diff --git a/package-lock.json b/package-lock.json
index 87f0c1d..6f8dc49 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,6 +10,7 @@
       "dependencies": {
         "@mdi/font": "^7.4.47",
         "@protobuf-ts/runtime": "^2.9.3",
+        "@reactgular/chunks": "^1.0.1",
         "@types/luxon": "^3.4.2",
         "luxon": "^3.4.4",
         "title-case": "^4.3.1",
@@ -59,6 +60,7 @@
         "vite-plugin-sass-dts": "^1.3.17",
         "vitest": "^1.2.2",
         "vitest-canvas-mock": "^0.3.3",
+        "vitest-fetch-mock": "^0.2.2",
         "vue-tsc": "^1.8.27"
       }
     },
@@ -4105,6 +4107,11 @@
         "@babel/runtime": "^7.13.10"
       }
     },
+    "node_modules/@reactgular/chunks": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/@reactgular/chunks/-/chunks-1.0.1.tgz",
+      "integrity": "sha512-Ndyq5oSpkyw5MxZAhV4/fIgmtwbEgIz1L3E3hWcqkCsrlA/auw0Ags5YFTBtaneatClbe4q0J5d1cO7f/MNJkw=="
+    },
     "node_modules/@rollup/pluginutils": {
       "version": "4.2.1",
       "resolved": "https://registry.npmjs.org/@rollup/pluginutils/-/pluginutils-4.2.1.tgz",
@@ -8436,6 +8443,15 @@
       "integrity": "sha512-ZQBvi1DcpJ4GDqanjucZ2Hj3wEO5pZDS89BWbkcrvdxksJorwUDDZamX9ldFkp9aw2lmBDLgkObEA4DWNJ9FYQ==",
       "dev": true
     },
+    "node_modules/cross-fetch": {
+      "version": "3.1.8",
+      "resolved": "https://registry.npmjs.org/cross-fetch/-/cross-fetch-3.1.8.tgz",
+      "integrity": "sha512-cvA+JwZoU0Xq+h6WkMvAUqPEYy92Obet6UdKLfW60qn99ftItKjB5T+BkyWOFWe2pUyfQ+IJHmpOTznqk1M6Kg==",
+      "dev": true,
+      "dependencies": {
+        "node-fetch": "^2.6.12"
+      }
+    },
     "node_modules/cross-spawn": {
       "version": "7.0.3",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.3.tgz",
@@ -20315,6 +20331,21 @@
         "vitest": "*"
       }
     },
+    "node_modules/vitest-fetch-mock": {
+      "version": "0.2.2",
+      "resolved": "https://registry.npmjs.org/vitest-fetch-mock/-/vitest-fetch-mock-0.2.2.tgz",
+      "integrity": "sha512-XmH6QgTSjCWrqXoPREIdbj40T7i1xnGmAsTAgfckoO75W1IEHKR8hcPCQ7SO16RsdW1t85oUm6pcQRLeBgjVYQ==",
+      "dev": true,
+      "dependencies": {
+        "cross-fetch": "^3.0.6"
+      },
+      "engines": {
+        "node": ">=14.14.0"
+      },
+      "peerDependencies": {
+        "vitest": ">=0.16.0"
+      }
+    },
     "node_modules/vitest/node_modules/@vitest/expect": {
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-1.2.2.tgz",
diff --git a/package.json b/package.json
index dd5b9aa..c937ee9 100644
--- a/package.json
+++ b/package.json
@@ -48,6 +48,7 @@
   "dependencies": {
     "@mdi/font": "^7.4.47",
     "@protobuf-ts/runtime": "^2.9.3",
+    "@reactgular/chunks": "^1.0.1",
     "@types/luxon": "^3.4.2",
     "luxon": "^3.4.4",
     "title-case": "^4.3.1",
@@ -97,6 +98,7 @@
     "vite-plugin-sass-dts": "^1.3.17",
     "vitest": "^1.2.2",
     "vitest-canvas-mock": "^0.3.3",
+    "vitest-fetch-mock": "^0.2.2",
     "vue-tsc": "^1.8.27"
   }
 }
diff --git a/src/api/mehari/client.spec.ts b/src/api/mehari/client.spec.ts
new file mode 100644
index 0000000..efa4982
--- /dev/null
+++ b/src/api/mehari/client.spec.ts
@@ -0,0 +1,125 @@
+import fs from 'fs'
+import path from 'path'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import createFetchMock from 'vitest-fetch-mock'
+
+import { SeqvarImpl } from '@/lib/genomicVars'
+
+import { LinearStrucvarImpl } from '../../lib/genomicVars'
+import { MehariClient } from './client'
+import { SeqvarResult, StrucvarResult } from './types'
+
+/** Fixture Seqvar */
+const seqvar = new SeqvarImpl('grch37', '1', 123, 'A', 'G')
+
+/** Fixture with BRCA1 seqvar consequence. */
+const seqvarCsqResponseBrca1 = JSON.parse(
