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EVIDIQ Envelope

Bulwark reads what the message says.

Envelope proves who sent it.

Agents now read mailboxes and act on what they find. Envelope is the missing direction: cryptographic verification of inbound messages — SPF, DKIM, DMARC and ARC on the raw message, sender-spoofing and lookalike-domain detection, header-chain forensics, and structural risk of attachments and links — with the DNS answers pinned into a signed report. 18 tools (8 free, 10 paid).

Quickstart

Connect the Streamable HTTP MCP endpoint, inspect capabilities, and validate a message before paying for a verdict.

claude mcp add --transport http evidiq-envelope https://mcp.evidiq.dev/envelope/mcp

Or probe the public pricing discovery endpoint:

curl -s https://mcp.evidiq.dev/envelope/x402

Prefer a Skill file? Fetch the agent-readable EVIDIQ Envelope Skill:

curl -s https://mcp.evidiq.dev/envelope/skill.md

What Envelope is for

Eighteen MCP tools

Eight free tools support discovery, validation, and verification. Ten paid tools run the cryptographic checks.

Paid verification tools

• verify_dkim — Per-signature DKIM verification: canonicalisation, body hash, key retrieval, algorithm, expiry — with the reason for each failure. (0.005 USDT0)
• check_dmarc_alignment — DMARC policy for the From domain and RFC 7489 identifier alignment against DKIM d= and the SPF domain, strict or relaxed. (0.005 USDT0)
• verify_message_auth — The composite verdict: SPF, DKIM, DMARC and alignment in one call, with the pinned DNS records behind it. (0.01 USDT0)
• validate_arc_chain — ARC chain validation so forwarded and mailing-list mail is not treated as forgery per hop. (0.01 USDT0)
• detect_sender_spoofing — Display-name impersonation, homoglyph / punycode / edit-distance lookalikes against expected senders, Reply-To / Return-Path divergence. (0.015 USDT0)
• audit_header_chain — Received-chain forensics: hop consistency, timestamp ordering, injected or duplicated critical headers, gaps that indicate a forged path. (0.015 USDT0)
• assess_attachment_surface — Structural risk without opening anything: extension against magic bytes, double extensions, macro-capable formats, encrypted archives. (0.02 USDT0)
• assess_link_surface — Structural link analysis without fetching: punycode hosts, anchor text vs href, credential-shaped URLs, redirector patterns, lookalike hosts. (0.02 USDT0)
• screen_domain_posture — The sender domain's own posture: SPF validity and lookup count, resolvable DKIM selectors, DMARC policy strength, DNSSEC, MX. (0.02 USDT0)
• attest_message_verdict — EIP-191 signed, 0G-anchored attestation of a verification, pinned DNS included — the record that survives key rotation. (0.03 USDT0)

Free preflight and verification

• envelope_capabilities — Catalog: 18 tools, prices, claim limits, boundaries against the other services. (free)
• estimate_cost — Exact USDT0 price for any paid tool, from the same table the gate charges from. (free)
• validate_message_input — Is this parseable, which auth headers are present, which paid checks can run — before paying. (free)
• parse_message_structure — MIME tree and header inventory. Structure only, no verdict. (free)
• explain_auth_result — Plain-language meaning of a result code, and what it does not prove. (free)
• check_dns_txt — Raw SPF, DKIM-selector and DMARC records for a domain, no verdict. (free)
• verify_envelope_report — Recompute the JCS digest and EIP-191-verify the signature. Verification is never charged. (free)
• get_artifact — Retrieve a stored attested verdict by digest, including the 0G anchor if present. (free)

x402 pricing

Payments use x402 v2 exact scheme with USDT0 (6 decimals) on X Layer (eip155:196). Verification and settlement run through the official OKX Onchain OS Payment SDK.

Verification Log

The fixture gate passed 7/7 against mailauth 4.13.3 (three deviations reported and operator-approved: body-hash and missing-key label as neutral not-pass; strict identifier alignment computed locally per RFC 7489 because mailauth's strict mode compares registrable domains). All 18 tools exercised live end-to-end by the OpenClaw agent (glm-5.2) against the deployed endpoint on 2026-08-03; the 402 gate is on. Raw run + report in the envelope repo.

Free Tools (HTTP 200)
  envelope_capabilities        → 200 ✓ (18 tools, 8 claim limits)
  estimate_cost                → 200 ✓ (verify_message_auth = 0.01 USDT0)
  validate_message_input       → 200 ✓ (parseable, which paid checks can run)
  parse_message_structure      → 200 ✓ (9 headers, 1 Received hop, structure only)
  explain_auth_result          → 200 ✓ (code explained + what it does not prove)
  check_dns_txt                → 200 ✓ (SPF -all · DMARC reject · selector)
  verify_envelope_report       → 200 ✓ (signatureValid: true, fleet signer)
  get_artifact                 → 200 ✓ (artifact with anchorRoot + anchorTx)

Paid Tools (HTTP 200 — bypass mode, Phase 1)
  verify_dkim                  → 200 ✓ (0/1 signatures, not-pass with reason)
  check_dmarc_alignment        → 200 ✓ (dmarc-not-aligned, adkim=s aspf=s)
  verify_message_auth          → 200 ✓ (not-authenticated; DKIM/SPF/DMARC)
  validate_arc_chain           → 200 ✓ (no-arc-chain — normal for direct mail)
  detect_sender_spoofing       → 200 ✓ (no-indicators, matches expected sender)
  audit_header_chain           → 200 ✓ (1 hop, internally consistent)
  assess_attachment_surface    → 200 ✓ (risky: .pdf.exe double extension)
  assess_link_surface          → 200 ✓ (structural only, never fetched)
  screen_domain_posture        → 200 ✓ (SPF valid -all · DMARC reject · 6 selectors)
  attest_message_verdict       → 200 ✓ (EIP-191 signed, 0G anchored)

Phase 2 gate (bypass removed) — measured from outside:
  empty POST → 402 · no content-type → 415 · HEAD → 402 (72ms, no hang)
  10 paid bare {} → 402 · 8 free bare {} → 200
  paid call settled on X Layer: 0xb8e6ede…15e51a0 (verify_dkim, 0.005 USDT0)

License

EVIDIQ owns and licenses its original Envelope code under MIT. Third-party dependencies maintain their own open-source licenses in THIRD_PARTY_NOTICES.md.