sandbox-agent/docs/conversion.md

Universal ↔ Agent Term Mapping

Source of truth: generated agent schemas in resources/agent-schemas/artifacts/json-schema/.

Identifiers

+----------------------+------------------------+------------------------------------------+-----------------------------+------------------------+ | Universal term | Claude | Codex (app-server) | OpenCode | Amp | +----------------------+------------------------+------------------------------------------+-----------------------------+------------------------+ | session_id | n/a (daemon-only) | n/a (daemon-only) | n/a (daemon-only) | n/a (daemon-only) | | native_session_id | none | threadId | sessionID | none | | item_id | synthetic | ThreadItem.id | Message.id | StreamJSONMessage.id | | native_item_id | none | ThreadItem.id | Message.id | StreamJSONMessage.id | +----------------------+------------------------+------------------------------------------+-----------------------------+------------------------+

Notes:

• When a provider does not supply IDs (Claude), we synthesize item_id values and keep native_item_id null.
• native_session_id is the only provider session identifier. It is intentionally used for thread/session/run ids.
• native_item_id preserves the agent-native item/message id when present.
• source indicates who emitted the event: agent (native) or daemon (synthetic).
• raw is always present on events. When clients do not opt-in to raw payloads, raw is null.
• opt-in via include_raw=true on events endpoints (HTTP + SSE).
• If parsing fails, emit agent.unparsed (source=daemon, synthetic=true). Tests must assert zero unparsed events.

Events / Message Flow

+------------------------+------------------------------+--------------------------------------------+-----------------------------------------+----------------------------------+ | Universal term | Claude | Codex (app-server) | OpenCode | Amp | +------------------------+------------------------------+--------------------------------------------+-----------------------------------------+----------------------------------+ | session.started | none | method=thread/started | type=session.created | none | | session.ended | SDKMessage.type=result | no explicit session end (turn/completed) | no explicit session end (session.deleted)| type=done | | message (user) | SDKMessage.type=user | item/completed (ThreadItem.type=userMessage)| message.updated (Message.role=user) | type=message | | message (assistant) | SDKMessage.type=assistant | item/completed (ThreadItem.type=agentMessage)| message.updated (Message.role=assistant)| type=message | | message.delta | synthetic | method=item/agentMessage/delta | type=message.part.updated (delta) | synthetic | | tool call | synthetic from tool usage | method=item/mcpToolCall/progress | message.part.updated (part.type=tool) | type=tool_call | | tool result | synthetic from tool usage | item/completed (tool result ThreadItem variants) | message.part.updated (part.type=tool, state=completed) | type=tool_result | | permission.requested | none | none | type=permission.asked | none | | permission.resolved | none | none | type=permission.replied | none | | question.requested | ExitPlanMode tool (synthetic)| experimental request_user_input (payload) | type=question.asked | none | | question.resolved | ExitPlanMode reply (synthetic)| experimental request_user_input (payload) | type=question.replied / question.rejected | none | | error | SDKResultMessage.error | method=error | type=session.error (or message error) | type=error | +------------------------+------------------------------+--------------------------------------------+-----------------------------------------+----------------------------------+

Synthetics

+------------------------------+------------------------+--------------------------+--------------------------------------------------------------+ | Synthetic element | When it appears | Stored as | Notes | +------------------------------+------------------------+--------------------------+--------------------------------------------------------------+ | session.started | When agent emits no explicit start | session.started event | Mark source=daemon | | session.ended | When agent emits no explicit end | session.ended event | Mark source=daemon; reason may be inferred | | item_id (Claude) | Claude provides no item IDs | item_id | Maintain provider_item_id map when possible | | user message (Claude) | Claude emits only assistant output | item.completed | Mark source=daemon; preserve raw input in event metadata | | question events (Claude) | Plan mode ExitPlanMode tool usage | question.requested/resolved | Synthetic mapping from tool call/result | | native_session_id (Codex) | Codex uses threadId | native_session_id | Intentionally merged threadId into native_session_id | +------------------------------+------------------------+--------------------------+--------------------------------------------------------------+ | message.delta (Claude/Amp) | No native deltas | item.delta | Synthetic delta with full message content; source=daemon | +------------------------------+------------------------+--------------------------+--------------------------------------------------------------+ | message.delta (OpenCode) | part delta before message | item.delta | If part arrives first, create item.started stub then delta | +------------------------------+------------------------+--------------------------+--------------------------------------------------------------+

Delta handling

• Codex emits agent message and other deltas (e.g., item/agentMessage/delta).
• OpenCode emits part deltas via message.part.updated with a delta string.
• Claude and Amp do not emit deltas in their schemas.

Policy:

• Always emit item.delta across all providers.
• For providers without native deltas, emit a single synthetic delta containing the full content prior to item.completed.
• For providers with native deltas, forward as-is; also emit item.completed when final content is known.

Message normalization notes

• user vs assistant: normalized via role in the universal item; provider role fields or item types determine role.
• file artifacts: always represented as content parts (type=file_ref) inside message/tool_result items, not a separate item kind.
• reasoning: represented as content parts (type=reasoning) inside message items, with visibility when available.
• subagents: OpenCode subtask parts and Claude Task tool usage are currently normalized into standard message/tool flow (no dedicated subagent fields).
• OpenCode unrolling: message.updated creates/updates the parent message item; tool-related parts emit separate tool item events (item.started/ item.completed) with parent_id pointing to the message item.
• If a message.part.updated arrives before message.updated, we create a stub item.started (source=daemon) so deltas have a parent.
• Tool calls/results are always emitted as separate tool items to keep behavior consistent across agents.