Squillify Cryptographic Signature

crypto.squillify_signature

ProductionBounded custom (Class B)verifiableinstantv1.0.0

No network

Overview

When you need proof that Squillify executed with a specific payload, we hash your text, bind tenant, request id, server time, and an optional nonce into a canonical string, and sign it with HMAC-SHA256 using a platform secret you cannot access. The receipt is independently verifiable with the shared secret. Do not use this for encryption, custom protocol HMAC, or signature verification — it only signs execution receipts.

Agents can fabricate text output. We sign a receipt with a secret you cannot read, so downstream systems can trust that execution happened on Squillify.

Reliability

Each call reads our clock, so server_time and therefore signature differ every time — only payload_sha256 and the canonical field order are stable for the same payload and nonce. What a receipt proves is narrow: that Squillify processed exactly that payload for that tenant and request at that moment. It is a shared-secret MAC, so anyone holding the verification secret could also mint one, and it says nothing about what your payload contains. Retries are safe but produce new receipts. Input validation errors (not retryable): missing or blank payload, non-string payload/nonce, payload over 2048 chars, or batch over 50 items — fix the input before retrying. To verify: recompute SHA-256(payload), rebuild canonical v=1|tool=...|tenant=...|request_id=...|server_time=...|payload_sha256=...|nonce=..., HMAC-SHA256 with the shared secret, base64url-compare to signature.

Context footprint

Returns a single receipt or a batch wrapper with up to 50 signed items. A single signature costs 1 execution credit; a batch costs 1 credit per item.

When to use it

When you need a verifiable proof-of-execution receipt for a specific payload.

When you need encryption, key generation, or to verify a signature in-band.

Scope

Note

Produces an HMAC-SHA256 signed receipt binding payload, tenant, request, time, and nonce.

Non-goals

Does not encrypt data
Does not verify signatures
Does not expose the platform secret
Not a public-key signature — the same shared secret both verifies and mints receipts
Does not track nonces or detect replays for you

Properties

IdempotentRetry safeStreaming supportedFile input supportedRequires external service

Capabilities

hashingsigning

Cost & billing

Flat rate per invocation

MetercallsBillable onsuccessCost per call1 credit

File handling

Accepts file_refProduces file_refMax input2 KB

How we handle your data

Sensitive input, safe output

What this means

This skill may receive sensitive content, but it does not target sensitive data and returns only a structured non-sensitive result.

Squillify guarantees

Runs inside Squillify
This skill runs inside Squillify.
Payloads are not sent to an external service by this skill.
Squillify does not permanently store submitted payloads.
Telemetry records metadata only, not submitted content.
Submitted payloads are not used for training.
Submitted payloads are not reviewed by humans.
This skill does not target sensitive data.
The response does not contain submitted content.

Your responsibility

Squillify does not determine whether submitted content is sensitive. Your application is responsible for deciding what data it is allowed to submit. Your application is responsible for securing the response.

Read the Microskill Data Handling Policy

Input schema

Field	Type	Required	Description
payload	string	No	Nonblank UTF-8 payload covered by the receipt. Required unless batch is provided.
nonce	string	No	Caller nonce; omit it for empty.
batch	array	No	From 1 through 50 closed signing items with payload and optional nonce; omit it when payload is used.

Output schema

Field	Type	Required	Description
tool	string	Yes	Receipt skill key naming crypto.squillify_signature.
version	string	Yes	Receipt format version.
tenant_id	string	Yes	Bounded authenticated context identifier.
request_id	string	Yes	Bounded authenticated context identifier.
server_time	string	Yes	UTC signing instant.
payload_sha256	string	Yes	Lowercase payload SHA-256.
nonce	string	Yes	Resolved caller nonce.
canonical	string	Yes	Exact bounded canonical signed text.
signature	string	Yes	Unpadded Base64url HMAC-SHA256.

API contract

POST /v1/execute

curl

curl -sS -X POST "$BASE/v1/execute" -H "Authorization: Bearer $KEY" -H 'Content-Type: application/json' -d '{"skillKey":"crypto.squillify_signature","input":{"payload":"Hello World"}}'

Integrations

TypeScript SDK

import { Squillify } from "@squillify/sdk";

const sq = new Squillify({ apiKey: process.env.SQUILLIFY_API_KEY });

const { output } = await sq.execute("crypto.squillify_signature", {"payload":"Hello World"});

Errors

Code	HTTP	Retryable	Description
VALIDATION_ERROR	400	No	The request payload failed schema validation.
UNAUTHORIZED	401	No	Missing or invalid API key.
SKILL_NOT_ACCESSIBLE	403	No	The API key is not granted access to this skill.
SKILL_NOT_AVAILABLE_FOR_PLAN	403	No	This skill is not included in your current plan.
PLAN_ELIGIBILITY_UNAVAILABLE	503	Yes	Plan eligibility could not be decided. Retry after backoff.
SKILL_NOT_FOUND	404	No	The requested skill or version does not exist.
TENANT_RATE_LIMITED	429	Yes	Request rate limit exceeded. Retry after backoff.
QUOTA_EXCEEDED	429	Yes	Plan quota exhausted. Retryable once the quota period resets.
EXECUTION_TIMEOUT	504	Yes	Execution exceeded the allowed time budget.

Other limits

Limit	Value
Recommended inline bytes	32 KiB

Limitations

Does not encrypt data
Does not verify signatures
Does not expose the platform secret
Not a public-key signature — the same shared secret both verifies and mints receipts
Does not track nonces or detect replays for you
General-purpose encryption
Custom protocol HMAC outside the receipt format

How to call

POST /v1/execute (requires authentication)

Request bodyjson

{
  "skillKey": "crypto.squillify_signature",
  "input": {
    "payload": "Hello World"
  }
}

Examples

Sign a payload without a nonce

Inputjson

{
  "payload": "Hello World"
}

Expected outputjson

{
  "nonce": "",
  "request_id": "req_example",
  "canonical": "v=1|tool=crypto.squillify_signature|tenant=t_example|request_id=req_example|server_time=2026-07-12T00:00:00Z|payload_sha256=a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e|nonce=",
  "tool": "crypto.squillify_signature",
  "signature": "FS22YC1bc6olNBWQPxAKi7g0rXTujy7qSAt0WypMr1g",
  "version": "1.0.0",
  "tenant_id": "t_example",
  "server_time": "2026-07-12T00:00:00Z",
  "payload_sha256": "a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e"
}

Sign with a nonce for replay protection