state-trace 0.2.0

Graph-native working memory for coding agents with causal retrieval and bounded capacity.

state-trace

Graph-native working memory for coding agents: typed memories, causal retrieval, bounded capacity, and compact briefs for small models.

state-trace is a bounded working-memory layer for coding and debugging agents that need the right file, failure, and next action under tight token budgets. It is not a replacement for a general-purpose temporal knowledge graph like Graphiti — see ARCHITECTURE.md for the honest comparison.

What it is optimized for:

• artifact-first retrieval for coding agents
• current-vs-stale task state (engine.current_state(), engine.failed_hypotheses())
• compact harness-facing briefs for smaller models
• online agent loops and post-hoc trajectory ingestion
• bounded memory with decay, compression, and lifecycle retention
• MCP-mountable, local-first deployment

Headline: SWE-bench-Verified localization — n=500

The credibility benchmark. Cold-start artifact localization on the full SWE-bench-Verified test split: given only the GitHub issue text and hints (no trajectory), rank the correct patch file at 1 and at 5.

pip install -e ".[bench]"
python3 examples/swebench_verified_eval.py --limit 500 --backends no_memory bm25 state_trace graphiti

backend	n	Artifact@1	Artifact@1 CI	Artifact@5	Artifact@5 CI	AvgLatencyMs
no_memory	500	0.000	[0.000, 0.000]	0.000	[0.000, 0.000]	0.00
bm25	500	0.176	[0.144, 0.208]	0.300	[0.262, 0.338]	0.14
state_trace	500	0.150	[0.122, 0.182]	0.150	[0.122, 0.182]	16.92
graphiti	500	0.098	[0.072, 0.126]	0.216	[0.182, 0.254]	4901.38

What this says, plainly:

• state_trace beats Graphiti on Artifact@1 (0.150 vs 0.098, non-overlapping 95% CIs). On "put the right file first, from just an issue," the typed coding-agent ontology helps.
• state_trace does not beat BM25 on Artifact@1 (0.150 vs 0.176, overlapping CIs). On cold-start without a trajectory, lexical search over file-path tokens is still a strong baseline.
• state_trace loses on Artifact@5 because retrieve_brief currently surfaces a single primary patch candidate, so A@5 ≡ A@1. This is a known brief-shape issue, not a retrieval-quality issue; see the "Known limitations" note below.

Where state_trace actually differentiates is not one-shot cold-start localization — it's the trajectory-informed and online-loop lane where current_state and failed_hypotheses come into play. See BENCHMARKS.md for the trajectory benchmarks (small-N, caveated).

Known limitations of this benchmark

• state_trace returns a single-file brief, so A@5 = A@1. Fixing the brief to expose top-5 candidates is a straightforward follow-up.
• Graphiti is run with stubbed LLM/embedder (deterministic hash embeddings, BM25 + cosine + BFS → RRF). Its full LLM-entity-extraction pipeline is not exercised — that's the same simplification used in graphiti_head_to_head_eval.py and is documented there.
• Cold-start localization from issue text is only one problem a memory layer solves. It is deliberately the hardest one we ship a number for; the trajectory benchmarks in BENCHMARKS.md test the other axes.

What makes the architecture different

Typed coding-agent ontology, not generic Entity/Edge:

• Nodes: task, observation, decision, file, goal, session, command, test, symbol, patch_hunk, error_signature, episode
• Edges: patches_file, fails_in, verified_by, rejected_by, supersedes, contradicts, solves, derived_from, precedes, motivates, and more
• Intent routing: the retrieval scorer re-prioritizes edge types per query intent (locate_file, failure_analysis, history, general).

Bounded working memory as a first-class constraint:

• enforce_capacity() runs decay, compression, and summarization on every step.
• current_state(session) answers "what's live right now" directly — cheap for state-trace, expensive for a general-purpose knowledge graph.
• failed_hypotheses(session) returns invalidated, superseded, or unrecovered-error nodes — the "don't propose this again" signal.

Local-first, MCP-mountable:

• Hot graph is an in-process networkx.MultiDiGraph. Cold storage is WAL SQLite+FTS5.
• state-trace-mcp is a stdio MCP server you can mount in Claude Code / Cursor / Codex CLI.

See ARCHITECTURE.md for why these choices matter vs. Graphiti, and BENCHMARKS.md for the smaller repo-local benchmarks.

vs. Graphiti

Graphiti is the stronger general-purpose temporal knowledge graph for AI agents. state-trace is narrower: working memory for one coding/debugging session at a time. We're not claiming to replace Graphiti — we're claiming a specific lane where the tradeoffs land differently.

Each row below is a concrete, measured axis, not a vibe.

