diff --git a/kontext/agent/v1/agent.proto b/kontext/agent/v1/agent.proto
index 1970f89..a0b16c5 100644
--- a/kontext/agent/v1/agent.proto
+++ b/kontext/agent/v1/agent.proto
@@ -2,36 +2,30 @@ syntax = "proto3";
 
 package kontext.agent.v1;
 
-// AgentService is the bidirectional streaming service between the CLI sidecar
-// and the Kontext backend. The sidecar maintains a persistent connection and
-// streams hook events for policy evaluation and telemetry.
+// AgentService handles session lifecycle and hook event streaming
+// between the CLI sidecar and the Kontext backend.
+//
+// Authentication: the user's OIDC bearer token from `kontext login`.
+// The backend verifies the JWT and derives org + user identity.
+//
+// Credential exchange uses the existing OAuth token exchange endpoint
+// (POST /oauth2/token, RFC 8693) — not this service.
 service AgentService {
   // ProcessHookEvent streams tool call events from the CLI to the backend
   // and receives policy decisions in return. Bidirectional streaming keeps
-  // the connection open for the session lifetime — no per-hook HTTP overhead.
+  // the connection open for the session lifetime.
   rpc ProcessHookEvent(stream ProcessHookEventRequest) returns (stream ProcessHookEventResponse);
 
   // CreateSession establishes a governed agent session. Called once at the
-  // start of `kontext start`. Returns session context used for all subsequent
-  // hook evaluations.
+  // start of `kontext start`.
   rpc CreateSession(CreateSessionRequest) returns (CreateSessionResponse);
 
   // Heartbeat keeps the session alive. The sidecar sends heartbeats on an
   // interval; the backend marks sessions as disconnected if heartbeats stop.
   rpc Heartbeat(HeartbeatRequest) returns (HeartbeatResponse);
 
-  // EndSession terminates the session and revokes any ephemeral credentials.
+  // EndSession terminates the session.
   rpc EndSession(EndSessionRequest) returns (EndSessionResponse);
-
-  // ExchangeCredential resolves a provider credential for a given user and
-  // provider handle. Used by the env template hydration and per-tool-call
-  // credential injection.
-  rpc ExchangeCredential(ExchangeCredentialRequest) returns (ExchangeCredentialResponse);
-
-  // SyncPolicy streams the current policy state for the session's org/agent.
-  // The sidecar caches this locally for fast hook evaluation. The server
-  // pushes updates when policy changes.
-  rpc SyncPolicy(SyncPolicyRequest) returns (stream SyncPolicyResponse);
 }
 
 // --- Hook Events ---
@@ -51,8 +45,6 @@ message ProcessHookEventResponse {
   Decision decision = 1;
   string reason = 2;
   string event_id = 3;
-  // Credential to inject for this tool call (if applicable)
-  CredentialInjection credential = 4;
 }
 
 enum Decision {
@@ -62,11 +54,6 @@ enum Decision {
   DECISION_ASK = 3; // Prompt user for approval
 }
 
-message CredentialInjection {
-  string provider = 1;
-  map<string, string> env_vars = 2; // e.g., {"GITHUB_TOKEN": "gho_..."}
-}
-
 // --- Sessions ---
 
 message CreateSessionRequest {
@@ -95,45 +82,3 @@ message EndSessionRequest {
 }
 
 message EndSessionResponse {}
-
-// --- Credentials ---
-
-message ExchangeCredentialRequest {
-  string provider = 1; // e.g., "github", "stripe", "postgres"
-  string user_id = 2;
-  string resource = 3; // optional: specific resource URI
-}
-
-message ExchangeCredentialResponse {
-  string provider = 1;
-  CredentialKind kind = 2;
-  string access_token = 3; // for OAuth providers
-  string value = 4; // for API key providers
-  string token_type = 5;
-  string scope = 6;
-  int64 expires_in = 7; // seconds
-}
-
-enum CredentialKind {
-  CREDENTIAL_KIND_UNSPECIFIED = 0;
-  CREDENTIAL_KIND_OAUTH = 1;
-  CREDENTIAL_KIND_KEY = 2;
-}
-
-// --- Policy Sync ---
-
-message SyncPolicyRequest {
-  string session_id = 1;
-}
-
-message SyncPolicyResponse {
-  // OpenFGA tuples for local evaluation
-  repeated PolicyTuple tuples = 1;
-  bool full_sync = 2; // true = replace all, false = incremental
-}
-
-message PolicyTuple {
-  string user = 1;
-  string relation = 2;
-  string object = 3;
-}