GET

/v1/schemas/meta/chat/v1/messages?kind=output

Accept:

kind outputactivity chathash 4d3a3416…extracted Oct 9, 2026version currentsource upstream spec ↗

field	recorded source
schema	Source linked above. docs-derived Source trace `c8b17b4c61aa64219d69432a6a009694dc925e898d73f54953145648f454f808` { "fetchedAt": 1791523841, "extractorVersion": "1", "verifiedAt": null }

Response body

8 properties · 8 required · 2 $defs

property	type	constraints
id*	string
type*	enum	message
role*	enum	assistant
content*	anthropic-content-block[]
model*	string
stop_reason*	enum	end_turn \| max_tokens \| stop_sequence \| tool_use \| pause_turn \| refusal
stop_sequence*	string	nullable
usage*	anthropic-usage

Types

2 $defs

anthropic-content-blockobject

type*

string

Content block discriminator, such as text, image, video, document, tool_use, or tool_result.

anthropic-usageobject

input_tokens*	integer
output_tokens*	integer
cache_creation_input_tokens	integer
cache_read_input_tokens	integer
output_tokens_details	object

Validate a payload

before you spend tokens

shell

$ curl -X POST https://modelschemas.com/v1/validate \
    -d '{"provider":"meta","endpointId":"v1/messages","payload":{…}}'
→ {"valid": false, "errors": [{"path": "#", "keyword": "required", …}]}