# Bush-Francis Catatonia Rating Scale

Bush-Francis

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/bush_francis`
HTML: https://magentlab.com/docs/bush-francis
Markdown: https://magentlab.com/docs/bush-francis.md

Not a medical device. Not a diagnosis, dose, or listing recommendation.

## What it computes

Sum Bush 1996 23-item catatonia rating scale points from caller-assigned integers and report the 14-item screen (positive iff at least two of items 1-14 score above 0). Does not diagnose catatonia.

## When to use

When an agent already has Bush 1996 23-item integers and needs the published severity sum and 14-item screen. magent does not perform the standardized examination, diagnose catatonia, or apply DSM catatonia criteria.

## When not to use

- Not a medical device and not a diagnosis of catatonia or a treatment order.
- Each of the 23 items is a caller-assigned Bush 1996 integer. magent does not perform the standardized examination and does not examine the patient.
- Screening uses the first 14 items only: screen_positive is true iff at least two of those items score above 0 (Bush 1996 cases defined by ≥2 signs on the 14-item screen). This is not DSM catatonia criteria as a separate tool.
- Items 17-21 (mitgehen, gegenhalten, ambitendency, grasp_reflex, perseveration) are 0 or 3 only in Bush 1996. magent does not apply later training-manual changes to those ranges.

## Formula

```
Bush-Francis CRS = excitement + immobility_stupor + mutism + staring + posturing_catalepsy + grimacing + echopraxia_echolalia + stereotypy + mannerisms + verbigeration + rigidity + negativism + waxy_flexibility + withdrawal + impulsivity + automatic_obedience + mitgehen + gegenhalten + ambitendency + grasp_reflex + perseveration + combativeness + autonomic_abnormality; Bush 1996 23-item catatonia rating scale; items 1-16 and 22-23 integers 0-3; items 17-21 (mitgehen, gegenhalten, ambitendency, grasp_reflex, perseveration) 0 or 3 only; severity score = sum of items 1-23; screening instrument = first 14 items; screen_positive iff count of items 1-14 with score > 0 is >= 2; max 69; not a diagnosis
```

## Citation

[Catatonia. I. Rating scale and standardized examination](https://doi.org/10.1111/j.1600-0447.1996.tb09814.x)
Bush G, Fink M, Petrides G, Dowling F, Francis A
Acta Psychiatr Scand. 1996;93(2):129-136
DOI: [10.1111/j.1600-0447.1996.tb09814.x](https://doi.org/10.1111/j.1600-0447.1996.tb09814.x)

## Worked example

### Two screen signs (screen-positive threshold)

Given: `ambitendency=0, automatic_obedience=0, autonomic_abnormality=0, combativeness=0, echopraxia_echolalia=0, excitement=1, gegenhalten=0, grasp_reflex=0, grimacing=0, immobility_stupor=1, impulsivity=0, mannerisms=0, mitgehen=0, mutism=0, negativism=0, perseveration=0, posturing_catalepsy=0, rigidity=0, staring=0, stereotypy=0, verbigeration=0, waxy_flexibility=0, withdrawal=0`

1. excitement is 1 and immobility_stupor is 1 as assigned by the caller; remaining items are 0
2. Severity score = 2 (max 69). Two of the first 14 items score above 0, so screen_positive is true (Bush 1996 ≥2 signs on the 14-item screen).


### All items at published minimum

Given: `ambitendency=0, automatic_obedience=0, autonomic_abnormality=0, combativeness=0, echopraxia_echolalia=0, excitement=0, gegenhalten=0, grasp_reflex=0, grimacing=0, immobility_stupor=0, impulsivity=0, mannerisms=0, mitgehen=0, mutism=0, negativism=0, perseveration=0, posturing_catalepsy=0, rigidity=0, staring=0, stereotypy=0, verbigeration=0, waxy_flexibility=0, withdrawal=0`

1. all 23 Bush 1996 items are 0 as assigned by the caller
2. Score = 0 (max 69). screen_signs_met = 0; screen_positive false.


### All items at published maximum

Given: `ambitendency=3, automatic_obedience=3, autonomic_abnormality=3, combativeness=3, echopraxia_echolalia=3, excitement=3, gegenhalten=3, grasp_reflex=3, grimacing=3, immobility_stupor=3, impulsivity=3, mannerisms=3, mitgehen=3, mutism=3, negativism=3, perseveration=3, posturing_catalepsy=3, rigidity=3, staring=3, stereotypy=3, verbigeration=3, waxy_flexibility=3, withdrawal=3`

1. each Bush 1996 item is at that paper's published maximum as assigned by the caller (0-3 items at 3; items 17-21 at 3)
2. Score = 69 (max 69). All 14 screen items are present, so screen_positive is true. Not a diagnosis.


