with interactive Swagger UI for testing queries.
• OpenAPI specification file available for download.
• Demonstration video showing complex datum queries returning correct filtered results from live data.

Delivery Month

1

Cost

22000

Progress

90 %

Milestone Title

Project Close-out Video

Milestone Outputs

• Project Close-out Video providing complete platform walkthrough and feature demonstration.
• Final sustainability roadmap for project future.
• Video Tutorial showcasing using platform with Vesting contract blueprint.

Acceptance Criteria

• Video demonstrates complete user journey from registration to querying decoded UTXOs.
• Platform achieves minimum 20+ indexed validators and 10+ registered developers actively using the system
• Video tutorial is shared on Youtube & X

Evidence of Completion

• Close-out Video published on YouTube with 10-15 minute duration showing full platform capabilities.
• Platform analytics dashboard screenshot showing user registrations, projects, and API usage metrics.
• Video Tutorial showcasing using platform with Vesting contract blueprint.

Delivery Month

1

Cost

500

Progress

100 %

[Final Pitch] Budget & Costs

Please provide a cost breakdown of the proposed work and resources

Total Budget: 132,500 ADA

Milestone 1: Foundation & Parser - Budget: 30,000 ADA

Primary Allocation: Development Work (100%)

All funds dedicated to core development work building the foundational libraries. Two Senior Elixir/Cardano developer working on two critical components: Blueprint parsing library that extracts datum and redeemer type definitions from Plutus blueprint JSON files following CIP-57 standard, and JSON to SQL query translation library that converts datum field filters into optimized database queries. This includes comprehensive testing with diverse blueprint files.

Milestone 2: Blockchain Integration - Budget: 40,000 ADA

Primary Allocation: Development Work (100%)

Complete budget allocated to work for blockchain connectivity and data processing. Two Senior developer implementing integration with Cardano node via Ogmios or Dolos protocols, building real-time UTXO synchronization system that tracks validator addresses and handles chain rollbacks, creating automatic datum decoding engine using the blueprint parser from Milestone 1, and developing robust storage system in PostgreSQL with proper indexing for query performance.

Milestone 3: Web Application & Deployment: 40,000 ADA

Resource Allocation:

• Frontend Development: developer building user interface components including registration/login flows, blueprint upload with drag-and-drop, project dashboard showing statistics and UTXO counts, user settings management & Validator Management
• Backend Development: Senior developer implementing user authentication system with API key management, backend APIs supporting UI functionality, project management features, and database operations for user data.
• UI/UX Design: Professional design work creating dashboard layouts, upload interface mockups, branding and logo, and responsive design system ensuring mobile compatibility.
• Infrastructure : Testnet server hosting, production-grade database, application servers with load balancing, and CDN for static assets.

Milestone 4: REST API & OpenAPI Integration - Budget: 22,000 ADA

Resource Allocation:

• API Development: Senior developer building REST endpoints for UTXO querying with datum filtering, implementing pagination and sorting, optimizing query performance, generating OpenAPI specification automatically, and creating interactive API documentation with Swagger UI.
• Marketing & Community: Social media promotion announcing API launch, content creation including integration tutorials and code examples, developer outreach to potential users, and community management in Discord/Telegram channels.
• Beta Testing: Onboarding beta testers with real projects, providing integration support, collecting detailed feedback, performance testing under real usage, and iterating based on user experience.

Milestone 5: Close-out Report & Tutorials - Budget: 500 ADA

Primary Allocation: Content Creation (100%)

All funds dedicated to documentation and educational content. Creating comprehensive close-out report documenting all milestone achievements, platform metrics, technical decisions, lessons learned, and future roadmap. Producing professional close-out video (10-15 minutes) with complete platform walkthrough and feature demonstrations. Recording tutorial series covering getting started guide, blueprint upload walkthrough, query API integration examples, and best practices. All content published on YouTube and documentation site with code samples available on GitHub.

[Final Pitch] Value for Money

How does the cost of the project represent value for the Cardano ecosystem?

The Core Value Proposition

111,000 ADA solves a problem costing the ecosystem millions in lost productivity.

Every Cardano project currently spends 4-8 weeks building custom indexers and datum decoders before they can query on-chain data. With 100+ projects launching annually, that's 400-800 weeks of duplicated effort. TxBuild eliminates this redundancy permanently.

• 50 projects use TxBuild in Year 1
• Each saves 6 weeks of senior developer time
• 300 weeks saved × $2,000/week = $600,000 saved

ROI: Around 10x the initial investment

Cost Justification by Milestone

Milestone 1 (30,000 ADA) - Foundation:

• Blueprint parsing is technically complex—understanding CIP-57 format, handling all Plutus Data variants, generating type-safe decoders. This is specialized Cardano knowledge, not commodity development. The parser becomes reusable infrastructure for the entire ecosystem.

Milestone 2 (40,000 ADA) - Blockchain Integration:

• Largest allocation because this is the hardest problem: maintaining real-time sync with Cardano, handling rollbacks, decoding thousands of UTXOs efficiently, managing database performance. This is where projects typically get stuck. We're solving it once so nobody else has to.

Milestone 3 (40,000 ADA) - Web Application & Deployment:

• Makes the infrastructure accessible. Without a user-friendly interface, only experts could use this. Frontend work, authentication, dashboard—this is what converts powerful backend into something any developer can use in 5 minutes.

Milestone 4 (22,000 ADA) - API & Marketing:

• REST APIs with OpenAPI specs make integration trivial.
• Marketing ensures developers know TxBuild exists.

Milestone 5 (500 ADA) - Documentation:

• Tutorials and videos are force multipliers. One good video teaching 1,000 developers saves 1,000 hours of support time.

[Self-Assessment] Self-Assessment Checklist

I confirm that evidence of prior research, whitepaper, design, or proof-of-concept is provided.

Yes

I confirm that the proposal includes ecosystem research and uses the findings to either (a) justify its uniqueness over existing solutions or (b) demonstrate the value of its novel approach.

Yes

I confirm that the proposal demonstrates technical capability via verifiable in-house talent or a confirmed development partner (GitHub, LinkedIn, portfolio, etc.)

Yes

I confirm that the proposer and all team members are in good standing with prior Catalyst projects.

Yes

I confirm that the proposal clearly defines the problem and the value of the on-chain utility.

Yes

I confirm that the primary goal of the proposal is a working prototype deployed on at least a Cardano testnet.

Yes

I confirm that the proposal outlines a credible and clear technical plan and architecture.

Yes

I confirm that the budget and timeline (≤ 12 months) are realistic for the proposed work.

Yes

I confirm that the proposal includes a community engagement and feedback plan to amplify prototype adoption with the Cardano ecosystem.

Yes

I confirm that the budget is for future development only; excludes retroactive funding, incentives, giveaways, re-granting, or sub-treasuries.

Yes

[Required Acknowledgements] Consent & Confirmation

I Agree

Yes