# io.github.celfons/kyb-brasil (remote · kyb-br-agents.marcelfons.workers.dev)

Brazilian KYB beyond registry checks: CGU sanctions, forced labour, PGFN, IBAMA, signed risk score

- Trust score: 69/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-18

## Components

- remote · `kyb-br-agents.marcelfons.workers.dev`: 69/100 (this document), [markdown](https://verifymcp.io/servers/celfons-kyb-brasil/kyb-br-agents.md), [page](https://verifymcp.io/servers/celfons-kyb-brasil/kyb-br-agents)

## Channel facts

- Endpoint: `https://kyb-br-agents.marcelfons.workers.dev/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.4.2`

## 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 2026-10-18.

- **Endpoint Security**: 63/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 406, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 73/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1526 tokens (~138/item across 11 items; 11 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 20/100
  - Stability observed for 6 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.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 11 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 11 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the io.github.celfons/kyb-brasil MCP server?

io.github.celfons/kyb-brasil is a hosted endpoint at https://kyb-br-agents.marcelfons.workers.dev/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http celfons-kyb-brasil 'https://kyb-br-agents.marcelfons.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "celfons-kyb-brasil": {
      "url": "https://kyb-br-agents.marcelfons.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "celfons-kyb-brasil": {
      "type": "http",
      "url": "https://kyb-br-agents.marcelfons.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.celfons-kyb-brasil]
url = "https://kyb-br-agents.marcelfons.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "celfons-kyb-brasil": {
      "type": "remote",
      "url": "https://kyb-br-agents.marcelfons.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add celfons-kyb-brasil --url 'https://kyb-br-agents.marcelfons.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  celfons-kyb-brasil:
    url: "https://kyb-br-agents.marcelfons.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "celfons-kyb-brasil": {
      "Transport": "http",
      "Url": "https://kyb-br-agents.marcelfons.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add celfons-kyb-brasil -t streamable-http -u 'https://kyb-br-agents.marcelfons.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "celfons-kyb-brasil": {
      "type": "http",
      "url": "https://kyb-br-agents.marcelfons.workers.dev/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.

### 2026-10-17 (score 69, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-15 (score 68, +1)

No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-13 (score 67, +1)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-12 (score 66)

First indexed and scored.

## MCP tools (11)

### `br_about` (~75 tokens)

Free. What KYB Brasil is and why to use it over a plain registry check: every tool with price and HTTP route, how x402 payment works, free-tier limits, the attestation key, docs (OpenAPI, llms.txt, skill.md) and sources. Call it first when you do not know the service.

Output parameters:

- `service` (string)
- `tools` (array)
- `version` (string)
- `why_this_one` (array)

### `br_company_check` (~110 tokens)

Free. Brazilian company (CNPJ) registration check at the Receita Federal: status (ATIVA/BAIXADA/INAPTA...), legal name, CNAE, size, age, normalized address. Structured JSON plus a summary in English and Portuguese, with sources[] and data_freshness. Rate limited (50/day).

Input parameters:

- `cnpj` (string, required): Brazilian CNPJ, 14 characters, with or without punctuation (e.g. 00.000.000/0001-91).

Output parameters:

- `address` (object)
- `cached` (boolean)
- `cnpj` (string): Normalized 14-character CNPJ.
- `data_freshness` (string)
- `generated_at` (string)
- `legal_name` (string)
- `main_activity`
- `opened_at` (string|null)
- `registration_status` (string): ATIVA, SUSPENSA, INAPTA, BAIXADA, NULA or UNKNOWN.
- `sources` (array): Source URL and fetch time of each fact.
- `summary` (object): Short summary in English and Portuguese.

### `br_company_search` (~150 tokens)

Free. Find a Brazilian company's CNPJ by name (legal or trade name, optional state/UF) in the Receita Federal registry of ACTIVE establishments (monthly dump; individual entrepreneurs/MEI not indexed, query those by CNPJ). Returns up to 20 candidates with CNPJ, names, city/state, main activity and opening date. Use the CNPJ with the other tools. Rate limited (50/day).