+  fs.readFileSync(path.resolve(__dirname, './fixture.seqvarCsqResponse.BRCA1.json'), 'utf8')
+)
+
+/** Fixture Strucvar affecting BRCA1 */
+const strucvar = new LinearStrucvarImpl('DEL', 'grch37', 'chr17', 43044295, 43044297)
+
+/** Fixture with strucvar (BRCA1) consequence */
+const strucvarCsqResponseBrca1 = JSON.parse(
+  fs.readFileSync(path.resolve(__dirname, './fixture.strucvarCsqResponse.BRCA1.json'), 'utf8')
+)
+
+/** Initialize mock for `fetch()`. */
+const fetchMocker = createFetchMock(vi)
+
+describe.concurrent('MehariClient/seqvar', () => {
+  beforeEach(() => {
+    fetchMocker.enableMocks()
+    fetchMocker.resetMocks()
+  })
+
+  it('fetches TxCsq info correctly', async () => {
+    // arrange:
+    fetchMocker.mockResponseOnce(JSON.stringify(seqvarCsqResponseBrca1))
+
+    // act:
+    const client = new MehariClient()
+    const result = await client.retrieveSeqvarsCsq(seqvar, 'HGNC:1100')
+
+    // assert:
+    expect(JSON.stringify(result)).toEqual(
+      JSON.stringify(SeqvarResult.fromJson(seqvarCsqResponseBrca1))
+    )
+  })
+
+  it('fetches TxCsq info correctly without HGNC id', async () => {
+    // arrange:
+    fetchMocker.mockResponseOnce(JSON.stringify(seqvarCsqResponseBrca1))
+
+    // act:
+    const client = new MehariClient()
+    const result = await client.retrieveSeqvarsCsq(seqvar)
+
+    // assert:
+    expect(JSON.stringify(result)).toEqual(
+      JSON.stringify(SeqvarResult.fromJson(seqvarCsqResponseBrca1))
+    )
+  })
+
+  it('fails to fetch variant info with wrong variant', async () => {
+    // arrange:
+    const seqVarInvalid = new SeqvarImpl('grch37', '1', 123, 'A', 'T')
+    fetchMocker.mockResponse((req) => {
+      if (req.url.includes('alternative=G')) {
+        return Promise.resolve(JSON.stringify(seqvarCsqResponseBrca1))
+      }
+      return Promise.reject('failed to fetch seqvar')
+    })
+
+    // act:
+    const client = new MehariClient()
+    // (with guard)
+    await expect(async () => await client.retrieveSeqvarsCsq(seqVarInvalid)).rejects.toThrow(
+      'failed to fetch seqvar'
+    )
+
+    // assert:
+  })
+})
+
+describe.concurrent('MehariClient/strucvar', () => {
+  beforeEach(() => {
+    fetchMocker.enableMocks()
+    fetchMocker.resetMocks()
+  })
+
+  it('fetches strucvar info correctly', async () => {
+    // arrange:
+    fetchMocker.mockResponseOnce(JSON.stringify(strucvarCsqResponseBrca1))
+
+    // act:
+    const client = new MehariClient()
+    const result = await client.retrieveStrucvarsCsq(strucvar)
+
+    // assert:
+    expect(JSON.stringify(result)).toEqual(
+      JSON.stringify(StrucvarResult.fromJson(strucvarCsqResponseBrca1))
+    )
+  })
+
+  it('fails to fetch variant info with wrong variant', async () => {
+    // arrange:
+    const strucVarInvalid = new LinearStrucvarImpl('DUP', 'grch37', 'chr17', 43044295, 43044297)
+    fetchMocker.mockResponse((req) => {
+      if (req.url.includes('DEL')) {
+        return Promise.resolve(JSON.stringify(strucvarCsqResponseBrca1))
+      }
+      return Promise.reject('failed to fetch strucvar')
+    })
+
+    // act:
+    const client = new MehariClient()
+    // (with guard)
+    await expect(async () => await client.retrieveStrucvarsCsq(strucVarInvalid)).rejects.toThrow(
+      'failed to fetch strucvar'
+    )
+
+    // assert:
+  })
+})
diff --git a/src/api/mehari/client.ts b/src/api/mehari/client.ts
new file mode 100644
index 0000000..5d95777
--- /dev/null
+++ b/src/api/mehari/client.ts
@@ -0,0 +1,65 @@
+import type { LinearStrucvar, Seqvar } from '../../lib/genomicVars'
+import { SeqvarResult, StrucvarResult } from './types'
+
+/** API base URL to use. */
+const API_BASE_URL = '/internal/proxy/pubtator3-api'
+
+/**
+ * Client for Mehari API requests.
