Core data types for the Agent-to-Agent (A2A) protocol. More...

#include <neograph/api.h>
#include <neograph/json.h>
#include <optional>
#include <string>
#include <vector>

Include dependency graph for types.h:

This graph shows which files directly or indirectly include this file:

Classes
struct	neograph::a2a::AgentCard
	Subset of AgentCard required to interact (spec §5.5). More...

struct	neograph::a2a::AgentInterface
	One protocol binding + version + URL an agent exposes (1.0 `AgentInterface`; 0.3 cards contribute `additionalInterfaces` entries). More...

struct	neograph::a2a::AgentSkill
	One capability the agent advertises (1.0 `AgentSkill`). More...

struct	neograph::a2a::Artifact
	Generated output (spec §6.7). More...

struct	neograph::a2a::Message
	A single conversational turn (spec §6.4). More...

struct	neograph::a2a::MessageSendConfiguration
	Optional knobs for `message/send` (spec §7.2). More...

struct	neograph::a2a::MessageSendParams
	Params object for `message/send` and `message/stream`. More...

struct	neograph::a2a::Part
	One content fragment of a Message or Artifact. More...

struct	neograph::a2a::StreamEvent
	Tagged union over the two streaming event types + the terminal Task message. More...

struct	neograph::a2a::Task
	A unit of work tracked by the agent (spec §6.1). More...

struct	neograph::a2a::TaskStatus
	Status snapshot of a running Task (spec §6.5). More...

struct	neograph::a2a::TaskStatusUpdateEvent
	SSE event emitted by `message/stream` and `tasks/resubscribe` while a Task is running. More...

Enumerations
enum class	neograph::a2a::Role
	Message role (spec §6.4).

enum class	neograph::a2a::TaskState
	TaskState — kebab-case strings on the 0.3 wire, `TASK_STATE_*` on 1.0.

enum class	neograph::a2a::WireDialect
	A2A wire dialect — the JSON encoding of the data model. More...

Functions
NEOGRAPH_API StreamEvent	neograph::a2a::parse_stream_event (const json &j)
	Parse a single SSE `data: {...}` JSON object into the right variant.

NEOGRAPH_API Role	neograph::a2a::role_from_string (std::string_view s)
	Accepts both `user`/`agent` (0.3) and `ROLE_USER`/`ROLE_AGENT` (1.0).

NEOGRAPH_API Task	neograph::a2a::task_from_result (const json &result)
	Coerce a `SendMessage` / `message/send` / `GetTask` / `CancelTask` result into a Task.

NEOGRAPH_API TaskState	neograph::a2a::task_state_from_string (std::string_view s)
	Accepts both the kebab-case (0.3) and `TASK_STATE_*` (1.0) spellings.

NEOGRAPH_API void	neograph::a2a::to_json (json &j, const AgentCard &c)
	The card a 0.3 reader receives: the 0.3 fields plus the 1.0 `supportedInterfaces` when the card lists them.

NEOGRAPH_API void	neograph::a2a::to_json (json &j, const AgentCard &c, WireDialect dialect)
	One card per protocol version.

Detailed Description

Core data types for the Agent-to-Agent (A2A) protocol.

Mirrors the canonical proto / JSON schema at https://github.com/a2aproject/A2A (specification/a2a.proto).

Only the surface needed by the client is modelled here. The wire format is JSON; structs round-trip through nlohmann::json via to_json/from_json ADL hooks defined in src/a2a/types.cpp.

Definition in file types.h.

Enumeration Type Documentation

◆ WireDialect

enum class neograph::a2a::WireDialect

strong

A2A wire dialect — the JSON encoding of the data model.

V0_3: A2A 0.3 JSON Schema form. kind discriminators on Message / Task / Part / stream events, lower-case role (user, agent) and kebab-case task states (input-required), slash-form JSON-RPC methods (message/send), FilePart.file = {bytes|uri, mimeType, name}.
V1_0: A2A 1.0 protobuf ProtoJSON form (lf.a2a.v1). No kind discriminators, flat Parts ({"text"} / {"raw"|"url", "filename", "mediaType"} / {"data"}), ROLE_USER / TASK_STATE_WORKING enums, PascalCase methods (SendMessage) and {"task"} / {"message"} / {"statusUpdate"} / {"artifactUpdate"} result wrappers.

Serialisation is dialect-selected (to_json(j, value, dialect)); the two-argument to_json overloads emit V0_3. Parsing (from_json) is dialect-tolerant and accepts either encoding.

Definition at line 40 of file types.h.

Function Documentation

◆ parse_stream_event()

NEOGRAPH_API StreamEvent neograph::a2a::parse_stream_event ( const json & j )

Parse a single SSE data: {...} JSON object into the right variant.

1.0 status updates carry no final flag; it is derived from the state (terminal or interrupted => final), matching the spec's stream-close rule.

References neograph::a2a::parse_stream_event().

Referenced by neograph::a2a::parse_stream_event().

◆ task_from_result()

NEOGRAPH_API Task neograph::a2a::task_from_result ( const json & result )

Coerce a SendMessage / message/send / GetTask / CancelTask result into a Task.

Accepts the 1.0 wrappers ({"task"} / {"message"}), the 0.3 kind-discriminated objects, and a bare 1.0 Task (object with id + status). A Message becomes a Completed Task carrying it as status.message and history. Null yields a Failed Task; anything unrecognised yields an Unknown Task with the payload in metadata.

References neograph::a2a::task_from_result().

Referenced by neograph::a2a::task_from_result().

◆ to_json() [1/2]

NEOGRAPH_API void neograph::a2a::to_json	(	json &	j,
		const AgentCard &	c
	)

The card a 0.3 reader receives: the 0.3 fields plus the 1.0 supportedInterfaces when the card lists them.

A card with raw set is emitted verbatim.

◆ to_json() [2/2]

NEOGRAPH_API void neograph::a2a::to_json	(	json &	j,
		const AgentCard &	c,
		WireDialect	dialect
	)

One card per protocol version.

V1_0 emits a pure 1.0 AgentCard (no 0.3 fields, non-empty skill tags, capabilities.extendedAgentCard); V0_3 is the two-argument form. A card with raw set is emitted verbatim.

Classes

Enumerations

Functions