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COSO

@ascent-partnersRun by its publisher: served from their own domain, namespace checked by the registry.MCP server · External

Open COSO internal-control review MCP: scope, risk, controls, sampling, testing, workpapers.

v0.1.2MITTypeScript
Freeno charge per call

One address for any MCP client. No sign-in needed on this server.

What it does

23 read8 act8 other

Grouped by tool name. At most: creates or changes data: records, files, settings.

What it costs

Free

Odel charges nothing per call. The publisher may charge for its own service.

Tools

39 · grouped by tool name · checked 15 Oct 2026

Read · 23Look things up

  • get_server_info
  • list_components
  • list_principles
  • get_principle
  • get_component
  • list_objective_categories
  • list_assertions
  • get_engagement
  • list_engagements
  • list_scope_items
  • list_risks
  • list_controls
  • get_audit_log
  • compute_sample_size
  • list_populations
  • list_test_results
  • list_exceptions
  • list_workpapers
  • get_workpaper
  • resolve_review_note
  • get_activity_log
  • list_deficiencies
  • framework_integration_check

Act · 8Change something

  • create_engagement
  • add_scope_item
  • register_risk
  • register_control
  • create_population
  • select_sample
  • add_review_note
  • sign_off

Other · 8Neither hinted nor named

  • record_test_result
  • note_exception
  • assemble_workpaper
  • classify_deficiency
  • aggregate_deficiencies
  • assess_principle
  • assess_component
  • generate_report
Try it in the Inspector
README4 min read

coso-mcp

npm license: MIT MCP

An open Model Context Protocol server for internal-control reviews under the COSO Internal Control—Integrated Framework (ICIF-2013). It covers the full review lifecycle — scope → risk assessment → control register → population → sampling → testing → workpapers → review sign-off → deficiency evaluation → report — grounded in the framework's 5 components, 17 principles and points of focus.

  • Local: runs over stdio (npx @simonmak-ascent/coso-mcp).
  • Hosted: public endpoint at https://internal-control.ascent-partners.com/mcp (reference + read tools, plus an ephemeral per-session sandbox for the full write lifecycle — nothing persists).

Not audit or legal advice. This server assists with internal-control review methodology. All workpapers and assessments must be reviewed by qualified professionals before use in audit documentation.

Why this exists (competitive advantage)

Existing MCP servers either expose a vendor's GRC records (read-mostly, proprietary, product-shaped) or cover ISO 27001 / security controls. None runs a traceable COSO review. coso-mcp is the first COSO/ICFR-native, write-capable, open MCP for the whole lifecycle.

Dimensioncoso-mcpVendor GRC MCPs (Workiva, Vanta, Drata, Optro, OpenPages, LogicGate…)Community MCPs (iso27001-mcp, unidoc/isms, mcp-server-scf…)AI skills (sox-testing / audit-support)
COSO ICIF-2013 native (5 components / 17 principles / points of focus)✅ core engine❌ product objects❌ ISO/SCF-shaped⚠️ text only
Full lifecycle to signed workpaper✅❌ retrieval; Workiva GRC tools are read-only❌ planning/findings at best⚠️ templates, not executable
Write/stateful workpapers + preparer/reviewer sign-off + audit trail✅❌ mostly read❌❌
Framework effectiveness (principle/component present & functioning)✅❌❌❌
Deterministic, reproducible computation (sample-size tables, seeded selection)✅partial❌❌ (freeform)
Open source + open access (MIT, public endpoint, no account)✅❌ paid platform⚠️ some OSS⚠️ not a server

Moat: it is the lifecycle layer, not the data layer — it can sit on top of Workiva/Vanta/Drata rather than compete for their data; its sampling and deficiency math are computed, not improvised; and openness gives zero-friction distribution no gated vendor can match.

Tools

ToolKindPurpose
get_server_inforeadServer identity, framework coverage, disclaimer.
list_componentsreadThe five COSO components.
list_principlesreadThe 17 principles (optionally filtered by component).
get_principlereadA principle by number or slug, with paraphrased points of focus.
get_componentreadA component by id, with its principles.
list_objective_categoriesreadOperations / reporting / compliance.
list_assertionsreadThe CEAVOP assertions used to frame control objectives.
create_engagementwriteCreate a review engagement.
get_engagementreadGet an engagement by id.
list_engagementsreadList engagements.
add_scope_itemwriteAdd a significant account/process to scope.
list_scope_itemsreadList scope items.
register_riskwriteRegister a risk to objectives (likelihood, assertions, principles, fraud).
list_risksreadList registered risks.
register_controlwriteRegister a control (type, frequency, linked risks, assertions).
list_controlsreadList registered controls.
get_audit_logreadAppend-only audit events for an engagement.
compute_sample_sizereadRecommended sample size from frequency × risk, with rationale.
create_populationwriteRegister a population (item list or declared size, bounded).
list_populationsreadList populations.
select_samplewriteSeeded, reproducible sample selection (random/systematic/targeted/haphazard).
record_test_resultwriteRecord attribute-level outcomes (pass/fail/na) and a conclusion.
list_test_resultsreadList test results.
note_exceptionwriteRecord an exception with root cause and impact.
list_exceptionsreadList exceptions.
assemble_workpaperwriteAssemble a Markdown control-testing workpaper.
list_workpapersreadList workpapers.
get_workpaperreadGet a workpaper with its Markdown.
add_review_notewriteAdd a reviewer note.
resolve_review_notewriteResolve a reviewer note.
sign_offwritePreparer/reviewer sign-off (warns on same-person independence).
get_activity_logreadAppend-only activity log for an engagement.
classify_deficiencywriteClassify a deficiency (deficiency / significant / material weakness).
list_deficienciesreadList deficiencies.
aggregate_deficienciesreadGroup and flag deficiencies that may aggregate.
assess_principlereadCoverage indicators for one COSO principle.
assess_componentreadCoverage indicators for one COSO component.
framework_integration_checkreadCheck all five components have coverage.
generate_reportreadGenerate the Markdown review report.

Resources: coso://framework/icif-2013 (framework reference), coso://engagement/{id} (engagement bundle: scope, risks, controls). Prompts: scope-review, assess-risk, build-control-matrix, draft-test-workpaper, evaluate-deficiencies.

Usage

Local (stdio)

bash
npx -y @simonmak-ascent/coso-mcp

Claude Desktop / generic MCP client config:

json
{
  "mcpServers": {
    "coso": {
      "command": "npx",
      "args": ["-y", "@simonmak-ascent/coso-mcp"]
    }
  }
}

Hosted (streamable HTTP)

https://internal-control.ascent-partners.com/mcp

The hosted endpoint is open. Write operations run in an ephemeral, isolated, rate-limited per-session sandbox and are not persisted.

Development

Compute runs on a box, never locally: cs run "<cmd>".

bash
pnpm install
pnpm typecheck
pnpm test
pnpm test:coverage
pnpm build        # tsc

Security

See SECURITY.md. Report vulnerabilities privately — do not open a public issue.

Contributing

See CONTRIBUTING.md and the Code of Conduct.

License

MIT © Simon Mak / Ascent Partners Group Limited.

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