proof

Proof

The universal record format for AI governance.

Why Proof Exists

AI agents are moving from pilot to production. Regulators are catching up — the EU AI Act, SOC 2 AI controls, state-level AI laws — and every one of them requires evidence: what did the agent do, what controls were in place, can you prove it?

Today that evidence is scattered across CloudWatch JSON, LangSmith exports, CSV dumps, screenshots, and PDF summaries. Every tool invents its own format. Auditors get a pile of incompatible files. Verification is manual. Tamper evidence is nonexistent.

Proof solves this by defining one record format that any tool can produce and any auditor can verify. One binary, one schema, one chain. Offline, signed, deterministic.

The primitive is separate from the products built on top of it. Discovery tools, compliance engines, and policy enforcers all import Proof as their shared record and signing layer. Third parties — agent frameworks, MCP servers, CI pipelines — can adopt the format independently by importing the Go module or implementing the JSON Schema spec. The format earns standard status through adoption, not announcement.

What Proof Is

An open-source Go module and verification CLI. Four operations:

• Create — Structured, schema-validated proof records with deterministic hashing
• Chain — Append records to tamper-evident hash chains (same mechanism as certificate transparency logs)
• Sign — Ed25519 or cosign (Sigstore) signatures on records, chains, and bundles
• Verify — Offline verification of any proof artifact with a single binary

What Proof Is Not

• Not a policy engine. Proof does not make allow/block decisions.
• Not a scanner or collector. Proof does not discover tools or capture agent activity.
• Not a compliance engine. Proof does not evaluate whether evidence satisfies controls — it defines what records look like and what controls require.
• Not AI-powered. Zero LLMs, zero ML, zero probabilistic components. Deterministic canonicalization, cryptographic hashing, schema validation. Same inputs, same outputs, always.

Quick Start

PROOF_VERSION="$(gh release view --repo Clyra-AI/proof --json tagName -q .tagName 2>/dev/null || curl -fsSL https://api.github.com/repos/Clyra-AI/proof/releases/latest | python3 -c 'import json,sys; print(json.load(sys.stdin)[\"tag_name\"])')"
go install github.com/Clyra-AI/proof/cmd/proof@"${PROOF_VERSION}"

proof types list          # 15 built-in record types
proof frameworks list     # 8 built-in starter frameworks (11 controls)
proof verify ./artifact   # Verify any proof artifact offline

Library Usage (4 lines)

import "github.com/Clyra-AI/proof"

record, _ := proof.NewRecord(proof.RecordOpts{
    Source:        "my-mcp-server",
    SourceProduct: "my-product",
    Type:          "tool_invocation",
    Event:         map[string]any{"tool": "postgres_query", "action": "SELECT"},
})

chain := proof.NewChain("default")
_ = proof.AppendToChain(chain, record)

key, _ := proof.GenerateSigningKey()
_, _ = proof.Sign(&chain.Records[0], key)

Every tool invocation now produces a signed, chainable, verifiable proof record. No configuration files, no account, no network access.

Custom Record Types

_ = proof.RegisterCustomTypeSchema("vendor.custom_event", "./custom.schema.json")

Custom types validate against the base proof record schema plus your type-specific schema. They chain and sign identically to built-in types.

Bundle Signing and Verification

manifest, _ := proof.SignBundle("./bundle", key)

result, _ := proof.VerifyBundle("./bundle", proof.BundleVerifyOpts{
    VerifySignatures: true,
    PublicKey:        proof.PublicKey{Public: key.Public},
})

Record Format

The atomic unit is the proof record — a structured, signed artifact that captures what happened, what controls were in place, and the cryptographic integrity needed to prove it wasn't tampered with.

record_id: "prf-2026-09-15T10:30:00Z-a7f3b2c1"
record_version: "1.0"
timestamp: "2026-09-15T10:30:00Z"
source: "my-mcp-server"
source_product: "my-product"
record_type: "tool_invocation"

event:
  tool: "postgres_query"
  action: "SELECT"
  parameters:
    query_hash: "sha256:abc123..."    # digest, not the query itself
    target: "payments.transactions"

controls:
  permissions_enforced: true
  approved_scope: "read-only on payments.*"
  within_scope: true

integrity:
  record_hash: "sha256:def456..."
  previous_record_hash: "sha256:ghi789..."   # chain link
  signing_key_id: "a1b2c3..."
  signature: "base64:..."

