Summary

Self-hosted Honcho memory silently fails to initialize when using ghcr.io/plastic-labs/honcho:latest (currently v3.0.5), because the honcho-ai SDK bundled in the Hermes image is 2.1.0, which is incompatible with the v3 API.

What happens

Hermes logs on every startup:

WARNING plugins.memory.honcho: Honcho init failed: An unexpected error occurred

No memory is saved or retrieved across sessions.

Root cause

The Honcho server v3.x exposes a /v3/ API with a different resource shape. The honcho-ai 2.1.0 SDK calls a v2-era API — specifically, h.workspaces is a bound method in 2.x, not a resource object, so h.workspaces.get_or_create() raises:

AttributeError: 'function' object has no attribute 'get_or_create'

Confirmed by running inside the hermes container:

from honcho import Honcho
h = Honcho(base_url='http://honcho-api:8000')
h.workspaces.get_or_create(name='hermes')
# AttributeError: 'function' object has no attribute 'get_or_create'

Versions

• nousresearch/hermes-agent:latest — honcho-ai 2.1.0
• ghcr.io/plastic-labs/honcho:latest — Honcho server 3.0.5
• pyproject.toml in this repo: honcho = ["honcho-ai>=2.0.1,<3"]

Attempted workaround

Pinning Honcho server to v2.5.1 resolves the SDK mismatch but introduces a separate incompatibility: v2.5.1 rejects EMBEDDING_PROVIDER=openrouter (only openai/gemini accepted), which the latest Hermes honcho.env.secret template uses.

Expected fix

Update the honcho-ai dependency in Hermes to >=3.0.0 and update the Honcho plugin code to match the v3 SDK API. The Honcho server latest tag should be the target.