# Satsignal

> Satsignal is a BSV-backed notary service. It anchors a sha256
> commitment of client-supplied input to the BSV blockchain and returns
> a .mbnt proof that the anchorer held that exact input by a specific
> time. What it proves: tamper-evidence and timing
> (anchorer-knowledge-by-block-time). What it does not prove:
> authorship, or that the content existed before the anchor.

## Start here

- [Homepage](https://satsignal.cloud/): product overview and the integration shapes Satsignal supports.
- [What a proof proves](https://satsignal.cloud/what-it-proves.html): the trust boundary, with the explicit "and what it doesn't" half.
- [The canonical proof model](https://satsignal.cloud/canonical-model.html): how a sha256 commitment becomes a BSV anchor and what the proof binds.
- [Use cases](https://satsignal.cloud/uses.html): regulated evidence trails, AI workflow evidence, litigation evidence.
- [Docs index](https://satsignal.cloud/docs.html): chooser + 10-minute quickstart + path-by-path entry into the integration guides.

## Quickstart paths

Six integration shapes. Pick by what you are anchoring; each guide ends with a "where this fits" coda pointing at adjacent paths.

- [Files on disk](https://proof.satsignal.cloud/guide-files): Direct API + CLI for files, reports, build artifacts.
- [Incoming webhooks](https://proof.satsignal.cloud/guide-webhooks): Stripe / GitHub / Langfuse / bring-your-own-signer. No SDK, no client-side hashing.
- [Agent runtime](https://proof.satsignal.cloud/guide-agents): four-part agent-session pattern using the Python `Session()` helper or MCP toolset.
- [CI/CD pipelines](https://proof.satsignal.cloud/guide-ci): GitHub Action + shell adapters for GitLab, Bitbucket, Docker, npm, PyPI.
- [Sealed mode](https://proof.satsignal.cloud/guide-sealed): privacy-preserving anchoring (Mirror + Blind) for sensitive content.
- [Manifest batches](https://proof.satsignal.cloud/guide-manifest): Merkle batch up to 10,000 items with selective disclosure.
- [What to hash](https://proof.satsignal.cloud/guide-what-to-hash): cross-cutting reference on which bytes to commit for each input shape.

## Worked examples

- [AcmeCorp anchors every order webhook](https://proof.satsignal.cloud/example-webhook-company): full integration walkthrough — wire-up, storage, 9-months-later disputed-order audit.
- [ResearchAgent makes its decisions auditable](https://proof.satsignal.cloud/example-agent-runtime): agent-session pattern with a 6-months-later regulator audit walkthrough.

## Production references

- [Production checklist](https://proof.satsignal.cloud/guide-production-checklist): pre-flight + ops concerns (key rotation, idempotency, broadcast-failure recovery, rate limits).
- [Compatibility map](https://proof.satsignal.cloud/guide-compatibility): canonical and legacy vocabulary mapping for API fields, routes, CLI flags, MCP inputs.

## Machine-readable

- [OpenAPI 3.1 spec](https://proof.satsignal.cloud/openapi.json): hand-authored, 24 operations × 37 schemas, drift-tested against the live wire.
- [Postman v2.1 collection](https://proof.satsignal.cloud/postman.json): generated offline from the OpenAPI spec.
- [API reference (ReDoc)](https://proof.satsignal.cloud/api-reference): vendored ReDoc viewer, no external CDN.
- [Sitemap](https://satsignal.cloud/sitemap.xml): all public guide / spec / landing URLs.
- [Agent signup discovery](https://app.satsignal.cloud/api/v1/signup): JSON capability document for the agent signup lanes this host currently accepts (invite, proof-of-work) and the live PoW difficulty; unauthenticated, always 200 — the source of truth for which lanes are on.

## Wire formats and specs

- [Bundle format (.mbnt v1)](https://proof.satsignal.cloud/spec-bundle): on-disk bundle structure and field semantics.
- [Sealed v2 spec](https://proof.satsignal.cloud/spec): Mirror + Blind sealed-mode wire format.
- [Merkle row format](https://proof.satsignal.cloud/spec-merkle-row): Merkle row + manifest leaf encoding.
- [.mbnt internals](https://proof.satsignal.cloud/spec-mbnt): byte-level .mbnt bundle format.
- [Provenance v1](https://proof.satsignal.cloud/spec-provenance): chain-of-custody fields on a proof.
- [Chain-anchor v1](https://proof.satsignal.cloud/spec-chain-anchor): cross-system Merkle batching format (AAR, RFC 3161, C2PA interop).
- [What's on chain](https://proof.satsignal.cloud/whats-on-chain): the byte layout of a Satsignal anchor as it appears in the BSV transaction.
- [Conformance suite](https://proof.satsignal.cloud/conformance) and [bundle conformance](https://proof.satsignal.cloud/conformance-bundle): test vectors for implementers.
- [Unseal guide](https://proof.satsignal.cloud/unseal-guide): how an auditor opens a sealed proof.

