diff --git a/bin/convert/types.ts b/bin/convert/types.ts
index 8dd4b3dea..2cc568adc 100644
--- a/bin/convert/types.ts
+++ b/bin/convert/types.ts
@@ -56,7 +56,7 @@ export const SUPPORTED_TYPES: readonly SupportedType[] = [
     name: "header",
     encode: Header.Codec,
     decode: Header.Codec,
-    json: (spec: ChainSpec) => headerFromJson(spec),
+    json: (_spec: ChainSpec) => headerFromJson,
     process: {
       options: ["as-hash"],
       run(spec, data, option, blake2b) {
@@ -132,7 +132,7 @@ export const SUPPORTED_TYPES: readonly SupportedType[] = [
     name: "stf-genesis",
     encode: StateTransitionGenesis.Codec,
     decode: StateTransitionGenesis.Codec,
-    json: (spec: ChainSpec) => StateTransitionGenesis.fromJson(spec),
+    json: (_spec: ChainSpec) => StateTransitionGenesis.fromJson,
     process: {
       options: ["as-state", "as-jip4", "as-fuzz-message"],
       run(spec: ChainSpec, data: unknown, option: string, blake2b) {
diff --git a/bin/test-runner/jam-conformance-071.ts b/bin/test-runner/jam-conformance-071.ts
index 7b78dfdfb..786af12cd 100644
--- a/bin/test-runner/jam-conformance-071.ts
+++ b/bin/test-runner/jam-conformance-071.ts
@@ -12,13 +12,6 @@ main(runners, "test-vectors/jam-conformance/fuzz-reports/0.7.1/traces", {
     // no timeslot in pre-state - valid behavior
     "1763371531/00000042.json",
     "1763489287/00000872.json",
-    // WorkItemsCount === 0 - valid behavior
-    "1763371098/00000006.json",
-    "1763372314/00000094.json",
-    // Invalid ticket attempt - valid behavior
-    "1763371155/00000055.json",
-    "1763488328/00000051.json",
-    "1763487981/00000051.json",
   ],
 })
   .then((r) => logger.log`${r}`)
diff --git a/bin/test-runner/jam-conformance-072.ts b/bin/test-runner/jam-conformance-072.ts
index 9b0583733..bb700f854 100644
--- a/bin/test-runner/jam-conformance-072.ts
+++ b/bin/test-runner/jam-conformance-072.ts
@@ -10,30 +10,6 @@ main(runners, "test-vectors/jam-conformance/fuzz-reports/0.7.2/traces", {
 
     // Block should be rejected?
     "1766565819_2010/00000225.json",
-
-    // Rejecting for WorkItemsCount: valid behavior
-    "1766244251_2939/00001634.json",
-    "1766243861_2056/00000022.json",
-    "1766243861_5589/00000207.json",
-    "1766479507_3250/00000001.json",
-    "1766565819_9888/00001868.json",
-    "1767871405_3616/00000386.json",
-    "1767872928_6833/00003568.json",
-    "1767872928_7682/00000035.json",
-    "1767895984_2203/00012889.json",
-    "1767895984_2519/00008157.json",
-    "1767895984_3511/00000469.json",
-    "1767895984_4076/00010619.json",
-    "1767896003_1048/00005219.json",
-    "1767896003_2541/00013907.json",
-    // Rejecting for invalid ticket attempt: valid behavior
-    "1766244251_1816/00000377.json",
-    "1766244122_5414/00000482.json",
-    "1766243315_2277/00000123.json",
-    "1766565819_7584/00000277.json",
-    "1767872928_1994/00000399.json",
-    "1767889897_4774/00002350.json",
-    "1767889897_7743/00000301.json",
   ],
 })
   .then((r) => logger.log`${r}`)
diff --git a/bin/test-runner/w3f/runners.ts b/bin/test-runner/w3f/runners.ts
index 2cb318a6e..0a9a47e42 100644
--- a/bin/test-runner/w3f/runners.ts
+++ b/bin/test-runner/w3f/runners.ts
@@ -67,8 +67,8 @@ export const runners = [
   runner("pvm", runPvmTest).fromJson(PvmTest.fromJson),
   runner("gas-cost-tests", runPvmGasCostTest).fromJson(PvmGasCostTest.fromJson),
   runner("reports", runReportsTest, tinyFull).fromJson(ReportsTest.fromJson),
-  runner("safrole", runSafroleTest, tiny).fromJson(SafroleTest.fromJson(tinyChainSpec)),
-  runner("safrole", runSafroleTest, full).fromJson(SafroleTest.fromJson(fullChainSpec)),
+  runner("safrole", runSafroleTest, tiny).fromJson(SafroleTest.fromJson),
+  runner("safrole", runSafroleTest, full).fromJson(SafroleTest.fromJson),
   runner("shuffle", runShufflingTests).fromJson(shufflingTestsFromJson),
   runner("statistics/tiny", runStatisticsTestTiny, tiny).fromJson(StatisticsTestTiny.fromJson),
   runner("statistics/full", runStatisticsTestFull, full).fromJson(StatisticsTestFull.fromJson),
@@ -92,14 +92,12 @@ function codecRunners(flavor: "tiny" | "full") {
     runner(`codec/${flavor}/guarantees_extrinsic`, runGuaranteesExtrinsicTest, [spec]).fromJson(
       guaranteesExtrinsicFromJson,
     ),
-    runner(`codec/${flavor}/header`, runHeaderTest, [spec]).fromJson(headerFromJson(spec)),
+    runner(`codec/${flavor}/header`, runHeaderTest, [spec]).fromJson(headerFromJson),
     runner(`codec/${flavor}/preimages_extrinsic`, runPreimagesExtrinsicTest, [spec]).fromJson(
       preimagesExtrinsicFromJson,
     ),
     runner(`codec/${flavor}/refine_context`, runRefineContextTest, [spec]).fromJson(refineContextFromJson),
-    runner(`codec/${flavor}/tickets_extrinsic`, runTicketsExtrinsicTest, [spec]).fromJson(
-      ticketsExtrinsicFromJson(spec),
-    ),
+    runner(`codec/${flavor}/tickets_extrinsic`, runTicketsExtrinsicTest, [spec]).fromJson(ticketsExtrinsicFromJson),
     runner(`codec/${flavor}/work_item`, runWorkItemTest, [spec]).fromJson(workItemFromJson),
     runner(`codec/${flavor}/work_package`, runWorkPackageTest, [spec]).fromJson(workPackageFromJson),
     runner(`codec/${flavor}/work_report`, runWorkReportTest, [spec]).fromJson(workReportFromJson),
diff --git a/bin/test-runner/w3f/safrole.ts b/bin/test-runner/w3f/safrole.ts
index d7878322e..33897067b 100644
--- a/bin/test-runner/w3f/safrole.ts
+++ b/bin/test-runner/w3f/safrole.ts
@@ -61,20 +61,18 @@ export enum TestErrorCode {
 }
 