Axis	state-trace	Graphiti	Winner for coding agents
Artifact@1 on SWE-bench-Verified, n=500	0.150 [0.122, 0.182]	0.098 [0.072, 0.126]	state-trace — non-overlapping 95% CIs
Per-retrieval latency (same benchmark)	16.9 ms	4,901 ms	state-trace — ~290× faster
Write path per agent step	Typed insert, zero LLM calls	add_episode → LLM entity extraction each step	state-trace — cheaper, deterministic, no API key
Default deploy	Pure Python + local SQLite/JSON; state-trace-mcp stdio binary	Neo4j / Kuzu / FalkorDB graph DB + embedder + LLM	state-trace — local-first, no external services
Coding-agent ontology	Typed: file, patch_hunk, error_signature, test, command, symbol, observation, decision, task, goal, session, episode	Generic EntityNode / EntityEdge / EpisodicNode	state-trace — retrieval scorer routes on these types
"What's true right now in this session?"	engine.current_state(session) — direct O(graph) query	Inferred from temporal facts via Cypher or LLM	state-trace — first-class API
"What have I already tried and rejected?"	engine.failed_hypotheses(session) — direct query returning invalid_at + superseded + unrecovered-error nodes	Has to be inferred from invalid_at + contradictions	state-trace — first-class API
Working-memory capacity bound	enforce_capacity with decay + compression + lifecycle retention. Long-horizon pressure benchmark: Artifact@1 0.771 while staying within a 96-unit budget 100% of the time	Unbounded by design; relies on the graph DB to scale	state-trace for long debugging sessions that need a memory ceiling
Small-model brief	retrieve_brief produces ~220-token structured brief (patch_file, rerun_command, tests_to_rerun, failed_attempts, recommended_actions, …) that fits a tight budget	Returns raw nodes/facts; caller compresses	state-trace — built for small-model harnesses
MCP-mountable	state-trace-mcp stdio server in the [mcp] extra — 11 tools exposed, drop into ~/.claude/settings.json	No official MCP server; library-first	state-trace — plug straight into Claude Code / Cursor / Codex / opencode
Long-lived temporal knowledge across weeks	Scoped to a session or repo namespace; no cross-namespace fact merging	First-class; bi-temporal validity, contradiction resolution, fact supersession across episodes	Graphiti
Multi-tenant SaaS scale	Single-writer process model; authoritative graph is in-process networkx	Built for it on Neo4j/Kuzu substrate	Graphiti
Cross-session learning about users / orgs / policies	Out of scope	First-class	Graphiti

When to pick which

Use state-trace when:

• Your agent is editing code in a single debugging or refactoring session.
• You talk to an MCP client (Claude Code, Cursor, Codex CLI, opencode) and want working memory without standing up a graph DB.
• Per-action latency matters — you're calling memory on every tool invocation in an agent loop.
• You run on small models where a 220-token structured brief beats a 1,000-token raw dump.
• You need "what file should I patch / what did I already try" to be a direct query, not inferred.

Use Graphiti when:

• You need a knowledge graph of facts about the world, users, or an organization that evolves across weeks.
• Multi-tenant, multi-agent shared memory is part of the design.
• You're willing to run Neo4j/Kuzu and pay the LLM-extraction cost per ingest for the ontological payoff.
• Your retrieval patterns are richer than "which file, which test, which failed hypothesis."

They solve adjacent problems. The only reason a comparison is even interesting is that both ship as "memory for AI agents" — the honest answer is they're different products that happen to live on the same shelf.

Installation

uv sync                       # or: pip install -e .
pip install -e ".[mcp]"       # stdio MCP server for Claude Code / Cursor / Codex CLI
pip install -e ".[bench]"     # graphiti-core[kuzu] + datasets (for the headline benchmark)
pip install -e ".[llm]"       # OpenAI-backed live benchmarks + LLM ingestion
pip install -e ".[adapters]"  # LangGraph / LlamaIndex adapter shims
pip install -e ".[api]"       # FastAPI app

Distribution name: state-trace. Python import path: state_trace.

Quickstart

from state_trace import MemoryEngine

engine = MemoryEngine(capacity_limit=24.0, storage_path="memory.json")

task = engine.store(
    "Fix login by tracing the refresh token path",
    {"type": "task", "session": "auth-debug", "goal": "restore login", "file": "auth.ts", "importance": 0.92},
)
engine.store(
    "Login still returns 401 after refresh token exchange",
    {"type": "observation", "session": "auth-debug", "goal": "restore login", "file": "auth.ts",
     "blocks": [task.id], "importance": 0.88},
)
engine.store(
    "Authorization header is dropped before the retry request reaches auth.ts",
    {"type": "decision", "session": "auth-debug", "goal": "restore login",
     "related_to": [task.id], "file": "auth.ts", "importance": 0.91},
)

result = engine.retrieve("Why is login still broken?", {"session": "auth-debug", "goal": "restore login"})

Current state, live hypotheses, failed attempts

The architectural wedge. These APIs return a live view of the session without re-ranking:

state = engine.current_state(session="auth-debug", goal="restore login")
# → {"active_task": ..., "latest_observation": ..., "active_files": [...], ...}

failures = engine.failed_hypotheses(session="auth-debug")
# → [{"id": ..., "reason": ["superseded"], "content": "Login still returns 401 ..."}, ...]

current_state filters out invalidated and superseded nodes; failed_hypotheses surfaces them as "do not propose again" context. A general-purpose temporal graph has to infer this from fact updates; here it's a direct query.