## Also searched as

- Bush-Francis Catatonia Rating Scale
- BFCRS
- Bush Francis catatonia scale
- catatonia rating scale
- Bush 1996 CRS
- 14-item catatonia screen
- BFCRS screening instrument
- Catatonia Screening Instrument

## Parameters

- `excitement` (integer, required): Caller-assigned Bush 1996 excitement (item 1; integer 0-3). magent does not examine the patient.
- `immobility_stupor` (integer, required): Caller-assigned Bush 1996 immobility/stupor (item 2; integer 0-3). magent does not examine the patient.
- `mutism` (integer, required): Caller-assigned Bush 1996 mutism (item 3; integer 0-3). magent does not examine the patient.
- `staring` (integer, required): Caller-assigned Bush 1996 staring (item 4; integer 0-3). magent does not examine the patient.
- `posturing_catalepsy` (integer, required): Caller-assigned Bush 1996 posturing/catalepsy (item 5; integer 0-3). magent does not examine the patient.
- `grimacing` (integer, required): Caller-assigned Bush 1996 grimacing (item 6; integer 0-3). magent does not examine the patient.
- `echopraxia_echolalia` (integer, required): Caller-assigned Bush 1996 echopraxia/echolalia (item 7; integer 0-3). magent does not examine the patient.
- `stereotypy` (integer, required): Caller-assigned Bush 1996 stereotypy (item 8; integer 0-3). magent does not examine the patient.
- `mannerisms` (integer, required): Caller-assigned Bush 1996 mannerisms (item 9; integer 0-3). magent does not examine the patient.
- `verbigeration` (integer, required): Caller-assigned Bush 1996 verbigeration (item 10; integer 0-3). magent does not examine the patient.
- `rigidity` (integer, required): Caller-assigned Bush 1996 rigidity (item 11; integer 0-3). magent does not examine the patient.
- `negativism` (integer, required): Caller-assigned Bush 1996 negativism (item 12; integer 0-3). magent does not examine the patient.
- `waxy_flexibility` (integer, required): Caller-assigned Bush 1996 waxy flexibility (item 13; integer 0-3). magent does not examine the patient.
- `withdrawal` (integer, required): Caller-assigned Bush 1996 withdrawal (item 14; integer 0-3). magent does not examine the patient.
- `impulsivity` (integer, required): Caller-assigned Bush 1996 impulsivity (item 15; integer 0-3). magent does not examine the patient.
- `automatic_obedience` (integer, required): Caller-assigned Bush 1996 automatic obedience (item 16; integer 0-3). magent does not examine the patient.
- `mitgehen` (integer, required): Caller-assigned Bush 1996 mitgehen (item 17; 0 absent or 3 present only). magent does not examine the patient.
- `gegenhalten` (integer, required): Caller-assigned Bush 1996 gegenhalten (item 18; 0 absent or 3 present only). magent does not examine the patient.
- `ambitendency` (integer, required): Caller-assigned Bush 1996 ambitendency (item 19; 0 absent or 3 present only). magent does not examine the patient.
- `grasp_reflex` (integer, required): Caller-assigned Bush 1996 grasp reflex (item 20; 0 absent or 3 present only). magent does not examine the patient.
- `perseveration` (integer, required): Caller-assigned Bush 1996 perseveration (item 21; 0 absent or 3 present only). magent does not examine the patient.
- `combativeness` (integer, required): Caller-assigned Bush 1996 combativeness (item 22; integer 0-3). magent does not examine the patient.
- `autonomic_abnormality` (integer, required): Caller-assigned Bush 1996 autonomic abnormality (item 23; integer 0-3). magent does not examine the patient.

## Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

Method: `POST /api/calc/bush_francis`
Max items: 25
Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic)
Status: PREVIEW

- 1 to 25 items. Each item uses the same keys as the GET query parameters.
- POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
- The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
- HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
- Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
- x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request:

```json
{
  "items": [
    {
      "ambitendency": "0",
      "automatic_obedience": "0",
      "autonomic_abnormality": "0",
      "combativeness": "0",
      "echopraxia_echolalia": "0",
      "excitement": "1",
      "gegenhalten": "0",
      "grasp_reflex": "0",
      "grimacing": "0",
      "immobility_stupor": "1",
      "impulsivity": "0",
      "mannerisms": "0",
      "mitgehen": "0",
      "mutism": "0",
      "negativism": "0",
      "perseveration": "0",
      "posturing_catalepsy": "0",
      "rigidity": "0",
      "staring": "0",
      "stereotypy": "0",
      "verbigeration": "0",
      "waxy_flexibility": "0",
      "withdrawal": "0"
    },
    {
      "ambitendency": "0",
      "automatic_obedience": "0",
      "autonomic_abnormality": "0",
      "combativeness": "0",
      "echopraxia_echolalia": "0",
      "excitement": "1",
      "gegenhalten": "0",
      "grasp_reflex": "0",
      "grimacing": "0",
      "immobility_stupor": "1",
      "impulsivity": "0",
      "mannerisms": "0",
      "mitgehen": "0",
      "mutism": "0",
      "negativism": "0",
      "perseveration": "0",
      "posturing_catalepsy": "0",
      "rigidity": "0",
      "staring": "0",
      "stereotypy": "0",
      "verbigeration": "0",
      "waxy_flexibility": "0",
      "withdrawal": "0"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/bush-francis

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/bush_francis",
  "items": [
    {
      "components": [
        {
          "value": 1,
          "factor": "excitement",
          "points": 1,
          "present": true
        },
        {
          "value": 1,
          "factor": "immobility_stupor",
          "points": 1,
          "present": true
        },
        {
          "value": 0,
          "factor": "mutism",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "staring",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "posturing_catalepsy",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "grimacing",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "echopraxia_echolalia",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "stereotypy",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "mannerisms",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "verbigeration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "rigidity",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "negativism",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "waxy_flexibility",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "withdrawal",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "impulsivity",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "automatic_obedience",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "mitgehen",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "gegenhalten",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "ambitendency",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "grasp_reflex",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "perseveration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "combativeness",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "autonomic_abnormality",
          "points": 0,
          "present": true
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Bush G, Fink M, Petrides G, Dowling F, Francis A",
        "doi": "10.1111/j.1600-0447.1996.tb09814.x",
        "id": "bush-1996",
        "pmid": "8686483",
        "source": "Acta Psychiatr Scand. 1996;93(2):129-136",
        "title": "Catatonia. I. Rating scale and standardized examination"
      },
      "formula": "bush_francis",
      "formula_expression": "Bush-Francis CRS = excitement + immobility_stupor + mutism + staring + posturing_catalepsy + grimacing + echopraxia_echolalia + stereotypy + mannerisms + verbigeration + rigidity + negativism + waxy_flexibility + withdrawal + impulsivity + automatic_obedience + mitgehen + gegenhalten + ambitendency + grasp_reflex + perseveration + combativeness + autonomic_abnormality; Bush 1996 23-item catatonia rating scale; items 1-16 and 22-23 integers 0-3; items 17-21 (mitgehen, gegenhalten, ambitendency, grasp_reflex, perseveration) 0 or 3 only; severity score = sum of items 1-23; screening instrument = first 14 items; screen_positive iff count of items 1-14 with score > 0 is >= 2; max 69; not a diagnosis",
      "max_score": 69,
      "score": 2,
      "screen_positive": true,
      "screen_signs_met": 2
    },
    {
      "components": [
        {
          "value": 1,
          "factor": "excitement",
          "points": 1,
          "present": true
        },
        {
          "value": 1,
          "factor": "immobility_stupor",
          "points": 1,
          "present": true
        },
        {
          "value": 0,
          "factor": "mutism",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "staring",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "posturing_catalepsy",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "grimacing",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "echopraxia_echolalia",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "stereotypy",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "mannerisms",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "verbigeration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "rigidity",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "negativism",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "waxy_flexibility",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "withdrawal",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "impulsivity",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "automatic_obedience",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "mitgehen",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "gegenhalten",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "ambitendency",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "grasp_reflex",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "perseveration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "combativeness",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "autonomic_abnormality",
          "points": 0,
          "present": true
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Bush G, Fink M, Petrides G, Dowling F, Francis A",
        "doi": "10.1111/j.1600-0447.1996.tb09814.x",
        "id": "bush-1996",
        "pmid": "8686483",
        "source": "Acta Psychiatr Scand. 1996;93(2):129-136",
        "title": "Catatonia. I. Rating scale and standardized examination"
      },
      "formula": "bush_francis",
      "formula_expression": "Bush-Francis CRS = excitement + immobility_stupor + mutism + staring + posturing_catalepsy + grimacing + echopraxia_echolalia + stereotypy + mannerisms + verbigeration + rigidity + negativism + waxy_flexibility + withdrawal + impulsivity + automatic_obedience + mitgehen + gegenhalten + ambitendency + grasp_reflex + perseveration + combativeness + autonomic_abnormality; Bush 1996 23-item catatonia rating scale; items 1-16 and 22-23 integers 0-3; items 17-21 (mitgehen, gegenhalten, ambitendency, grasp_reflex, perseveration) 0 or 3 only; severity score = sum of items 1-23; screening instrument = first 14 items; screen_positive iff count of items 1-14 with score > 0 is >= 2; max 69; not a diagnosis",
      "max_score": 69,
      "score": 2,
      "screen_positive": true,
      "screen_signs_met": 2
    }
  ]
}
```

