# AG-UI CURRENT_STATUS: UNKNOWN OBSERVATION: SPEC_ONLY FRESHNESS: UNKNOWN PAGE_TYPE: reference CANONICAL_URL: /tools/ea-159-ag-ui CLAIM_IDS: none EVIDENCE_IDS: EVD-EA-159-URL-D203E8FD41A4, EVD-EA-159-URL-7E888B93B8A0, EVD-EA-159-URL-6591BA851A2D, EVD-EA-159-URL-10A12ACB9645, EA-159-R11-RESEARCH, EA-159-R11-WEB-READBACK UNKNOWN_IDS: EA-159-UNKNOWN-01, EA-159-UNKNOWN-CURRENTNESS OPS_IDS: none ## Summary 「AG-UIは、agentic backendとユーザー向けfrontendの間を、HTTP／WebSocket等の上にイベント駆動・双方向で接続するプロトコルである。イベント仕様1.0は当該資料でDraftと表示されているため、採用時は版・SDK・再接続・認可・表示安全性を個別に確認する。」 ## Current judgment 1. ESTABLISHED [S1 support]: AG-UI describes itself as an open, lightweight, event-based protocol for connecting AI agents to user-facing applications, designed as a general-purpose bi-directional connection between frontend and agentic backend. 2. ESTABLISHED [S1+S2 support]: The documentation places AG-UI at the agent↔user interaction layer and distinguishes it from MCP (agent↔tools/data) and A2A (agent↔agent). The architecture is described as building on web foundations such as HTTP and WebSockets. 3. ESTABLISHED [S1 support]: The documentation says the protocol carries agent state, UI intents, and user interactions; it also describes streaming tool results/logs and custom events as part of the interaction surface. 4. ESTABLISHED [S3 limit]: The event documentation labels the 1.0 specification as Draft and documents event changes/deprecations. Therefore the stable interoperability claim must be version-qualified. 5. INFERENCE [S1-S4]: AG-UI can reduce ad-hoc frontend/backend wiring for long-running, stateful agent interactions, but the protocol description does not establish that a UI is safe, that an event is authorized, or that a streamed tool result is correct. ## Scope interoperability / implementation / Enterprise AI Core / UI boundary / governance / security ## Confirmed - ESTABLISHED [S1 support]: AG-UI describes itself as an open, lightweight, event-based protocol for connecting AI agents to user-facing applications, designed as a general-purpose bi-directional connection between frontend and agentic backend. - ESTABLISHED [S1+S2 support]: The documentation places AG-UI at the agent↔user interaction layer and distinguishes it from MCP (agent↔tools/data) and A2A (agent↔agent). The architecture is described as building on web foundations such as HTTP and WebSockets. - ESTABLISHED [S1 support]: The documentation says the protocol carries agent state, UI intents, and user interactions; it also describes streaming tool results/logs and custom events as part of the interaction surface. - ESTABLISHED [S3 limit]: The event documentation labels the 1.0 specification as Draft and documents event changes/deprecations. Therefore the stable interoperability claim must be version-qualified. - INFERENCE [S1-S4]: AG-UI can reduce ad-hoc frontend/backend wiring for long-running, stateful agent interactions, but the protocol description does not establish that a UI is safe, that an event is authorized, or that a streamed tool result is correct. ## UNKNOWN - EA-159-UNKNOWN-01: stable release and governance; SDK parity; event ordering/replay/idempotency; auth and user-consent profile; browser security guidance; accessibility; cross-framework compatibility; production incident history; cost/SLO. - EA-159-UNKNOWN-CURRENTNESS: 外部根拠の再確認日がcanonical body/control-planeで確定していないため、currentnessはUNKNOWNとして保持する。日付を推測補完しない。 ## Evidence - EVD-EA-159-URL-D203E8FD41A4 (RESEARCH): Agent User Interaction Protocol | AUTHOR_ORG: AG-UI project | CANONICAL_URL: — https://docs.ag-ui.com/introduction - EVD-EA-159-URL-7E888B93B8A0 (RESEARCH): AG-UI | AUTHOR_ORG: AG-UI project | CANONICAL_URL: — https://docs.ag-ui.com/concepts/architecture - EVD-EA-159-URL-6591BA851A2D (RESEARCH): AG-UI | AUTHOR_ORG: AG-UI project | CANONICAL_URL: — https://docs.ag-ui.com/concepts/events - EVD-EA-159-URL-10A12ACB9645 (RESEARCH): Agent User Interaction Protocol | AUTHOR_ORG: ag-ui-protocol | CANONICAL_URL: — https://github.com/ag-ui-protocol/ag-ui - EA-159-R11-RESEARCH (RESEARCH): EA-159 監査済みresearch / canonical revision binding - EA-159-R11-WEB-READBACK (IMPL): EA-159 Web body identity / canonical readback ## Failure / limits Documentation is not proof of adoption or cross-implementation compatibility. Draft