# OpenAccountants (remote · www.openaccountants.com)

Open-source AI accounting skills verified by licensed accountants (tax, VAT, payroll).

- Trust score: 76/100 (medium)
- Change this week: +13
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-08-03

## Components

- remote · `www.openaccountants.com`: 76/100 (this document), [markdown](https://verifymcp.io/servers/openaccountants-openaccountants/api-mcp.md), [page](https://verifymcp.io/servers/openaccountants-openaccountants/api-mcp)

## Channel facts

- Endpoint: `https://www.openaccountants.com/api/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-08-03.

- **Endpoint Security**: 89/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation is enforced on tool calls, advertised via RFC 9728 protected-resource metadata. Discovery is public, which costs nothing: no tool can be invoked without a token.
  - HTTPS is enforced; there's no plaintext access path.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
  - The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 71/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 7079 tokens (~505/item across 14 items; 14 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 27/100
  - Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Capabilities**: 40/100
  - Spec-recency check failed: implements MCP spec 2025-03-26; the latest is 2026-07-28.

## Install

### Claude

```bash
claude mcp add --transport http openaccountants-openaccountants https://www.openaccountants.com/api/mcp
```

### Codex

```toml
[mcp_servers.openaccountants-openaccountants]
url = "https://www.openaccountants.com/api/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "openaccountants-openaccountants": {
      "type": "remote",
      "url": "https://www.openaccountants.com/api/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add openaccountants-openaccountants --url https://www.openaccountants.com/api/mcp --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  openaccountants-openaccountants:
    url: "https://www.openaccountants.com/api/mcp"
```

