feat: read a market's details from a create_market transaction

[MicBun]

resolves: https://github.com/trufnetwork/trufscan/issues/173

A block explorer reading a create_market transaction gets back its five raw action arguments, one of which (query_components) is a nested double-encoding — an ABI tuple wrapping a kwil-native argument blob. Decoding that meant knowing create_market's argument order and stitching two decoders together by hand. The SDK owns the encode side (OrderbookAction.createMarket, encodeQueryComponents), so it should own the symmetric decode.

Adds decodeCreateMarketPayload(payload), the transaction-level counterpart to createMarket. Given a decoded execute payload (from TransactionAction.getTransactionInput / decodeTransactionPayload) it returns a structured CreateMarketPayload:

const payload = await client.loadTransactionAction().getTransactionInput({ txId });
const created = decodeCreateMarketPayload(payload);
if (created) {
  // { bridge, queryComponents, market: { type, thresholds, streamId, dataProvider },
  //   settleTime, maxSpread, minOrderSize }
}

• Returns null when the transaction isn't a create_market call, so callers branch cleanly.
• Throws when it is a create_market but doesn't carry its five arguments.
• The nested query_components are decoded to MarketData (type + thresholds) via the existing decodeMarketData. Decode is non-fatal: a committed-but-execution-failed create_market can carry empty/garbage components, so market is left null rather than crashing an explorer that's iterating a block.

The argument order ($bridge, $query_components, $settle_time, $max_spread, $min_order_size) matches the on-chain create_market signature in node migration 032-order-book-actions.sql.

Test-first: four cases watched fail before the code existed — structured fields, the nested market decode, the null-when-not-create_market path, and the throw-on-truncated path. Also verified against the exact query_components byte vector from trufscan#173. test:unit (292), typecheck, and build are green.

Summary by CodeRabbit

• New Features

  • Added support for decoding create_market transaction details into a structured, easy-to-use format.
  • Exposed additional market-related fields, including bridge, settlement timing, spread, minimum order size, and nested market data when available.

• Bug Fixes

  • Improved handling for malformed market details by preserving the main payload and safely returning no nested market data when decoding fails.
  • Returns no result for unrelated transaction actions and validates required inputs more strictly.

• Tests

  • Added coverage for successful decoding, missing fields, invalid actions, and fallback behavior.

[holdex]

Time Submission Status

Member	#	Time	Running Total	Status	Last Update
MicBun			4h	✅ Submitted	Jul 9, 2026, 3:38 PM

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[coderabbitai]

📝 Walkthrough

Walkthrough

Adds a new CreateMarketPayload interface and decodeCreateMarketPayload function in orderbookHelpers.ts that decode create_market transaction payloads, including nested market data via decodeMarketData. Re-exports these from internal.ts and adds corresponding test coverage.

Changes

decodeCreateMarketPayload decoder

Layer / File(s)	Summary
Decoder implementation src/util/orderbookHelpers.ts	Adds CreateMarketPayload interface and decodeCreateMarketPayload function that validates the create_market action, checks argument count (throwing if insufficient), converts query_components to bytes and decodes nested market data (setting market to null on decode failure), and maps remaining arguments to typed fields.
Public export src/internal.ts	Re-exports decodeCreateMarketPayload and expands the type re-export to include CreateMarketPayload alongside MarketData.
Test coverage src/util/orderbookHelpers.test.ts	Adds tests for decoding top-level and nested market fields, handling undecodable query_components, returning null for non-create_market actions, and throwing on missing arguments.

Estimated code review effort: 2 (Simple) | ~10 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Caller
  participant decodeCreateMarketPayload
  participant decodeMarketData

  Caller->>decodeCreateMarketPayload: payload (DecodedTransactionPayload)
  decodeCreateMarketPayload->>decodeCreateMarketPayload: check action === "create_market"
  decodeCreateMarketPayload->>decodeCreateMarketPayload: validate call arguments length
  decodeCreateMarketPayload->>decodeMarketData: query_components bytes
  decodeMarketData-->>decodeCreateMarketPayload: market or decode error
  decodeCreateMarketPayload-->>Caller: CreateMarketPayload or null

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Possibly related PRs

• trufnetwork/sdk-js#149: Both PRs extend the orderbook helpers module and its public exports via src/internal.ts.
• trufnetwork/sdk-js#153: Both PRs update src/internal.ts to re-export additional decoding utilities from ./util/orderbookHelpers.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: decoding market details from a create_market transaction.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/decode-create-market-tx

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[MicBun]

@holdex pr submit-time 4h