Skip to main content

Hermes Agent

Hindsight memory integration for Hermes Agent. Gives your Hermes agent persistent long-term memory via retain, recall, and reflect tools.

What it does​

This package registers three tools into Hermes via its plugin system:

  • hindsight_retain — Stores information to long-term memory. Hermes calls this when the user shares facts, preferences, or anything worth remembering.
  • hindsight_recall — Searches long-term memory for relevant information. Returns a numbered list of matching memories.
  • hindsight_reflect — Synthesizes a thoughtful answer from stored memories. Use this when you want Hermes to reason over what it knows rather than return raw facts.

These tools appear under the [hindsight] toolset in Hermes's /tools list.

Setup​

1. Install hindsight-hermes into the Hermes venv​

The package must be installed in the same Python environment that Hermes runs in, so the entry point is discoverable.

uv pip install hindsight-hermes --python $HOME/.hermes/hermes-agent/venv/bin/python

2. Set environment variables​

The plugin reads its configuration from environment variables. Set these before launching Hermes:

# Required — tells the plugin where Hindsight is running
export HINDSIGHT_API_URL=http://localhost:8888

# Required — the memory bank to read/write. Think of this as a "brain" for one user or agent.
export HINDSIGHT_BANK_ID=my-agent

# Optional — only needed if using Hindsight Cloud (https://api.hindsight.vectorize.io)
export HINDSIGHT_API_KEY=your-api-key

# Optional — recall budget: low (fast), mid (default), high (thorough)
export HINDSIGHT_BUDGET=mid

If neither HINDSIGHT_API_URL nor HINDSIGHT_API_KEY is set, the plugin silently skips registration — Hermes starts normally without the Hindsight tools.

3. Disable Hermes's built-in memory tool​

Hermes has its own memory tool that saves to local files (~/.hermes/). If both are active, the LLM tends to prefer the built-in one since it's familiar. Disable it so the LLM uses Hindsight instead:

hermes tools disable memory

This persists across sessions. You can re-enable it later with hermes tools enable memory.

4. Start Hindsight API​

Follow the Quick Start guide to get the Hindsight API running, then come back here.

5. Launch Hermes​

hermes

Verify the plugin loaded by typing /tools — you should see:

[hindsight]
  * hindsight_recall     - Search long-term memory for relevant information.
  * hindsight_reflect    - Synthesize a thoughtful answer from long-term memories.
  * hindsight_retain     - Store information to long-term memory for later retrieval.

6. Test it​

Store a memory:

Remember that my favourite colour is red

You should see ⚡ hindsight in the response, confirming it called hindsight_retain.

Recall a memory:

What's my favourite colour?

Reflect on memories:

Based on what you know about me, suggest a colour scheme for my IDE

This calls hindsight_reflect, which synthesizes a response from all stored memories.

Verify via API:

curl -s http://localhost:8888/v1/default/banks/my-agent/memories/recall \
  -H "Content-Type: application/json" \
  -d '{"query": "favourite colour", "budget": "low"}' | python3 -m json.tool

Troubleshooting​

Tools don't appear in /tools​

  1. Check the plugin is installed in the right venv. Run this from the Hermes venv:

    python -c "from hindsight_hermes import register; print('OK')"

  2. Check the entry point is registered:

    python -c "
    import importlib.metadata
    eps = importlib.metadata.entry_points(group='hermes_agent.plugins')
    print(list(eps))
    "

    You should see EntryPoint(name='hindsight', value='hindsight_hermes', group='hermes_agent.plugins').

  3. Check env vars are set. The plugin skips registration silently if HINDSIGHT_API_URL and HINDSIGHT_API_KEY are both unset.

Hermes uses built-in memory instead of Hindsight​

Run hermes tools disable memory and restart. The built-in memory tool and Hindsight tools have overlapping purposes — the LLM will prefer whichever it's more familiar with, which is usually the built-in one.

Bank not found errors​

The plugin auto-creates banks on first use. If you see bank errors, check that the Hindsight API is running and HINDSIGHT_API_URL is correct.

Connection refused​

Make sure the Hindsight API is running and listening on the URL you configured. Test with:

curl http://localhost:8888/health

Manual registration (advanced)​

If you don't want to use the plugin system, you can register tools directly in a Hermes startup script or custom agent:

from hindsight_hermes import register_tools

register_tools(
    bank_id="my-agent",
    hindsight_api_url="http://localhost:8888",
    budget="mid",
    tags=["hermes"],           # applied to all retained memories
    recall_tags=["hermes"],    # filter recall to only these tags
)

This imports tools.registry from Hermes at call time and registers the three tools directly. This approach gives you more control over parameters but requires Hermes to be importable.

Memory instructions (system prompt injection)​

Pre-recall memories at startup and inject them into the system prompt, so the agent starts every conversation with relevant context:

from hindsight_hermes import memory_instructions

context = memory_instructions(
    bank_id="my-agent",
    hindsight_api_url="http://localhost:8888",
    query="user preferences and important context",
    budget="low",
    max_results=5,
)
# Returns:
# Relevant memories:
# 1. User's favourite colour is red
# 2. User prefers dark mode

This never raises — if the API is down or no memories exist, it returns an empty string.

Global configuration (advanced)​

Instead of passing parameters to every call, configure once:

from hindsight_hermes import configure

configure(
    hindsight_api_url="http://localhost:8888",
    api_key="your-key",
    budget="mid",
    tags=["hermes"],
)

Subsequent calls to register_tools() or memory_instructions() will use these defaults if no explicit values are provided.

MCP alternative​

Hermes also supports MCP servers natively. You can use Hindsight's MCP server directly instead of this plugin — no hindsight-hermes package needed:

# In your Hermes config
mcp_servers:
  - name: hindsight
    url: http://localhost:8888/mcp

This exposes the same retain/recall/reflect operations through Hermes's MCP integration. The tradeoff is that MCP tools may have different naming and the LLM needs to discover them, whereas the plugin registers tools with Hermes-native schemas.

Configuration reference​

ParameterEnv VarDefaultDescription
hindsight_api_urlHINDSIGHT_API_URLhttps://api.hindsight.vectorize.ioHindsight API URL
api_keyHINDSIGHT_API_KEY—API key for authentication
bank_idHINDSIGHT_BANK_ID—Memory bank ID
budgetHINDSIGHT_BUDGETmidRecall budget (low/mid/high)
max_tokens—4096Max tokens for recall results
tags——Tags applied when storing memories
recall_tags——Tags to filter recall results
recall_tags_match—anyTag matching mode (any/all/any_strict/all_strict)
toolset—hindsightHermes toolset group name