Input parameters:

- `limit` (integer): Max results, default 10.
- `query` (string, required): Company name, legal or trade (e.g. 'Petrobras', 'construtora alfa').
- `state` (string): Optional UF to narrow down (e.g. 'SP').

Output parameters:

- `cached` (boolean)
- `data_freshness` (string)
- `generated_at` (string)
- `query` (string)
- `reference_month` (string)
- `results` (array)
- `sources` (array)
- `state` (string|null)
- `summary` (object): Short summary in English and Portuguese.

### `br_company_count` (~186 tokens)

Free. How many ACTIVE Brazilian establishments match a prospecting filter (CNAE code or prefix, state/UF, city, opening date range, headquarters only), from the Receita Federal monthly registry. Use it to budget pages before paying for br_company_list. Rate limited (50/day).

Input parameters:

- `city` (string): Municipality name (accents and case ignored).
- `cnae` (string): CNAE code or prefix: '6201-5/00', '6201500', '6201' (class) or '62' (division).
- `hq_only` (boolean): Only headquarters (one row per company).
- `opened_after` (string): Opened on or after (YYYY-MM-DD).
- `opened_before` (string): Opened on or before (YYYY-MM-DD).
- `state` (string): UF, e.g. 'SP'.

Output parameters:

- `cached` (boolean)
- `data_freshness` (string)
- `filters` (object)
- `generated_at` (string)
- `pages_of_100` (number)
- `reference_month` (string)
- `sources` (array)
- `summary` (object): Short summary in English and Portuguese.
- `total` (number)

### `br_replay` (~73 tokens)

Free. Fetch again, without paying, a paid answer from the last 10 minutes using the receipt.replay_token it carried. Use it when the first response was lost (timeout, disconnect) instead of paying twice.

Input parameters:

- `token` (string, required): receipt.replay_token from a paid answer (valid 10 minutes).

Output parameters:

- `attestation` (object): Ed25519 signature of this answer; verify at verify_url or with the public key at /.well-known/kyb-attestation.json.
- `cached` (boolean)
- `generated_at` (string)
- `receipt` (object): Re-read this answer free for 10 minutes with br_replay.

### `br_sanctions_screen` (~160 tokens)

Screen a Brazilian CNPJ, all branches of the same company (CNPJ root) and its corporate partners against the official CGU sanction lists: CEIS (debarred), CNEP (anti-corruption penalties), CEPIM (barred non-profits), leniency agreements, plus the Ministry of Labour forced-labour employer list. Each hit has type, body, dates, active flag and an evidence URL. Beyond a plain CEIS/CNEP check. Signed answer (Ed25519 attestation), verifiable at /v1/verify.

Input parameters:

- `cnpj` (string, required): Brazilian CNPJ, 14 characters, with or without punctuation (e.g. 00.000.000/0001-91).

Output parameters:

- `active_hits` (number)
- `attestation` (object): Ed25519 signature of this answer; verify at verify_url or with the public key at /.well-known/kyb-attestation.json.
- `cached` (boolean)
- `clear` (boolean): True when there is no ACTIVE sanction on the company, its branches or corporate partners.
- `cnpj` (string): Normalized 14-character CNPJ.
- `data_freshness` (string)
- `expired_hits` (number)
- `generated_at` (string)
- `hits` (array): Each hit: list, sanctioned_entity, sanction_type, dates, active, evidence_url.
- `receipt` (object): Re-read this answer free for 10 minutes with br_replay.
- `screened_entities` (array)
- `sources` (array): Source URL and fetch time of each fact.
- `summary` (object): Short summary in English and Portuguese.

### `br_risk_screen` (~172 tokens)

Red flags a registry check misses, a third of the dossier price: Receita Federal status + sanctions (CEIS/CNEP/CEPIM/leniency/forced labour) + PGFN debt and fiscal regularity (Simples/MEI, CND hint) + IBAMA embargoes + court cases (DJEN, 12 months) + OFAC/UN/EU screening + economic group (companies sharing partners) + 0-100 risk score + per-section data quality. No contracts, BNDES or gazettes. Signed answer (Ed25519 attestation), verifiable at /v1/verify.

