RSA sign

POST /api/rsa-sign2 quota units per call · cache hits free

Sign arbitrary data with an RSA private key. Supports PSS and the legacy PKCS1-v1_5 scheme, SHA-256/384/512. PEM-encoded private key input. Returns signature in hex / base64 / base64url.

Signs `data` with an RSA private key (PKCS#8 PEM). Two signature schemes are supported: - **RSA-PSS** (`scheme="pss"`) — RFC 8017 §8.1. Recommended for new applications. Randomised; safer reductions to RSA. - **RSASSA-PKCS1-v1_5** (`scheme="pkcs1"`) — RFC 8017 §8.2. Deterministic; required for compatibility with older systems (JWT RS256/384/512, SAML, many TLS stacks). **Output:** signature as hex / base64 / base64url, plus the scheme and hash actually used.

Inputs

Name	Type	Default	Description
data*	string	—	Message to sign.
dataFormat	enum (text \| hex \| base64)	"text"	Encoding of `data`.
privateKeyPem*	string	—	Private key in PKCS#8 PEM format.
scheme	enum (pss \| pkcs1)	"pss"	Signature scheme: PSS (recommended) or PKCS1-v1_5 (legacy).
hash	enum (SHA-256 \| SHA-384 \| SHA-512)	"SHA-256"	Hash algorithm.
saltLength	number (0…256)	32	PSS salt length in bytes. Common: equal to hash length. Ignored for PKCS1.
outputFormat	enum (hex \| base64 \| base64url)	"base64"	Encoding of the signature.

Response

Modes: json. Cache: not cacheable.

Every response carries x-cache (HIT / MISS / BYPASS), x-cache-signature (stable across identical inputs), and the rate-limit headers listed below.

Quota & limits

Cost per call	2 units against the 10,000-unit monthly quota. Cache hits are free — only cache misses decrement.
Burst limit	200 requests per rolling minute, shared across all tools.
Max request size	`4 MiB` (base64 inflates file payloads ~33% — the limit applies to the decoded bytes).
Max response size	`16 KiB`
Timeout	30s wall clock.
Rate-limit headers	`X-RateLimit-Limit`, `X-RateLimit-Remaining`, `X-RateLimit-Burst-Limit` on every response; `X-Quota-Warning` once 80% of the monthly quota is spent; `Retry-After` on 429s.

Errors

Errors are JSON with an error string; schema failures add a details object (Zod's flattened field errors).

Status	When	Body
400	Input fails the tool's schema (wrong type, missing required field, malformed base64) or the file bytes can't be parsed as the expected format.	{ "error": "invalid inputs", "details": { "fieldErrors": { … } } }
401	Missing or invalid X-Api-Key / X-Account-Id headers (or no session when called from the browser).	{ "error": "unauthorized" }
404	Unknown tool id, or calling /api/* on the website hostname instead of api.xtract.bot.	{ "error": "not found" }
413	Request body over the tool's max request size, or an image header declaring more megapixels than the tool's pixel budget.	{ "error": "…exceeds maxRequestBytes…" }
415	Content-Type isn't application/json on the json-body transport.	{ "error": "unsupported content-type; expected application/json" }
429	Monthly quota or the 200/min burst limit exhausted. Check Retry-After and the X-RateLimit-* headers.	{ "error": "monthly quota exceeded", "monthRemaining": 0, … }
5xx	Conversion engine failure. Safe to retry; if it persists, the input is hitting a bug — please report it.	{ "error": "…" }

Code samples

Built from the sign-pkcs1 example.