Records are immutable, deterministic, and JSON-native — readable by any language, any tool, any text editor.

Built-in Record Types

15 types covering the full AI governance surface, each with its own JSON Schema:

Record types are extensible. Define a custom type by providing a JSON Schema that extends the base record schema.

Hash Chains

Records are chained — each record's hash includes the previous record's hash, creating a tamper-evident sequence. Modify or delete a record and the chain breaks. proof chain verify identifies the exact break point.

Record 1 → hash(record_1)                      →┐
Record 2 → hash(record_2 + prev_hash)           →┐
Record 3 → hash(record_3 + prev_hash)           →┐
...
$ proof chain verify ./records/
Chain intact. 1,427 records. No gaps.

This is not blockchain. It is the same mechanism used in certificate transparency logs. Simple, proven, auditable.

Signing

Two backends, one verification surface:

• Ed25519 (default) — Fast, offline, no external dependencies
• Cosign / Sigstore — Supply chain ecosystem alignment, OIDC keyless signing

Both backends produce records that pass chain verification. The signing backend is transparent to the verifier. Key management supports customer-managed keys, ephemeral keys for development, and key revocation with signed revocation lists.

Canonicalization

Deterministic serialization is essential for hash stability. Proof implements canonicalization across four domains:

All digests carry algo_id (sha256 or hmac-sha256) and optional salt_id metadata.

Compliance Framework Definitions

YAML files that declare what regulatory controls require — which record types, required fields, and evidence frequency. Zero evaluation logic. Configuration data consumed by downstream compliance tools.

controls:
  - id: article-12
    title: Record-Keeping
    required_record_types: [tool_invocation, decision, guardrail_activation, permission_check]
    required_fields: [record_id, timestamp, source, source_product, record_type, event, integrity.record_hash]
    minimum_frequency: continuous

8 built-in starter frameworks ship with v1 (11 controls total). Add custom frameworks via YAML.

Built-ins are starter definitions; teams can add custom frameworks via YAML files.

CLI Reference

proof verify <path>                    Verify record, chain, bundle, or Gait artifact
  --chain                              Verify chain integrity
  --signatures                         Verify signatures
  --public-key <hex|base64>            Ed25519 public key
  --cosign-key <path>                  Cosign public key
  --cosign-cert <path>                 Cosign certificate
  --cosign-cert-identity <id>          Expected certificate identity
  --cosign-cert-issuer <issuer>        Expected OIDC issuer
  --custom-type-schema <type>=<path>   Custom type schema (repeatable)
  --revocation-list <path>             Signed key revocation list
  --revocation-key <hex>               Revocation list signer public key

proof inspect <path>                   Human-readable artifact display
  --record <record_id>                 Inspect specific record by ID

proof chain verify <path>              Verify chain integrity
  --from <RFC3339>                     Start of time range
  --to <RFC3339>                       End of time range

proof types list                       List all registered record types
proof types validate <schema-path>     Validate a custom record type schema

proof frameworks list                  List built-in starter framework definitions
proof frameworks show <id|path>        Display framework controls

proof completion <shell>               Shell completion generation

Global flags: --json, --quiet, --explain

Exit Codes

Stable contract. CI pipelines can rely on consistent semantics across all tools that adopt this vocabulary.

