Manav signed the canonical JSON below with its server secret. Hash the JSON with HMAC-SHA256 using the MANAV_SERVER_SIGNING_SECRET and compare - if it matches, this proof is authentic.
Canonical proof JSON
{"actionPayloadHash":"4aa674d9fb7147df24ced394623b61099349082f2be1e9216f2512da58eef64b","actionTitle":"MSA: Acme AI Labs ↔ GreenLeaf Designs LLC","actionType":"contract_sign","actorHandle":"itsbala12_5b3290","externalReference":null,"organizationSlug":null,"signatureSlug":"mnav_sig_9SoRjXGtBV-Q","signedAt":"2026-06-02 09:28:59"}
Action payload hash · SHA-256 of the canonical action payload
4aa674d9fb7147df24ced394623b61099349082f2be1e9216f2512da58eef64b
Server signature · HMAC-SHA256 over canonical JSON above
82f488d8a5e041bd65e782af93ed809994fee8e611bccb48223b6996bff4fc53
Recompute it yourself
$ printf '%s' '{"actionPayloadHash":"4aa674d9fb7147df24ced394623b61099349082f2be1e9216f2512da58eef64b","actionTitle":"MSA: Acme AI Labs ↔ GreenLeaf Designs LLC","actionType":"contract_sign","actorHandle":"itsbala12_5b3290","externalReference":null,"organizationSlug":null,"signatureSlug":"mnav_sig_9SoRjXGtBV-Q","signedAt":"2026-06-02 09:28:59"}' \
| openssl dgst -sha256 -hmac "$MANAV_SERVER_SIGNING_SECRET" -hex
$ # expected: 82f488d8a5e041bd65e782af93ed809994fee8e611bccb48223b6996bff4fc53