SSH public-key fingerprint

POST /api/ssh-pubkey-fingerprint1 quota unit per call · cache hits free

Get the SHA-256 fingerprint of an OpenSSH public key. Output matches what `ssh-keygen -lf` and GitHub / GitLab show. Useful for verifying a key out-of-band before trusting it.

Computes the SHA-256 fingerprint of an OpenSSH public key — the string GitHub, GitLab, and `ssh-keygen -lf` show. Input is the standard `<algorithm> <base64-data> [comment]` line. All current key types are supported: `ssh-ed25519`, `ssh-rsa`, `ecdsa-sha2-nistp256/384/521`, `ssh-dss`, `sk-ssh-ed25519@openssh.com`, `sk-ecdsa-sha2-nistp256@openssh.com`. **Output:** the fingerprint in OpenSSH's canonical `SHA256:<base64-no-padding>` format, plus the key type, the comment (if present), and the underlying SHA-256 bytes in hex for callers that need a different rendering.

Inputs

Name	Type	Default	Description
publicKey*	string	—	OpenSSH public key line, e.g. `ssh-ed25519 AAAA... user@host`.

Response

Modes: json. Cache: yes (24h TTL).

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	1 unit 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	`16 KiB` (base64 inflates file payloads ~33% — the limit applies to the decoded bytes).
Max response size	`4 KiB`
Timeout	5s 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 default example.


curl -X POST https://api.xtract.bot/api/ssh-pubkey-fingerprint \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "X-Account-Id: $XTRACT_ACCOUNT_ID" \
  -H "X-Api-Key: $XTRACT_API_KEY" \
  -d '{
  "publicKey": "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIH8Tn8jZyG3CrI8WjvtMb+u3mxJDgnUKfFlx+JRfYI7T xtract-demo"
}'