Self-awareness — Claude Science's own database and SDK

host.query(sql, params=[], limit=None, df=False) runs read-only SQLite against Claude Science's own metadata DB. It is only available via the repl tool (not python/r). Results are automatically scoped to the current project, so SELECT * FROM frames returns only frames in this project. The repl tool is stdlib-only — df=True returns the raw dict there (use json.dump(..., open("handoff/q.json","w")) and load in a python cell if you want pandas).

Dialect and limits

SQLite. Epoch-milliseconds for all timestamps (created_at > strftime('%s','now','-1 day')*1000). Booleans are 0/1. JSON columns are TEXT — use json_extract(col, '$.key'). Recursive CTEs OK.
SELECT / WITH / PRAGMA / EXPLAIN only; one statement per call; ? placeholders with params=[...].
Scoping. Most tables are transparently filtered to the current project (and memories to the current user) via CTEs that shadow the real tables — session_claims, verification_checks, and poller_lease are unscoped. You therefore cannot use main.table / temp.table — schema-qualified names are rejected.
Caps. Default 200 rows (max limit=1000); cells >2000 chars are clipped in place with a …[+N chars] marker; total serialized output capped at ~100k chars (truncated=True, truncation_reason="total_size_cap" — narrow your columns). 5-second timeout.
Schema introspection: host.query("PRAGMA table_info(frames)") or host.query("SELECT name, sql FROM sqlite_master WHERE type='table'").

Queryable tables

Session / conversation

frames — one row per agent frame (a root conversation or a delegated sub-agent). The frame you are running in now is one of these rows. Key columns: id, parent_frame_id, root_frame_id, agent_name, delegate_name, status (processing/completed/failed/cancelled/ awaiting_user_response/awaiting_plan_approval), model, effort, input_tokens, output_tokens, cache_read_tokens, cache_write_tokens, total_cost, task_summary, status_description, conversation_type, name, project_id, created_at, updated_at, completed_at, last_user_message_at, is_hidden. JSON columns: input_data (what started the frame), output_data (json_extract(output_data,'$.response') is the final response text), context_data (the full serialized runner state — see below), mentioned_artifact_ids, specialists_used.

context_data is large. It holds the entire runner state under underscore-prefixed keys — notably $._messages (the full conversation array), $._input_tokens / $._output_tokens / $._total_cost (same values as the top-level columns), $._running_children, $._plan_json, $._compaction_count, $._tool_id_to_frame_id. Selecting it raw will hit the cell cap; use json_extract/json_array_length to read specific keys. For the messages themselves, prefer host.frames(frame_id=...) which paginates — _messages via SQL will truncate on any non-trivial session.

compaction_archives — pre-compaction message snapshots. frame_id, compaction_index, message_count, token_count, summary, messages (JSON array), created_at. When a frame's _compaction_count > 0, the original messages that were summarized live here.

notifications — parent↔child messages. sender_frame_id, recipient_frame_id, root_frame_id, notification_type, payload (JSON), read_at, created_at.

projects — id (proj_*, not a UUID), name, description, context, user_id, uploads_frame_id, memory_enabled, created_at, updated_at.

notes — user annotations. project_id, target_type, target_frame_id, target_message_index, target_artifact_id, content.

Artifacts

artifacts — one row per file. id, project_id, root_frame_id, frame_id, filename, latest_version_id, is_user_upload, is_ephemeral, folder_id, sort_order, priority, created_at.

artifact_versions — one row per saved revision. id, artifact_id, version_number, frame_id, content_type, size_bytes, checksum, storage_path, extracted_code, code_description, language, agent_name, is_intermediate, is_checkpoint, parent_version_id, producing_cell_id (→ execution_log.id), created_at. JSON: lineage_messages, dependency_mappings, environment_snapshot, annotations, cell_sources. Join artifacts.latest_version_id = artifact_versions.id for size/type.

artifact_dependencies — DAG edges. artifact_version_id, depends_on_version_id, reference_name.

artifact_folders — id, project_id, parent_id, name, root_frame_id, is_conversation_folder, is_user_uploads_folder, sort_order.

content_snapshots — content-addressed dedup store. hash, content, size_bytes. Referenced by artifact_versions.lineage_snapshot_hash / env_snapshot_hash.

Execution history

execution_log — one row per python/r/bash/repl cell, in order. id, frame_id, cell_index (monotonic), kernel_id, kernel_kind (analysis/operon), conda_env, language, source (exact submitted code), stdout, stderr, exit_status (ok/error/kernel_died/ cancelled), error_lineno, files_written (JSON [{path, sha256}]), created_at. This is the ground-truth record of everything you've run.

host_call_log — one row per host.* SDK call made inside a cell. id, execution_log_id (→ execution_log.id), seq, method (query_db/llm/mcp/list_frames/…), args_json, derivable, data_inline, data_ref, error, bytes, created_at. Ordered by (execution_log_id, seq).

Compute and verification

compute_usage — remote compute jobs. job_id, environment, tier_type (gpu/cpu), provider, frame_id, project_id, started_at, ended_at (null ⇒ running), expires_at, state, remote_workdir, submit_cell_id. JSON: output_specs, remote_handle.

session_claims — falsifiable claims extracted for verification. root_frame_id, frame_id, step_id, claim_text, entities (JSON), source (agent/haiku_extracted).

verification_checks — reviewer verdicts. root_frame_id, artifact_version_id, claim_id, claim, verdict (pass/warn/fail/inconclusive), severity, evidence, rebuttal, reviewer_model, reviewer_frame_id, source_ref (JSON), status (open/resolved/unaddressed), reflag_count.

memories — durable beliefs (user-scoped; may be absent on some builds). id (mem_*), body, subject_project_id, subject_artifact_id, subject_version_id, subject_frame_id, source_frame_id, origin (extractor/agent_tool/user), evidence (stated/observed/inferred), superseded_by, last_surfaced_at.

poller_lease — single-writer guard for compute polling. provider, holder, expires_at.

