Runs

One transform plus any number of checks in a single run, all on your input at the same time. The run bills the characters in and the characters the transform hands back, once.

A run is not limited to one service. Name one transform in transform and any number of checks in checks; they all run on your input at the same time, and one response carries every result.

curl -X POST https://api.chersus.com/v1/run \
-H "Authorization: Bearer $CHERSUS_KEY" \
-H "Content-Type: application/json" \
-d '{
  "type": "text",
  "input": "Contact Jane Doe at jane.doe@example.com. Your service is garbage.",
  "transform": "governance.pii.redact",
  "checks": ["security.toxicity.flag"]
}'

const res = await fetch("https://api.chersus.com/v1/run", {
method: "POST",
headers: {
  Authorization: "Bearer " + process.env.CHERSUS_KEY,
  "Content-Type": "application/json",
},
body: JSON.stringify({
  type: "text",
  input: "Contact Jane Doe at jane.doe@example.com. Your service is garbage.",
  transform: "governance.pii.redact",
  checks: ["security.toxicity.flag"],
}),
});

const data = await res.json();

import os

import requests

res = requests.post(
  "https://api.chersus.com/v1/run",
  headers={"Authorization": "Bearer " + os.environ["CHERSUS_KEY"]},
  json={
      "type": "text",
      "input": "Contact Jane Doe at jane.doe@example.com. Your service is garbage.",
      "transform": "governance.pii.redact",
      "checks": ["security.toxicity.flag"],
  },
)

data = res.json()

The rewritten text arrives in output, its details in transformed; each check reports under its own name in checked:

{
  "trace_id": "chs_01J9X4Q7K2M8N3P5R6T7V8W9X0",
  "status": "completed",
  "output": "Contact [REDACTED] at [REDACTED]. Your service is garbage.",
  "transformed": {
    "service": "governance.pii.redact",
    "changes": 2
  },
  "checked": {
    "security.toxicity.flag": {
      "kind": "classify",
      "verdict": "flag",
      "score": 0.84,
      "labels": ["threat"]
    }
  },
  "usage": {
    "billed": { "unit": "characters", "input": 66, "output": 58, "quantity": 124 }
  }
}

The run billed 124: 66 characters in, 58 handed back by the redaction. The toxicity check added latency and nothing to the bill.

Classify and extract services go in checks and combine freely: every one of them reads your input and leaves it alone. Transforms rewrite the input, so transform takes exactly one: governance.pii.redact, governance.pii.tokenize, governance.pii.rehydrate, or data.date.normalize. A transform listed under checks is rejected with invalid_services before anything runs.

The request names the transform in transform and the checks in checks, and the response mirrors it: the rewritten text arrives in output, its details in transformed, each verdict in checked. With no transform in the run, both are null and nothing is handed back.

A run that cleans and checks in one pass:

curl -X POST https://api.chersus.com/v1/run \
-H "Authorization: Bearer $CHERSUS_KEY" \
-H "Content-Type: application/json" \
-d '{
  "type": "text",
  "input": "Contact Jane Doe at jane.doe@example.com. Your service is garbage.",
  "transform": "governance.pii.redact",
  "checks": [
    "security.toxicity.flag",
    "routing.language.detect"
  ]
}'

const res = await fetch("https://api.chersus.com/v1/run", {
method: "POST",
headers: {
  Authorization: "Bearer " + process.env.CHERSUS_KEY,
  "Content-Type": "application/json",
},
body: JSON.stringify({
  type: "text",
  input: "Contact Jane Doe at jane.doe@example.com. Your service is garbage.",
  transform: "governance.pii.redact",
  checks: [
    "security.toxicity.flag",
    "routing.language.detect"
  ],
}),
});

const data = await res.json();

import os

import requests

res = requests.post(
  "https://api.chersus.com/v1/run",
  headers={"Authorization": "Bearer " + os.environ["CHERSUS_KEY"]},
  json={
      "type": "text",
      "input": "Contact Jane Doe at jane.doe@example.com. Your service is garbage.",
      "transform": "governance.pii.redact",
      "checks": [
        "security.toxicity.flag",
        "routing.language.detect"
      ],
  },
)

data = res.json()

The three services read the same input: the redaction reports in transformed, the two checks in checked, and usage.billed still says 66 in, 58 out, 124 billed. The run took 11 ms, the slowest service, not the 23 ms the three would need one after another. Attach a fourth check and the bill does not move; the wait grows only if the new one is the slowest.

The audit trace

Every response includes an audit trace, no flag needed. Per run: region, retention, timing. Per service: the version, the model, input and output sizes, SHA-256 hashes of the content, and the verdict or change count. The hashes let you prove a given text went through a given service with a given result, while Chersus stores no content at all.

Billing

A run bills the characters you send plus the characters its transform hands back, once, whatever the number of checks. usage.billed shows the split: input, output, and their sum. A failed run hands nothing back, so it bills its input only; rejected requests and failures on our side bill nothing. The pricing page has the rate rule.

The free allowance works like everything else: the characters in your runs count toward the 1M monthly allowance. The API reference has the full request and response contract.

What can share a run

The audit trace

Billing