 class JsonState {
-  static fromJson(spec: ChainSpec): FromJson<JsonState> {
-    return {
-      tau: "number",
-      eta: json.array(fromJson.bytes32()),
-      lambda: json.array(validatorDataFromJson),
-      kappa: json.array(validatorDataFromJson),
-      gamma_k: json.array(validatorDataFromJson),
-      iota: json.array(validatorDataFromJson),
-      gamma_a: json.array(ticketFromJson(spec)),
-      gamma_s: TicketsOrKeys.fromJson(spec),
-      gamma_z: json.fromString((v) => Bytes.parseBytes(v, BANDERSNATCH_RING_ROOT_BYTES).asOpaque()),
-      post_offenders: json.array(fromJson.bytes32()),
-    };
-  }
+  static fromJson: FromJson<JsonState> = {
+    tau: "number",
+    eta: json.array(fromJson.bytes32()),
+    lambda: json.array(validatorDataFromJson),
+    kappa: json.array(validatorDataFromJson),
+    gamma_k: json.array(validatorDataFromJson),
+    iota: json.array(validatorDataFromJson),
+    gamma_a: json.array(ticketFromJson),
+    gamma_s: TicketsOrKeys.fromJson(),
+    gamma_z: json.fromString((v) => Bytes.parseBytes(v, BANDERSNATCH_RING_ROOT_BYTES).asOpaque()),
+    post_offenders: json.array(fromJson.bytes32()),
+  };
   // timeslot
   tau!: TimeSlot;
   // entropy
@@ -124,23 +122,19 @@ export class EpochMark {
 }
 
 export class OkOutput {
-  static fromJson(spec: ChainSpec): FromJson<OkOutput> {
-    return {
-      epoch_mark: json.optional(EpochMark.fromJson),
-      tickets_mark: json.optional<Ticket[]>(json.array(ticketFromJson(spec))),
-    };
-  }
+  static fromJson: FromJson<OkOutput> = {
+    epoch_mark: json.optional(EpochMark.fromJson),
+    tickets_mark: json.optional<Ticket[]>(json.array(ticketFromJson)),
+  };
   epoch_mark?: EpochMark | null;
   tickets_mark?: Ticket[] | null;
 }
 
 export class Output {
-  static fromJson(spec: ChainSpec): FromJson<Output> {
-    return {
-      ok: json.optional(OkOutput.fromJson(spec)),
-      err: json.optional("string"),
-    };
-  }
+  static fromJson: FromJson<Output> = {
+    ok: json.optional(OkOutput.fromJson),
+    err: json.optional("string"),
+  };
 
   ok?: OkOutput;
   err?: TestErrorCode;
@@ -202,14 +196,12 @@ class TestInput {
 }
 
 export class SafroleTest {
-  static fromJson(spec: ChainSpec): FromJson<SafroleTest> {
-    return {
-      input: TestInput.fromJson,
-      pre_state: JsonState.fromJson(spec),
-      output: Output.fromJson(spec),
-      post_state: JsonState.fromJson(spec),
-    };
-  }
+  static fromJson: FromJson<SafroleTest> = {
+    input: TestInput.fromJson,
+    pre_state: JsonState.fromJson,
+    output: Output.fromJson,
+    post_state: JsonState.fromJson,
+  };
 
   input!: TestInput;
   pre_state!: JsonState;
diff --git a/package-lock.json b/package-lock.json
index c1aea339e..18ae8ed29 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -5667,9 +5667,9 @@
       }
     },
     "node_modules/flatted": {
-      "version": "3.3.3",
-      "resolved": "https://registry.npmjs.org/flatted/-/flatted-3.3.3.tgz",
-      "integrity": "sha512-GX+ysw4PBCz0PzosHDepZGANEuFCMLrnRTiEy9McGjmkCQYwRq4A/X786G/fjM/+OjsWSU1ZrY5qyARZmO/uwg==",
+      "version": "3.4.2",
+      "resolved": "https://registry.npmjs.org/flatted/-/flatted-3.4.2.tgz",
+      "integrity": "sha512-PjDse7RzhcPkIJwy5t7KPWQSZ9cAbzQXcafsetQoD7sOJRQlGikNbx7yZp2OotDnJyrDcbyRq3Ttb18iYOqkxA==",
       "dev": true,
       "license": "ISC"
     },
diff --git a/packages/jam/block-json/block.ts b/packages/jam/block-json/block.ts
index 1f026cdfe..524ce0374 100644
--- a/packages/jam/block-json/block.ts
+++ b/packages/jam/block-json/block.ts
@@ -7,7 +7,7 @@ import { headerFromJson } from "./header.js";
 export const blockFromJson = (spec: ChainSpec) =>
   json.object<Block>(
     {
-      header: headerFromJson(spec),
+      header: headerFromJson,
       extrinsic: getExtrinsicFromJson(spec),
     },
     ({ header, extrinsic }) => Block.create({ header, extrinsic }),
diff --git a/packages/jam/block-json/common.ts b/packages/jam/block-json/common.ts
index 1f64e3e0d..61ab55315 100644
--- a/packages/jam/block-json/common.ts
+++ b/packages/jam/block-json/common.ts
@@ -1,6 +1,5 @@
 import { type TicketAttempt, tryAsTicketAttempt } from "@typeberry/block/tickets.js";
 import { Bytes, BytesBlob } from "@typeberry/bytes";
-import type { ChainSpec } from "@typeberry/config";
 import type { Ed25519Signature } from "@typeberry/crypto";
 import { type FromJson, json } from "@typeberry/json-parser";
 