## Disclosure & redaction

Selective disclosure / redaction — anchor a CSV, text, or JSON file, then later publish a validated redacted copy where the revealed rows/columns/lines/keys still prove into the original committed merkle root (anchored on chain as its 20-byte doc_hash); local-only, no upload, no re-anchor. Four native profiles; all four support both standard and sealed (per-leaf HMAC privacy) mode.

- [Disclosure v1 spec](https://proof.satsignal.cloud/spec-disclosure): the disclosure-v1 index and shared model across profiles.
- [CSV row profile](https://proof.satsignal.cloud/spec-disclosure-csv-row): `csv-row-v1`, reveal selected rows.
- [CSV column profile](https://proof.satsignal.cloud/spec-disclosure-csv-column): `csv-column-v1`, reveal selected columns.
- [Text line profile](https://proof.satsignal.cloud/spec-disclosure-text-line): `text-line-v1`, reveal selected lines.
- [JSON keypath profile](https://proof.satsignal.cloud/spec-disclosure-json-keypath): `json-keypath-v1`, reveal selected top-level keys.
- [JSON AST profile](https://proof.satsignal.cloud/spec-disclosure-json-ast): `json-ast-v1`, sealed-only deep-field JSON disclosure (reveal selected nested fields).
- [Disclosure conformance](https://proof.satsignal.cloud/conformance-disclosure): test vectors and fail-codes for implementers.
- [Disclosure Builder](https://proof.satsignal.cloud/static/disclosure-builder/index.html): in-browser tool to produce a validated redacted copy from a file you already anchored; nothing is uploaded.
- [Headless redaction guide](https://proof.satsignal.cloud/guide-headless-redaction): produce the same validated redacted copy offline, from the command line, for automation.

## Clients and integration tooling

- [Agents implementer spec](https://proof.satsignal.cloud/agents): full `satsignal-agent-handoff-v1` schema and lifecycle categories.
- [Agent signup guide](https://proof.satsignal.cloud/guide-agent-signup): programmatic account creation for autonomous agents — invite-code and proof-of-work lanes; the magic link needs a readable inbox. A `keys:admin` key (minted once in the dashboard) can then `POST /api/v1/keys` to issue per-tenant scoped sub-keys headlessly, for multi-tenant provisioning.
- [Mobile / share targets](https://proof.satsignal.cloud/mobile): mobile capture flows.
- [`satsignal-mcp`](https://pypi.org/project/satsignal-mcp/): MCP server exposing the notary as six tools for MCP-compatible agent runtimes.
- [`satsignal-cli`](https://pypi.org/project/satsignal-cli/): command-line client. Requires `SATSIGNAL_API_KEY`.
- [`langchain-satsignal`](https://github.com/Steleet/langchain-satsignal): LangChain adapter wrapping the same primitives as LangChain tools.

## Verifier

- [Public verifier](https://proof.satsignal.cloud/verify): paste or drop a .mbnt proof; verifies cryptographic integrity AND chain-confirms by default. The only auth-free anchor-side surface.

## Pricing and policies

- [Pricing](https://satsignal.cloud/pricing.html): currently opening with design partners; see the page for current plan structure.
- [Trust posture](https://satsignal.cloud/trust.html): operational guarantees and what Satsignal is and is not.
- [Security](https://satsignal.cloud/security.html): operator security model.
- [Privacy](https://satsignal.cloud/privacy.html): data handling, retention, sealed-blind opacity.
- [Terms of use](https://satsignal.cloud/terms.html): legal terms. Operator: Satsignal LLC, Iowa.

## What Satsignal does not prove

A Satsignal proof binds an exact byte-string to a block time and to the operator that submitted it. It does not establish:

- **Authorship** — the same hash can be produced by anyone holding the input.
- **Existence before the anchor** — the proof attests "the anchorer held this by block time T," not "this existed at time T−1."
- **Truth of the content** — anchoring a false statement makes it tamper-evident, not true.

For preimage-revealed timing claims, see the sealed-mode reveal flow. For agent decision-trail integrity, see the four-part session pattern in the agents guide.