+ */
+export class MehariClient {
+  private apiBaseUrl: string
+
+  constructor(apiBaseUrl?: string) {
+    this.apiBaseUrl = apiBaseUrl ?? API_BASE_URL
+  }
+
+  /**
+   * Retrieve consequences for sequence variants.
+   *
+   * @param seqvar Sequence variant to retrieve consequences for.
+   * @param hgncId HGNC ID of gene to restrict results to.
+   * @returns The response from the API.
+   * @throws Error if the API request fails.
+   */
+  async retrieveSeqvarsCsq(seqvar: Seqvar, hgncId?: string): Promise<SeqvarResult> {
+    const { genomeBuild, chrom, pos, del, ins } = seqvar
+    const hgncSuffix = hgncId ? `&hgnc_id=${hgncId}` : ''
+    const url =
+      `${this.apiBaseUrl}seqvars/csq?genome_release=${genomeBuild}&` +
+      `chromosome=${chrom}&position=${pos}&reference=${del}&` +
+      `alternative=${ins}${hgncSuffix}`
+
+    const response = await fetch(url, {
+      method: 'GET'
+    })
+    if (!response.ok) {
+      throw new Error(`Failed to fetch sequence variant consequences: ${response.statusText}`)
+    }
+    const responseJson = await response.json()
+    return SeqvarResult.fromJson(responseJson)
+  }
+
+  /**
+   * Retrieve consequences for structural variants.
+   *
+   * @param strucvar Structural variant to retrieve consequences for.
+   * @returns The response from the API.
+   * @throws Error if the API request fails.
+   */
+  async retrieveStrucvarsCsq(strucvar: LinearStrucvar): Promise<StrucvarResult> {
+    const { genomeBuild, chrom, start, stop, svType } = strucvar
+    const url =
+      `${this.apiBaseUrl}strucvars/csq?genome_release=${genomeBuild}&` +
+      `chromosome=${chrom}&start=${start}&stop=${stop}&sv_type=${svType}`
+
+    const response = await fetch(url, {
+      method: 'GET'
+    })
+    if (!response.ok) {
+      throw new Error(`Failed to fetch structural variant consequences: ${response.statusText}`)
+    }
+    const responseJson = await response.json()
+    return StrucvarResult.fromJson(responseJson)
+  }
+}
diff --git a/src/api/mehari/fixture.seqvarCsqResponse.BRCA1.json b/src/api/mehari/fixture.seqvarCsqResponse.BRCA1.json
new file mode 100644
index 0000000..64d3a61
--- /dev/null
+++ b/src/api/mehari/fixture.seqvarCsqResponse.BRCA1.json
@@ -0,0 +1,98 @@
+{
+  "version": { "tx_db": "0.5.0", "mehari": "0.7.0" },
+  "query": {
+    "genome_release": "grch37",
+    "chromosome": "chr17",
+    "position": 41197751,
+    "reference": "G",
+    "alternative": "T",
+    "hgnc_id": null
+  },
+  "result": [
+    {
+      "consequences": ["MissenseVariant"],
+      "putative_impact": "Moderate",
+      "gene_symbol": "BRCA1",
+      "gene_id": "HGNC:1100",
+      "feature_type": { "SoTerm": { "term": "Transcript" } },
+      "feature_id": "NM_007294.4",
+      "feature_biotype": "Coding",
+      "rank": { "ord": 23, "total": 23 },
+      "hgvs_t": "c.5536C>A",
+      "hgvs_p": "p.Q1846K",
+      "tx_pos": { "ord": 5649, "total": 7088 },
+      "cds_pos": { "ord": 5536, "total": 5592 },
+      "protein_pos": { "ord": 1846, "total": 1864 },
+      "distance": -1440,
+      "messages": null
+    },
+    {
+      "consequences": ["MissenseVariant"],
+      "putative_impact": "Moderate",
+      "gene_symbol": "BRCA1",
+      "gene_id": "HGNC:1100",
+      "feature_type": { "SoTerm": { "term": "Transcript" } },
+      "feature_id": "NM_007297.4",
+      "feature_biotype": "Coding",
+      "rank": { "ord": 22, "total": 22 },
+      "hgvs_t": "c.5395C>A",
+      "hgvs_p": "p.Q1799K",
+      "tx_pos": { "ord": 5589, "total": 7028 },
+      "cds_pos": { "ord": 5395, "total": 5451 },
+      "protein_pos": { "ord": 1799, "total": 1817 },
+      "distance": -1440,
+      "messages": null
+    },
