Article summary — original
Hugging Face Introduces funes: A Durable Local Memory Layer for Coding Agents
Hugging Face has released funes, an open-source tool that provides coding agents like Claude Code, Codex, pi, and Hermes with persistent memory derived from past session traces. Operating as a single binary with local embedding and reranking, funes enables agents to index, search, and recall past decisions across different sessions, machines, and agent platforms.
funes indexes local agent traces into a Lance dataset using local embeddings and cross-encoder reranking, without hosted ML runtime dependencies.
Memories can sync across machines as Hugging Face datasets, which are private by default and feature automated credential redaction.
Cross-agent compatibility allows different tools—such as Claude Code and Codex—to query and build upon the same historical execution records.
On the handoff-vs-recall benchmark, retrieval via recall was 4x to 8x cheaper than written handoffs and avoided failure modes seen in context compaction.
Architecture and Local Integration
funes operates as a single binary that plugs directly into existing agents via an 'add' command. Its deterministic pipeline parses execution traces from Claude Code, Codex, pi, and Hermes into standardized turns and blocks, embedding them locally and storing them in an append-only Lance dataset. When an agent queries its history, funes executes a combined BM25 and vector search, fuses the candidate rankings, reranks them using a local cross-encoder, and adjusts for recency. Raw source traces are preserved rather than summarized into distilled facts, ensuring results link directly back to the exact turn and session where a decision was made.
Cross-Host Synchronization and Security
Local memories can be bound to Hugging Face datasets to synchronize across machines and team members. In this configuration, funes performs incremental indexing locally and pushes updates at session boundaries. Remote datasets are cached on local disk so subsequent queries maintain local latency. Security measures include stripping credentials during initial indexing, followed by a secondary scanning pass before any data is published to the Hugging Face Hub.
Standalone Queries and Benchmark Efficiency
For ad-hoc queries outside an active agent session, the read-only 'funes ask' command enables direct retrieval against local or public repository memories without modifying persistent agent setups. In empirical evaluations on the handoff-vs-recall benchmark, recall proved significantly more cost-effective than writing manual handoffs—reducing costs by 4x on one task and 8x on another. Additionally, recall avoided the failure observed in standard context compaction, where aggressive summarization dropped critical project details required to solve subsequent tasks.
Saved original article
I work across several machines, and I switch coding agents depending on the task.
Every one of them meets my projects as a stranger. The reasoning from “last Tuesday”
disappears when the session ends. Each new agent, on each new host, starts from zero.
Earlier this year,
Software Forgets: Agent Traces Are the
Memory
made the case
that coding agents already produce the record we keep losing. As they search a
codebase, try approaches, hit errors, read documentation, and change direction, they
leave behind a dense account of not just
what
changed, but
why
.
While the diagnosis is correct, traces are only potential memory. The session logs of
an agent are still just an archive. You cannot
grep
your way to
“why did we move
off the streaming parser?”
across ten thousand turns. For an agent to use those traces
while it works, they need indexing, retrieval, ranking, and exact provenance.
That is what
funes
provides. It is a durable
memory layer for your agents (Claude Code, Codex, pi, and Hermes). It is built from the
sessions already on your machine. It works locally and becomes part of your agent's
normal workflow with one command. When you want it to, it can also travel to a Hugging
Face dataset you own, private by default.
Add memory to the agent you already use
funes is a single binary. Its default inference backend has no ML runtime dependency,
and embedding and reranking happen
on your machine
. Install it:
curl -fsSL https://huggingface.co/buckets/huggingface/funes/resolve/install.sh | sh
Then add it to an agent:
funes add claude
# or: codex, pi, hermes
That one
add
command builds the first index, gives the agent
recall
and
get
tools, and installs the automation that indexes each completed turn. Indexing is
incremental, with new runs adding new turns rather than embedding the whole history
again. The older and deeper content can backfill in bounded steps.
From there, you just work. When a task touches a past decision, rationale, or finding,
the agent can reach for
recall
itself. You do not need to remember the old session or
paste its context into the new one.
With funes added, recall happens inside the conversation. The agent reaches for its
memory on its own and names the session behind its answer.
recall
returns the original text, not a summary, and shows exactly where it came from
(the agent, timestamp, session, and turn). Each result includes a
get
command that
opens the full turn and its surrounding context.
Underneath, one deterministic pipeline parses every supported trace into the same
turn-and-block shape, chunks it, embeds it with a pinned local model, and writes it to
a local
Lance
dataset. A query combines vector and BM25 search, fuses their
rankings, reranks the candidates with a cross-encoder, reweights them by recency, and
attaches neighboring chunks.
That design gives funes three important properties:
One memory across agents:
Claude Code, Codex, pi, and Hermes all write to the
same shape.
recall
spans their histories, and every hit says which agent produced
it.