@@ -22,10 +21,9 @@ export namespace fromJson {
 
   export const ed25519Signature = json.fromString<Ed25519Signature>((v) => Bytes.parseBytes(v, 64).asOpaque());
 
-  export const ticketAttempt = (spec: ChainSpec) =>
-    json.fromNumber((v) => {
-      return tryAsTicketAttempt(v, spec);
-    }) as FromJson<TicketAttempt>;
+  export const ticketAttempt = json.fromNumber((v) => {
+    return tryAsTicketAttempt(v);
+  }) as FromJson<TicketAttempt>;
 
   export const uint8Array = json.fromAny((v) => {
     if (Array.isArray(v)) {
diff --git a/packages/jam/block-json/extrinsic.ts b/packages/jam/block-json/extrinsic.ts
index 9d8180b51..3157cdf29 100644
--- a/packages/jam/block-json/extrinsic.ts
+++ b/packages/jam/block-json/extrinsic.ts
@@ -11,7 +11,7 @@ import { ticketsExtrinsicFromJson } from "./tickets-extrinsic.js";
 export const getExtrinsicFromJson = (ctx: ChainSpec) =>
   json.object<Extrinsic>(
     {
-      tickets: ticketsExtrinsicFromJson(ctx),
+      tickets: ticketsExtrinsicFromJson,
       preimages: preimagesExtrinsicFromJson,
       guarantees: guaranteesExtrinsicFromJson,
       assurances: getAssurancesExtrinsicFromJson(ctx),
diff --git a/packages/jam/block-json/header.ts b/packages/jam/block-json/header.ts
index 78ff2d2f1..7b87ee342 100644
--- a/packages/jam/block-json/header.ts
+++ b/packages/jam/block-json/header.ts
@@ -13,7 +13,6 @@ import {
 } from "@typeberry/block";
 import { Ticket } from "@typeberry/block/tickets.js";
 import { Bytes } from "@typeberry/bytes";
-import type { ChainSpec } from "@typeberry/config";
 import type { BandersnatchKey, Ed25519Key } from "@typeberry/crypto";
 import type { BandersnatchVrfSignature } from "@typeberry/crypto/bandersnatch.js";
 import { json } from "@typeberry/json-parser";
@@ -58,57 +57,55 @@ type JsonHeader = {
   seal: BandersnatchVrfSignature;
 };
 
-export const headerFromJson = (spec: ChainSpec) => {
-  const ticket = json.object<Ticket>(
-    {
-      id: fromJson.bytes32(),
-      attempt: fromJson.ticketAttempt(spec),
-    },
-    (x) => Ticket.create({ id: x.id, attempt: x.attempt }),
-  );
+const ticket = json.object<Ticket>(
+  {
+    id: fromJson.bytes32(),
+    attempt: fromJson.ticketAttempt,
+  },
+  (x) => Ticket.create({ id: x.id, attempt: x.attempt }),
+);
 
-  return json.object<JsonHeader, Header>(
-    {
-      parent: fromJson.bytes32(),
-      parent_state_root: fromJson.bytes32(),
-      extrinsic_hash: fromJson.bytes32(),
-      slot: "number",
-      epoch_mark: json.optional(epochMark),
-      tickets_mark: json.optional(json.array(ticket)),
-      offenders_mark: json.array(fromJson.bytes32<Ed25519Key>()),
-      author_index: "number",
-      entropy_source: bandersnatchVrfSignature,
-      seal: bandersnatchVrfSignature,
-    },
-    ({
-      parent,
-      parent_state_root,
-      extrinsic_hash,
-      slot,
-      epoch_mark,
-      tickets_mark,
-      offenders_mark,
-      author_index,
-      entropy_source,
+export const headerFromJson = json.object<JsonHeader, Header>(
+  {
+    parent: fromJson.bytes32(),
+    parent_state_root: fromJson.bytes32(),
+    extrinsic_hash: fromJson.bytes32(),
+    slot: "number",
+    epoch_mark: json.optional(epochMark),
+    tickets_mark: json.optional(json.array(ticket)),
+    offenders_mark: json.array(fromJson.bytes32<Ed25519Key>()),
+    author_index: "number",
+    entropy_source: bandersnatchVrfSignature,
+    seal: bandersnatchVrfSignature,
+  },
+  ({
+    parent,
+    parent_state_root,
+    extrinsic_hash,
+    slot,
+    epoch_mark,
+    tickets_mark,
+    offenders_mark,
+    author_index,
+    entropy_source,
+    seal,
+  }) => {
+    const epochMarker = epoch_mark ?? null;
+    const ticketsMarker =
+      tickets_mark === undefined || tickets_mark === null
+        ? null
+        : TicketsMarker.create({ tickets: asOpaqueType(tickets_mark) });
+    return Header.create({
+      parentHeaderHash: parent,
+      priorStateRoot: parent_state_root,
+      extrinsicHash: extrinsic_hash,
+      timeSlotIndex: slot,
+      epochMarker,
+      ticketsMarker,
+      offendersMarker: offenders_mark,
+      bandersnatchBlockAuthorIndex: author_index,
+      entropySource: entropy_source,
       seal,
-    }) => {
-      const epochMarker = epoch_mark ?? null;
-      const ticketsMarker =
-        tickets_mark === undefined || tickets_mark === null
-          ? null
-          : TicketsMarker.create({ tickets: asOpaqueType(tickets_mark) });
-      return Header.create({
-        parentHeaderHash: parent,
-        priorStateRoot: parent_state_root,
-        extrinsicHash: extrinsic_hash,
-        timeSlotIndex: slot,
-        epochMarker,
-        ticketsMarker,
-        offendersMarker: offenders_mark,
-        bandersnatchBlockAuthorIndex: author_index,
-        entropySource: entropy_source,
-        seal,
-      });
-    },
-  );
-};
+    });
+  },
+);
diff --git a/packages/jam/block-json/tickets-extrinsic.ts b/packages/jam/block-json/tickets-extrinsic.ts
index 58fc4838b..ffbdd9985 100644
--- a/packages/jam/block-json/tickets-extrinsic.ts
+++ b/packages/jam/block-json/tickets-extrinsic.ts
@@ -1,18 +1,15 @@
 import { SignedTicket } from "@typeberry/block/tickets.js";
 import { Bytes } from "@typeberry/bytes";
-import type { ChainSpec } from "@typeberry/config";
 import { BANDERSNATCH_PROOF_BYTES } from "@typeberry/crypto/bandersnatch.js";
 import { json } from "@typeberry/json-parser";
 import { fromJson } from "./common.js";
 
