v0.3.0

OpenAPI 3.1.0

Create a Claude message

Felo API Support

MIT

Server

https://openapi.felo.ai

Client Libraries

Shell Curl

Create a Claude message

Claude Messages API-compatible endpoint. Set stream=true to receive Claude-style message stream events. Request, response, and validation-error fields follow the Claude Messages protocol; the Router may also return a sanitized gateway error envelope for infrastructure failures.

Body·ClaudeMessagesRequest

required

application/json

max_tokens
Type: integer
min:
1
required

Integer numbers.
messages
Type: array object[] · ClaudeMessage[] 1…
required
- content
  required
  Type: string
- role
  Type: string enum
  required
  values
  user
  assistant
- propertyName
  Type: anything
model
Type: string
required
metadata
Type: object
- propertyName
  Type: anything
service_tier
Type: string
stop_sequences
Type: array string[]
stream
Type: boolean
system
Type: string
temperature
Type: number
min:
0
max:
1
thinking
Type: object
- propertyName
  Type: anything
tool_choice
Type: string
tools
Type: array object[]
- propertyName
  Type: anything
propertyName
Type: anything

top_k
Type: integer
min:
0

Integer numbers.
top_p
Type: number
min:
0
max:
1
propertyName
Type: anything

Responses

200
Type: object · ClaudeMessageResponse

Claude message or streaming response
content
Type: array object[] · ClaudeContentBlock[]
required
type
Type: string enum
required
values
text
image
document
tool_use
tool_result
thinking
content
Type: string | array
id
Type: string
input
Type: object
propertyName
Type: anything
name
Type: string
source
Type: object
propertyName
Type: anything
text
Type: string
propertyName
Type: anything
id
Type: string
required
model
Type: string
required
role
const:
assistant
required
stop_reason
Type: string | null
required
type
const:
message
required
stop_sequence
Type: string | null
usage
Type: object · Usage

Provider usage object. Fields vary by endpoint and provider.

propertyName
Type: anything
propertyName
Type: anything
400
Type: object · ClaudeErrorResponse

Claude invalid_request_error or Router request validation error

Claude Errors API-compatible error envelope for Messages requests.
error
Type: object
required
message
Type: string
required
type
Type: string
required
propertyName
Type: anything
type
const:
error
required
request_id
Type: string
propertyName
Type: anything
application/json
401
Type: object · ClaudeErrorResponse

Invalid or missing Felo API key

Claude Errors API-compatible error envelope for Messages requests.
error
Type: object
required
message
Type: string
required
type
Type: string
required
propertyName
Type: anything
type
const:
error
required
request_id
Type: string
propertyName
Type: anything
application/json
402
Type: object · ClaudeErrorResponse

Insufficient balance

Claude Errors API-compatible error envelope for Messages requests.
error
Type: object
required
message
Type: string
required
type
Type: string
required
propertyName
Type: anything
type
const:
error
required
request_id
Type: string
propertyName
Type: anything
application/json
403
Type: object · ClaudeErrorResponse

Account is not permitted to use the model. Disabled models are also rejected before upstream calls. Existing accepted requests and tasks continue.

Claude Errors API-compatible error envelope for Messages requests.
error
Type: object
required
message
Type: string
required
type
Type: string
required
propertyName
Type: anything
type
const:
error
required
request_id
Type: string
propertyName
Type: anything
application/json
429
Type: object · ClaudeErrorResponse

Spending or request limit reached

Claude Errors API-compatible error envelope for Messages requests.
error
Type: object
required
message
Type: string
required
type
Type: string
required
propertyName
Type: anything
type
const:
error
required
request_id
Type: string
propertyName
Type: anything
application/json
502
Type: object · ClaudeErrorResponse

Upstream provider request failed

Claude Errors API-compatible error envelope for Messages requests.
error
Type: object
required
message
Type: string
required
type
Type: string
required
propertyName
Type: anything
type
const:
error
required
request_id
Type: string
propertyName
Type: anything
application/json
503
Type: object · ClaudeErrorResponse

Provider or billing service unavailable

Claude Errors API-compatible error envelope for Messages requests.
error
Type: object
required
message
Type: string
required
type
Type: string
required
propertyName
Type: anything
type
const:
error
required
request_id
Type: string
propertyName
Type: anything
application/json

post/api/v1/messages

curl https://openapi.felo.ai/api/v1/messages \
  --request POST \
  --header 'Content-Type: application/json' \
  --header 'Authorization: Bearer YOUR_SECRET_TOKEN' \
  --data '{
  "model": "claude-sonnet-4-5",
  "max_tokens": 256,
  "messages": [
    {
      "role": "user",
      "content": "Write a one-sentence greeting."
    }
  ],
  "stream": false
}'

Show Schema

{
  "id": "string",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "string",
      "id": "string",
      "name": "string",
      "input": {
        "additionalProperty": "anything"
      },
      "content": "string",
      "source": {
        "additionalProperty": "anything"
      },
      "additionalProperty": "anything"
    }
  ],
  "model": "string",
  "stop_reason": null,
  "stop_sequence": null,
  "usage": {
    "additionalProperty": "anything"
  },
  "additionalProperty": "anything"
}

Claude message or streaming response

Create a Claude message

AuthenticationRequired

Create a Claude message