+    {
+      "consequences": ["MissenseVariant"],
+      "putative_impact": "Moderate",
+      "gene_symbol": "BRCA1",
+      "gene_id": "HGNC:1100",
+      "feature_type": { "SoTerm": { "term": "Transcript" } },
+      "feature_id": "NM_007298.3",
+      "feature_biotype": "Coding",
+      "rank": { "ord": 22, "total": 22 },
+      "hgvs_t": "c.2224C>A",
+      "hgvs_p": "p.Q742K",
+      "tx_pos": { "ord": 2243, "total": 3682 },
+      "cds_pos": { "ord": 2224, "total": 2280 },
+      "protein_pos": { "ord": 742, "total": 760 },
+      "distance": -1440,
+      "messages": null
+    },
+    {
+      "consequences": ["MissenseVariant"],
+      "putative_impact": "Moderate",
+      "gene_symbol": "BRCA1",
+      "gene_id": "HGNC:1100",
+      "feature_type": { "SoTerm": { "term": "Transcript" } },
+      "feature_id": "NM_007300.4",
+      "feature_biotype": "Coding",
+      "rank": { "ord": 24, "total": 24 },
+      "hgvs_t": "c.5599C>A",
+      "hgvs_p": "p.Q1867K",
+      "tx_pos": { "ord": 5712, "total": 7151 },
+      "cds_pos": { "ord": 5599, "total": 5655 },
+      "protein_pos": { "ord": 1867, "total": 1885 },
+      "distance": -1440,
+      "messages": null
+    },
+    {
+      "consequences": ["ThreePrimeUtrVariant"],
+      "putative_impact": "Modifier",
+      "gene_symbol": "BRCA1",
+      "gene_id": "HGNC:1100",
+      "feature_type": { "SoTerm": { "term": "Transcript" } },
+      "feature_id": "NM_007299.4",
+      "feature_biotype": "Coding",
+      "rank": { "ord": 22, "total": 22 },
+      "hgvs_t": "c.*50C>A",
+      "hgvs_p": "p.?",
+      "tx_pos": { "ord": 2257, "total": 3696 },
+      "cds_pos": { "ord": 50, "total": 2100 },
+      "protein_pos": null,
+      "distance": -1440,
+      "messages": null
+    }
+  ]
+}
diff --git a/src/api/mehari/fixture.strucvarCsqResponse.BRCA1.json b/src/api/mehari/fixture.strucvarCsqResponse.BRCA1.json
new file mode 100644
index 0000000..a2e3a0f
--- /dev/null
+++ b/src/api/mehari/fixture.strucvarCsqResponse.BRCA1.json
@@ -0,0 +1,45 @@
+{
+  "version": {
+    "tx_db": "0.5.0",
+    "mehari": "0.8.0"
+  },
+  "query": {
+    "genome_release": "grch37",
+    "chromosome": "chr17",
+    "start": 41176312,
+    "stop": 41277500,
+    "sv_type": "DEL"
+  },
+  "result": [
+    {
+      "hgnc_id": "HGNC:16919",
+      "transcript_effects": ["upstream_variant"]
+    },
+    {
+      "hgnc_id": "HGNC:1100",
+      "transcript_effects": [
+        "transcript_variant",
+        "exon_variant",
+        "splice_region_variant",
+        "intron_variant",
+        "upstream_variant",
+        "downstream_variant"
+      ]
+    },
+    {
+      "hgnc_id": "HGNC:18315",
+      "transcript_effects": [
+        "transcript_variant",
+        "exon_variant",
+        "splice_region_variant",
+        "intron_variant",
+        "upstream_variant",
+        "downstream_variant"
+      ]
+    },
+    {
+      "hgnc_id": "HGNC:20691",
+      "transcript_effects": ["upstream_variant"]
+    }
+  ]
+}
diff --git a/src/api/mehari/index.ts b/src/api/mehari/index.ts
new file mode 100644
index 0000000..886d07b
--- /dev/null
+++ b/src/api/mehari/index.ts
@@ -0,0 +1,2 @@
+export * from './types'
+export * from './client'
diff --git a/src/api/mehari/types.ts b/src/api/mehari/types.ts
new file mode 100644
index 0000000..ca436b9
--- /dev/null
+++ b/src/api/mehari/types.ts
@@ -0,0 +1,478 @@
+/**
+ * Types for interfacing with the Mehari API.
+ */
+import { GenomeBuild } from '@/lib/genomeBuilds'
+
+/**
+ * Enumeration for the putative impact.
+ */
+export enum SeqvarPutativeImpact {
+  High = 'HIGH',
+  Moderate = 'MODERATE',
+  Low = 'LOW',
+  Modifier = 'MODIFIER'
+}
+
+/**
+ * Enumeration for the consequence.
