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C-07 Session Manager

Brick C: Agents, autonomy, execution. French version: C-07-session-manager

1. Role and responsibilities​

Manages conversational sessions (history, user, channel): PostgreSQL for durability, Redis for hot state.

  • Create, list, delete sessions
  • Append and read messages
  • Expire according to the retention policy (E-12)

2. Position in the architecture and interactions​

  • Callers: Channel Gateway (D-13), portal, SDK, Agent Runtime.
  • Execution path: Synchronous.
  • Every interaction goes through the Control Plane API v1 (/v1) behind the API Gateway (D-14).

3. Open source component and developed part​

  • Open source: PostgreSQL, Redis
  • Developed: Session model, write-through Redis cache.
  • External integration through an adapter eai/integrations/<system>.py with an in-process fallback when the URL is not configured.

4. Data model​

Tables (schema eai, tenant_id RLS):

  • eai.sessions
  • eai.session_messages

Common columns: id uuid, tenant_id uuid NOT NULL, created_at, updated_at; RLS policy current_setting('app.tenant_id', true)::uuid.

5. Contract​

  • Applied contract: execution-contract (session_id), memory-contract (scope session)
  • JSON Schema: contracts/v1/execution-contract.schema.json, contracts/v1/memory-contract.schema.json
  • Key fields: session_id, channel, user_id, ttl
  • Validation: POST /v1/contracts/{name}/validate; manifest apply: POST /v1/manifests/apply.

6. API endpoints​

  • GET /v1/sessions
  • POST /v1/sessions
  • GET /v1/sessions/{id}
  • DELETE /v1/sessions/{id}
  • POST /v1/sessions/{id}/messages
  • GET /v1/sessions/{id}/messages

Request POST /v1/sessions/{id}/messages:

{
  "role": "user",
  "content": "Hello, where is my order?"
}

Response:

{
  "message_id": "smsg_12",
  "session_id": "ses_7f2",
  "seq": 5
}

7. SDK examples​

Python:

from enterprise_ai import EnterpriseAI

client = EnterpriseAI(base_url="<control-plane-url>", api_key="eai_xxx_secret")
s = client.sessions.create(agent_id="agt_support")
client.sessions.post_message(s.id, role="user", content="Hello")

TypeScript:

import { EnterpriseAI } from "@enterprise-ai/sdk";

const client = new EnterpriseAI({ baseUrl: "<control-plane-url>", apiKey: process.env.EAI_API_KEY });
const s = await client.sessions.create({ agent_id: "agt_support" });

Java:

EnterpriseAIClient client = EnterpriseAIClient.builder()
    .baseUrl("<control-plane-url>")
    .apiKey(System.getenv("EAI_API_KEY"))
    .build();
JsonNode s = client.sessions().create(Map.of("agent_id", "agt_support"));

Go:

c, _ := eai.NewClient(eai.WithBaseURL("<control-plane-url>"), eai.WithAPIKey(os.Getenv("EAI_API_KEY")))
s, _ := c.Sessions.Create(ctx, map[string]any{"agent_id": "agt_support"})

8. Configuration​

  • Environment variables: EAI_DATABASE_URL
  • Helm values keys: redis.enabled

9. Security controls​

  • Session bound to the principal; read by another user forbidden
  • DLP on inbound messages
  • Every request carries the tenant resolved from the credential; PostgreSQL RLS
  • Every mutation and policy decision writes a hash-chained audit event

10. Observability​

  • Prometheus metrics: eai_sessions_active, eai_session_messages_total
  • Traces: OpenTelemetry spans with GenAI semantic conventions (gen_ai.operation.name, gen_ai.agent.id, gen_ai.tool.name), attributes eai.tenant_id, eai.run_id, traceparent propagation.
  • Audit actions: session.create, session.delete

11. FinOps units​

  • Message storage, Redis cache.
  • Emitted as Usage Event (POST /v1/finops/usage) with tenant, project, agent and run.

12. Failure modes and resilience​

  • Redis down: direct PostgreSQL read
  • Monotonic sequence number
  • Normalized errors (error envelope, message_i18n en/fr)

13. Standalone adoption (client of a client)​

  • enterprise_ai.agent + PostgreSQL (Redis optional).
  • SDK: enterprise_ai.agent (AgentsClient, RunsClient, SessionsClient)
  • Minimal deployment: Helm chart with controlPlane.enabled=true and PostgreSQL; disabled external components use their in-process fallback.

14. Acceptance tests​

  1. Message order preserved
  2. DELETE erases messages and cache
  3. Cross-tenant access refused
  4. Error returned in fr with Accept-Language: fr