Denied tables

These are rejected with Table '<name>' is not queryable — use the listed SDK accessor instead.

Secrets (encrypted at rest, blocked defense-in-depth): oauth_tokens, user_secrets, anthropic_api_keys, cloud_credentials. → host.credentials.list() for non-secret metadata; .get(name) for the decrypted fields — usable in client libraries, redacted only from printed cell output.
Agent/skill/connector configuration (enumerating attack surface has no legitimate raw-SQL use): user_agents, agents, custom_agent_prompts, bundled_agent_settings, capability_settings, custom_skills, agent_skill_assignments, custom_mcp_servers, mcp_agent_assignments, mcp_tool_grants, directory_attachments. → host.agents.list() / host.skills.list() / host.agents.list_connectors() (load the customize skill for that API).
Host filesystem mounts: host_grants. → the list_host_grants tool (present on sandboxed-network builds).
Compute provider configuration: compute_providers. → the list_compute / compute_details tools.

The denylist matches on word boundaries anywhere in the SQL, so a column alias or string literal that happens to equal a denied table name will also be rejected.

Host identity (hostname, workspace/pod name) is intentionally not exposed anywhere in this DB (and on Linux builds the sandbox masks it as well) — to know where you're running, ask the user or use list_compute labels.

Worked examples

All of these run via the repl tool.

# Token and cost accounting across every frame in THIS PROJECT (all
# sessions). Add `WHERE root_frame_id = ?` with the current root's id to
# scope to one session tree. Aggregate server-side so the row cap can't
# undercount.
r = host.query("""
  SELECT COUNT(*)                   AS n_frames,
         SUM(input_tokens)          AS input_tokens,
         SUM(output_tokens)         AS output_tokens,
         SUM(cache_read_tokens)     AS cache_read_tokens,
         SUM(cache_write_tokens)    AS cache_write_tokens,
         SUM(total_cost)            AS total_cost
  FROM frames
""")
n, itok, otok, crd, cwr, cost = r["rows"][0]
print(f"{n} frames, ${cost or 0:.4f} total")

# Last 10 code cells executed in this project (any frame), with outcome.
# Add `WHERE e.frame_id = ?` with the current frame's id to scope to one
# frame.
host.query("""
  SELECT e.frame_id, e.cell_index, e.language, e.kernel_kind, e.conda_env,
         e.exit_status, substr(e.source, 1, 120) AS src,
         json_array_length(e.files_written) AS n_files
  FROM execution_log e
  ORDER BY e.created_at DESC
  LIMIT 10
""")

# How far into context is each root conversation in this project? Reads
# _messages length and compaction count without pulling the whole blob.
host.query("""
  SELECT id, name,
         json_array_length(context_data, '$._messages')   AS n_messages,
         json_extract(context_data, '$._compaction_count') AS compactions,
         input_tokens, output_tokens
  FROM frames
  WHERE parent_frame_id IS NULL
  ORDER BY updated_at DESC
""")

# Every artifact this project has, with current size/type, newest first.
host.query("""
  SELECT a.filename, v.content_type, v.size_bytes, v.version_number,
         a.is_user_upload, a.latest_version_id
  FROM artifacts a
  JOIN artifact_versions v ON a.latest_version_id = v.id
  WHERE a.is_ephemeral = 0
  ORDER BY v.created_at DESC
""")

SDK surface — which tool runs what

The host object is a Python SDK backed by host-side RPCs. Run help(host) / help(host.<x>) for signatures.

| Accessor | Tool | Returns | |---|---|---| | host.query(sql, params, limit, df) | repl | Raw SQL over the tables above | | host.frames(...) | repl | List/search/detail frames (paginated messages) | | host.children() | repl | Live sub-agents (delegation-enabled profiles only) | | host.delegate(task_or_list, name=?, profile=?, output_schema=?, model=?) | repl | Spawn child agent(s), block until done (ultra-mode roots; requires [delegation] sdk_enabled). model= pins the child's model per request — e.g. a haiku-class id for cheap fan-outs. Blocks the cell — for long-running children run it in a background cell (a user message mid-call backgrounds it; a Stop / cell interrupt cancels the children) | | host.agents.* / host.skills.* | repl | Profile and skill CRUD — load customize skill | | host.submit_output(output, completion_bullets=[...]) | repl | Submit your structured result when your task carries an OUTPUT SCHEMA section (required before completing). Build the dict in-kernel — the payload rides the host-call wire, not your prose; on a validation/review bounce, mutate the dict in memory and resubmit (replaces the recorded output) | | host.compute.* | repl | Remote job submit/wait — load the compute skill it names | | host.artifacts(...) | python | Filtered artifact search (wraps the join above) | | host.artifact_path(vid) / host.artifact_marker(vid) | python | Resolve a version_id to a readable path / marker | | host.lineage[vid] | python | {code, messages, env, inputs} for one version | | host.llm(prompt_or_list, model=?, ...) | python | Single-turn completion via the host's API client. Omitting model= uses the Haiku-class kernel default (via [llm] kernel_default_model); for harder reasoning pass model=host.reasoning_model() (the Sonnet-class reasoning default via [llm] kernel_reasoning_model); model=host.current_model() only when the task needs your session's own model level — never hardcode a literal model id (they go stale) | | host.credentials.list() / .get(name) | python | User-configured credential metadata | | host.mcp(server, method, **kw) | repl | MCP/connector call — only exists in the repl tool; pass results to python/r via ./handoff/*.json |

The repl tool and the python tool are separate processes that share only the workspace directory — move data between them via ./handoff/*.json, not variables.