Raw evidence stays intact:
Nothing is distilled into a fact at write time. A
result can always lead back to the turn that produced it.
recall
is local by default:
No account or Hub repository is required. A hosted
model does not process your sessions for indexing; embedding and reranking run on
your machine, and your coding agent does the reasoning.
The
agent as a stranger
problem is already solved on one machine. But memory gets
more useful when the next agent is running somewhere else.
A memory is a dataset, not a service
To make a memory follow your work, bind one when you add funes to an agent:
funes add codex acme/funes-memory
The bind publishes your current memory there. funes then keeps it current, indexing
each turn locally and publishing at session boundaries. The agent recalls from it
throughout. Run the same command on another machine and the memory follows you there.
Underneath, the local memory is a Lance dataset, and the shared memory is a Hugging
Face dataset (private by default) you own.
Before anything reaches the Hub, credentials have already been redacted during
indexing. Publishing then scans every chunk again and withholds anything that still
looks like a secret. The scanner behind this is documented in
SECURITY.md
, including
what it does and doesn't cover.
When an agent reads a remote memory, funes caches the dataset files locally, so warm
queries return to local speed. The Hub supplies the ownership, access control,
versioning, and distribution it already supplies for other datasets. Your memory does
not become an account in a separate memory service, and you do not rent it back
through an API.
Ask first, wire later
recall
is shaped for agents. When you want to put a question to a memory yourself,
use
ask
. It reads your local memory by default:
funes ask claude
"what did we decide about the streaming parser"
Or point it at a shared memory. We published a
memory
of funes development,
so you can ask why funes works the way it does without creating a memory of your own:
funes ask claude
"why is funes append-only"
--memory huggingface/funes-memory
funes ask
is the read-only, one-question sibling of
funes add
. It recalls the
passages, hands them to a coding agent, and returns a grounded answer that names its
sources. It does not install an integration or change the agent's persistent setup.
A retrieval miss is not papered over. If the passages do not support an answer, the
agent says so. You can rephrase the question or add funes to the agent so it can search
the memory iteratively during normal work.
Switching agents without losing the thread
A shared memory is not tied to the agent or model that created it. Start a task in
Claude Code, continue it in Codex next week, and the second agent can recall the first
agent's reasoning. Use pi with a local model or one served through the Hugging Face
router, then return to Claude.
Claude makes a decision; a hook indexes it; Codex recalls it in another session. The
older hits in the demo are earlier recordings of the same experiment: an append-only
memory remembered the rehearsals too.
This matters in a few different scopes:
Across your machines:
Bind each agent to one memory and recall the history from
whichever host you are using.
Across a team:
A new teammate's agent can retrieve months of decisions on day
one, including dead ends and rationale that never made it into a pull request.
Alongside an open-source project:
A maintainer can publish the sessions behind a
release, naming them on the push. Think of it as a searchable
CLAUDE.md
that holds
the history of why the project is the way it is, instead of a page someone must keep
rewriting. Anyone can read a public memory with
--memory
.
Published memories carry a dataset card and the funes tag, making them recognizable
and
discoverable on the Hub
. The Hub
already hosts open weights and datasets. funes adds open working memory. It holds
the decisions, failed approaches, and rationale behind a project, queryable by another
agent and traceable to the sessions that produced them.
The cheapest way out of a long session
A long investigation bloats a session until each turn costs more to carry the context
than to do the work. The usual answers are to let the agent compact and carry on, or to
write a handoff and start fresh. Recall is a third, so we measured them against each
other on the
handoff-vs-recall
benchmark
:
two tasks whose answer cannot be reconstructed without the session prior knowledge.
Compaction is what most agents do by default, and it was the only one of the three whose
result divided: it arrived on one task and never arrived on the other. Where it failed,
its summary had flattened the findings that mattered. Recall returns the passages
themselves, so a finding does not have to survive summarization.
Recall was the cheapest of the three on both tasks, 8x cheaper than a written handoff on
one and 4x on the other.
The lighter segment of each bar is the one-time charge for preparing the channel, the
handoff or the compaction, paid before the first question is asked and counted once. A
cross marks a channel that never arrives, and so has no cost per success.
Stop starting from zero
“To think is to forget differences, generalize, make abstractions.”
— Jorge Luis Borges,
Funes the Memorious
Your agents already wrote the record. funes lives at
github.com/huggingface/funes
, one command away
from turning that record into a memory the next agent can read, on whichever machine you
happen to be on.
Built on open source
funes invents little of this. It leans on open-source embedding models good enough to
run locally, on
Lance
's append-only datasets with
cheap incremental writes, and on the Hub's caching and content-dedup for datasets. The
work is in fitting them into a memory an agent can actually use.
funes is open source too.
Open an issue
for anything from an install snag to a recall that missed, or an agent you'd like
supported.