MCP Server

pip install -e ".[mcp]"
state-trace-mcp

Environment config:

• STATE_TRACE_STORAGE_PATH — durable path; .db/.sqlite uses the SQLite backend. Default: ~/.state-trace/memory.db.
• STATE_TRACE_NAMESPACE — default namespace (e.g. the repo slug).
• STATE_TRACE_CAPACITY_LIMIT — working-memory budget (default 256).

Tools exposed: store, retrieve, retrieve_brief, record_action, record_observation, record_test_result, ingest_agent_log_file, current_state, failed_hypotheses, list_namespaces, graph_snapshot.

Example Claude Code config (~/.claude/settings.json):

{
  "mcpServers": {
    "state-trace": {
      "command": "state-trace-mcp",
      "env": {
        "STATE_TRACE_STORAGE_PATH": "/Users/me/.state-trace/memory.db",
        "STATE_TRACE_NAMESPACE": "repo-x"
      }
    }
  }
}

Online agent loop

engine = MemoryEngine(capacity_limit=256.0)
ctx = {"session": "auth-debug", "goal": "restore login", "repo": "example/auth-service"}

engine.record_action('open "src/auth.ts"', {**ctx, "files": ["src/auth.ts"]})
engine.record_observation(
    "AttributeError: login still fails with a 401 in src/auth.ts",
    {**ctx, "files": ["src/auth.ts"], "status": "error"},
)
engine.record_action('edit "src/auth.ts"', {**ctx, "files": ["src/auth.ts"], "action_kind": "edit"})
engine.record_test_result(
    "pytest tests/test_auth.py::test_refresh_retry",
    "tests/test_auth.py::test_refresh_retry PASSED",
    {**ctx, "files": ["src/auth.ts", "tests/test_auth.py::test_refresh_retry"]},
)

brief = engine.retrieve_brief(
    "Which file should I patch and what test should I rerun?",
    {"session": "auth-debug", "goal": "restore login"},
    mode="small_model",
)

The brief fields: patch_file, rerun_command, target_files, tests_to_rerun, current_state, failed_attempts, recommended_actions, evidence, symbols, patch_hints, confidence, token_estimate.

Trajectory ingestion

engine = MemoryEngine(capacity_limit=256.0)
engine.store_agent_log_file("examples/data/agent_logs/marshmallow__marshmallow-1867.json")

Supported inputs: normalized agent_log JSON, raw SWE-agent .traj files, raw OpenHands event JSON logs.

Live solve-rate (next credibility step)

examples/swebench_verified_solve_rate.py scaffolds end-to-end solve-rate measurement: state-trace brief → LLM patch proposal → SWE-bench-Verified prediction JSONL. It does not run the swebench docker harness; that step is documented in the script's header.

python3 examples/swebench_verified_solve_rate.py --limit 5 --model gpt-5.1-mini --dry-run

Storage backends

MemoryEngine(storage_path=...) picks the backend from the file extension:

• .db / .sqlite / .sqlite3 — durable SQLite with WAL journal + FTS5 seed index. Recommended for long-running agent harnesses.
• any other path — JSON blob (simple, single-writer, fine for benchmarks).

See ARCHITECTURE.md for the "why networkx + SQLite, not Neo4j" explainer.

Namespaces

engine = MemoryEngine(storage_path="memory.db", namespace="payments-api")
engine.retrieve("why is login broken?")  # scoped to payments-api by default
engine.retrieve("...", include_all_namespaces=True)  # opt out

Nodes without a namespace remain visible in every view so pre-namespace data is not lost.

Framework adapters

from state_trace.adapters import StateTraceLangGraphMemory, StateTraceLlamaIndexMemory

lg_memory = StateTraceLangGraphMemory(default_session="coding-session")
li_memory = StateTraceLlamaIndexMemory(session_id="agent-session")

Neither adapter imports the host framework; they satisfy the duck-typed memory contract used by each.

FastAPI

from state_trace.api import app  # POST /store, /retrieve, /retrieve_brief, GET /graph

Pass "explain": true on retrieve to include per-node score breakdowns.

Tests

python3 -m pytest -q

Benchmarks

Full set of repo-local benchmarks and their honest caveats lives in BENCHMARKS.md. The SWE-bench-Verified row above is the only one that's at a scale worth citing externally.

Positioning

See vs. Graphiti above for the head-to-head comparison and ARCHITECTURE.md for the architecture tradeoffs in detail. tl;dr: different products, adjacent problems — state-trace owns the narrow coding-agent working-memory lane; Graphiti owns weeks-of-history temporal knowledge graphs.