-export const ticketsExtrinsicFromJson = (spec: ChainSpec) => {
-  const ticketEnvelopeFromJson = json.object<SignedTicket>(
-    {
-      attempt: fromJson.ticketAttempt(spec),
-      signature: json.fromString((v) => Bytes.parseBytes(v, BANDERSNATCH_PROOF_BYTES).asOpaque()),
-    },
-    (x) => SignedTicket.create({ attempt: x.attempt, signature: x.signature }),
-  );
+const ticketEnvelopeFromJson = json.object<SignedTicket>(
+  {
+    attempt: fromJson.ticketAttempt,
+    signature: json.fromString((v) => Bytes.parseBytes(v, BANDERSNATCH_PROOF_BYTES).asOpaque()),
+  },
+  (x) => SignedTicket.create({ attempt: x.attempt, signature: x.signature }),
+);
 
-  return json.array(ticketEnvelopeFromJson);
-};
+export const ticketsExtrinsicFromJson = json.array(ticketEnvelopeFromJson);
diff --git a/packages/jam/block-json/work-result.ts b/packages/jam/block-json/work-result.ts
index 3c80c0059..aa04ead88 100644
--- a/packages/jam/block-json/work-result.ts
+++ b/packages/jam/block-json/work-result.ts
@@ -58,7 +58,7 @@ type JsonWorkExecResult = {
 
 const workRefineLoadFromJson = json.object<JsonWorkRefineLoad, WorkRefineLoad>(
   {
-    gas_used: json.fromNumber((x) => tryAsServiceGas(x)),
+    gas_used: json.fromBigInt((x) => tryAsServiceGas(x)),
     imports: "number",
     extrinsic_count: "number",
     extrinsic_size: "number",
@@ -66,7 +66,7 @@ const workRefineLoadFromJson = json.object<JsonWorkRefineLoad, WorkRefineLoad>(
   },
   ({ gas_used, imports, extrinsic_count, extrinsic_size, exports }) =>
     WorkRefineLoad.create({
-      gasUsed: tryAsServiceGas(gas_used),
+      gasUsed: gas_used,
       importedSegments: tryAsU32(imports),
       extrinsicCount: tryAsU32(extrinsic_count),
       extrinsicSize: tryAsU32(extrinsic_size),
diff --git a/packages/jam/block/tickets.ts b/packages/jam/block/tickets.ts
index 3ea537bf4..dba83be97 100644
--- a/packages/jam/block/tickets.ts
+++ b/packages/jam/block/tickets.ts
@@ -1,7 +1,6 @@
 import type { Bytes } from "@typeberry/bytes";
 import { type CodecRecord, codec } from "@typeberry/codec";
 import type { KnownSizeArray } from "@typeberry/collections";
-import type { ChainSpec } from "@typeberry/config";
 import { BANDERSNATCH_PROOF_BYTES, type BandersnatchProof } from "@typeberry/crypto/bandersnatch.js";
 import { HASH_SIZE } from "@typeberry/hash";
 import { tryAsU8, tryAsU32, type U8 } from "@typeberry/numbers";
@@ -14,23 +13,15 @@ import { codecKnownSizeArray, codecWithContext } from "./codec-utils.js";
  * Constrained by `N = 2`:
  * https://graypaper.fluffylabs.dev/#/579bd12/417200417400
  */
-export type TicketAttempt = Opaque<U8, "TicketAttempt[0|1|2]">;
-export function tryAsTicketAttempt(x: number, chainSpec: ChainSpec): TicketAttempt {
-  if (x >= chainSpec.ticketsPerValidator) {
-    throw new Error(`Ticket attempt ${x} is out of bounds [0, ${chainSpec.ticketsPerValidator})`);
-  }
+export type TicketAttempt = Opaque<U8, "TicketAttempt[u8]">;
+export function tryAsTicketAttempt(x: number): TicketAttempt {
   return asOpaqueType(tryAsU8(x));
 }
 
