stamp

Query an NTP server for current UTC time and this clock's offset. Appends the sample to the drift log and returns the trend inline: current offset, drift rate (ms/day), and whether the clock is stable, drifting, or accelerating.

{
  "type": "object",
  "properties": {
    "server": {
      "type": "string",
      "description": "NTP server to query",
      "default": "time.cloudflare.com"
    },
    "timezone": {
      "type": "string",
      "description": "IANA timezone for a 'local' field, e.g. America/New_York. Optional -- the HTTP transport also takes ?tz= in the URL."
    }
  }
}

Generate one or more random UUIDv4 identifiers -- for records, sessions, and IDs created in agent pipelines.

{
  "type": "object",
  "properties": {
    "count": {
      "type": "integer",
      "description": "How many UUIDs to generate",
      "default": 1,
      "minimum": 1,
      "maximum": 1000
    }
  }
}

Unified diff between two texts, with added/removed line counts. For reviewing edits, comparing outputs, or validating transformations.

{
  "type": "object",
  "properties": {
    "text_a": {
      "type": "string",
      "description": "Original text"
    },
    "text_b": {
      "type": "string",
      "description": "Revised text"
    },
    "context": {
      "type": "integer",
      "description": "Lines of context around each change",
      "default": 3,
      "minimum": 0
    }
  },
  "required": [
    "text_a",
    "text_b"
  ]
}

Evaluate a math expression safely: + - * / // % **, parentheses, functions (abs round min max sqrt floor ceil exp log log2 log10 pow sin cos tan), constants pi e tau inf. Parsed to an AST and only whitelisted nodes are computed -- no eval(), no names, no arbitrary code.

{
  "type": "object",
  "properties": {
    "expression": {
      "type": "string",
      "description": "e.g. \"(1500 * 0.23) + 47\""
    }
  },
  "required": [
    "expression"
  ]
}

Wrap any payload in a tamper-evident record: a UUID, a timestamp (NTP-verified when reachable, local clock otherwise -- the record says which), and a sha256 over the canonical record. One call, the record is complete and tamper-evident.

{
  "type": "object",
  "properties": {
    "payload": {
      "description": "Any JSON value to attest"
    },
    "server": {
      "type": "string",
      "description": "NTP server for the verified timestamp",
      "default": "time.cloudflare.com"
    }
  },
  "required": [
    "payload"
  ]
}

Check a record produced by attest: recompute the sha256 over the record and compare. Pass/fail -- did this payload produce this hash at this timestamp. Any modified field breaks it.

{
  "type": "object",
  "properties": {
    "attested": {
      "type": "object",
      "description": "The record returned by attest"
    }
  },
  "required": [
    "attested"
  ]
}