Spreadsheet computing, governed

Your spreadsheet logic, running as a governed cloud service.

Pebble Stream compiles the logic in Excel workbooks into validated, auditable workflows and APIs. Model in Excel with Zen, run at scale with Flow, deliver to clients with Board.

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From workbook to your enterprise systems

Logic modeled in an Excel workbook compiles into a Flow workflow that pulls data from ERPs, general ledgers, databases and files, and pushes results to ERPs, journal entries, data warehouses and custom applications
USPTO-patented spreadsheet computingOfficial reference data from nine publishersFlow 3.0 released October 2026Built in Washington, DC

One platform, three ways in.

Start free in Excel. Run in the cloud when your models need to. Put a delivery loop around them when clients are waiting on the results.

Zen

Free Excel add-in

Model in Excel with directives. See the dependency graph of every sheet, validate, execute in graph order, apply reporting palettes and pull official reference data.

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Flow

Headless spreadsheet runtime

Run compiled workbooks as workflows and APIs on parallel workers, in GSH's cloud or your own tenancy. Connectors, scheduling, telemetry and provenance of every output cell.

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Board

Client delivery loop

Clients upload, documents are read into inputs, workflows run, outputs are approved and delivered. One Board per client engagement, every action kept.

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Your spreadsheet is the specification. We just make it run.

  • No rewrite. The people who understand the logic keep working in Excel. PebbleScript directives in header notes describe inputs, outputs and checks; the compiler does the rest.
  • Governed by construction. Validation runs before any calculation. Every output cell carries its lineage back to the inputs that produced it.
  • Open by design. The Pebble Stream Open Spreadsheet Format keeps your models in plain text, readable by people and by agents, with no VBA anywhere.

Fund accounting and tax

Allocations, distributions, excise and 1099 work with a full audit trail.

Partnership allocations

K-1 packages read into inputs, computed, approved and delivered.

Reference data

Rates, curves and FX from official publishers, signed and versioned.

FP&A and operations

Models that survive the handoff and run on a schedule.

Decks and whitepapers

All resources →
deck · PDFPebble Stream overviewThe platform in twelve slides: Zen, Flow, Board and the Data Service.Download
whitepaper · PDFHeadless spreadsheet computingHow Flow executes compiled workbooks on parallel workers with cell-level provenance.Download
specification · PDFPebble Stream Open Spreadsheet FormatThe plain-text, VBA-free format for Pebble Stream spreadsheets.Download

Start in the spreadsheet you already have.

Zen is free. Add it to Excel and see your model's dependency graph in minutes. Ready for the cloud? Talk to us about Flow.

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