-const ticketAttemptCodec = codecWithContext((context) => {
-  return codec.varU32.convert<TicketAttempt>(
-    (x) => {
-      tryAsTicketAttempt(x, context);
-      return tryAsU32(x);
-    },
-    (x) => tryAsTicketAttempt(x, context),
-  );
-});
+const ticketAttemptCodec = codec.varU32.convert<TicketAttempt>(
+  (x) => tryAsU32(x),
+  (x) => tryAsTicketAttempt(x),
+);
 
 /* Bandersnatch-signed ticket contest entry. */
 export class SignedTicket extends WithDebug {
diff --git a/packages/jam/block/work-package.ts b/packages/jam/block/work-package.ts
index 6fee24567..1423e5946 100644
--- a/packages/jam/block/work-package.ts
+++ b/packages/jam/block/work-package.ts
@@ -3,7 +3,7 @@ import { type CodecRecord, codec, type DescribedBy } from "@typeberry/codec";
 import { FixedSizeArray } from "@typeberry/collections";
 import { HASH_SIZE } from "@typeberry/hash";
 import { tryAsU8, type U8 } from "@typeberry/numbers";
-import { check, WithDebug } from "@typeberry/utils";
+import { WithDebug } from "@typeberry/utils";
 import type { ServiceId } from "./common.js";
 import type { CodeHash } from "./hash.js";
 import { RefineContext } from "./refine-context.js";
@@ -13,12 +13,8 @@ import { WorkItem } from "./work-item.js";
 /** Constrained by I=16 https://graypaper.fluffylabs.dev/#/68eaa1f/417a00417a00?v=0.6.4 */
 export type WorkItemsCount = U8;
 
-/** Convert the value to `WorkItemsCount` bounds. */
+/** Convert the value to `WorkItemsCount`. Validation is done at runtime by `isWorkItemsCount`. */
 export function tryAsWorkItemsCount(len: number): WorkItemsCount {
-  check`
-    ${isWorkItemsCount(len)}
-    WorkItemsCount: Expected '${MIN_NUMBER_OF_WORK_ITEMS} <= count <= ${MAX_NUMBER_OF_WORK_ITEMS}' got ${len}
-  `;
   return tryAsU8(len);
 }
 
diff --git a/packages/jam/jamnp-s/protocol/ce-131-ce-132-safrole-ticket-distribution.test.ts b/packages/jam/jamnp-s/protocol/ce-131-ce-132-safrole-ticket-distribution.test.ts
index 9a867da0c..9c35be276 100644
--- a/packages/jam/jamnp-s/protocol/ce-131-ce-132-safrole-ticket-distribution.test.ts
+++ b/packages/jam/jamnp-s/protocol/ce-131-ce-132-safrole-ticket-distribution.test.ts
@@ -15,7 +15,7 @@ import { testClientServer } from "./test-utils.js";
 
 const TEST_EPOCH = tryAsEpoch(1);
 const TEST_TICKET = SignedTicket.create({
-  attempt: tryAsTicketAttempt(0, tinyChainSpec),
+  attempt: tryAsTicketAttempt(0),
   signature: Bytes.zero(BANDERSNATCH_PROOF_BYTES).asOpaque(),
 });
 
diff --git a/packages/jam/jamnp-s/tasks/ticket-distribution.test.ts b/packages/jam/jamnp-s/tasks/ticket-distribution.test.ts
index 1eb670304..703e6e015 100644
--- a/packages/jam/jamnp-s/tasks/ticket-distribution.test.ts
+++ b/packages/jam/jamnp-s/tasks/ticket-distribution.test.ts
@@ -24,7 +24,7 @@ function createTestTicket(attempt: number, signatureByte = 0): SignedTicket {
   signatureBytes.raw[0] = attempt;
   signatureBytes.raw[1] = signatureByte;
   return SignedTicket.create({
-    attempt: tryAsTicketAttempt(attempt, tinyChainSpec),
+    attempt: tryAsTicketAttempt(attempt),
     signature: signatureBytes.asOpaque(),
   });
 }
diff --git a/packages/jam/safrole/bandersnatch-vrf.test.ts b/packages/jam/safrole/bandersnatch-vrf.test.ts
index 4f5a38cea..5618fdfda 100644
--- a/packages/jam/safrole/bandersnatch-vrf.test.ts
+++ b/packages/jam/safrole/bandersnatch-vrf.test.ts
@@ -5,7 +5,6 @@ import { tryAsValidatorIndex } from "@typeberry/block";
 import { type SignedTicket, tryAsTicketAttempt } from "@typeberry/block/tickets.js";
 import { Bytes, BytesBlob } from "@typeberry/bytes";
 import { asKnownSize } from "@typeberry/collections";
-import { tinyChainSpec } from "@typeberry/config";
 import { BANDERSNATCH_KEY_BYTES, SEED_SIZE } from "@typeberry/crypto";
 import {
   BANDERSNATCH_PROOF_BYTES,
@@ -22,7 +21,7 @@ import { BandernsatchWasm } from "./bandersnatch-wasm.js";
 
 const bandersnatchWasm = BandernsatchWasm.new();
 
-const attempt = (v: number) => tryAsTicketAttempt(v, tinyChainSpec);
+const attempt = (v: number) => tryAsTicketAttempt(v);
 
 describe("Bandersnatch verification", () => {
   describe("getRingCommitment", () => {
@@ -311,8 +310,7 @@ describe("Bandersnatch verification", () => {
         proverIndex,
         secrets[proverIndex],
         entropy,
-        tryAsTicketAttempt(2, tinyChainSpec),
-        tinyChainSpec,
+        2,
       );
 