### Other

```json
{
  "mcpServers": {
    "openaccountants-openaccountants": {
      "type": "http",
      "url": "https://www.openaccountants.com/api/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-08-03 (score 76, +1)

No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-08-01 (score 75, +1)

No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-31 (score 74, +4)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-30 (score 70, +6)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-28 (score 64, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-27 (score 63, +1)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-26 (score 62)

First indexed and scored.

## MCP tools (14)

### `list_skills` (~300 tokens)

List tax & accounting skills

List published OpenAccountants skills with their quality tier and verification status. Optionally filter by jurisdiction (e.g. 'US', 'MT', 'DE', 'GB'), domain (the accounting area, e.g. 'vat-gst', 'payroll', 'income-tax'), or role ('foundation' | 'compute' | 'orchestrator' | 'reference'). Results are paginated (default 100, max 200 per call) — unfiltered browsing of the full ~1,100-skill catalogue requires paging via offset/next_offset, so jurisdiction/domain filters are strongly recommended.

Input parameters:

- `category` (string): (Legacy) display label; prefer domain/role.
- `domain` (string): Filter by accounting domain: income-tax, vat-gst, payroll, bookkeeping, e-invoicing, formation, financial-statements, transfer-pricing, tax-optimization, crypto, cross-border, corporate-tax, estate-w…
- `jurisdiction` (string): Filter by jurisdiction code, e.g. 'US', 'MT', 'DE'
- `limit` (integer): Max skills to return (default 100, max 200).
- `offset` (integer): Number of skills to skip — use the next_offset from the previous response to page through results (default 0).
- `role` (string): Filter by pipeline role: foundation, compute, orchestrator, reference.

Output parameters:

- `limit` (integer): Page size applied to this response.
- `next_action` (string)
- `next_offset` (integer): Present when more results remain — pass as offset to fetch the next page.
- `offset` (integer): Offset applied to this response.
- `skills` (array): Matching published skills.
- `total` (integer): Total skills matching the filter (across all pages).

### `get_skill` (~89 tokens)

Get a tax skill

Fetch a published skill by slug, including its current-version markdown, quality tier, named verifier (where accountant-verified), and a provenance/attribution footer.

Input parameters:

- `reason` (string): One sentence on WHY you're making this call, in the user's terms (for routing analysis only). Optional.
- `slug` (string, required): Skill slug, e.g. 'us-schedule-c-and-se-computation'

Output parameters:

- `current_version` (object|null): Current version. markdown_content holds the compute-core (rates, box maps, rules, worksheet contract); bulky reference sections may be omitted — see section_index.
- `guardrails` (array)
- `key_facts` (object): Optional at-a-glance facts (rates/thresholds/deadlines/verifier/advisory) — present only where the skill carries a structured key_facts block; omitted otherwise.
- `next_action` (string)
- `provenance` (object)
- `section_index` (array): Every section of the skill with {index, heading, level, chars, priority, included}. For any section with included:false, fetch it via get_skill_sections({slug, section_index}).
- `skill` (object): The skill record (slug, name, jurisdiction, tier, etc.)
- `verification` (object|null): Verification summary

### `get_skill_sections` (~130 tokens)

Get a skill's sections

Fetch the parsed sections of a skill's current version. Each section has a heading and its markdown content. Use this to pull a specific section that get_skill listed in `section_index` as not inlined (e.g. a supplier-pattern library) — pass `section_index` to fetch just that one. Omit it to get every section.

Input parameters:

- `section_index` (integer): Optional. Return only this section (matches the `index` from get_skill's `section_index`).
- `section_indices` (array): Optional. Return only these sections.
- `slug` (string, required): Skill slug

Output parameters:

- `guardrails` (array)
- `key_facts` (object): Optional at-a-glance facts — present only where the skill carries a structured key_facts block; omitted otherwise.
- `next_action` (string)
- `sections` (array)
- `slug` (string)
- `version` (integer|number)

### `search_skills` (~286 tokens)

Search skills by keyword

Full-text search across all published tax and accounting skills. Find, lookup, query, or discover skills by keyword, tax concept, deduction type, form number, or regulation (e.g. 'home office deduction', 'crypto capital gains', 'reverse charge', 'Schedule C', '60-day reporting'). Optionally limit to one jurisdiction. Use this when you don't know the exact skill slug. Set content_type='method' to discover step-by-step METHODS (guided procedures — what you EXECUTE via start()) instead of reference material; each method carries a review_status (accountant-reviewed | source-cited).

Input parameters:

- `content_type` (string): What kind of Guide to find. 'method' = step-by-step procedures you EXECUTE via start() (formerly 'workflows'); 'fact' or omitted = reference material (rates/thresholds/rules). A Guide can be either o…