curl -X POST https://api.xtract.bot/api/rsa-sign \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "X-Account-Id: $XTRACT_ACCOUNT_ID" \
  -H "X-Api-Key: $XTRACT_API_KEY" \
  -d '{
  "data": "the eagle has landed",
  "privateKeyPem": "-----BEGIN PRIVATE KEY-----\nMIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCO+Tokrkjy6Egb\n/irJHkLzlTm2vebJHKThQvP/zRP+izzKqFb12ijLhDH5uTRTn0aDaAyV4vyqKRJS\nQHwmWRCywAWHX1Y334JZ8K+1dDALT9BgEEp0N8dMt2xf14ngKUlbCfHK+vpvj18h\n/yr1n1Pqj9sqQkZy7aPKBaZWy+QZ/EAC04t+TvgFgCy4Wu3XDKf8Pi407KqvMHAG\nCuozFl6aNIwZNiQYw3h7qagD+XaQrnIy5RnOW+Cjx4ae+r5jAzW8FLL6/5fixfBF\nw8Tsy/RQ6ZVCsd07eIoYtMZSxdLdxt46MBUfJshYK2Qmy++oMcN/VQF7+muKd7Vf\nEs3G8+ZDAgMBAAECggEAFwx0REvjzw5a6vGvacBwUFQQZkvjToJIzaxyqRx2qono\nJnmQmfjDVoUnXgKZPhkxZRIbOUygU+Q5eRC+kvC3zEFALZcqeekVMApToTUrtknL\nJg6/mfsQrObtrd5m8pVlUdZevaIhSREmvSnQKKG4sFnkSJc/mTEt6ZhokkSIr2wp\nDE3/LOHujh2T3y1R5tiSf7BU3+ab9FFZPrQWf7bvlYqWxe8G3GfO5UI3g0zlBorl\n6XDYRQkHZAfd2/DlVlJB9kLpBpedyLxpydeM3QrszTBYAknO+MlxkYsGuWzoxstx\nQbQFcnqwQmLhkD31g2niwMdYBjm+3YhWSIrn9CToKQKBgQDJjJ2T0kfH534xpq8I\nmUHHEx0KzQLQNOC8TaCj0NnhGX9Ixt+ofdjlwaQ254nUsYJEeTXHFghPMw4UAv3k\nWBG59CNyyhXUKrszyBO07+cfkWfG7MdxdqZHbyIOA+lCTVTq5yysPLQnYs2tKtAK\nvCaX0TAPXh2uhJBC1p9D08Fz6QKBgQC1mXHsJjQ/B60RrZUb10gbHDYrPSalu8+z\n2SzE0MghwReyMjV6Sk4gDtJM+YziAOdDka2Rw0aEiT5Y0g9jsw18uLVfxHlPNbWB\nMlWnOYk3CmiGUbQ6H0OUAj8jYUw9DoUAps7ZlsjW4LO7AOwjXxCGjInIMjKBGin9\nLukmbP3JSwKBgEzDiszfXUmNKOo+QxIyVPQ+mmQfuz+TtDjkFBfwltt+O5V7cXoa\nHH89po7m1v80cJol1E60XIvVtTn3/b13saCylMHGqFO7xrstLBxQ9yV12yHP0xKr\nDx/L+xt9b9052OrzC3e6Ux9hKVcYJE7CZKyUFwrzXLi4cr2SQuyxfU/pAoGAazMU\nlAGNb/O5D6l3TwMLlq1VsLqdeNJgbttx2REiQwK4WUHYXcNFURlOvY/GwZck7bcu\nTdCHbS+TNV1zJjiJaqmir9DMh5y983FiLKADRxGG2Fuc136jJtkYqmsCVTyf+N1/\nV+Tx1B67GlYWD19L4xFNOHehZqKqTMIHcd5/BfcCgYEAhxmFtlE73J1nMMfYoViY\n+l++KcLndQmKeS7/Dd7hkNSIbXyacN1O7vE6RSGnA0zt2mqOmqIbhFRSr3NTyix1\nRZrMTZHB7qLG45y0PkPbMnOykuGs6opC9ElShoXk9TGIYTu64uPTzlgZc4dzQTk8\nI4NAVr+nRtOVSSek7N8syro=\n-----END PRIVATE KEY-----",
  "scheme": "pkcs1"
}'