       assert.ok(genResult.isOk);
diff --git a/packages/jam/safrole/bandersnatch-vrf.ts b/packages/jam/safrole/bandersnatch-vrf.ts
index c662d4b76..6668463d0 100644
--- a/packages/jam/safrole/bandersnatch-vrf.ts
+++ b/packages/jam/safrole/bandersnatch-vrf.ts
@@ -1,7 +1,6 @@
 import type { EntropyHash } from "@typeberry/block";
 import { SignedTicket, tryAsTicketAttempt } from "@typeberry/block/tickets.js";
 import { Bytes, BytesBlob } from "@typeberry/bytes";
-import type { ChainSpec } from "@typeberry/config";
 import type { BandersnatchKey, BandersnatchSecretSeed } from "@typeberry/crypto";
 import {
   BANDERSNATCH_PROOF_BYTES,
@@ -213,7 +212,6 @@ async function generateTickets(
   key: BandersnatchSecretSeed,
   entropy: EntropyHash,
   ticketsPerValidator: number,
-  chainSpec: ChainSpec,
 ): Promise<Result<SignedTicket[], null>> {
   // Build VRF inputs: JAM_TICKET_SEAL || entropy || attempt_byte for each attempt
   const vrfInputParts: Uint8Array[] = [];
@@ -249,7 +247,7 @@ async function generateTickets(
 
     tickets.push(
       SignedTicket.create({
-        attempt: tryAsTicketAttempt(attempt, chainSpec),
+        attempt: tryAsTicketAttempt(attempt),
         signature,
       }),
     );
diff --git a/packages/jam/safrole/safrole.test.ts b/packages/jam/safrole/safrole.test.ts
index 5d39dd8bc..dccd4dfca 100644
--- a/packages/jam/safrole/safrole.test.ts
+++ b/packages/jam/safrole/safrole.test.ts
@@ -160,19 +160,12 @@ describe("Safrole", () => {
     const timeslot = tryAsTimeSlot(2);
     const entropy: EntropyHash = Bytes.zero(HASH_SIZE).asOpaque();
 
-    let extrinsic: TicketsExtrinsic;
-    try {
-      extrinsic = asKnownSize([
-        {
-          attempt: tryAsTicketAttempt(tinyChainSpec.ticketsPerValidator + 2, tinyChainSpec),
-          signature: Bytes.zero(BANDERSNATCH_PROOF_BYTES).asOpaque(),
-        },
-      ]);
-    } catch {
-      // Expected: invalid ticket attempt throws during creation
-      // Skip this test as the validation now happens earlier
-      return;
-    }
+    const extrinsic: TicketsExtrinsic = asKnownSize([
+      {
+        attempt: tryAsTicketAttempt(tinyChainSpec.ticketsPerValidator + 2),
+        signature: Bytes.zero(BANDERSNATCH_PROOF_BYTES).asOpaque(),
+      },
+    ]);
 
     const input = {
       slot: timeslot,
@@ -220,7 +213,7 @@ describe("Safrole", () => {
     const entropy: EntropyHash = Bytes.zero(HASH_SIZE).asOpaque();
     const extrinsic: TicketsExtrinsic = asKnownSize([
       {
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         signature: Bytes.zero(BANDERSNATCH_PROOF_BYTES).asOpaque(),
       },
     ]);
@@ -274,11 +267,11 @@ describe("Safrole", () => {
     const entropy: EntropyHash = Bytes.zero(HASH_SIZE).asOpaque();
     const extrinsic: TicketsExtrinsic = asKnownSize([
       {
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         signature: Bytes.zero(BANDERSNATCH_PROOF_BYTES).asOpaque(),
       },
       {
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         signature: Bytes.zero(BANDERSNATCH_PROOF_BYTES).asOpaque(),
       },
     ]);
@@ -332,11 +325,11 @@ describe("Safrole", () => {
     const entropy: EntropyHash = Bytes.zero(HASH_SIZE).asOpaque();
     const extrinsic: TicketsExtrinsic = asKnownSize([
       {
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         signature: Bytes.fill(BANDERSNATCH_PROOF_BYTES, 1).asOpaque(),
       },
       {
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         signature: Bytes.zero(BANDERSNATCH_PROOF_BYTES).asOpaque(),
       },
     ]);
@@ -378,51 +371,51 @@ describe("Safrole", () => {
       nextValidatorData: validators,
       ticketsAccumulator: asKnownSize([
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 1),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 2),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 3),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 4),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 5),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 6),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 7),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 8),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 9),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 10),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 11),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 12),
         }),
       ]),
@@ -437,51 +430,51 @@ describe("Safrole", () => {
 