event semantics may change; frontend and backend may disagree on event ordering, replay, reconnect, cancellation, or schema. HTTP/WebSockets transport does not provide agent authorization or user-consent semantics by itself. No independent UI reliability, accessibility, security, latency, or event-conformance benchmark was adopted. ## Failure / limits Do not present AG-UI Draft events as a finalized universal standard. Do not claim that an event stream authorizes a tool action, proves backend correctness, or safely exposes all agent state. UNIT_CLOSE_STATUS: INDIVIDUAL_BOUNDED_CLOSE / EVIDENCE_RECORDED / UNKNOWN_PRESERVED ## Practice AG-UI event/spec version; frontend/backend SDK release; transport choice; auth/session/tenant binding; event schema and custom-event policy; reconnect/replay behavior; browser/CSP/origin policy; tool-result redaction; user approval mechanism; state persistence; region/data handling; observability and retention. ## Practice Evidence-only desk research. No AG-UI SDK, browser session, WebSocket, event stream, or user-facing application was run. ## Practice No event-conformance, reconnect, ordering, latency, accessibility, UI safety, or cross-framework benchmark was run. ## Practice UI events may contain prompts, tool arguments/results, identity, and business data; classify/redact before client delivery. Audit should link user/session, agent run, event sequence, approval, tool call, and rendered action. Reconnect and duplicate events require sequence/idempotency policy. Cost/operability must count long-lived connections, streamed tokens/events, retries, and frontend failure; not measured. ## Practice Future update Work should pin the event specification and SDK commits, then test text/state/tool-result/custom events under reconnect, duplicate, out-of-order, cancellation, partial failure, approval, redaction, and browser-origin controls. Preserve the layer distinction from MCP and A2A. ## WHY_THIS_MATTERS_TO_UPDATE AG-UI addresses the user-facing boundary that is often incorrectly merged with agent-to-tool or agent-to-agent protocols. It is relevant to future updates on streaming, interactive approval, state visibility, and frontend auditability. ## SCOPE_ROUTING interoperability / implementation / Enterprise AI Core / UI boundary / governance / security ## CLAIM_OR_RESEARCH_QUESTION What does AG-UI claim to standardize between an agentic frontend and backend, what is its maturity boundary, and what remains application-specific? ## EVIDENCE_TABLE [S1] SOURCE_CLASS: official_project_docs | EXACT_TITLE: AG-UI Overview - Agent User Interaction Protocol | AUTHOR_ORG: AG-UI project | CANONICAL_URL: https://docs.ag-ui.com/introduction | PUBLICATION_UPDATE_ACCESS: current documentation accessed 2026-09-14 00:10 JST | VERSION_RELEASE_TAG: page does not expose a stable release pin | SUPPORTING_LOCATOR: overview lines 20-27 and agentic-protocol distinction lines 35-39 | EVIDENCE_LABEL: VERIFIED_SPEC + PRODUCT_VOLATILE | RELATION: support for protocol scope; limit for release pin and security guarantees. [S2] SOURCE_CLASS: official_project_docs | EXACT_TITLE: Architecture - AG-UI | AUTHOR_ORG: AG-UI project | CANONICAL_URL: https://docs.ag-ui.com/concepts/architecture | PUBLICATION_UPDATE_ACCESS: current documentation accessed 2026-09-14 00:10 JST | VERSION_RELEASE_TAG: unpinned current docs | SUPPORTING_LOCATOR: architecture page describing event-driven connection between frontend and agents; current page boundary recorded | EVIDENCE_LABEL: VERIFIED_SPEC + PRODUCT_VOLATILE | RELATION: support/context; limit for maturity. [S3] SOURCE_CLASS: official_project_docs | EXACT_TITLE: Events - AG-UI | AUTHOR_ORG: AG-UI project | CANONICAL_URL: https://docs.ag-ui.com/concepts/events | PUBLICATION_UPDATE_ACCESS: current documentation accessed 2026-09-14 00:10 JST | VERSION_RELEASE_TAG: 1.0 Specification (Draft); TypeScript/Python/.NET SDK references; deprecated events removed in 1.0 per page | SUPPORTING_LOCATOR: events page maturity/version note and event catalog | EVIDENCE_LABEL: VERIFIED_SPEC + PRODUCT_VOLATILE | RELATION: support for event surface; limit because 1.0 is explicitly draft. [S4] SOURCE_CLASS: author_maintained_repo | EXACT_TITLE: ag-ui - Agent User Interaction Protocol | AUTHOR_ORG: