diff --git a/packages/cli/src/commands/rca/run.ts b/packages/cli/src/commands/rca/run.ts
index e5acfaf68..f6fc48d5c 100644
--- a/packages/cli/src/commands/rca/run.ts
+++ b/packages/cli/src/commands/rca/run.ts
@@ -1,7 +1,7 @@
 import { Flags } from '@oclif/core'
 import chalk from 'chalk'
 import { AuthCommand } from '../authCommand'
-import { outputFlag } from '../../helpers/flags'
+import { normalizeFlagAliases, outputFlag } from '../../helpers/flags.js'
 import * as api from '../../rest/api'
 import { NotFoundError, InadequateEntitlementsError } from '../../rest/errors'
 import { formatRcaPending, formatRcaCompleted } from '../../formatters/rca'
@@ -10,13 +10,19 @@ export default class RcaRun extends AuthCommand {
   static hidden = false
   static readOnly = false
   static idempotent = false
-  static description = 'Trigger a root cause analysis for an error group.'
+  static description = 'Trigger a root cause analysis for a check or test session error group.'
+  static usage = 'rca run [-e <value> | -te <value>] [-w] [-o detail|json|md]'
 
   static flags = {
     'error-group': Flags.string({
       char: 'e',
       description: 'The error group ID to analyze.',
-      required: true,
+      exactlyOne: ['error-group', 'test-session-error-group'],
+      exclusive: ['test-session-error-group'],
+    }),
+    'test-session-error-group': Flags.string({
+      description: 'The test session error group ID to analyze.',
+      helpLabel: '-te, --test-session-error-group',
     }),
     'watch': Flags.boolean({
       char: 'w',
@@ -27,20 +33,51 @@ export default class RcaRun extends AuthCommand {
   }
 
   async run (): Promise<void> {
-    const { flags } = await this.parse(RcaRun)
+    const { flags } = await this.parse(RcaRun, normalizeFlagAliases(this.argv, [
+      { alias: '-te', flag: '--test-session-error-group' },
+    ]))
     this.style.outputFormat = flags.output
 
+    const source = flags['test-session-error-group']
+      ? {
+          type: 'test-session-error-group' as const,
+          id: flags['test-session-error-group'],
+        }
+      : {
+          type: 'error-group' as const,
+          id: flags['error-group']!,
+        }
+
     try {
-      // Fetch the error group to get the checkId for navigation hints
-      const { data: errorGroup } = await api.errorGroups.get(flags['error-group'])
+      let pendingInfo
+      let rcaId: string
 
-      // Trigger the RCA
-      const { data: { id: rcaId } } = await api.rca.trigger(flags['error-group'])
+      if (source.type === 'error-group') {
+        // Fetch the error group to get the checkId for navigation hints
+        const { data: errorGroup } = await api.errorGroups.get(source.id)
 
-      const pendingInfo = {
-        rcaId,
-        errorGroupId: flags['error-group'],
-        checkId: errorGroup.checkId,
+        const response = await api.rca.trigger(source.id)
+        rcaId = response.data.id
+        pendingInfo = {
+          rcaId,
+          source: {
+            type: 'error-group' as const,
+            errorGroupId: source.id,
+            checkId: errorGroup.checkId,
+          },
+        }
+      } else {
+        await api.testSessionErrorGroups.get(source.id)
+
+        const response = await api.rca.triggerTestSessionErrorGroup(source.id)
+        rcaId = response.data.id
+        pendingInfo = {
+          rcaId,
+          source: {
+            type: 'test-session-error-group' as const,
+            testSessionErrorGroupId: source.id,
+          },
+        }
       }
 
