Support decoding codama program events (#25)

* Support decoding codama program events

* Update changelogs

* Tidy up

Author: stwiname

packages/common-solana/CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- Util function to get discriminator from name (#25)
 
 ## [1.1.1] - 2025-09-10
 ### Fixed

packages/common-solana/src/codegen/idl.ts

@@ -1,6 +1,7 @@
 // Copyright 2020-2025 SubQuery Pte Ltd authors & contributors
 // SPDX-License-Identifier: GPL-3.0
 
+import {createHash} from 'node:crypto';
 import fs from 'node:fs';
 import {AnchorIdl, IdlV01, rootNodeFromAnchor} from '@codama/nodes-from-anchor';
 import {getBase16Encoder, getBase58Encoder, getBase64Encoder, getUtf8Encoder} from '@solana/codecs-strings';
@@ -87,3 +88,9 @@ export function findInstructionDiscriminatorByName(rootNode: RootNode, name: str
     return undefined;
   }
 }
+
+// Discriminator are the first 8 bytes of the sha256 over the event's name
+export function getDiscriminator(name: string): Uint8Array {
+  const hash = createHash('sha256').update(`event:${name}`).digest();
+  return new Uint8Array(hash.subarray(0, 8));
+}

packages/node/CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- Support for decoding codama program logs (#25)
 
 ## [6.1.2] - 2025-09-11
 ### Fixed

packages/node/src/solana/decoder.spec.ts

@@ -11,8 +11,11 @@ import { SolanaDecoder } from './decoder';
 import { getProgramId, filterInstructionsProcessor } from './utils.solana';
 
 const HTTP_ENDPOINT =
-  process.env.HTTP_ENDPOINT ?? 'https://solana.api.onfinality.io/public';
+  process.env.HTTP_ENDPOINT ??
+  'https://api.mainnet-beta.solana.com' ??
+  'https://solana.api.onfinality.io/public';
 
+const IDL_codama_0_1_0: IdlV01 = require('../../test/8t2R21V3vjS1ucZzmX2memtGptjYZi2yGY3cYVa8dak7.idl.json');
 const IDL_Jupiter: IdlV01 = require('../../test/JUP6LkbZbjS1jKKwapdHNy74zcZ3tLUZoi5QNyVTaV4.idl.json');
 const IDL_swap: IdlV01 = require('../../test/swapFpHZwjELNnjvThjajtiVmkz3yPQEHjLtka2fwHW.idl.json');
 const IDL_token: RootNode = require('../../test/TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA.idl.json');
@@ -47,6 +50,9 @@ describe('SolanaDecoder', () => {
     decoder.idls['swapFpHZwjELNnjvThjajtiVmkz3yPQEHjLtka2fwHW'] = IDL_swap;
     // eslint-disable-next-line @typescript-eslint/dot-notation
     decoder.idls['TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA'] = IDL_token;
+    // eslint-disable-next-line @typescript-eslint/dot-notation
+    decoder.idls['8t2R21V3vjS1ucZzmX2memtGptjYZi2yGY3cYVa8dak7'] =
+      IDL_codama_0_1_0;
   };
 
