Free e-signature for humans and AI agents - zero-document PDF signing from hashes only.
Scored across 5 tools
Each tool has a clearly distinct purpose: creation of an envelope, retrieval of OTS proof, retrieval of full receipt, verification of audit chain integrity, and lookup by document hash. No overlap.
All tool names follow a consistent 'verb_object' pattern with underscores (e.g., create_signing_envelope, get_ots_proof, verify_audit_chain). Verbs are clear and objects specific.
With 5 tools, the server is well-scoped for its domain—envelope creation, evidence retrieval, and verification. No unnecessary tools and sufficient coverage for core operations.
The tool surface covers creation, evidence retrieval, and verification of audit chains and document hashes. A minor gap is the absence of a direct signature verification tool, but this is partially addressed by get_receipt providing signature data.
Create a FreeSign envelope from a PDF SHA-256 hash. Do not send PDF bytes. The created envelope is NOT yet session-bound — the browser that opens the returned signing_url generates an ECDSA P-256 keypair locally and POSTs the public JWK to /api/envelopes/{id}/session-bind before any protected request will succeed. AI agents calling this tool just hand the signing_url to a human, who continues in a browser.
Inputs: document_sha256 (required). Returns: expires_at, envelope_id, signing_url, session_binding_required
Return the .ots proof (base64) for a given OpenTimestamps anchor on an envelope. Use the official ots-cli to verify offline against Bitcoin block headers. Each seal has two anchors: kind: "byterange" commits to the signed document, kind: "signed_attrs" commits to SHA-256 of the CMS SignedAttributes (which carry the post-quantum key commitment).
Inputs: anchor_id (required), envelope_id (required). Returns: kind, status, anchor_id, envelope_id, +5 more
Return the envelope record (including final_pdf_sha256, final_signature_base64url, final_payload_json), per-signer signing receipts, and OpenTimestamps anchor metadata. Evidence only, never PDF bytes.
Inputs: envelope_id (required). Returns: envelope, receipts, ots_anchors
Return an envelope's append-only audit-event hash chain together with a server-computed integrity verdict: every event_hash is recomputed from its canonical material, and the prev_event_hash linkage and per-envelope seq contiguity are checked. Evidence only, never PDF bytes. The raw events are included verbatim so the caller can independently re-derive the verdict instead of trusting chain.valid.
Inputs: envelope_id (required). Returns: chain, events, envelope_id, attested_audit_chain_head_hash, +1 more
Find FreeSign receipts matching a local document SHA-256 hash.
Inputs: document_sha256 (required). Returns: matches
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
Loading tool schema changelog…
Add one secure layer between your agents and this server.