ProbaFide
Verification, evidence receipts, and notarial handoff for workflows that require legal authority.
ProbaFide is a live, MCP-native verification and notarial-handoff API for AI agents working in legal, financial, corporate, real-estate, and diligence workflows.
Evidence receipt
{
"ok": true,
"tool_name": "br_cnpj_lookup",
"source": "brasilapi",
"legal_assurance_level":
"public_api_observation",
"timestamp_utc": "2026-06-10T13:01:13Z",
"request_sha256": "f910…413f",
"response_sha256": "71c5…8535",
"limitations": ["Public API
observation only. No legal or notarial
conclusion was produced."]
}02What it is
ProbaFide gives AI agents a safe way to verify legal-adjacent facts, create audit receipts, and escalate to authorized notarial channels.
It provides structured verification tools, source-bound outputs, evidence receipts, and human notarial handoff packets for workflows where the agent must separate observed facts from legal authority.
ProbaFide is not a cartório, notary, legal authority, government service, or substitute for legal advice.
03Use cases
Three workflows ProbaFide is designed around — each one ends with receipts an auditor can replay, and a clear decision about what still needs human authority.
01 An agent drafting a contract checks the counterparty's CNPJ registration, status, and partners, attaches a receipt for every lookup, and flags anything that requires human legal review before signature.
02 An agent assembling a property closing verifies addresses and the seller entity, collects the evidence into a receipted dossier, and creates a notarial handoff packet for the escritura at the cartório.
03 An agent receives a signed PDF, runs a technical ICP-Brasil signature-conformity check, gets a receipt that states what was not proven, and escalates when the workflow needs an act with legal authority.
04Trust ladder
ProbaFide separates evidence, technical checks, and authorized human acts so agents know when to stop and escalate.
01 A source-bound observation can answer what was seen, when, and from where.
02 The receipt makes the check auditable without turning it into legal authority.
03 A configured provider can return a signature-conformity report; otherwise ProbaFide fails closed.
04 A handoff packet packages the facts, hashes, limitations, and requested review path.
05 This requires a partner-confirmed event from an authorized notarial rail.
observed verified validated notarized
05How it works
The product surface is built for agents first: deterministic tools, structured outputs, and a clear escalation decision.
01 Receives a counterparty, address, file, or workflow question.
02 Calls a narrow ProbaFide tool with explicit input.
03 Returns what was checked, which source was used, and what came back.
04 Records timestamp, source, hashes, assurance level, and limitations.
05 Creates a handoff when human review or an authorized notarial act is required.
Product contract
06Assurance levels
The assurance level states what ProbaFide can support from the source and what still requires review or authority.
public_api_observation | Observed from a public or community API. |
|---|---|
official_api_observation | Observed from an official API. |
signature_conformity_check | Technical signature validation performed. |
notary_handoff_pending | Local or submitted handoff pending human or legal authority. |
notarial_act_completed | Completed by an authorized notarial partner or system; requires a partner-confirmed event. |
unavailable | Tool failed, source unavailable, or credentials missing. |
07For developers
ProbaFide is a live public API — no account, no API key — plus a narrow MCP tool layer agents can call before acting inside legal-adjacent workflows. Every call returns a receipt.
GET https://api.probafide.ai/ — the machine-readable guide: endpoints, response shape, and receipt semantics an agent can discover on its own.
Unavailable credentials, disabled providers, and missing partner rails return structured limitations instead of optimistic conclusions.
$ curl -s https://api.probafide.ai/v1/verify/cnpj \
-H 'Content-Type: application/json' \
-d '{"cnpj":"00000000000191"}'
{
"ok": true,
"source": "brasilapi",
"legal_assurance_level": "public_api_observation",
"receipt_id": "rec_..."
}
# claude_desktop_config.json · MCP, agent-native
{
"mcpServers": {
"probafide": {
"command": "uv",
"args": ["--directory", "/path/to/probafide",
"run", "probafide", "mcp"]
}
}
}Brazil first
Brazil is the first market because it combines a civil-law notarial tradition, digital notarial infrastructure, and public or official data rails.
08Roadmap
Each phase only claims what its rails can support — the assurance levels grow with the integrations behind them.
P1 Deterministic tools, native evidence receipts, fail-closed posture.
in development
P2 SERPRO, DataJud, and ITI VALIDAR credentialing unlock the official assurance levels.
P3 e-Notariado / CENAD partnership (technical cooperation agreement with CNB-CF) for handoffs and completed acts.
P4 ICP-Brasil trusted timestamps on receipts first; batch blockchain anchoring as a later option.
09Principles
01 If credentials, sources, or partner rails are missing, return a structured limitation.
02 No source, no verification.
03 No receipt, no auditability.
04 The receipt should say what it does not prove.
05 A good result can say human notarial review required.
06 Build for civil-law markets, with Brazil as the beachhead.
For notarial partners
ProbaFide routes agent workflows that require fé pública to human notarial channels as structured, receipted handoff packets — new demand arriving in a reviewable form. We are looking for a first cartório partner for the pilot.
10FAQ
A receipt is structured evidence: what was checked, when, from which source, with which hashes. It supports audit and review — it is not fé pública, a notarial act, or a certification. When a workflow needs legal authority, the receipt's job is to say so and route the handoff.
KYC and data platforms verify people and companies for human-driven onboarding. ProbaFide is built for the agent loop: deterministic MCP tools, source-bound responses, explicit assurance levels, receipts, and an escalation path. It complements data providers rather than replacing them.
No — KYA verifies the identity and authority of agents themselves. ProbaFide works in the other direction: it equips agents to verify external facts and to escalate to human authority. The two layers are complementary.
Verification queries go to public or official sources with a stated purpose. Receipts are designed for data minimization — hashes and source references rather than copies of personal data wherever possible. Full LGPD documentation ships with the MVP.
If credentials are missing, a provider is disabled, or a partner rail is unavailable, the tool returns unavailable plus a structured limitation. ProbaFide never substitutes an optimistic guess for a source.
Whenever the workflow requires legal authority or human judgment: a notarial act, a certified copy, a contested fact. The handoff tool packages the evidence, hashes, and limitations into a packet a qualified human can act on.
11Contact
Building agents for legal, financial, or diligence workflows — or running a notarial practice that wants reviewable, receipted demand? Ask for early access to the MCP server and the receipt spec.
[email protected]