+ */
+export enum SeqvarConsequence {
+  // high impact
+  ChromosomeNumberVariation = 'chromosome_number_variation',
+  ExonLossVariant = 'exon_loss_variant',
+  FrameshiftVariant = 'frameshift_variant',
+  RareAminoAcidVariant = 'rare_amino_acid_variant',
+  SpliceAcceptorVariant = 'splice_acceptor_variant',
+  SpliceDonorVariant = 'splice_donor_variant',
+  StartLost = 'start_lost',
+  StopGained = 'stop_gained',
+  StopLost = 'stop_lost',
+  TranscriptAblation = 'transcript_ablation',
+  // moderate impact
+  ThreePrimeUtrTruncation = '3_prime_UTR_truncation',
+  FivePrimeUtrTruncaction = '5_prime_UTR_truncation',
+  ConservativeInframeDeletion = 'conservative_inframe_deletion',
+  ConservativeInframeInsertion = 'conservative_inframe_insertion',
+  DisruptiveInframeDeletion = 'disruptive_inframe_deletion',
+  DisruptiveInframeInsertion = 'disruptive_inframe_insertion',
+  MissenseVariant = 'missense_variant',
+  RegulatoryRegionAblation = 'regulatory_region_ablation',
+  SpliceRegionVariant = 'splice_region_variant',
+  TbfsAblation = 'TFBS_ablation',
+  // low impact
+  FivePrimeUtrPrematureStartCodonGainVariant = '5_prime_UTR_premature_start_codon_gain_variant',
+  InitiatorCodonVariant = 'initiator_codon_variant',
+  StartRetained = 'start_retained',
+  StopRetainedVariant = 'stop_retained_variant',
+  SynonymousVariant = 'synonymous_variant',
+  // modifier
+  ThreePrimeUtrVariant = '3_prime_UTR_variant',
+  FivePrimeUtrVariant = '5_prime_UTR_variant',
+  CodingSequenceVariant = 'coding_sequence_variant',
+  ConservedIntergenicVariant = 'conserved_intergenic_variant',
+  ConservedIntronVariant = 'conserved_intron_variant',
+  DownstreamGeneVariant = 'downstream_gene_variant',
+  ExonVariant = 'exon_variant',
+  FeatureElongation = 'feature_elongation',
+  FeatureTruncation = 'feature_truncation',
+  GeneVariant = 'gene_variant',
+  IntergenicVariant = 'intergenic_variant',
+  IntronVariant = 'intron_variant',
+  MatureMirnaVariant = 'mature_miRNA_variant',
+  Mirna = 'miRNA',
+  NmdTranscriptVariant = 'NMD_transcript_variant',
+  NonCodingTranscriptExonVariant = 'non_coding_transcript_exon_variant',
+  NonCodingTranscriptIntronVariant = 'non_coding_transcript_intron_variant',
+  RegulatoryRegionAmplification = 'regulatory_region_amplification',
+  RegulatoryRegionVariant = 'regulatory_region_variant',
+  TfBindingSiteVariant = 'TF_binding_site_variant',
+  TfbsAmplification = 'TFBS_amplification',
+  TranscriptAmplification = 'transcript_amplification',
+  TranscriptVariant = 'transcript_variant',
+  UpstreamGeneVariant = 'upstream_gene_variant'
+}
+
+/**
+ * Interface for one entry in the result as returned by API.
+ */
+export interface SeqvarResultEntry$Api {
+  /** The consequences of the allele. */
+  consequences: SeqvarConsequence[]
+  /** The putative impact. */
+  putative_impact: SeqvarPutativeImpact
+  /** The gene symbol. */
+  gene_symbol: string
+  /** The gene identifier. */
+  gene_id: string
+  /** The feature type. */
+  feature_type: string
+  /** The feature identifier. */
+  feature_id: string
+  /** The feature biotype. */
+  feature_biotype: string
+  /** The feature tags. */
+  feature_tag: string[]
+  /** The exon / intron rank. */
+  rank?: number
+  /** HGVS c. notation. */
+  hgvs_t?: string
+  /** HGVS p. notation. */
+  hgvs_p?: string
+  /** cDNA position. */
+  tx_pos?: number
+  /** CDS position. */
+  cds_pos?: number
+  /** Protein position. */
+  protein_pos?: number
+  /** Distance to feature. */
+  distance?: number
+  /** Optional list of warnings and error messages. */
+  messages?: string[]
+}
+
+/**
+ * Interface for one entry in the result.