- `domain` (string): Optional accounting domain to limit the search (e.g. 'vat-gst', 'payroll', 'income-tax', 'crypto').
- `jurisdiction` (string): Optional ISO 2-letter country code to limit the search
- `query` (string, required): Search term, e.g. 'home office deduction', 'crypto capital gains', 'reverse charge'. With content_type='method', a broad term (or the domain word) lists the available methods.

Output parameters:

- `human_backing` (object|null): Named accountant(s) who review this jurisdiction's guidance (guidance-level, not a per-figure sign-off).
- `next_action` (string)
- `results` (array)
- `total` (integer)

### `search_rules` (~399 tokens)

Search rules across jurisdictions

Query individual tax RULES/FACTS (rates, thresholds, rules, definitions, tables) ACROSS jurisdictions and metadata, and get back a bundled markdown rule set the user can save and run locally. Unlike get_skill (one whole skill), this assembles a cross-cutting SET — e.g. 'VAT rates in MT, IE and DE', 'all income-tax thresholds for 2025', or 'rules mentioning reverse charge'. By default returns ALL matching rules, each tagged with its verification status; pass status:'verified' for accountant-/research-verified only. Call `list_rule_facets` first to see the queryable values.

Input parameters:

- `block_types` (array): Rule kinds to include. Default = all of these (framing prose + workflow steps are excluded).
- `domains` (array): Accounting domains, e.g. ['vat-gst','income-tax']. See list_rule_facets.
- `jurisdictions` (array): ISO codes to include, e.g. ['MT','US-CA']. Omit for all jurisdictions.
- `limit` (integer): Max rules to return (default 200, max 500).
- `offset` (integer): Pagination offset — pass the previous response's next_offset.
- `reason` (string): One sentence on WHY you're making this call, in the user's terms (for routing analysis only). Optional.
- `roles` (array): Skill roles: foundation | compute | orchestrator | reference.
- `status` (string): Shorthand for `statuses`: 'verified' = accountant- + research-verified only. Default 'all'.
- `statuses` (array): Verification statuses to include. Default = all (each rule is tagged).
- `tax_year` (integer): Limit to a tax year, e.g. 2025.
- `text` (string): Free-text search over each rule's label, value, and citation.
- `topic` (string): Filter by a fact topic.

Output parameters:

- `accountant_verified_count` (integer)
- `fact_count` (integer): Rules returned on this page.
- `jurisdictions` (array)
- `markdown` (string): The bundled rule set as markdown — the user saves/runs this locally.
- `next_action` (string)
- `next_offset` (integer|null)
- `total` (integer): Total matching rules (across all pages).
- `truncated` (boolean)

### `get_deadlines` (~154 tokens)

Upcoming tax deadlines for a jurisdiction

Upcoming filing/payment deadlines and recurring filing rhythms (monthly VAT, quarterly instalments) for a country or US state, from the OpenAccountants tax calendar. Use it whenever the user asks 'when is X due', mentions a filing date, or when a heads-up about an imminent deadline would help. Signed-in users with a saved home jurisdiction can omit `jurisdiction` — it fills from their profile (the response marks jurisdiction_source accordingly).

Input parameters:

- `horizon_days` (integer): How far ahead to look (default 120, max 366).
- `jurisdiction` (string): ISO code, slug, or name ('MT', 'US-CA', 'Malta'). Optional for signed-in users with a saved home jurisdiction.

Output parameters:

- `calendar_url` (string)
- `horizon_days` (integer)
- `jurisdiction` (string)
- `jurisdiction_source` (string)
- `next_action` (string)
- `recurring_rhythms` (array)
- `upcoming_deadlines` (array)

### `list_rule_facets` (~70 tokens)

List queryable rule facets (no args)

Returns the metadata you can filter on with `search_rules` — the live jurisdictions, the domains, roles, block types (rule kinds), statuses, tax years, and a sample of topics — plus the defaults. Call this before `search_rules` to learn the valid filter values rather than guessing.

Output parameters:

- `defaults` (object)
- `filters` (array)
- `next_action` (string)

### `start_help` (~120 tokens)

Get tax-workflow scoping guidance (no args)

No-argument front door — call this FIRST whenever a user asks 'how can you help me?', 'what can you do?', 'where do I start?', or otherwise opens vaguely (do NOT answer such questions by listing your tools or calling list_jurisdictions). For a signed-in approved accountant it returns a personalized `orientation` briefing (their standing + what their jurisdiction needs + one next action). For everyone else it returns the two scoping questions plus the available intents and jurisdictions. Once you have an intent, call `start(intent, jurisdiction)`.

Output parameters:

- `available_intents` (array)
- `available_jurisdictions` (array)
- `needs` (array)
- `next_action` (string)
- `status` (string)

### `start` (~473 tokens)

Start a tax workflow

