generated: '2026-07-22'
method: searched
source: https://data-api.b3.fun/
docs: https://docs.b3.fun/data/api-reference/introduction
note: >-
  B3 publishes no classic hosted sandbox environment, but ships a real test
  surface: dedicated testnet chains (with public explorers), an in-API faucet
  that sends testnet tokens to an organization's default wallet, and no-charge
  test/query modes for B3OS workflow actions. Everything below is taken verbatim
  from the live Data API root document and the B3OS Workflow OpenAPI — no values
  invented.
testnets:
  - chainId: 1993
    name: B3 Testnet
    network: b3-testnet
    explorer: https://sepolia.explorer.b3.fun
    source: https://data-api.b3.fun/ (supported_chains)
  - chainId: 243
    name: Reach Testnet
    network: reach-testnet
    explorer: https://reach-testnet.explorer.caldera.xyz
    source: https://data-api.b3.fun/ (supported_chains)
faucet:
  api: openapi/b3-b3os-workflow-openapi.json
  operation: POST /v1/faucet/claim
  detail: >-
    Send testnet tokens from the faucet to the organization's default wallet.
    Request body: ClaimFaucetParams {walletAddress, tokens[]}.
test_modes:
  - name: Action test
    operation: POST /v1/actions/{type}/test
    detail: Test an action with a custom payload before wiring it into a workflow.
  - name: Action query (read-only)
    operation: POST /v1/action-proxy/{type}/query
    detail: Query an action read-only — no Compute Unit (CU) charge.
  - name: Workflow validate
    operation: POST /v1/workflows/validate
    detail: Validate a workflow definition without saving it.
  - name: Inline ephemeral run
    operation: POST /v1/runs
    detail: Execute an inline workflow definition as an ephemeral run (no saved workflow).
live_vs_test:
  detail: >-
    The B3 Data API serves mainnet and testnet chains from the same host —
    select the chain per request; testnet chains (b3-testnet, reach-testnet)
    are the test surface. B3OS actions execute against whichever chain the
    connector/workflow targets.