       // If not watching, show pending state and exit
@@ -73,7 +110,8 @@ export default class RcaRun extends AuthCommand {
         return
       }
       if (err instanceof NotFoundError) {
-        this.style.shortError(`Error group not found: ${flags['error-group']}`)
+        const label = source.type === 'error-group' ? 'Error group' : 'Test session error group'
+        this.style.shortError(`${label} not found: ${source.id}`)
         process.exitCode = 1
         return
       }
diff --git a/packages/cli/src/formatters/__tests__/rca.spec.ts b/packages/cli/src/formatters/__tests__/rca.spec.ts
index 3f8ba6990..7fd9b2ff8 100644
--- a/packages/cli/src/formatters/__tests__/rca.spec.ts
+++ b/packages/cli/src/formatters/__tests__/rca.spec.ts
@@ -130,8 +130,11 @@ describe('transformErrorGroupForJson', () => {
 describe('formatRcaPending', () => {
   const pendingInfo = {
     rcaId: 'rca-123',
-    errorGroupId: 'eg-456',
-    checkId: 'check-789',
+    source: {
+      type: 'error-group' as const,
+      errorGroupId: 'eg-456',
+      checkId: 'check-789',
+    },
   }
 
   it('renders pending state in terminal', () => {
@@ -158,6 +161,44 @@ describe('formatRcaPending', () => {
     expect(result).toContain('pending')
     expect(result).toContain('rca-123')
   })
+
+  it('renders test session error group pending state', () => {
+    const result = stripAnsi(formatRcaPending({
+      rcaId: 'rca-456',
+      source: {
+        type: 'test-session-error-group',
+        testSessionErrorGroupId: 'tseg-123',
+      },
+    }, 'terminal'))
+
+    expect(result).toContain('Test session error group:')
+    expect(result).toContain('tseg-123')
+    expect(result).toContain('checkly rca get rca-456 --watch')
+    expect(result).not.toContain('checkly checks get')
+
+    const lines = result.split('\n')
+    const rcaLine = lines.find(line => line.includes('RCA ID:'))!
+    const groupLine = lines.find(line => line.includes('Test session error group:'))!
+    const statusLine = lines.find(line => line.includes('Status:'))!
+
+    expect(rcaLine.indexOf('rca-456')).toBe(groupLine.indexOf('tseg-123'))
+    expect(statusLine.indexOf('pending')).toBe(groupLine.indexOf('tseg-123'))
+  })
+
+  it('renders test session error group pending state in json', () => {
+    const result = formatRcaPending({
+      rcaId: 'rca-456',
+      source: {
+        type: 'test-session-error-group',
+        testSessionErrorGroupId: 'tseg-123',
+      },
+    }, 'json')
+
+    const parsed = JSON.parse(result)
+    expect(parsed.id).toBe('rca-456')
+    expect(parsed.status).toBe('pending')
+    expect(parsed.testSessionErrorGroupId).toBe('tseg-123')
+  })
 })
 
 describe('formatRcaCompleted', () => {
diff --git a/packages/cli/src/formatters/rca.ts b/packages/cli/src/formatters/rca.ts
index 3f015d0b4..da7512bc6 100644
--- a/packages/cli/src/formatters/rca.ts
+++ b/packages/cli/src/formatters/rca.ts
@@ -118,40 +118,62 @@ export interface ErrorGroupJsonOutput {
 
 export interface RcaPendingInfo {
   rcaId: string
-  errorGroupId: string
-  checkId: string
+  source: {
+    type: 'error-group'
+    errorGroupId: string
+    checkId: string
+  } | {
+    type: 'test-session-error-group'
+    testSessionErrorGroupId: string
+  }
 }
 
 export function formatRcaPending (info: RcaPendingInfo, format: OutputFormat | 'json'): string {
   if (format === 'json') {
-    return JSON.stringify({
+    const output: Record<string, string> = {
       id: info.rcaId,
       status: 'pending',
-      errorGroupId: info.errorGroupId,
-    }, null, 2)
+    }
+    if (info.source.type === 'error-group') {
+      output.errorGroupId = info.source.errorGroupId
+    } else {
+      output.testSessionErrorGroupId = info.source.testSessionErrorGroupId
+    }
+    return JSON.stringify(output, null, 2)
   }
 
   if (format === 'md') {
+    const sourceLabel = info.source.type === 'error-group' ? 'Error group' : 'Test session error group'
+    const sourceId = info.source.type === 'error-group'
+      ? info.source.errorGroupId
+      : info.source.testSessionErrorGroupId
     return [
       '# Root Cause Analysis',
       '',
       '| Field | Value |',
       '| --- | --- |',
       `| RCA ID | ${info.rcaId} |`,
-      `| Error group | ${info.errorGroupId} |`,
+      `| ${sourceLabel} | ${sourceId} |`,
       '| Status | pending |',
     ].join('\n')
   }
 