     const tickets = asKnownSize([
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 1),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 12),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 2),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 11),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 3),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 10),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 4),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 9),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 5),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 8),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 6),
       }),
       Ticket.create({
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         id: Bytes.fill(HASH_SIZE, 7),
       }),
     ]);
@@ -503,51 +496,51 @@ describe("Safrole", () => {
       TicketsMarker.create({
         tickets: asKnownSize([
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 1),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 12),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 2),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 11),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 3),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 10),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 4),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 9),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 5),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 8),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 6),
           }),
           Ticket.create({
-            attempt: tryAsTicketAttempt(0, tinyChainSpec),
+            attempt: tryAsTicketAttempt(0),
             id: Bytes.fill(HASH_SIZE, 7),
           }),
         ]),
@@ -581,7 +574,7 @@ describe("Safrole", () => {
     const entropy: EntropyHash = Bytes.zero(HASH_SIZE).asOpaque();
     const extrinsic: TicketsExtrinsic = asKnownSize([
       {
-        attempt: tryAsTicketAttempt(0, tinyChainSpec),
+        attempt: tryAsTicketAttempt(0),
         signature: Bytes.zero(BANDERSNATCH_PROOF_BYTES).asOpaque(),
       },
     ]);
@@ -724,51 +717,51 @@ describe("Safrole", () => {
       nextValidatorData: validators,
       ticketsAccumulator: asKnownSize([
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 1),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 2),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 3),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 4),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 5),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 6),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 7),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 8),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 9),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 10),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 11),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 12),
         }),
       ]),
@@ -825,51 +818,51 @@ describe("Safrole", () => {
     const tickets = tryAsPerEpochBlock(
       [
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 1),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 2),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 3),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 4),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 5),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 6),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 7),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 8),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 9),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 10),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 11),
         }),
         Ticket.create({
-          attempt: tryAsTicketAttempt(0, tinyChainSpec),
+          attempt: tryAsTicketAttempt(0),
           id: Bytes.fill(HASH_SIZE, 12),
         }),
       ],
diff --git a/packages/jam/state-json/dump.ts b/packages/jam/state-json/dump.ts
index 90e2202b2..2cba652e9 100644
--- a/packages/jam/state-json/dump.ts
+++ b/packages/jam/state-json/dump.ts
@@ -68,8 +68,8 @@ export const fullStateDumpFromJson = (spec: ChainSpec) =>
       beta: json.nullable(recentBlocksHistoryFromJson),
       gamma: {
         gamma_k: json.array(validatorDataFromJson),
-        gamma_a: json.array(ticketFromJson(spec)),
-        gamma_s: TicketsOrKeys.fromJson(spec),
+        gamma_a: json.array(ticketFromJson),
+        gamma_s: TicketsOrKeys.fromJson(),
         gamma_z: json.fromString((v) => Bytes.parseBytes(v, BANDERSNATCH_RING_ROOT_BYTES).asOpaque()),
       },
       psi: disputesRecordsFromJson,
diff --git a/packages/jam/state-json/safrole.ts b/packages/jam/state-json/safrole.ts
index a7fc70003..776da8975 100644
--- a/packages/jam/state-json/safrole.ts
+++ b/packages/jam/state-json/safrole.ts
@@ -6,20 +6,19 @@ import type { BandersnatchKey } from "@typeberry/crypto";
 import { type FromJson, json } from "@typeberry/json-parser";
 import { type SafroleSealingKeys, SafroleSealingKeysData } from "@typeberry/state";
 
-export const ticketFromJson = (spec: ChainSpec): FromJson<Ticket> =>
-  json.object<Ticket>(
-    {
-      id: fromJson.bytes32(),
-      attempt: fromJson.ticketAttempt(spec),
-    },
-    Ticket.create,
-  );
+export const ticketFromJson: FromJson<Ticket> = json.object<Ticket>(
+  {
+    id: fromJson.bytes32(),
+    attempt: fromJson.ticketAttempt,
+  },
+  Ticket.create,
+);
 
 export class TicketsOrKeys {
-  static fromJson(spec: ChainSpec): FromJson<TicketsOrKeys> {
+  static fromJson(): FromJson<TicketsOrKeys> {
     return {
       keys: json.optional<BandersnatchKey[]>(json.array(fromJson.bytes32())),
-      tickets: json.optional<Ticket[]>(json.array(ticketFromJson(spec))),
+      tickets: json.optional<Ticket[]>(json.array(ticketFromJson)),
     };
   }
 
diff --git a/packages/jam/state-vectors/index.ts b/packages/jam/state-vectors/index.ts
index b5c981f78..fc462a87e 100644
--- a/packages/jam/state-vectors/index.ts
+++ b/packages/jam/state-vectors/index.ts
@@ -2,7 +2,7 @@ import { Block, type BlockView, Header, type StateRootHash } from "@typeberry/bl
 import { blockViewFromJson, fromJson, headerFromJson } from "@typeberry/block-json";
 import type { BytesBlob } from "@typeberry/bytes";
 import { codec } from "@typeberry/codec";
-import { type ChainSpec, tinyChainSpec } from "@typeberry/config";
+import { tinyChainSpec } from "@typeberry/config";
 import { HASH_SIZE, TRUNCATED_HASH_SIZE, type TruncatedHash } from "@typeberry/hash";
 import { type FromJson, json } from "@typeberry/json-parser";
 
@@ -36,12 +36,10 @@ export class TestState {
 }
 
 export class StateTransitionGenesis {
-  static fromJson(spec: ChainSpec = tinyChainSpec): FromJson<StateTransitionGenesis> {
-    return {
-      header: headerFromJson(spec),
-      state: TestState.fromJson,
-    };
-  }
+  static fromJson: FromJson<StateTransitionGenesis> = {
+    header: headerFromJson,
+    state: TestState.fromJson,
+  };
 
   static Codec = codec.object({
     header: Header.Codec,
diff --git a/packages/jam/state/test.utils.ts b/packages/jam/state/test.utils.ts
index 02f9b9890..a5dd831c0 100644
--- a/packages/jam/state/test.utils.ts
+++ b/packages/jam/state/test.utils.ts
@@ -360,7 +360,7 @@ export const testState = (): InMemoryState => {
 const emptyHash = () => b32("0x0000000000000000000000000000000000000000000000000000000000000000");
 const testAuth = () => b32("0x0b27478648cd19b4f812f897a26976ecf312eac28508b4368d0c63ea949c7cb0");
 
-const attempt = (x: number) => tryAsTicketAttempt(x, spec);
+const attempt = (x: number) => tryAsTicketAttempt(x);
 const b32 = (s: string) => Bytes.parseBytes(s, HASH_SIZE).asOpaque();
 const repeat = <T>(len: number, factory: () => T) => Array.from({ length: len }, factory);
 
diff --git a/packages/jam/transition/hasher.test.ts b/packages/jam/transition/hasher.test.ts
index 31ea93282..c7fc730a7 100644
--- a/packages/jam/transition/hasher.test.ts
+++ b/packages/jam/transition/hasher.test.ts
@@ -53,7 +53,7 @@ describe("TransitionHasher", () => {
     function prepareTickets() {
       return rawTickets.map(({ attempt, signature }) =>
         SignedTicket.create({
-          attempt: tryAsTicketAttempt(attempt, tinyChainSpec),
+          attempt: tryAsTicketAttempt(attempt),
           signature: Bytes.parseBytes(signature, BANDERSNATCH_PROOF_BYTES).asOpaque(),
         }),
       );
diff --git a/packages/workers/block-authorship/main.ts b/packages/workers/block-authorship/main.ts
index 5708e62e4..d29624bdc 100644
--- a/packages/workers/block-authorship/main.ts
+++ b/packages/workers/block-authorship/main.ts
@@ -238,7 +238,6 @@ export async function main(config: Config, comms: GeneratorInternal, networkingC
           validatorKeys,
           ticketEntropy,
           chainSpec.ticketsPerValidator,
-          chainSpec,
         );
 