+ */
+export interface SeqvarResultEntry {
+  /** The consequences of the allele. */
+  consequences: SeqvarConsequence[]
+  /** The putative impact. */
+  putativeImpact: SeqvarPutativeImpact
+  /** The gene symbol. */
+  geneSymbol: string
+  /** The gene identifier. */
+  geneId: string
+  /** The feature type. */
+  featureType: string
+  /** The feature identifier. */
+  featureId: string
+  /** The feature biotype. */
+  featureBiotype: string
+  /** The feature tags. */
+  featureTag: string[]
+  /** The exon / intron rank. */
+  rank?: number
+  /** HGVS c. notation. */
+  hgvsT?: string
+  /** HGVS p. notation. */
+  hgvsP?: string
+  /** cDNA position. */
+  txPos?: number
+  /** CDS position. */
+  cdsPos?: number
+  /** Protein position. */
+  proteinPos?: number
+  /** Distance to feature. */
+  distance?: number
+  /** Optional list of warnings and error messages. */
+  messages?: string[]
+}
+
+/**
+ * Helper class for converting `ResultEntry$Api` to `ResultEntry`.
+ */
+class SeqvarResultEntry$Type {
+  /** Convert `SeqvarResultEntry$Api` to `SeqvarResultEntry`. */
+  fromJson(json: SeqvarResultEntry$Api): SeqvarResultEntry {
+    return {
+      consequences: json.consequences,
+      putativeImpact: json.putative_impact,
+      geneSymbol: json.gene_symbol,
+      geneId: json.gene_id,
+      featureType: json.feature_type,
+      featureId: json.feature_id,
+      featureBiotype: json.feature_biotype,
+      featureTag: json.feature_tag,
+      rank: json.rank,
+      hgvsT: json.hgvs_t,
+      hgvsP: json.hgvs_p,
+      txPos: json.tx_pos,
+      cdsPos: json.cds_pos,
+      proteinPos: json.protein_pos,
+      distance: json.distance,
+      messages: json.messages
+    }
+  }
+}
+
+/**
+ * Helper for converting `SeqvarResultEntry$Api` to `SeqvarResultEntry`.
+ */
+export const SeqvarResultEntry: SeqvarResultEntry$Type = new SeqvarResultEntry$Type()
+
+/**
+ * Interface for the version as returned by API.
+ */
+export interface Version$Api {
+  /** Transcript database version. */
+  tx_db: string
+  /** The application version. */
+  mehari: string
+}
+
+/**
+ * Interface for the version.
+ */
+export interface SeqvarVersion {
+  /** Transcript database version. */
+  txDb: string
+  /** The application version. */
+  mehari: string
+}
+
+/**
+ * Helper class for converting `Version$Api` to `Version`.
+ */
+class Version$Type {
+  /** Convert `Version$Api` to `Version`. */
+  fromJson(json: Version$Api): SeqvarVersion {
+    return {
+      txDb: json.tx_db,
+      mehari: json.mehari
+    }
+  }
+}
+
+/**
+ * Helper for converting `Version$Api` to `Version`.
+ */
+export const Version: Version$Type = new Version$Type()
+
+/**
+ * Interface for the query as returned by API.
+ */
+export interface SeqvarQuery$Api {
+  /** The assembly. */
+  genome_release: string
+  /** SPDI sequence. */
+  chromosome: string
+  /** SPDI position. */
+  position: number
+  /** SPDI deletion. */
+  reference: string
+  /** SPDI insertion. */
+  alternative: string
+  /** Optionally, the HGNC ID of the gene to limit to. */
+  hgnc_id?: string
+}
+
+/**
+ * Interface for the query.
+ */
+export interface SeqvarQuery {
+  /** The assembly. */
+  genomeRelease: string
+  /** SPDI sequence. */
+  chromosome: string
+  /** SPDI position. */
+  position: number
+  /** SPDI deletion. */
+  reference: string
+  /** SPDI insertion. */
+  alternative: string
+  /** Optionally, the HGNC ID of the gene to limit to. */
+  hgncId?: string
+}
+
+/**
+ * Helper class for converting `SeqvarQuery$Api` to `SeqvarQuery`.
+ */
+class SeqvarQuery$Type {
+  /** Convert `SeqvarQuery$Api` to `SeqvarQuery`. */
+  fromJson(json: SeqvarQuery$Api): SeqvarQuery {
+    return {
+      genomeRelease: json.genome_release,
+      chromosome: json.chromosome,
+      position: json.position,
+      reference: json.reference,
+      alternative: json.alternative,
+      hgncId: json.hgnc_id
+    }
+  }
+}
+
+/**
+ * Helper for converting `SeqvarQuery$Api` to `SeqvarQuery`.
+ */
+export const SeqvarQuery: SeqvarQuery$Type = new SeqvarQuery$Type()
+
+/**
+ * Interface for the result as returned by API.
+ */
+export interface SeqvarResult$Api {
+  /** Version information. */
+  version: Version$Api
+  /** The original query records. */
+  query: SeqvarQuery$Api
+  /** The resulting records for the scored genes. */
+  result: SeqvarResultEntry$Api[]
+}
+
+/**
+ * Interface for the result.