   const lines: string[] = []
+  const pendingLabelWidth = 'Test session error group:'.length + 2
   lines.push(chalk.bold('Root cause analysis triggered.'))
   lines.push('')
-  lines.push(`${label('RCA ID:')}${info.rcaId}`)
-  lines.push(`${label('Error group:')}${info.errorGroupId}`)
-  lines.push(`${label('Status:')}${chalk.yellow('pending')}`)
+  lines.push(`${label('RCA ID:', pendingLabelWidth)}${info.rcaId}`)
+  if (info.source.type === 'error-group') {
+    lines.push(`${label('Error group:', pendingLabelWidth)}${info.source.errorGroupId}`)
+  } else {
+    lines.push(`${label('Test session error group:', pendingLabelWidth)}${info.source.testSessionErrorGroupId}`)
+  }
+  lines.push(`${label('Status:', pendingLabelWidth)}${chalk.yellow('pending')}`)
   lines.push('')
   lines.push(`  ${chalk.dim('Watch progress:')}  checkly rca get ${info.rcaId} --watch`)
-  lines.push(`  ${chalk.dim('View result:')}    checkly checks get ${info.checkId} --error-group ${info.errorGroupId}`)
+  if (info.source.type === 'error-group') {
+    lines.push(`  ${chalk.dim('View result:')}    checkly checks get ${info.source.checkId} --error-group ${info.source.errorGroupId}`)
+  }
   return lines.join('\n')
 }
 
diff --git a/packages/cli/src/helpers/__tests__/flags.spec.ts b/packages/cli/src/helpers/__tests__/flags.spec.ts
new file mode 100644
index 000000000..cc4a8ac9d
--- /dev/null
+++ b/packages/cli/src/helpers/__tests__/flags.spec.ts
@@ -0,0 +1,54 @@
+import { describe, expect, it } from 'vitest'
+import { normalizeFlagAliases } from '../flags.js'
+
+describe('normalizeFlagAliases', () => {
+  const aliases = [
+    { alias: '-te', flag: '--test-session-error-group' },
+    { alias: '-eg', flag: '--error-group' },
+  ]
+
+  it('normalizes alias flags with separate values', () => {
+    expect(normalizeFlagAliases(['-te', 'tseg-123'], aliases)).toEqual([
+      '--test-session-error-group',
+      'tseg-123',
+    ])
+  })
+
+  it('normalizes alias flags with equals values', () => {
+    expect(normalizeFlagAliases(['-te=tseg=123'], aliases)).toEqual([
+      '--test-session-error-group=tseg=123',
+    ])
+  })
+
+  it('normalizes multiple aliases', () => {
+    expect(normalizeFlagAliases(['-eg', 'eg-123', '-te=tseg-123'], aliases)).toEqual([
+      '--error-group',
+      'eg-123',
+      '--test-session-error-group=tseg-123',
+    ])
+  })
+
+  it('leaves arguments after -- unchanged', () => {
+    expect(normalizeFlagAliases(['-te', 'tseg-123', '--', '-eg'], aliases)).toEqual([
+      '--test-session-error-group',
+      'tseg-123',
+      '--',
+      '-eg',
+    ])
+  })
+
+  it('leaves non-flag-shaped arguments unchanged', () => {
+    expect(normalizeFlagAliases(['value=with-equals', '--test-session-error-group=tseg-123'], aliases)).toEqual([
+      'value=with-equals',
+      '--test-session-error-group=tseg-123',
+    ])
+  })
+
+  it('returns a copy when no aliases are configured', () => {
+    const argv = ['-te', 'tseg-123']
+    const normalized = normalizeFlagAliases(argv, [])
+
+    expect(normalized).toEqual(argv)
+    expect(normalized).not.toBe(argv)
+  })
+})
diff --git a/packages/cli/src/helpers/flags.ts b/packages/cli/src/helpers/flags.ts
index 82899c46d..a5ab64bd2 100644
--- a/packages/cli/src/helpers/flags.ts
+++ b/packages/cli/src/helpers/flags.ts
@@ -1,5 +1,37 @@
 import { Flags } from '@oclif/core'
 