Input parameters:

- `cnpj` (string, required): Brazilian CNPJ, 14 characters, with or without punctuation (e.g. 00.000.000/0001-91).

Output parameters:

- `attestation` (object): Ed25519 signature of this answer; verify at verify_url or with the public key at /.well-known/kyb-attestation.json.
- `cached` (boolean)
- `cnpj` (string): Normalized 14-character CNPJ.
- `company` (object)
- `data_freshness` (string)
- `data_quality` (array): Per-section data age: fresh, aging, stale, unavailable or unknown.
- `economic_group`: Other active companies sharing a partner, with their sanction/embargo flags (null = registry unavailable).
- `environmental_embargoes`
- `federal_debt`
- `fiscal_regularity` (object)
- `generated_at` (string)
- `international_sanctions`
- `receipt` (object): Re-read this answer free for 10 minutes with br_replay.
- `risk` (object)
- `sanctions`
- `sources` (array): Source URL and fetch time of each fact.
- `summary` (object): Short summary in English and Portuguese.
- `warnings` (array)

### `br_company_dossier` (~163 tokens)

One-call KYB due diligence, beyond a registry check: Receita Federal registration + ownership (no personal IDs) + economic group + sanctions (CEIS/CNEP/CEPIM/leniency/forced labour) + PGFN debt and fiscal regularity + IBAMA embargoes + court cases (DJEN) + federal contracts + BNDES + OFAC/UN/EU screening + gazettes + 0-100 risk score with explained red flags + per-section data quality, sources[]. Signed answer (Ed25519 attestation), verifiable at /v1/verify.

Input parameters:

- `cnpj` (string, required): Brazilian CNPJ, 14 characters, with or without punctuation (e.g. 00.000.000/0001-91).

Output parameters:

- `attestation` (object): Ed25519 signature of this answer; verify at verify_url or with the public key at /.well-known/kyb-attestation.json.
- `bndes_financing`
- `cached` (boolean)
- `cnpj` (string): Normalized 14-character CNPJ.
- `company` (object)
- `data_freshness` (string)
- `data_quality` (array): Per-section data age: fresh, aging, stale, unavailable or unknown.
- `economic_group`: Other active companies sharing a partner, with their sanction/embargo flags (null = registry unavailable).
- `environmental_embargoes`: IBAMA embargo terms.
- `federal_contracts`
- `federal_debt`: PGFN active federal debt (null = dataset unavailable).
- `fiscal_regularity` (object)
- `gazette_mentions`: Querido Diário mentions in municipal official gazettes.
- `generated_at` (string)
- `international_sanctions`: OFAC/UN/EU name-only matches; informational, never scored.
- `partners` (array)
- `receipt` (object): Re-read this answer free for 10 minutes with br_replay.
- `risk` (object)
- `sanctions`
- `sources` (array): Source URL and fetch time of each fact.
- `summary` (object): Short summary in English and Portuguese.
- `warnings` (array)

### `br_batch_sanctions` (~99 tokens)

Up to 10 CNPJs in one paid call (one payment, 25% off): br_sanctions_screen for each. Per-item errors are reported inline in results[]; the call fails (and is not charged) only when no item succeeds. Signed answer (Ed25519 attestation), verifiable at /v1/verify.

Input parameters:

- `cnpjs` (array, required): 1 to 10 CNPJs.

Output parameters:

- `cached` (boolean)
- `count` (number)
- `data_freshness` (string)
- `failed` (number)
- `generated_at` (string)
- `receipt` (object): Re-read this answer free for 10 minutes with br_replay.
- `results` (array)
- `sources` (array)
- `succeeded` (number)
- `summary` (object): Short summary in English and Portuguese.

### `br_batch_dossier` (~96 tokens)

Up to 10 CNPJs in one paid call (one payment, a third off): br_company_dossier for each. Per-item errors are reported inline in results[]; the call fails (and is not charged) only when no item succeeds. Signed answer (Ed25519 attestation), verifiable at /v1/verify.

