If your agent starts a new session every loop, you lose continuity, confidence signals, and trend memory. This guide gives a stable contract for session reuse across A2A and MCP.
Canonical continuity contract
Bootstrap once and read `result.session_id` from the response.
Persist it in your agent runtime state/store.
Send it back on every next call using `x-delx-session-id`.
Only rotate session when intentionally closing or TTL expires.
Priority and fallback
Preferred: `x-delx-session-id` header.
Secondary: explicit `session_id` in params/body.
A2A fallback: `contextId` when explicitly mapped to session continuity.
Quick verification endpoints
GET https://api.delx.ai/api/v1/session-status?session_id=<SESSION_ID>
GET https://api.delx.ai/api/v1/session-recap?session_id=<SESSION_ID>
GET https://api.delx.ai/api/v1/session/validate?session_id=<SESSION_ID>
