fix: SDK strips tags from agent list/retrieve responses

[nouamanecodes]

Bug: SDK strips tags from agent list/retrieve responses

Description

The SDK strips the tags field from agent responses. The REST API correctly returns tags on both GET /v1/agents/ and GET /v1/agents/{id}/, but the SDK's deserialized AgentState objects always have tags: [] regardless of actual tag values.

Steps to Reproduce

1. Create an agent with tags via the SDK (this works correctly):

import Letta from '@letta-ai/letta-client';

const client = new Letta({ baseUrl: 'http://localhost:8283' });

await client.agents.create({
  name: 'test-agent',
  tags: ['tenant:acme', 'role:support'],
  llm_config: { model: 'openai/gpt-4o', context_window: 128000 },
});

2. List agents with tag filter (filter works, but tags are empty in response):

const result = await client.agents.list({ tags: ['tenant:acme'] });
for (const agent of result.items) {
  console.log(agent.name, agent.tags);
  // Output: "test-agent []"    <-- should be ["tenant:acme", "role:support"]
}

3. Retrieve a single agent (same issue):

const agent = await client.agents.retrieve(agentId);
console.log(agent.tags);
// Output: []    <-- should be ["tenant:acme", "role:support"]

Expected Behavior

agent.tags should return ["tenant:acme", "role:support"] — matching the raw API response.

Actual Behavior

agent.tags always returns [] (empty array), despite the REST API returning the correct tags.

Verification

The REST API returns tags correctly:

# List endpoint
curl -s http://localhost:8283/v1/agents/ | python3 -c "
import sys, json
for a in json.load(sys.stdin):
    if a['tags']: print(a['name'], a['tags'])
"
# Output: test-agent ['tenant:acme', 'role:support']

# Retrieve endpoint
curl -s http://localhost:8283/v1/agents/{agent_id}/ | python3 -c "
import sys, json; print(json.load(sys.stdin)['tags'])
"
# Output: ['tenant:acme', 'role:support']

Impact

This blocks any SDK consumer from reading agent tags after creation. Tags can be written (create/update) and used for filtering (list with tags param works), but they cannot be read back from the response objects.

Currently working around this by making a parallel raw HTTP fetch and patching tags onto the SDK response objects.

Environment

• @letta-ai/letta-client: ^1.7.1
• Letta server: self-hosted (0.16.4)
• Node.js: v22
• Platform: Linux

Likely Cause

The SDK's AgentState type definition or response deserializer is not mapping the tags field from the raw JSON response. The field exists on the type (since agent.tags returns [] rather than undefined), but it defaults to an empty array instead of reading from the response payload.