io.github.DrBaher/sign-cli

Official

by DrBaher · TypeScript

Agent-first e-signature MCP server with offline PAdES signing and hash-chained audit.

E-signature MCP server with offline PAdES signing and audit chain verification.

Topics

ai-agentaudit-logclicompliancedocusigndropbox-signe-signatureeidasllmmcpmodel-context-protocolpadespdf-signingrfc3161signwelltypescriptagent-firstcontract-automationcontract-ops

README.md15 KBView on GitHub

sign-cli

Fully-offline e-signature CLI. The built-in PAdES signer (PKCS#7 in /ByteRange, self-issued cert) produces real, cryptographically verifiable signed PDFs with no signup and no third-party provider — or routes through Dropbox Sign / DocuSign / SignWell when you need an external trust anchor. Per-signer approval tokens (TTL-bounded, scoped to one email), hash-chained audit events, RFC 3161 timestamping, named profiles, a 19-tool MCP server, and a 20-route HTTP API.

The asymmetry is the architecture: an agent can drive every step except the actual signing gesture, which stays gated behind a human.

Part of the contract-ops CLI suite — optional. sign-cli works entirely on its own; it's also the signing + audit step of the contract-ops suite: template-vault-cli → draft-cli → nda-review-cli → docx2pdf-cli → sign-cli, with drift detection via compare-cli.

Run this

bash

npx @drbaher/sign-cli demo

That single command runs the entire lifecycle — create → send → sign → verify chain → export receipt — against the offline local provider, then deletes everything. No signup. No keys. ~5 seconds.

Live demo → — read-only, resets every 4 hours. Self-host: see deploy/README.md.

Where to go next

If you are…	Start here
A new user evaluating the tool	This README's Quick start, then Standard user journey
An operator wiring up a hosted provider	docs/setup/ — Dropbox / DocuSign / SignWell / embedded
An LLM agent driving the CLI	AGENTS.md → docs/agent-guide.md → docs/recipes/
An auditor verifying a signed bundle	docs/reference/audit-chain.md, docs/reference/legal.md
A contributor	docs/reference/architecture.md, docs/regression-testing.md
Adding a new CLI to the suite	The build-a-CLI playbook — the conventions every suite CLI follows

Concept deep-dives live in docs/reference/; task-oriented recipes in docs/recipes/.

Quick start

bash

# Install
npm i -g @drbaher/sign-cli

# Or run without installing
npx @drbaher/sign-cli demo

# After install, the binary is named `sign`
sign --version
sign demo
sign init        # wizard: provider selection + .env
sign doctor preflight   # structured per-check readiness report

Or download a standalone binary from Releases — ./sign-linux-x64 demo. See DISTRIBUTION.md for every install path.

What this gives you

Offline PAdES signing with a self-issued cert — real PKCS#7 signed PDFs, no signup, no API keys.
Three hosted providers when you need them: Dropbox Sign, DocuSign, SignWell. Same surface across all four.
Per-signer approval tokens (single-use, TTL-bounded, tied to one email). Tokens go to the human, not the agent.
Hash-chained audit chain with append-only DB triggers + RFC 3161 anchors. See docs/reference/audit-chain.md.
Idempotent request send — refuses to double-send unless --force true; pair with --idempotency-key for safe retries.
Multi-document + multi-signer requests; CSV-driven bulk send.
Templates from each provider's dashboard via request from-template.
Auto-detect signature field (sign pdf detect-signature-field + sign sign --auto-place). Detects AcroForm /Sig widgets and anchor text in English + French/EU conventions.
Inspect any signed PDF with sign pdf inspect — parses PAdES PKCS#7 from sign-cli or any other producer (Adobe, DocuSign, Dropbox Sign, SignWell). Returns signer CN/email, cert subject + issuer, validity window, fingerprint, trust label (self_signed_local / self_signed_other / ca_signed / unknown), and message-digest match.
Counter-sign visibility — signer fetch-document and the MCP signer_fetch_document tool surface existingSignatures, so a signer can see what they're countersigning before they sign.
One-shot DOCX → sealed PDF via sign document (chains the bundled docx2pdf-cli, auto-place, stamp, PAdES-seal, verify in one call against a scoped temp DB).
Sandbox via --read-only true on both mcp serve and serve. Mutating tools/routes return FORBIDDEN_READ_ONLY.
Path-traversal guards on every input and output path. See docs/reference/security-controls.md.
Named profiles bundle provider + dbPath + credentials (with {{env:VAR}} references for shell-managed secrets). See docs/reference/profiles.md.
PDF verification end-to-end offline: request verify-signed-pdf recomputes the digest, extracts X.509 signer certs, supports --recipient <email> for a redacted single-signer view, and reports per-signer trust labels.