ag-ui-protocol | CANONICAL_URL: https://github.com/ag-ui-protocol/ag-ui | PUBLICATION_UPDATE_ACCESS: repository accessed 2026-09-14 00:10 JST | VERSION_RELEASE_TAG: default branch not pinned | SUPPORTING_LOCATOR: repository description identifying AG-UI as open, lightweight, event-based protocol | EVIDENCE_LABEL: OSS_PRACTICE + PRODUCT_VOLATILE | RELATION: implementation context; limit because default branch is mutable. ## FINDINGS 1. ESTABLISHED [S1 support]: AG-UI describes itself as an open, lightweight, event-based protocol for connecting AI agents to user-facing applications, designed as a general-purpose bi-directional connection between frontend and agentic backend. 2. ESTABLISHED [S1+S2 support]: The documentation places AG-UI at the agent↔user interaction layer and distinguishes it from MCP (agent↔tools/data) and A2A (agent↔agent). The architecture is described as building on web foundations such as HTTP and WebSockets. 3. ESTABLISHED [S1 support]: The documentation says the protocol carries agent state, UI intents, and user interactions; it also describes streaming tool results/logs and custom events as part of the interaction surface. 4. ESTABLISHED [S3 limit]: The event documentation labels the 1.0 specification as Draft and documents event changes/deprecations. Therefore the stable interoperability claim must be version-qualified. 5. INFERENCE [S1-S4]: AG-UI can reduce ad-hoc frontend/backend wiring for long-running, stateful agent interactions, but the protocol description does not establish that a UI is safe, that an event is authorized, or that a streamed tool result is correct. ## LIMITS / COUNTEREVIDENCE / FAILURE ENVELOPE Documentation is not proof of adoption or cross-implementation compatibility. Draft event semantics may change; frontend and backend may disagree on event ordering, replay, reconnect, cancellation, or schema. HTTP/WebSockets transport does not provide agent authorization or user-consent semantics by itself. No independent UI reliability, accessibility, security, latency, or event-conformance benchmark was adopted. ## AVAILABILITY_GATES AG-UI event/spec version; frontend/backend SDK release; transport choice; auth/session/tenant binding; event schema and custom-event policy; reconnect/replay behavior; browser/CSP/origin policy; tool-result redaction; user approval mechanism; state persistence; region/data handling; observability and retention. ## IMPLEMENTATION_STATE Evidence-only desk research. No AG-UI SDK, browser session, WebSocket, event stream, or user-facing application was run. ## BENCHMARK_OR_EVAL No event-conformance, reconnect, ordering, latency, accessibility, UI safety, or cross-framework benchmark was run. ## SECURITY / PRIVACY / AUDIT / COST / OPERABILITY UI events may contain prompts, tool arguments/results, identity, and business data; classify/redact before client delivery. Audit should link user/session, agent run, event sequence, approval, tool call, and rendered action. Reconnect and duplicate events require sequence/idempotency policy. Cost/operability must count long-lived connections, streamed tokens/events, retries, and frontend failure; not measured. ## SAFE_WORDING_FOR_FUTURE_BOOK 「AG-UIは、agentic backendとユーザー向けfrontendの間を、HTTP／WebSocket等の上にイベント駆動・双方向で接続するプロトコルである。イベント仕様1.0は当該資料でDraftと表示されているため、採用時は版・SDK・再接続・認可・表示安全性を個別に確認する。」 ## UPDATE_WORK_HANDOFF Future update Work should pin the event specification and SDK commits, then test text/state/tool-result/custom events under reconnect, duplicate, out-of-order, cancellation, partial failure, approval, redaction, and browser-origin controls. Preserve the layer distinction from MCP and A2A. ## OPEN_UNKNOWN stable release and governance; SDK parity; event ordering/replay/idempotency; auth and user-consent profile; browser security guidance; accessibility; cross-framework compatibility; production incident history; cost/SLO. ## STOP_CONDITION Do not present AG-UI Draft events as a finalized universal standard. Do not claim that an event stream authorizes a tool action, proves backend correctness, or safely exposes all agent state. UNIT_CLOSE_STATUS: INDIVIDUAL_BOUNDED_CLOSE / EVIDENCE_RECORDED / UNKNOWN_PRESERVED ## EVIDENCE PACKET --- NEXT: /agent/start.json STOP: This is a knowledge projection, not an execution order.