+export interface FlagAlias {
+  alias: string
+  flag: string
+}
+
+export function normalizeFlagAliases (argv: string[], aliases: FlagAlias[]): string[] {
+  if (aliases.length === 0) {
+    return [...argv]
+  }
+
+  const flagByAlias = new Map(aliases.map(({ alias, flag }) => [alias, flag]))
+  const passthroughIndex = argv.indexOf('--')
+  const argsToNormalize = passthroughIndex === -1 ? argv : argv.slice(0, passthroughIndex)
+  const passthroughArgs = passthroughIndex === -1 ? [] : argv.slice(passthroughIndex)
+
+  return [
+    ...argsToNormalize.map(arg => {
+      const match = arg.match(/^(-[a-z0-9-]+)(?:=(.*))?$/i)
+      const alias = match?.[1]
+      const flag = alias ? flagByAlias.get(alias) : undefined
+
+      if (!flag) {
+        return arg
+      }
+
+      const value = match?.[2]
+      return value === undefined ? flag : `${flag}=${value}`
+    }),
+    ...passthroughArgs,
+  ]
+}
+
 export function outputFlag (opts: { default: string, options?: string[] }) {
   return Flags.string({
     char: 'o',
diff --git a/packages/cli/src/rest/api.ts b/packages/cli/src/rest/api.ts
index 4ca1eb075..df7f2f9dc 100644
--- a/packages/cli/src/rest/api.ts
+++ b/packages/cli/src/rest/api.ts
@@ -18,6 +18,7 @@ import CheckStatuses from './check-statuses'
 import CheckResults from './check-results'
 import CheckGroups from './check-groups'
 import ErrorGroups from './error-groups'
+import TestSessionErrorGroups from './test-session-error-groups.js'
 import StatusPages from './status-pages'
 import Incidents from './incidents'
 import Analytics from './analytics'
@@ -122,6 +123,7 @@ export const checkStatuses = new CheckStatuses(api)
 export const checkResults = new CheckResults(api)
 export const checkGroups = new CheckGroups(api)
 export const errorGroups = new ErrorGroups(api)
+export const testSessionErrorGroups = new TestSessionErrorGroups(api)
 export const statusPages = new StatusPages(api)
 export const incidents = new Incidents(api)
 export const analytics = new Analytics(api)
diff --git a/packages/cli/src/rest/rca.ts b/packages/cli/src/rest/rca.ts
index eb2762607..cbd797a3a 100644
--- a/packages/cli/src/rest/rca.ts
+++ b/packages/cli/src/rest/rca.ts
@@ -19,6 +19,12 @@ class Rca {
     )
   }
 
+  triggerTestSessionErrorGroup (testSessionErrorGroupId: string) {
+    return this.api.post<TriggerRcaResponse>(
+      `/v1/root-cause-analyses/test-session-error-groups/${testSessionErrorGroupId}`,
+    )
+  }
+
   get (id: string) {
     return this.api.get<RootCauseAnalysis>(`/v1/root-cause-analyses/${id}`)
   }
diff --git a/packages/cli/src/rest/test-session-error-groups.ts b/packages/cli/src/rest/test-session-error-groups.ts
new file mode 100644
index 000000000..8d68e954c
--- /dev/null
+++ b/packages/cli/src/rest/test-session-error-groups.ts
@@ -0,0 +1,26 @@
+import type { AxiosInstance } from 'axios'
+
+export interface TestSessionErrorGroup {
+  id: string
+  projectId: string
+  environments: string[]
+  errorHash: string
+  rawErrorMessage: string | null
+  cleanedErrorMessage: string
+  firstSeen: string
+  lastSeen: string
+  archivedUntilNextEvent: boolean
+}
+
+class TestSessionErrorGroups {
+  api: AxiosInstance
+  constructor (api: AxiosInstance) {
+    this.api = api
+  }
+
+  get (id: string) {
+    return this.api.get<TestSessionErrorGroup>(`/v1/test-session-error-groups/${id}`)
+  }
+}
+
+export default TestSessionErrorGroups