readers: method

Turns each harness's local session logs into event records (schemas/event.schema.json, source: "transcript"). Token normalization and cost come from schemas (C-tokens, C-cost, C-cache-ttl); this file covers only what the readers decide. Tests: 02-measure/tests/test_readers.py (synthetic fixtures in 02-measure/tests/fixtures/readers/, sqlite dbs built in a temp dir).

Common rules

R-paths. Each reader has a default root (constant ROOT/ROOTS at the top of its file). readers.paths.<harness> in config replaces it; ~ is expanded. Antigravity also reads conversation_metadata.json from the overridden dir instead of ~/.gemini/... (so tests never touch the real home).

R-window. since = now - --days (UTC). A record is kept when ts >= since. Files with mtime < since are skipped without opening. Z timestamps compare as strings; others are parsed (unparseable -> dropped).

R-project. Label from cwd: strip file:// and $HOME, split on /. Empty -> (unknown); first part in SCRATCH_DIRS (tmp) -> (scratch); under projects/ with depth > 2 -> last two parts; else last part. Example: /home/user/projects/demo/app -> demo/app (test_claude).

R-repo. Nearest ancestor of cwd that is a git repo (.git file, or .git/HEAD exists; an empty .git dir does not count), else null. $HOME prefix written as ~ (no user name in events; consumers expanduser). Cached per cwd. It is a local path; consumers must not publish it.

R-privacy. No prompt text, tool arguments or outputs are copied. user_prompt events carry only ts/session/project with zero tokens. Test: fixtures contain LEAKCANARY and /home/user/models; neither may appear in the output (test_no_leak).

R-isolate. Each harness runs in its own try; an exception sets summary[h].error = "<Type>: <msg>" and the other harnesses still run. The summary always has events, calls, cost, unpriced_calls, error per harness (unpriced_calls = calls with cost_basis "unknown").

R-output. <data dir>/events/transcript.jsonl, sorted by (ts, harness, session_id), written to .tmp then renamed. With --harness, lines of the other harnesses already in the file are kept as-is. --out DIR replaces the data dir.

Fields every reader leaves fixed: user null (no harness logs it), retries 0, tool/decision/decision_source null.

Claude Code (~/.claude/projects/**/*.jsonl)

R-claude-dedup. One call per requestId (fallback message.id). A streamed response writes several lines with the same id; usage is taken from the last line (its counts are final), tools are the union of tool_use block names. Model <synthetic> (SKIP_MODELS) is not an API call. isApiErrorMessage -> error: "api_error". isSidechain -> subagent: true. Example: req_1 has lines with output 3 then 250 -> one call, output 250, tools ["Bash"].

R-claude-agent-type. A subagent transcript <session>/subagents/agent-<id>.jsonl has agent-<id>.meta.json next to it; its agentType (e.g. Explore, general-purpose) goes to the optional event field agent_type on that file's api_calls. Missing or unreadable meta -> field absent.

R-claude-ttl. usage.cache_creation.ephemeral_5m_input_tokens / ephemeral_1h_input_tokens go to cache_write_5m / cache_write_1h (C-cache-ttl prices each at its own rate; 1h writes cost 2x input instead of 1.25x). Example (claude-sonnet-4-6: input 3, output 15, cache_read 0.3, 5m 3.75, 1h 6 USD/Mtok): input 1000, output 250, cache_read 10000, writes 1500 (5m) + 500 (1h) -> 0.003 + 0.00375 + 0.003 + 0.005625 + 0.003 = $0.018375 (without the split, all 2000 at 3.75: $0.01725).

R-claude-truncated. A call where no line carries message.stop_reason was cut off mid-stream (seen: 139 of ~25.6k calls in 30 days, output ~5 tokens). It gets error: "truncated" (unless already api_error); tokens are kept as logged and the call still counts in calls/cost. Example: req_2 -> "truncated", req_1/req_3 -> null.

R-claude-prompt. A human turn = a user line, not isMeta, not isSidechain, whose content is a string or has a text block (tool results are not prompts). Example fixture has 3 user lines, 1 prompt.

Unknown model (example claude-mystery-1) -> cost_basis "unknown", total 0 (C-cost).

Codex (~/.codex/sessions/**/rollout-*.jsonl)

R-codex-delta. token_count events hold cumulative total_token_usage; per call = current total minus previous total. A negative delta (counter reset) falls back to that event's last_token_usage. input_tokens includes cached input and output_tokens includes reasoning (input_includes_cache, output_includes_reasoning). request_id is null (not logged). R-codex-repeat. A token_count whose total equals the previous total is a repeat, not a call. Subagent: session_meta.source.subagent.thread_spawn.parent_thread_id -> parent_session_id, subagent: true. Example: totals (input 1000 incl. 600 cached, output 100 incl. 20 reasoning), the same total again, an info: null event, then (2500, 1600, 300, 50) -> calls {input 400, cache_read 600, output 80, reasoning 20} $0.001575 and {input 500, cache_read 1000, output 170, reasoning 30} $0.00275; parent cx-0 (test_codex).

OpenCode (~/.local/share/opencode/opencode.db)

R-opencode-ro. Opened as file:...?mode=ro&immutable=1: a live WAL db is never locked or written. R-opencode-empty. Assistant messages with zero tokens and no error are skipped; zero-token messages with an error (e.g. MessageAbortedError) are kept as error calls (this is why counts can exceed the public script by a few). R-opencode-cost. cost > 0 -> passed as reported_total (C-cost allocates it by list-price shares, basis reported_total_allocated); 0 -> list price. Reasoning is separate from output. duration_ms = time.completed - time.created when completed >= created. Example: input 7898, output 13, reasoning 53, cache_read 64, cost 0.0247032, 4 s -> basis reported_total_allocated, total 0.0247032, duration 4000, tools ["bash"].

Pi ($PI_CODING_AGENT_DIR or ~/.pi/agent, sessions/<cwd>/*.jsonl)

R-pi-calls. Each assistant message with usage is one call; output includes reasoning. R-pi-cost. When usage.cost.total > 0, the per-type USD (input, output, cacheRead, cacheWrite) is passed as reported (basis reported); else list price. Local gguf models have no price -> unknown. Example: output 75 incl. reasoning 28, reported total $0.01644125 -> basis reported; model Qwen3.5-0.8B-BF16.gguf -> unknown.

Antigravity (~/.gemini/antigravity-cli/conversations/*.db, ~/.gemini/antigravity/conversations/*.db)

Rows are protobuf; parsed with a stdlib wire-format reader using field numbers from the descriptors in the agy binary (see docstrings in antigravity.py). Reasoning = usage field 9, included in output. Tool calls attach to the last call of the conversation. R-agy-coverage. A db or conversation that fails to parse is skipped and recorded in antigravity.coverage[path] = reason; the summary gets skipped and the first reason as error. Example: gemini-3-flash, input 1000, output 100, cache_read 4000 -> (1000x0.5 + 100x3 + 4000x0.05)/1e6 = $0.001, tools ["run_command"], coverage empty.

Validation against real data (2026-10-18)

30 days, same moment as the public from-transcripts.py: Claude 25411 calls vs 25410, codex 1137 = 1137, pi = public, opencode 38 vs 35 (R-opencode-empty). With R-claude-ttl, Claude cost is ~3.7% above public (public prices every write at 5m rate); val-measure recomputed $1187.51 for its window. Later run (16:45Z): 25597 calls, $1195.02, 139 truncated; schemas/check.py ok.