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nexos.ai

nexos.ai Messages API

Anthropic-native Messages API for prompt-cache-preserving passthrough.

Documentation Provider Profile APIs.io OpenAPI GitHub

nexos.ai Messages API is one of 16 APIs that nexos.ai publishes on the APIs.io network, described by a machine-readable OpenAPI specification.

Tagged areas include Message. The published artifact set on APIs.io includes an OpenAPI specification.

This API exposes 1 operation across 1 path, and defines 57 schemas. It is described by OpenAPI 3.2.0, at version 1.0.0.

Requests are made against a single base URL, https://api.nexos.ai.

1 operations 1 paths 57 schemas 1 POST

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.2.0
API Version
1.0.0
Base URL
https://api.nexos.ai
Authentication
HTTP Bearer, API Key
Resource Areas
1

Authentication & Security 2

nexos.ai Messages API declares 2 security schemes for authenticating requests. It accepts HTTP bearer tokens (bearerAuth). An API key is passed in the header as X-Api-Key (apiKeyHeader). By default, every request must be authenticated.

  • apiKeyHeader — Authenticate by sending your nexos API key in the X-Api-Key header (e.g. X-Api-Key: nexos-... for a user key or X-Api-Key: nexos-team-... for a team key). This…

Paths & Operations 1

Across 1 path, the API surfaces 1 operation — 1 POST. Each is listed below with its method, path, parameters, and response codes.

Messages 1

Anthropic-native Messages API for prompt-cache-preserving passthrough.

POST
/v1/messages
Create a message (Anthropic-native)
createMessage body → 200

Schemas 57

The contract defines 57 schemas that model the data the API accepts and returns. The most detailed are CreateMessageRequest (16 properties), MessagesResponse (9 properties), Usage (8 properties), SearchResultBlock (6 properties). Each schema is shown below with its type and property counts.

MessageStopEvent
object
1 property 1 required
ContentBlockDeltaEvent
object
3 properties 3 required
RedactedThinkingBlock
object
2 properties 2 required
ImageSourceURL
object
2 properties 2 required
TextDelta
object
2 properties 2 required
ToolUseBlock
object
5 properties 4 required
MessagesStreamEvent
Anthropic-native Messages API SSE event. Discriminated by type. Forwarded byte-for-byte from the upstream provider — public-api does not transform individual e…
CustomTool
object
A function tool that the client defines and implements.
5 properties 2 required
ToolChoiceTool
object
3 properties 2 required
DocumentSource
CacheCreation
object
Breakdown of cache-write tokens split by cache lifetime tier.
2 properties
ServerTool
object
A provider-hosted built-in tool, identified by its versioned type (for example websearch20250305, codeexecution20250825, bash20250124, texteditor20250124, or m…
3 properties 2 required
DocumentSourceContent
object
2 properties 2 required
SystemBlock
object
A system prompt content block. Supports cachecontrol for caching the system prefix.
3 properties 2 required
ThinkingDelta
object
2 properties 2 required
MessageDelta
object
Top-level message delta carrying terminal stopreason / stopsequence.
2 properties
InputJsonDelta
object
2 properties 2 required
Container
object
Details of the execution container, included when the request used server-side code execution.
2 properties 2 required
Tool
Tool definition. Either a custom tool (function with inputschema) or a built-in server tool (typed by versioned type).
InputMessage
object
A single input message in the messages array.
2 properties 2 required
CitationsConfig
object
1 property 1 required
EnabledThinkingConfig
object
2 properties 2 required
ImageSourceBase64
object
3 properties 3 required
ContentBlockDelta
CreateMessageRequest
object
Anthropic-native Messages API request body. Forwarded byte-for-byte to the upstream provider — cachecontrol markers are preserved exactly where the client plac…
16 properties 3 required
ThinkingBlock
object
4 properties 3 required
ContentBlockStopEvent
object
2 properties 2 required
SignatureDelta
object
2 properties 2 required
CitationsDelta
object
2 properties 2 required
Metadata
object
Optional request metadata passed through to the provider. The userid field helps the provider associate the request with an end user.
1 property
Usage
object
Token counts reported for the request.
8 properties 2 required
DocumentSourceURL
object
2 properties 2 required
ToolChoice
Controls how the model selects tools.
ServerToolUseBlock
object
A built-in tool call (such as websearch or codeexecution) that the provider runs on its own side.
5 properties 4 required
DocumentSourceText
object
3 properties 3 required
PingEvent
object
1 property 1 required
WebSearchToolResultBlock
object
4 properties 3 required
MessageStartEvent
object
2 properties 2 required
MessageDeltaEvent
object
3 properties 3 required
ToolChoiceAuto
object
2 properties 1 required
ToolChoiceNone
object
1 property 1 required
TextBlock
object
4 properties 2 required
ThinkingConfig
Extended thinking configuration.
MessagesResponse
object
Anthropic-native non-streaming Messages API response.
9 properties 6 required
ContentBlock
A content block within a message's content array. Discriminator is type. Strict-typed concrete subtypes cover the full Anthropic Messages API surface; cachecon…
ContentBlockStartEvent
object
3 properties 3 required
ImageBlock
object
3 properties 2 required
DisabledThinkingConfig
object
1 property 1 required
CacheControlEphemeral
object
Marks a caching breakpoint for prompt caching. Attach it to any cacheable element — system text blocks, message content blocks, tool definitions, tooluse, tool…
2 properties 1 required
ToolChoiceAny
object
2 properties 1 required
SearchResultBlock
object
6 properties 2 required
ErrorEvent
object
2 properties 2 required
ImageSource
ServerToolUsage
object
Usage counts for each server-side tool, present when those tools ran during the request.
1 property
DocumentBlock
object
6 properties 2 required
DocumentSourceBase64
object
3 properties 3 required
ToolResultBlock
object
5 properties 2 required

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

nexosai-messages-api-openapi.yml Raw ↑

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#Message
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API Details
ID
nexosai:nexosai-messages-api
Base URL
https://api.nexos.ai
Docs
https://docs.nexos.ai/gateway-api
Provider
nexos.ai
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