         if (ticketsResult.isError) {
diff --git a/packages/workers/block-authorship/ticket-generator.test.ts b/packages/workers/block-authorship/ticket-generator.test.ts
index 9f9031693..e2fa2aa55 100644
--- a/packages/workers/block-authorship/ticket-generator.test.ts
+++ b/packages/workers/block-authorship/ticket-generator.test.ts
@@ -2,7 +2,6 @@ import assert from "node:assert";
 import { afterEach, beforeEach, describe, it, mock } from "node:test";
 import { type SignedTicket, tryAsTicketAttempt } from "@typeberry/block/tickets.js";
 import { Bytes } from "@typeberry/bytes";
-import { tinyChainSpec } from "@typeberry/config";
 import { BANDERSNATCH_KEY_BYTES, initWasm, SEED_SIZE } from "@typeberry/crypto";
 import { HASH_SIZE } from "@typeberry/hash";
 import bandersnatchVrf from "@typeberry/safrole/bandersnatch-vrf.js";
@@ -42,7 +41,7 @@ describe("Ticket Generator", () => {
         const tickets: SignedTicket[] = [];
         for (let attempt = 0; attempt < ticketsPerValidator; attempt++) {
           tickets.push({
-            attempt: tryAsTicketAttempt(attempt, tinyChainSpec),
+            attempt: tryAsTicketAttempt(attempt),
             signature: Bytes.zero(784).asOpaque(),
           } as SignedTicket);
         }
@@ -67,7 +66,6 @@ describe("Ticket Generator", () => {
         validatorKeys,
         MOCK_ENTROPY,
         ticketsPerValidator,
-        tinyChainSpec,
       );
 
       assert.ok(result.isOk);
@@ -85,29 +83,21 @@ describe("Ticket Generator", () => {
         validatorKeys,
         MOCK_ENTROPY,
         ticketsPerValidator,
-        tinyChainSpec,
       );
 
       assert.ok(result.isOk);
       const tickets = result.ok;
-      assert.strictEqual(tickets[0].attempt, tryAsTicketAttempt(0, tinyChainSpec));
-      assert.strictEqual(tickets[1].attempt, tryAsTicketAttempt(1, tinyChainSpec));
-      assert.strictEqual(tickets[2].attempt, tryAsTicketAttempt(0, tinyChainSpec));
-      assert.strictEqual(tickets[3].attempt, tryAsTicketAttempt(1, tinyChainSpec));
+      assert.strictEqual(tickets[0].attempt, tryAsTicketAttempt(0));
+      assert.strictEqual(tickets[1].attempt, tryAsTicketAttempt(1));
+      assert.strictEqual(tickets[2].attempt, tryAsTicketAttempt(0));
+      assert.strictEqual(tickets[3].attempt, tryAsTicketAttempt(1));
     });
 
     it("should return empty array for no validator keys", async () => {
       const ringKeys = createMockRingKeys(3);
       const ticketsPerValidator = 2;
 
-      const result = await generateTickets(
-        MOCK_BANDERSNATCH,
-        ringKeys,
-        [],
-        MOCK_ENTROPY,
-        ticketsPerValidator,
-        tinyChainSpec,
-      );
+      const result = await generateTickets(MOCK_BANDERSNATCH, ringKeys, [], MOCK_ENTROPY, ticketsPerValidator);
 
       assert.ok(result.isOk);
       assert.strictEqual(result.ok.length, 0);
@@ -131,7 +121,6 @@ describe("Ticket Generator", () => {
         validatorKeys,
         MOCK_ENTROPY,
         ticketsPerValidator,
-        tinyChainSpec,
       );
 
       assert.ok(result.isOk);
@@ -159,7 +148,6 @@ describe("Ticket Generator", () => {
         invalidValidatorKeys,
         MOCK_ENTROPY,
         ticketsPerValidator,
-        tinyChainSpec,
       );
 
       assert.ok(result.isError);
diff --git a/packages/workers/block-authorship/ticket-generator.ts b/packages/workers/block-authorship/ticket-generator.ts
index 871ef51f7..bbee0f5a7 100644
--- a/packages/workers/block-authorship/ticket-generator.ts
+++ b/packages/workers/block-authorship/ticket-generator.ts
@@ -1,6 +1,5 @@
 import type { EntropyHash } from "@typeberry/block";
 import type { SignedTicket } from "@typeberry/block/tickets.js";
-import type { ChainSpec } from "@typeberry/config";
 import type { BandersnatchKey, BandersnatchSecretSeed } from "@typeberry/crypto";
 import { Logger } from "@typeberry/logger";
 import bandersnatchVrf from "@typeberry/safrole/bandersnatch-vrf.js";
@@ -31,7 +30,6 @@ export async function generateTickets(
   validatorKeys: ValidatorKey[],
   entropy: EntropyHash,
   ticketsPerValidator: number,
-  chainSpec: ChainSpec,
 ): Promise<Result<SignedTicket[], TicketGeneratorError>> {
   const allTickets: SignedTicket[] = [];
 
@@ -49,7 +47,6 @@ export async function generateTickets(
       validatorKey.secret,
       entropy,
       ticketsPerValidator,
-      chainSpec,
     );
 
     if (ticketResult.isOk) {