Front door for any tax / accounting question once you know what the user wants. `intent` is REQUIRED (e.g. 'taxes', 'VAT return', 'set up a company', 'find deductions', 'classify transactions', 'payroll'); pass a jurisdiction too (ISO 2-letter, e.g. 'MT', 'GB', 'US-CA'). If you don't yet have an intent, call `start_help` first. Returns either a clarification request (if jurisdiction is missing) or a ready-to-execute plan with the list of skills to load. Call this FIRST (after start_help if needed) whenever the user asks for tax help.

Input parameters:

- `acting_as` (string, required): REQUIRED. Who the user is: 'self' = a taxpayer handling their OWN taxes; 'client' = a professional (accountant/advisor) working on behalf of a CLIENT. Establish this before calling — if it isn't clea…
- `intent` (string, required): User intent — REQUIRED. Free text, e.g. 'taxes', 'VAT return', 'set up a company'.
- `jurisdiction` (string): ISO 2-letter code or US state code (e.g. 'MT', 'GB', 'US-CA').
- `reason` (string): One sentence, in the user's own words, on what they actually asked for here — captured only to improve routing. E.g. 'user sold ETH and wants to know what to report'. Optional but helpful.
- `taxpayer_type` (string): The taxpayer's occupation, when known. Some return-prep workflows fork by it (an employee's Form 1040 is a different guide from a freelancer's). Pass it if the conversation already makes it clear; ot…

Output parameters:

- `available_intents` (array)
- `available_jurisdictions` (array)
- `expectations` (string)
- `guardrails` (array)
- `intent` (string)
- `jurisdiction` (string)
- `needs` (array)
- `next_action` (string)
- `skills_to_load` (array)
- `status` (string)

### `list_jurisdictions` (~84 tokens)

List all jurisdictions covered

Returns every jurisdiction with published skills — countries (ISO 2), US states (US-XX), Canadian provinces — with skill counts, accountant-verified counts, and named lead verifier. Use when the user asks 'which countries does OpenAccountants cover?' or 'what's available for [country]?' Avoids paginating through list_skills to compute this.

Output parameters:

- `jurisdictions` (array)
- `next_action` (string)
- `total_jurisdictions` (integer)
- `total_skills` (integer)

### `list_verifiers` (~103 tokens)

List named accountant verifiers

Returns named licensed accountants who have signed off on OpenAccountants jurisdictions, with their credentials and covered jurisdictions. Use when the user asks who verified a skill or wants to see the verifier network. If the user wants one of them to review their work, that goes through `share_with_openaccountants` with `request_review: true` — at the user's explicit request only.

Input parameters:

- `jurisdiction` (string): Optional ISO code filter — only return verifiers for this jurisdiction.

Output parameters:

- `next_action` (string)
- `total` (integer)
- `verifiers` (array)

### `validate_vat_number` (~321 tokens)

Validate a business VAT / tax-ID number (live registry lookup)

Check whether a business's VAT / tax-registration number is real and registered, in real time against the official government registry — and return the registered business NAME and ADDRESS when the authority discloses them. This is an authoritative, unfakeable confirmation you cannot get from a knowledge lookup or from training data. Use it whenever a user wants to verify a supplier's or customer's tax ID: before applying a B2B reverse charge, zero-rating a cross-border sale, or onboarding a vendor. COVERAGE TODAY IS EU ONLY — the 27 EU member states plus 'XI' (Northern Ireland), live via the European Commission's VIES registry (use 'EL' for Greece). Other jurisdictions (e.g. UK/HMRC and beyond) are NOT supported yet but are on the roadmap — for a non-EU number, tell the user live validation isn't available for that country yet rather than guessing a verdict. This is a LIVE external lookup — if the registry is temporarily unavailable it says so plainly rather than inventing an answer.

Input parameters:

- `country_code` (string): 2-letter EU member-state code of the VAT number, e.g. 'DE', 'IE', 'FR'. Use 'EL' for Greece and 'XI' for Northern Ireland. May be omitted if the country prefix is already part of vat_number.
- `vat_number` (string, required): The VAT number, with or without the country prefix and spaces, e.g. 'IE6388047V', 'IE 6388047V', or '6388047V'.

Output parameters:

- `address` (string|null)
- `business_name` (string|null)
- `checked_at` (string)
- `confirm_available` (boolean): Whether the user can ask a named accountant to confirm the VAT treatment via ask_accountant_to_confirm.
- `country_code` (string|null)
- `full_vat_id` (string)
- `human_backing` (object|null): Named accountant(s) who review that country's VAT guidance (guidance-level, not a per-figure sign-off).
- `message` (string)
- `next_action` (string)
- `source` (string)
- `source_url` (string)
- `summary` (string)
- `valid` (boolean|null): true/false verdict from VIES, or null if the service could not be reached (an availability issue, not a verdict).
- `vat_number` (string)
- `vies_error` (string)

### `check_audit_exemption` (~439 tokens)

Check statutory audit exemption (deterministic, cited, verified)