Gait Compatibility

Proof verifies Gait artifacts directly — packs, runpacks, and signed JSON — without any Gait dependency:

proof verify ./gait-pack.zip
proof verify ./gait-runpack.zip
proof verify --signatures --public-key <key> ./gait-pack.zip

The signing and canonicalization code in Proof was extracted from Gait's production codebase. KeyID(), Signature{}, and JCS digest functions produce byte-identical output, so artifacts signed by Gait before the extraction verify correctly with Proof.

Compatibility packages for migration:

• github.com/Clyra-AI/proof/signing — Ed25519 key management with dev/prod modes
• github.com/Clyra-AI/proof/canon — CanonicalizeJSON() and DigestJCS() aliases
• github.com/Clyra-AI/proof/schema — ValidateJSON() and ValidateJSONL() helpers
• github.com/Clyra-AI/proof/exitcode — Exit code constants with legacy aliases

Design Principles

1. The spec is the product. JSON Schema files are the normative specification. The Go module is the reference implementation. If they disagree, the spec wins.
2. Zero opinions. Proof does not know what compliance means. It creates, chains, signs, and verifies. What records mean is someone else's problem.
3. Boring cryptography. Ed25519 (RFC 8032), SHA-256, RFC 8785. No novel constructions, no experimental algorithms.
4. Library-first, CLI-second. The Go module is the primary artifact. The CLI is a thin wrapper. Every command maps to a module function.
5. Extracted, not greenfield. Built by extracting production-proven code from Gait, not by writing from scratch. Same pattern as Sigstore (extracted from cosign), OCI (extracted from Docker), HCL (extracted from Terraform).
6. Offline-first. All core operations — create, chain, sign, verify — work without network access. Air-gapped environments are first-class.

Repository Layout

cmd/proof/           CLI (Cobra-based)
core/
  record/            Record creation, validation, hashing
  chain/             Hash chain append and verification
  signing/           Ed25519 + cosign signing
  canon/             Canonicalization (JSON, SQL, URL, text)
  schema/            JSON Schema validation + type registry
  framework/         YAML framework definition loading
  gait/              Gait pack/runpack compatibility verification
  exitcode/          Exit code constants
signing/             Compatibility package (Gait migration)
canon/               Compatibility package (Gait migration)
schema/              Compatibility package (Gait migration)
exitcode/            Compatibility package (Gait migration)
schemas/v1/          JSON Schema spec files (language-agnostic contract)
  types/             15 record type schemas
frameworks/          8 compliance framework YAML definitions
testdata/            Golden vectors and test fixtures
scripts/             Test and validation scripts
perf/                Performance budgets

Development

make fmt             # Format
make lint            # Vet + golangci-lint
make test            # Unit tests
make prepush-full    # Full gate: lint + test + coverage + contract + integration + e2e + acceptance
make test-uat-local  # UAT for source, go-install, and local release-archive install paths

CI pipelines: main, PR, determinism (cross-platform), CodeQL, nightly (hardening + chaos + performance + soak), release (GoReleaser + checksums + SBOM + cosign + SLSA provenance).

Install

PROOF_VERSION="$(gh release view --repo Clyra-AI/proof --json tagName -q .tagName 2>/dev/null || curl -fsSL https://api.github.com/repos/Clyra-AI/proof/releases/latest | python3 -c 'import json,sys; print(json.load(sys.stdin)[\"tag_name\"])')"

# From module source at latest published release tag
go install github.com/Clyra-AI/proof/cmd/proof@"${PROOF_VERSION}"

# From release assets
gh release download "${PROOF_VERSION}" -R Clyra-AI/proof -D /tmp/proof-release
cd /tmp/proof-release && sha256sum -c checksums.txt

Go module:

PROOF_VERSION="$(gh release view --repo Clyra-AI/proof --json tagName -q .tagName 2>/dev/null || curl -fsSL https://api.github.com/repos/Clyra-AI/proof/releases/latest | python3 -c 'import json,sys; print(json.load(sys.stdin)[\"tag_name\"])')"
go get github.com/Clyra-AI/proof@"${PROOF_VERSION}"

License

See LICENSE.