## Response fields

- `formula` (string): bush_francis
- `formula_expression` (string): Exact expression used
- `score` (integer): Bush 1996 severity sum of 23 caller-assigned items (0-69)
- `max_score` (integer): Always 69
- `screen_positive` (boolean): true iff at least two of the first 14 Bush 1996 screen items score above 0. Not a diagnosis.
- `screen_signs_met` (integer): Count of items 1-14 with score > 0 (0-14)
- `components` (array): Per-item caller-assigned points
- `citation` (object): Bush Acta Psychiatr Scand 1996 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "components": [
    {
      "value": 1,
      "factor": "excitement",
      "points": 1,
      "present": true
    },
    {
      "value": 1,
      "factor": "immobility_stupor",
      "points": 1,
      "present": true
    },
    {
      "value": 0,
      "factor": "mutism",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "staring",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "posturing_catalepsy",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "grimacing",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "echopraxia_echolalia",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "stereotypy",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "mannerisms",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "verbigeration",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "rigidity",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "negativism",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "waxy_flexibility",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "withdrawal",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "impulsivity",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "automatic_obedience",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "mitgehen",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "gegenhalten",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "ambitendency",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "grasp_reflex",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "perseveration",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "combativeness",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "autonomic_abnormality",
      "points": 0,
      "present": true
    }
  ],
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Bush G, Fink M, Petrides G, Dowling F, Francis A",
    "doi": "10.1111/j.1600-0447.1996.tb09814.x",
    "id": "bush-1996",
    "pmid": "8686483",
    "source": "Acta Psychiatr Scand. 1996;93(2):129-136",
    "title": "Catatonia. I. Rating scale and standardized examination"
  },
  "formula": "bush_francis",
  "formula_expression": "Bush-Francis CRS = excitement + immobility_stupor + mutism + staring + posturing_catalepsy + grimacing + echopraxia_echolalia + stereotypy + mannerisms + verbigeration + rigidity + negativism + waxy_flexibility + withdrawal + impulsivity + automatic_obedience + mitgehen + gegenhalten + ambitendency + grasp_reflex + perseveration + combativeness + autonomic_abnormality; Bush 1996 23-item catatonia rating scale; items 1-16 and 22-23 integers 0-3; items 17-21 (mitgehen, gegenhalten, ambitendency, grasp_reflex, perseveration) 0 or 3 only; severity score = sum of items 1-23; screening instrument = first 14 items; screen_positive iff count of items 1-14 with score > 0 is >= 2; max 69; not a diagnosis",
  "max_score": 69,
  "score": 2,
  "screen_positive": true,
  "screen_signs_met": 2
}
```

## Errors

- HTTP 400 `invalid_bush_francis`: Bush-Francis needs the 1996 catatonia item integers in published ranges. Returned before settlement; you are not charged.
- HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
- HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
- HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [BARS](https://magentlab.com/docs/bars) — Return the Swift 2002 Behavioural Activity Rating Scale (BARS) 1-7 from a caller-assigned integer, with a stable label.
- [GDS-15](https://magentlab.com/docs/gds-15) — Sum fifteen Sheikh 1986 GDS-15 yes/no items using that paper's reverse-scoring key and return the published 0-15 total. Does not apply later total-score severity bands.
- [RASS](https://magentlab.com/docs/rass) — Return the Sessler 2002 Richmond Agitation-Sedation Scale term and description from a caller-assigned integer -5 to +4.

## Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s.

- GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall).
- HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote.
- Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional.
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402.

- offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront.
- offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization.

- not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search.

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers).

Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments

Stdio MCP (one process per host): https://magentlab.com/docs/mcp

## Guarantees

- HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
- exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
- HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
- Execution is timeout-bounded and concurrency-capped.
- Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.