+ */
+export interface SeqvarResult {
+  /** Version information. */
+  version: SeqvarVersion
+  /** The original query records. */
+  query: SeqvarQuery
+  /** The resulting records for the scored genes. */
+  result: SeqvarResultEntry[]
+}
+
+/**
+ * Helper class for converting `Result$Api` to `Result`.
+ */
+class SeqvarResult$Type {
+  /** Convert `Result$Api` to `Result`. */
+  fromJson(json: SeqvarResult$Api): SeqvarResult {
+    return {
+      version: Version.fromJson(json.version),
+      query: SeqvarQuery.fromJson(json.query),
+      result: json.result.map((entry) => SeqvarResultEntry.fromJson(entry))
+    }
+  }
+}
+
+/**
+ * Helper for converting `SeqvarResult$Api` to `SeqvarResult`.
+ */
+export const SeqvarResult: SeqvarResult$Type = new SeqvarResult$Type()
+
+/**
+ * Enumeration for the effect on transcript.
+ */
+export enum TranscriptEffect {
+  TranscriptVariant = 'transcript_variant',
+  ExonVariant = 'exon_variant',
+  SpliceRegionVariant = 'splice_region_variant',
+  IntronVariant = 'intron_variant',
+  UpstreamVariant = 'upstream_variant',
+  DownstreamVariant = 'downstream_variant',
+  IntergenicVariant = 'intergenic_variant'
+}
+
+/**
+ * Interface for one entry in the result as returned by API.
+ */
+export interface GeneTranscriptEffects$Api {
+  /** HGNC identifier */
+  hgnc_id: string
+  /** Transcript effects for the gene. */
+  transcript_effects: TranscriptEffect[]
+}
+
+/**
+ * Explanation of transcript effect per individual gene.
+ */
+export interface GeneTranscriptEffects {
+  /** HGNC identifier */
+  hgncId: string
+  /** Transcript effects for the gene. */
+  transcriptEffects: TranscriptEffect[]
+}
+
+/**
+ * Helper class for converting `GeneTranscriptEffects$Api` to `GeneTranscriptEffects`.
+ */
+class GeneTranscriptEffects$Type {
+  /** Convert `GeneTranscriptEffects$Api` to `GeneTranscriptEffects`. */
+  fromJson(json: GeneTranscriptEffects$Api): GeneTranscriptEffects {
+    return {
+      hgncId: json.hgnc_id,
+      transcriptEffects: json.transcript_effects
+    }
+  }
+}
+
+/**
+ * Helper for converting `GeneTranscriptEffects$Api` to `GeneTranscriptEffects`.
+ */
+export const GeneTranscriptEffects: GeneTranscriptEffects$Type = new GeneTranscriptEffects$Type()
+
+/**
+ * Enumeration for the structural variant type.
+ */
+export enum StrucVarType {
+  Del = 'del',
+  Dup = 'dup',
+  Ins = 'ins',
+  Bnd = 'bnd',
+  Inv = 'inv'
+}
+
+/**
+ * Parameters for `/strucvars/csq` as returned by the API.
+ */
+export interface StrucvarsQuery$Api {
+  /** The assembly. */
+  genome_release: GenomeBuild
+  /** Chromosome sequence. */
+  chromosome: string
+  /** Start position. */
+  start: number
+  /** 1-based stop position. */
+  stop: number
+  /** Type of SV. */
+  sv_type: StrucVarType
+}
+
+/**
+ * Parameters for `/strucvars/csq`.
+ */
+export interface StrucvarsQuery {
+  /** The assembly. */
+  genomeRelease: GenomeBuild
+  /** Chromosome sequence. */
+  chromosome: string
+  /** Start position. */
+  start: number
+  /** 1-based stop position. */
+  stop: number
+  /** Type of SV. */
+  svType: StrucVarType
+}
+
+/**
+ * Helper class for converting `StrucvarsQuery$Api` to `StrucvarsQuery`.
+ */
+class StrucvarsQuery$Type {
+  /** Convert `StrucvarsQuery$Api` to `StrucvarsQuery`. */
+  fromJson(json: StrucvarsQuery$Api): StrucvarsQuery {
+    return {
+      genomeRelease: json.genome_release,
+      chromosome: json.chromosome,
+      start: json.start,
+      stop: json.stop,
+      svType: json.sv_type
+    }
+  }
+}
+
+/**
+ * Helper for converting `StrucvarsQuery$Api` to `StrucvarsQuery`.
+ */
+export const StrucvarsQuery: StrucvarsQuery$Type = new StrucvarsQuery$Type()
+
+/**
+ * Interface for the result as returned by API.