DETERMINISTIC check of whether a private limited company qualifies for statutory audit exemption, from aggregate figures any ledger can provide (turnover, balance sheet total, average employees). Returns a determination ('exempt' | 'review' | 'audit_required' | 'cannot_determine'), the per-criterion threshold table showing exactly why, the canonical rule citation it rests on, and the LIVE verification envelope (whether a named accountant has attested the thresholds — surface that status prominently; 'draft' means treat as a source-cited draft). COVERAGE TODAY: MT (Article 185(2) micro thresholds) and GB (small-company thresholds, both pre and post 6 April 2025 eras). Most exemption regimes are two-consecutive-years tests, so pass prior_year figures when available — without them a qualifying year returns 'review', not 'exempt'; that is correct behaviour, not an error. 'cannot_determine' is a first-class outcome (unsupported jurisdiction, wrong currency, entity shapes needing judgment, or the cited fact changed since calibration). Never override the determination with training-data thresholds.

Input parameters:

- `balance_sheet_total` (number, required): Total assets at the balance sheet date.
- `currency` (string, required): Currency of the figures — must match the regime (EUR for MT, GBP for GB); convert first, never guess a rate.
- `employees_average` (number, required): Average number of employees during the year.
- `entity_type` (string): Optional. 'private_ltd' (default), 'plc', 'branch'. Non-private shapes route to a human.
- `financial_year_end` (string, required): ISO date the financial year ends, e.g. '2025-12-31'.
- `group_member` (boolean): Optional. True if the company is part of a group — group thresholds need a reviewer, so this forces 'review'.
- `jurisdiction` (string, required): ISO-style code. MT and GB supported today.
- `prior_year` (object): Prior-year figures for the two-consecutive-years test.
- `turnover` (number, required): Revenue/turnover for the year, in the jurisdiction's currency.

Output parameters:

- `caveats` (array)
- `criteria_rule` (string|null)
- `determination` (string): 'exempt' | 'review' | 'audit_required' | 'cannot_determine'
- `escalate` (boolean)
- `next_action` (string)
- `rule_citation` (object|null): skill_slug, fact_id, canonical_key, statutory_reference, url.
- `thresholds_applied` (array): Per-criterion: threshold vs actual, met true/false.
- `verification` (object|null): status ('accountant_verified'|'research_verified'|'draft'), verified_by[], last_verified_at, skill_slug, era. Surface the status to the user.

### `share_with_openaccountants` (~455 tokens)

Share this with OpenAccountants

Sends feedback or a review request to OpenAccountants. This is the single outbound channel; it does nothing unless the user has explicitly asked to send feedback or to request a review. Two modes: (1) `note` — an anonymized note about the guidance (a gap, a workaround you needed, or via `skill_slug` a bug in a specific skill). Anonymize hard: no names, amounts, or PII. (2) `request_review: true` — submits the user's working paper for review by a licensed accountant; also requires `working_paper` (complete), `jurisdiction`, `scenario`, and `contact_email`. The review is a paid professional engagement (never describe it as free); the request is saved to the user's own queue and the response returns a booking link — nothing reaches an accountant until the user engages. Call at most once per explicit user request; never call as a routine closing step, and never solicit the request.

Input parameters:

- `contact_email` (string): Review only, REQUIRED when request_review: the user's email. Ask for it first.
- `contact_name` (string): Review only: the user's name.
- `jurisdiction` (string): Review only: ISO code or slug for the user's tax jurisdiction (e.g. 'US-CA').
- `note` (string, required): Anonymized improvement note: what the guidance covered vs what you added or worked around and why, or a bug in a specific skill. No names, amounts, or PII.
- `request_review` (boolean): true only when the user has asked for a licensed accountant to review their figures. Requires working_paper + jurisdiction + scenario + contact_email. Omit/false = just the note.
- `scenario` (string): Review only: brief description of the situation to review.
- `skill_slug` (string): Optional: set when the note is feedback about a SPECIFIC skill (e.g. 'us-sales-tax'). Replaces the old submit_feedback.
- `tax_year` (integer): Review only: tax year, if relevant.
- `working_paper` (string): Review only: the COMPLETE working paper markdown — every line item and assumption, not a summary.

Output parameters:

- `booking_url` (string)
- `message` (string)
- `note_recorded` (boolean)
- `status` (string)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/openaccountants-openaccountants/api-mcp#diagnostics

## Score history

- 2026-08-03: 76
- 2026-08-02: 75
- 2026-08-01: 75
- 2026-07-31: 74
- 2026-07-30: 70
- 2026-07-29: 64
- 2026-07-28: 64
- 2026-07-27: 63
- 2026-07-26: 62

## Links

- Remote endpoint: https://www.openaccountants.com/api/mcp
- Repository: https://github.com/openaccountants/openaccountants
- Changelog RSS feed: https://verifymcp.io/servers/openaccountants-openaccountants/api-mcp/changelog.xml
- Changelog JSON feed: https://verifymcp.io/servers/openaccountants-openaccountants/api-mcp/changelog.json
- HTML version of this page: https://verifymcp.io/servers/openaccountants-openaccountants/api-mcp