Evaluate Flags (Bulk)

curl -X POST https://fly.feather.mupeni.dev/v1/evaluate/bulk \
  -H "Authorization: Bearer <api_key>" \
  -H "Content-Type: application/json" \
  -d '{
    "flags": ["new-checkout", "checkout-copy"],
    "context": {
      "userId": "user_123",
      "attributes": { "country": "DE" }
    }
  }'

{
  "results": {
    "new-checkout": { "value": true, "reason": "DEFAULT" },
    "checkout-copy": { "value": "variant-b", "reason": "ROLLOUT", "variant": "b" }
  },
  "meta": {
    "environmentId": "env_01hx...",
    "evaluatedAt": "2026-04-03T10:00:00.000Z",
    "cacheAge": 2,
    "requestId": "73d24f43-d5ac-428e-b57a-fce4cb4d5685"
  }
}

{
  "results": {
    "new-checkout": { "value": null, "reason": "ERROR" },
    "checkout-copy": { "value": null, "reason": "ERROR" }
  },
  "meta": {
    "environmentId": "env_01hx...",
    "evaluatedAt": "2026-04-03T10:00:00.000Z",
    "cacheAge": 0
  }
}

POST

evaluate

bulk

curl -X POST https://fly.feather.mupeni.dev/v1/evaluate/bulk \
  -H "Authorization: Bearer <api_key>" \
  -H "Content-Type: application/json" \
  -d '{
    "flags": ["new-checkout", "checkout-copy"],
    "context": {
      "userId": "user_123",
      "attributes": { "country": "DE" }
    }
  }'

{
  "results": {
    "new-checkout": { "value": true, "reason": "DEFAULT" },
    "checkout-copy": { "value": "variant-b", "reason": "ROLLOUT", "variant": "b" }
  },
  "meta": {
    "environmentId": "env_01hx...",
    "evaluatedAt": "2026-04-03T10:00:00.000Z",
    "cacheAge": 2,
    "requestId": "73d24f43-d5ac-428e-b57a-fce4cb4d5685"
  }
}

{
  "results": {
    "new-checkout": { "value": null, "reason": "ERROR" },
    "checkout-copy": { "value": null, "reason": "ERROR" }
  },
  "meta": {
    "environmentId": "env_01hx...",
    "evaluatedAt": "2026-04-03T10:00:00.000Z",
    "cacheAge": 0
  }
}

Returns a results map keyed by flag key and a meta block with evaluation metadata. Auth: API key only (Authorization: Bearer <key>).

Body

string[]

required

List of flag keys to evaluate. Minimum 1, maximum 100.

object

required

Shared evaluation context for all requested flags.

string

Stable user identifier.

string

Anonymous identifier when userId is not available.

Record<string, string | number | boolean>

Additional attributes used by flag rules.

Response

Record<string, { value: boolean | string | number | null; reason: "DISABLED" | "RULE_MATCH" | "ROLLOUT" | "DEFAULT" | "FLAG_NOT_FOUND" | "ERROR"; ruleId?: string; variant?: string }>

required

string

required

string

required

number

required

string

Unknown flags and client-restricted flags both return FLAG_NOT_FOUND.

Status codes

Status	Meaning
`200`	Evaluation succeeded
`400`	Invalid JSON body (`INVALID_JSON`)
`401`	Missing/invalid API key (`UNAUTHORIZED`, `INVALID_API_KEY`)
`422`	Validation failed (`VALIDATION_ERROR`)
`429`	Rate-limited (`RATE_LIMITED`)
`503`	Bundle unavailable; all results return `reason: "ERROR"`

curl -X POST https://fly.feather.mupeni.dev/v1/evaluate/bulk \
  -H "Authorization: Bearer <api_key>" \
  -H "Content-Type: application/json" \
  -d '{
    "flags": ["new-checkout", "checkout-copy"],
    "context": {
      "userId": "user_123",
      "attributes": { "country": "DE" }
    }
  }'

{
  "results": {
    "new-checkout": { "value": true, "reason": "DEFAULT" },
    "checkout-copy": { "value": "variant-b", "reason": "ROLLOUT", "variant": "b" }
  },
  "meta": {
    "environmentId": "env_01hx...",
    "evaluatedAt": "2026-04-03T10:00:00.000Z",
    "cacheAge": 2,
    "requestId": "73d24f43-d5ac-428e-b57a-fce4cb4d5685"
  }
}

{
  "results": {
    "new-checkout": { "value": null, "reason": "ERROR" },
    "checkout-copy": { "value": null, "reason": "ERROR" }
  },
  "meta": {
    "environmentId": "env_01hx...",
    "evaluatedAt": "2026-04-03T10:00:00.000Z",
    "cacheAge": 0
  }
}

Evaluate Flag

Getting Started

Concepts

Management API

Delivery API

Body

Response

Status codes

​Body

​Response

​Status codes

Body

Response

Status codes