Input parameters:

- `cnpjs` (array, required): 1 to 10 CNPJs.

Output parameters:

- `cached` (boolean)
- `count` (number)
- `data_freshness` (string)
- `failed` (number)
- `generated_at` (string)
- `receipt` (object): Re-read this answer free for 10 minutes with br_replay.
- `results` (array)
- `sources` (array)
- `succeeded` (number)
- `summary` (object): Short summary in English and Portuguese.

### `br_company_list` (~242 tokens)

Prospecting list: one page of 100 ACTIVE Brazilian establishments matching a filter (CNAE code or prefix, state/UF, city, opening date range, headquarters only), with CNPJ, legal and trade name, city/state, main activity and opening date. Stable paging by CNPJ; total and next_page included. Source: Receita Federal monthly registry; MEI owners' CPFs masked. Signed answer (Ed25519 attestation), verifiable at /v1/verify.

Input parameters:

- `city` (string): Municipality name (accents and case ignored).
- `cnae` (string): CNAE code or prefix: '6201-5/00', '6201500', '6201' (class) or '62' (division).
- `hq_only` (boolean): Only headquarters (one row per company).
- `opened_after` (string): Opened on or after (YYYY-MM-DD).
- `opened_before` (string): Opened on or before (YYYY-MM-DD).
- `page` (integer): Page of 100, default 1.
- `state` (string): UF, e.g. 'SP'.

Output parameters:

- `attestation` (object): Ed25519 signature of this answer; verify at verify_url or with the public key at /.well-known/kyb-attestation.json.
- `cached` (boolean)
- `data_freshness` (string)
- `filters` (object)
- `generated_at` (string)
- `next_page` (number|null)
- `page` (number)
- `page_size` (number)
- `receipt` (object): Re-read this answer free for 10 minutes with br_replay.
- `reference_month` (string)
- `results` (array)
- `sources` (array)
- `summary` (object): Short summary in English and Portuguese.
- `total` (number)
- `total_pages` (number)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/celfons-kyb-brasil/kyb-br-agents#diagnostics

## Score history

- 2026-10-18: 69
- 2026-10-17: 69
- 2026-10-16: 68
- 2026-10-15: 68
- 2026-10-14: 67
- 2026-10-13: 67
- 2026-10-12: 66

## Common questions

### What is the io.github.celfons/kyb-brasil MCP server?

io.github.celfons/kyb-brasil is an MCP server listed in the public MCP registry as io.github.celfons/kyb-brasil. Brazilian KYB beyond registry checks: CGU sanctions, forced labour, PGFN, IBAMA, signed risk score. This page covers its hosted endpoint (https://kyb-br-agents.marcelfons.workers.dev/mcp).

### Is the io.github.celfons/kyb-brasil MCP server safe to use?

io.github.celfons/kyb-brasil scores 69 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the io.github.celfons/kyb-brasil MCP server expose?

io.github.celfons/kyb-brasil exposes 11 tools: br_about, br_company_check, br_company_search, br_company_count, br_replay, and 6 more. Their descriptions and schemas cost roughly 1,526 tokens of context every time the server is loaded.

### Does the io.github.celfons/kyb-brasil MCP server require authentication?

No. We connected to io.github.celfons/kyb-brasil without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the io.github.celfons/kyb-brasil MCP server still maintained?

io.github.celfons/kyb-brasil is still listed as active in the MCP registry. We last reached this channel on 18 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://kyb-br-agents.marcelfons.workers.dev/mcp
- Website: https://kyb-br-agents.marcelfons.workers.dev/
- Changelog RSS feed: https://verifymcp.io/servers/celfons-kyb-brasil/kyb-br-agents.xml
- Changelog JSON feed: https://verifymcp.io/servers/celfons-kyb-brasil/kyb-br-agents.json
- HTML version of this page: https://verifymcp.io/servers/celfons-kyb-brasil/kyb-br-agents