Agentica Server + Claude Proxy Setup

Complete reference for running Agentica SDK with a local Claude proxy. This enables Python agents to use Claude CLI as their inference backend.

When to Use

Use this skill when: - Starting Agentica development with Claude proxy - Debugging connection issues between SDK, server, and proxy - Setting up a fresh Agentica environment - Troubleshooting agent tool access or hallucination issues

Architecture

Agentica SDK (client code)
    | S_M_BASE_URL=http://localhost:2345
    v
ClientSessionManager
    |
    v
Agentica Server (agentica-server)
    | INFERENCE_ENDPOINT_URL=http://localhost:8080/v1/chat/completions
    v
Claude Proxy (claude_proxy.py)
    |
    v
Claude CLI (claude -p)

Environment Variables

KEY: These are NOT the same endpoint! - SDK connects to server (port 2345) - Server connects to proxy (port 8080)

Startup Sequence

Must start in this order (each in a separate terminal):

Terminal 1: Claude Proxy

uv run python scripts/agentica/claude_proxy.py --port 8080

Terminal 2: Agentica Server

MUST run from its directory:

cd workspace/agentica-research/agentica-server
INFERENCE_ENDPOINT_URL=http://localhost:8080/v1/chat/completions uv run agentica-server --port 2345

Terminal 3: Your Agent Script

S_M_BASE_URL=http://localhost:2345 uv run python scripts/agentica/your_script.py

Health Checks

# Claude proxy health
curl http://localhost:8080/health

# Agentica server health
curl http://localhost:2345/health

Common Errors & Fixes

1. APIConnectionError after agent spawn

Symptom: Agent spawns successfully but fails on first call with connection error.

Cause: Claude proxy returning plain JSON instead of SSE format.

Fix: Proxy must return Server-Sent Events format:

data: {"choices": [...]}\n\n

2. ModuleNotFoundError for agentica-server

Symptom: ModuleNotFoundError: No module named 'agentica_server'

Cause: Running uv run agentica-server from wrong directory.

Fix: Must cd workspace/agentica-research/agentica-server first.

3. Agent can't use Read/Write/Edit tools

Symptom: Agent asks for file contents instead of reading them.

Cause: Missing --allowedTools in claude_proxy.py CLI call.

Fix: Proxy must pass tool permissions:

claude -p ... --allowedTools Read Write Edit Bash

4. Agent claims success but didn't do task

Symptom: Agent says "I've created the file" but file doesn't exist.

Cause: Hallucination - agent describing intended actions without executing.

Fix: Added emphatic anti-hallucination prompt in REPL_BASELINE:

CRITICAL: Use ACTUAL tools. Never DESCRIBE using tools.

5. Timeout on agent.call()

Symptom: Call hangs for 30+ seconds then times out.

Cause: Claude CLI taking too long or stuck in a loop.

Fix: Check proxy logs for the actual CLI output. May need to simplify prompt.

Key Files

Quick Verification

Test the full stack:

# 1. Verify proxy responds
curl http://localhost:8080/health

# 2. Verify server responds
curl http://localhost:2345/health

# 3. Test inference through proxy
curl http://localhost:8080/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{"model":"claude","messages":[{"role":"user","content":"Say hello"}]}'

Checklist

Before running agents: - [ ] Claude proxy running on port 8080 - [ ] Agentica server running on port 2345 (from its directory) - [ ] S_M_BASE_URL set for client scripts - [ ] INFERENCE_ENDPOINT_URL set for server - [ ] Both health checks return 200