   describe('caching IDLs', () => {
@@ -265,5 +271,43 @@ describe('SolanaDecoder', () => {
       expect(decoded!.name).toBe('poolBalanceUpdatedEvent');
       expect(decoded!.data).toEqual(logData);
     });
+
+    it('can decode codama 0.1.0 spec idl events', async () => {
+      const solanaApi = await SolanaApi.create(
+        'https://api.devnet.solana.com',
+        new EventEmitter2(),
+        decoder,
+      );
+
+      const block = await solanaApi.fetchBlock(405402294);
+
+      const tx = findTx(
+        block.block,
+        '4xHLJtomvuF2DAwtDoHgGqABv47kmqMCvd691bRe9XhiAP99grjvpAdvNQGnA4PETZSvhXdfHvvHUNWu2SNM3aqE',
+      );
+
+      expect(tx).toBeDefined();
+
+      const programLogs = tx!.meta!.logs?.filter((l) =>
+        l.message.startsWith('Program data:'),
+      );
+      expect(programLogs).toBeDefined();
+      const decoded = await programLogs![0].decodedMessage;
+      expect(decoded).not.toBeNull();
+      expect(decoded!.name).toEqual('createCampaign');
+      expect(decoded!.data).toMatchObject({
+        aggregateAmount: 10000n,
+        campaign: 'BjYpCVaiksvD8Dw4LixUJVNaCptefKk86nDtw419b7Y5',
+        campaignName: 'HODL or Nothing',
+        campaignStartTime: 1754142441n,
+        creator: 'HTtnrJ5iq9HVVypJZxFKMCcR6JDiUqT6yaE7c6BvfeTp',
+        expirationTime: 1757776469n,
+        ipfsCid: 'bafkreiecpwdhvkmw4y6iihfndk7jhwjas3m5htm7nczovt6m37mucwgsrq',
+        merkleRoot: ['base64', '1SVJywcqH80FJBL8gPZ47/6Sru7czRyuYyxcbh3ok3k='],
+        recipientCount: 100,
+        tokenDecimals: 6,
+        tokenMint: '4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU',
+      });
+    });
   });
 });

packages/node/src/solana/decoder.ts

@@ -10,6 +10,9 @@ import {
   isAnchorIdlV01,
   getInstructionDiscriminatorBytes,
   findInstructionDiscriminatorByName,
+  getDiscriminator,
+  isRootNode,
+  isAnchorIdl,
 } from '@subql/common-solana';
 import { getLogger } from '@subql/node-core';
 import {
@@ -21,7 +24,14 @@ import {
 } from '@subql/types-solana';
 import { isHex } from '@subql/utils';
 import bs58 from 'bs58';
-import { camelCase, DefinedTypeNode, InstructionNode, RootNode } from 'codama';
+import {
+  camelCase,
+  DefinedTypeNode,
+  InstructionNode,
+  pascalCase,
+  RootNode,
+  titleCase,
+} from 'codama';
 import { Memoize } from '../utils/decorators';
 import { allAccounts, getProgramId } from './utils.solana';
 
@@ -99,14 +109,36 @@ export function decodeInstruction(
 
 // Codama doesn't support Logs so extra work is required to decode logs
 export function decodeLog(idl: Idl, message: string): DecodedData | null {
+  const msgData = message.replace('Program data: ', '');
+  const msgBuffer = basedToBuffer(msgData);
+
+  // Codama IDL, doesn't include events in the IDL but it should decoded to a definedType in the IDL
+  if (!isAnchorIdl(idl)) {
+    if (msgBuffer.length < 8) {
+      // Not enough data for a discriminator
+      return null;
+    }
+
+    // Split the discriminator and data
+    const logDisc = msgBuffer.subarray(0, 8);
+    const data = msgBuffer.subarray(8);
+
+    // Attempt to find the matching type by discriminator and decode the data
+    return decodeData(idl, data.toString('base64'), (root) => {
+      return root.program.definedTypes.find(
+        (t) =>
+          // Warning this is fragile as there can be various casings of the type names, but because it requires hashing data we can only go one way
+          logDisc.indexOf(getDiscriminator(t.name)) === 0 ||
+          logDisc.indexOf(getDiscriminator(pascalCase(t.name))) === 0,
+      );
+    });
+  }
+
   // Older versions don't support events
   if (!isAnchorIdlV01(idl)) {
     throw new Error('Only Anchor IDL v0.1.0 is supported for decoding logs');
   }
 
-  const msgData = message.replace('Program data: ', '') as any;
-  const msgBuffer = basedToBuffer(msgData);
-
   // Codama doesn't include events so we have to find it manually
   const event = idl.events?.find(
     (e) => msgBuffer.indexOf(Buffer.from(e.discriminator)) === 0,
@@ -121,7 +153,7 @@ export function decodeLog(idl: Idl, message: string): DecodedData | null {
     .subarray(event.discriminator.length)
     .toString('base64');
 
-  return decodeData(idl, input as any, (root, data) => {
+  return decodeData(idl, input, (root) => {
     return root.program.definedTypes.find(
       (t) => t.name === event.name || t.name === camelCase(event.name),
     );