DESKTOP INSPECTOR · @ton/sandbox

Make TON's async execution visible.

Pontoon is a local-first desktop tool for @ton/sandbox. Deploy contracts, send messages, and watch the whole async transaction tree: phase-level fees, TVM traces, and state changes, without leaving your desk or reading raw VM logs.

@ton/sandbox/57 wire methods/local-first/no testnet
transaction inspector
bridge · 37631
EXT-INWallet v4 · Alice0.0038 TON
INTERNALJetton Wallet · Alice0.0121 TON
INTERNALJetton Wallet · Bob0.0104 TON
INTERNALWallet v4 · Bob0.0021 TON
INTERNALJetton Wallet · Alice0.0006 TON
·LOGevent · burn
PHASE BREAKDOWN · transfertotal 0.0121 TON
compute 0.0071 action 0.0038 storage 0.0002
WHAT YOU SEE

Every message, phase, and fee in one place.

Pontoon is a display layer for the sandbox you already run. It turns raw VM output into the structures TON developers actually reason about.

INSPECT

Transaction-tree inspector

The async message tree is the primary view. Expand every internal message, see the fan-out, and read status and fees inline.

FEES

Phase-level breakdown

Compute, action, and storage fees split out per transaction, so you know exactly where the gas went.

DEBUG

TVM step debugger

Step through VM instructions with a synchronized stack view and the current opcode kept in focus.

DECODE

Cell & TL-B viewer

Inspect BOC cells as a typed tree with breadcrumbs, decoded against your TL-B schema.

STATE

Snapshots & time control

Branch, fork, and revert sandbox state. Advance logical time to test timeouts deterministically.

MEASURE

Coverage & benchmarks

FunC and Tact source coverage plus gas benchmarks, pulled straight from your test runs.

Local-first, deterministic, no testnet.

Everything runs on your machine against @ton/sandbox. Same inputs, same results, every run.

01blueprint

Point it at your project

Attach a Blueprint project or run against seeded treasuries. Pontoon spins up one live Blockchain.create() instance locally.

02bridge

The bridge streams the sandbox

A local WebSocket bridge speaks a fixed 57-method wire contract over port 37631: every deploy, message, and trace, as it happens.

03inspect

Read the execution

The desktop app renders the async tree, phase fees, TVM traces, and state. A failed transaction becomes something you look at, not something you decode.

Twenty focused panels, one keyboard away.

Two-level navigation in the Supabase-studio pattern, with a ⌘K command palette. Every panel keeps its trace when you leave, so you never lose a response.

COMPOSE
  • Deploy
  • Send message
  • Get-method runner
INSPECT
  • Transaction inspector
  • Message tree
  • TVM step debugger
  • Cell & TL-B viewer
CHAIN STATE
  • Accounts
  • Contracts
  • State inspector
  • Block explorer
OBSERVABILITY
  • Logs console
  • Coverage
  • Benchmarks
  • Snapshots
  • Time control
  • Test runner

Debug your next TON transaction without reading a single VM log.

Free and local-first. Open a project, send a message, and watch the tree.