Standard user journey

bash

sign request create \
  --title "Mutual NDA" \
  --document ./nda.pdf \
  --signer name:Alice,email:alice@acme.com,order:1 \
  --signer name:Bob,email:bob@beta.com,order:2 \
  --provider signwell

sign approve --request-id <id> --token <token1>
sign approve --request-id <id> --token <token2>

sign request send --request-id <id> --provider signwell --test-mode true

sign request watch \
  --request-id <id> --provider signwell \
  --interval-seconds 5 --fetch-final true \
  --out ./signed.pdf

sign audit show --request-id <id>

Or fully offline:

bash

sign request create --title "Mutual NDA" --document ./nda.pdf \
  --signer name:Alice,email:alice@example.com,order:1 \
  --signer name:Bob,email:bob@example.com,order:2 \
  --provider local --auto-approve true
sign request send --request-id <id> --provider local
# Each signer runs:
sign sign --request-id <id> --token <their-token> \
  --require-hash <sha256> --require-title "^Mutual NDA$"

For full provider-specific setup, see docs/setup/.

One-shot DOCX → sealed PDF

bash

sign document contract.docx \
  --signer "Alice Founder" --signer-email "alice@acme.com" \
  --name-signature "Alice Founder" --auto-place first \
  --out contract.sealed.pdf

sign document chains: convert (via the bundled docx2pdf-cli) → detect signature field → stamp → PAdES-seal → verify chain. All intermediate state lives in a scoped temp DB.

MCP server (for LLM agents)

bash

sign mcp serve                  # stdio MCP server
sign mcp serve --read-only true # sandboxed: mutating tools return FORBIDDEN_READ_ONLY
sign mcp tools                  # print the catalog (live; don't hardcode the list)

19 tools, split read-only vs mutating. Backed by the same SignCliError envelopes you'd see at the CLI. The full discovery contract, wire-up snippets (Claude Desktop, Cursor), and read-only walkthrough are in AGENTS.md. Three resource shapes (request://<id> snapshot, .../document PDF blob, .../audit chain) and four agent-as-signer prompt templates (review_and_sign, policy_check, inbox_triage, verify_receipt) are also exposed.

HTTP API (for non-MCP clients)

bash

sign serve --port 4000 --auth-token <t> --read-only true --rate-limit 5
curl http://127.0.0.1:4000/v1/openapi.json    # discover the route catalog

Twenty routes under /v1/*, 1:1 parity with the MCP tool surface — same input shape, same path-traversal guards, same read-only gating. Bearer auth via --auth-token or SIGN_HTTP_AUTH_TOKEN. Responses are { ok, result } on success or the standard error envelope on failure.

Signer-side flow (agent-friendly)

For --provider local, an agent can act as a signer end-to-end without an email link. Set SIGN_LOCAL_AUTOCOMPLETE=false so the local provider holds at sent until each signer explicitly runs sign sign.

bash

# As the requester (agent or human)
sign request create --title "Mutual NDA" --document ./nda.pdf \
  --signer name:Alice,email:alice@example.com,order:1 \
  --signer name:Bob,email:bob@example.com,order:2 \
  --provider local --auto-approve true
# response includes per-signer tokens
sign request send --request-id <id> --provider local

# As the signer, with their token
sign signer list --signer-email alice@example.com
sign signer fetch-document --request-id <id> --token alice-tok-... --out ./nda.pdf
# fetch-document surfaces `existingSignatures` so the signer can see what they're countersigning
sign sign --request-id <id> --token alice-tok-... \
  --require-hash <sha256> --require-title "^Mutual NDA$" --require-signer-email alice@example.com
# or
sign signer decline --request-id <id> --token alice-tok-... --reason "Terms changed"

Multi-signer: status only flips to completed when every signer is in signedBy[]. Pre-sign safety checks (--require-hash / --require-title / --require-signer-email) throw PRE_SIGN_*_MISMATCH before any state mutation.

Templates

Reuse a template defined in the provider dashboard (no PDF upload):

bash

sign request from-template \
  --template-id tmpl_abc --provider dropbox \
  --signer role:Buyer,name:Alice,email:alice@example.com,order:1 \
  --signer role:Seller,name:Bob,email:bob@example.com,order:2 \
  --prefill name:purchase_price,value:1000 \
  --auto-approve true

sign request send --request-id <id> --provider dropbox --test-mode true

Each --signer must include role:<roleName> matching a template role. --prefill name:K,value:V[,signer:N] populates template fields. Per-provider behavior: DocuSign uses per-signer text tabs; Dropbox uses custom_fields; SignWell uses placeholders.