+ */
+export interface StrucvarResult$Api {
+  /** Version information. */
+  version: Version$Api
+  /** The original query records. */
+  query: SeqvarQuery$Api
+  /** The resulting records for the scored genes. */
+  result: SeqvarResultEntry$Api[]
+}
+
+/**
+ * Interface for the result.
+ */
+export interface StrucvarResult {
+  /** Version information. */
+  version: SeqvarVersion
+  /** The original query records. */
+  query: SeqvarQuery
+  /** The resulting records for the scored genes. */
+  result: SeqvarResultEntry[]
+}
+
+/**
+ * Helper class for converting `Result$Api` to `Result`.
+ */
+class StrucvarResult$Type {
+  /** Convert `Result$Api` to `Result`. */
+  fromJson(json: StrucvarResult$Api): StrucvarResult {
+    return {
+      version: Version.fromJson(json.version),
+      query: SeqvarQuery.fromJson(json.query),
+      result: json.result.map((entry) => SeqvarResultEntry.fromJson(entry))
+    }
+  }
+}
+
+/**
+ * Helper for converting `StrucvarResult$Api` to `StrucvarResult`.
+ */
+export const StrucvarResult: StrucvarResult$Type = new StrucvarResult$Type()
diff --git a/src/lib/genomicVars.ts b/src/lib/genomicVars.ts
index 5fb158d..2d65198 100644
--- a/src/lib/genomicVars.ts
+++ b/src/lib/genomicVars.ts
@@ -117,6 +117,54 @@ export interface Seqvar {
   userRepr: string
 }
 
+/**
+ * Implementation of the `Seqvar` interface.
+ */
+export class SeqvarImpl implements Seqvar {
+  genomeBuild: GenomeBuild
+  chrom: string
+  pos: number
+  del: string
+  ins: string
+  userRepr: string
+
+  constructor(
+    genomeBuild: GenomeBuild,
+    chrom: string,
+    pos: number,
+    del: string,
+    ins: string,
+    userRepr?: string
+  ) {
+    this.genomeBuild = genomeBuild
+    this.chrom = chrom
+    this.pos = pos
+    this.del = del
+    this.ins = ins
+    this.userRepr =
+      userRepr ?? `${this.genomeBuild}-${this.chrom}-${this.pos}-${this.del}-${this.ins}`
+  }
+
+  /** Return the "object name" to be used in the API to the backend etc. */
+  toName(): string {
+    return `${this.genomeBuild}-${this.chrom}-${this.pos}-${this.del}-${this.ins}`
+  }
+}
+
+/**
+ * Construct a `SeqvarImpl` from a `Seqvar`.
+ */
+export function seqvarImplFromSeqvar(variant: Seqvar): SeqvarImpl {
+  return new SeqvarImpl(
+    variant.genomeBuild,
+    variant.chrom,
+    variant.pos,
+    variant.del,
+    variant.ins,
+    variant.userRepr
+  )
+}
+
 /** Base class for exceptions when parsing variants. */
 export class InvalidVariant extends Error {
   constructor(message: string) {
@@ -295,6 +343,58 @@ export interface LinearStrucvar {
   userRepr: string
 }
 
+/**
+ * Implementation of the `LinearStrucvar` interface.
+ */
+export class LinearStrucvarImpl implements LinearStrucvar {
+  svType: 'DEL' | 'DUP'
+  genomeBuild: GenomeBuild
+  chrom: string
+  start: number
+  stop: number
+  copyNumber?: number
+  userRepr: string
+
+  constructor(
+    svType: 'DEL' | 'DUP',
+    genomeBuild: GenomeBuild,
+    chrom: string,
+    start: number,
+    stop: number,
+    copyNumber?: number,
+    userRepr?: string
+  ) {
+    this.svType = svType
+    this.genomeBuild = genomeBuild
+    this.chrom = chrom
+    this.start = start
+    this.stop = stop
+    this.copyNumber = copyNumber
+    this.userRepr =
+      userRepr ?? `${this.svType}-${this.genomeBuild}-${this.chrom}-${this.start}-${this.stop}`
+  }
+
+  /** Return the "object name" to be used in the API to the backend etc. */
+  toName(): string {
+    return `${this.svType}-${this.genomeBuild}-${this.chrom}-${this.start}-${this.stop}`
+  }
+}
+
+/**
+ * Construct a `LinearStrucvarImpl` from a `LinearStrucvar`.
+ */
+export function linearStrucvarImplFromLinearStrucvar(variant: LinearStrucvar): LinearStrucvarImpl {
+  return new LinearStrucvarImpl(
+    variant.svType,
+    variant.genomeBuild,
+    variant.chrom,
+    variant.start,
+    variant.stop,
+    variant.copyNumber,
+    variant.userRepr
+  )
+}
+
 /** All supported structural variant types. */
 export type Strucvar = LinearStrucvar // | ...