Field placement

By default the hosted providers auto-append a generic signature page. For real contracts, pass --field (repeatable) on request create:

bash

sign request create \
  --title "NDA" --document ./contract.pdf \
  --signer name:Alice,email:alice@example.com,order:1 \
  --field signer:1,page:1,x:100,y:200,type:signature \
  --field signer:1,page:1,x:100,y:240,type:date

Spec: signer:<order> (required), doc:<i> (multi-doc index), type:signature|initials|date|text|name|email, page:<n> x:<pt> y:<pt> (coordinate), or DocuSign-only anchor:"text" with optional x-offset / y-offset / anchor-units. The fields persist on the request and forward to the provider at send time.

Auto-detect signature field

For --provider local, sign sign --auto-place calls the detector and uses the top candidate iff there's a unique high-confidence (≥0.8) match.

bash

# Inspect candidates first
sign pdf detect-signature-field --pdf ./contract.pdf

# Auto-place (errors loudly on ambiguity)
sign sign --request-id <id> --token <t> --name-signature "Alice" \
  --auto-place first   # or true | last | all | page:N | index:N

Adjustment strategies in priority order: underline-snap (0.95), below-anchor-probe (0.85, French/EU conventions), whitespace-probe (0.75), shrink-to-fit (0.50). Date anchors are detected separately via sign pdf detect-date-field. Full reference in docs/agent-guide.md §6.4a.

Bulk send

bash

sign request bulk \
  --csv ./signers.csv \
  --document ./contract.pdf --provider dropbox \
  --title "Q2 NDA for {{email}}" --test-mode true

Each row becomes its own request with autoApprove: true. Title template supports {{email}}, {{name}}, {{row}}. Exit code 3 if any row failed; JSON output lists per-row results.

Trust beyond the provider

bash

# Inspect any signed PDF (ours, Adobe's, DocuSign's, …) — no DB lookup required
sign pdf inspect --pdf ./signed.pdf

# Inspect the embedded PKCS#7 of a request we sent
sign request verify-signed-pdf --request-id <id>
sign request verify-signed-pdf --request-id <id> --recipient alice@example.com   # single-signer view

# Anchor the audit head against a public RFC 3161 TSA
sign audit anchor --request-id <id>

# Bundle for archival
sign audit export --request-id <id> --out ./bundle/

audit verify walks the local hash chain. request verify-signed-pdf recomputes the SHA-256 over the /ByteRange, compares it to the messageDigest in the embedded PKCS#7, and verifies the PKCS#7 signature value against the signer certificate's public key (RSA/ECDSA) — so a forged or tampered signature fails, exit 3, not just a modified-after-signing one. sign pdf inspect works on any signed PDF (no request id required). audit anchor issues a TimeStamp token from a TSA. See docs/reference/audit-chain.md for the full model.

Profiles

bash

sign profile init --name prod --provider signwell --db "~/.sign-cli/prod.db" --strict-provider true
sign profile set --name prod --key credentials.SIGNWELL_API_KEY --value "{{env:SIGNWELL_API_KEY}}"
sign --profile prod request show --request-id <id>
# Or implicitly via a project-level sign-profile.json (git/npm-style upward discovery)

Resolution order: flag > env > project profile > user profile > built-in default. Credentials redacted by default in profile show (--show-secrets true to reveal). Over the MCP HTTP transport, show_secrets is refused unless an --http-auth-token is configured (it stays available on stdio MCP and the CLI). See docs/reference/profiles.md.

Doctor

bash

sign doctor                       # legacy env-report; always exits 0
sign doctor preflight             # structured per-check report; exit 0 ok, 1 failed
sign doctor providers             # capability matrix across all providers
sign doctor account-check --provider signwell   # provider /me check

preflight runs env-health checks (runtime:node_version, storage:db_path) on every provider, then provider-scoped checks layer on top. Branch on checks[].name for agent self-recovery.

Security notes

Never commit .env or API keys.
Rotate keys if shared in chat/logs.
Keep test mode on during development.
For path-traversal guards, secret redaction, idempotency, and read-only mode, see docs/reference/security-controls.md.
For what the chain proves vs. what it doesn't, see docs/reference/security-model.md.

License

MIT. See LICENSE.

Install

claude_desktop_config.json

{
  "mcpServers": {
    "sign-cli": {
      "command": "npx",
      "args": [
        "-y",
        "@drbaher/sign-cli@0.8.0"
      ]
    }
  }
}

Topics

sign-cli

Run this

Where to go next

Quick start

What this gives you

Standard user journey

One-shot DOCX → sealed PDF

MCP server (for LLM agents)

HTTP API (for non-MCP clients)

Signer-side flow (agent-friendly)

Templates

Field placement

Auto-detect signature field

Bulk send

Trust beyond the provider

Profiles

Doctor

Security notes

License

See also

Install