[vicgupta]

Summary

Adds an opt-in local SQLite event log that records the same events as --json, so runs can be queried afterwards.

• OnEvent now fans out to sinks (internal/eventlog): the JSONL writer and an optional SQLite sink get identical events. --json output is byte-for-byte the same as before, except a new provider.retry event when a model request is retried.
• Turn it on with --log-db, --log-db=path, or config log_db.enabled/path/level/max_days/max_runs/max_payload_bytes. Default path is <cwd>/.tinyagent/tinyagent.db. Off by default; nothing is created unless enabled.
• Uses pure-Go modernc.org/sqlite, so no cgo. WAL mode, 10s busy timeout, one connection, all queries parameterized, embedded migrations tracked in schema_migrations.
• Tables: runs, events (run_id, seq, step, ts, type, JSON payload), tool_calls (args, result summary, duration, is_error).
• Default level: metadata stores no bodies: text, arguments, and output become *_len, and the task is stored only as a sha256 hash plus its length. level: full stores bodies after redaction (*_KEY/_TOKEN/_SECRET/_PASSWORD env values, MCP/hook env secrets, common token shapes). Payloads are capped at 64 KiB by default.
• Old runs are pruned when a run starts (30 days / 500 runs by default; 0 keeps all).
• If the database fails at open or during writes, tinyagent prints exactly one warning and the run continues. A DB error never fails a run or changes the exit code.

Decisions

• Default level is metadata and the DB is per-repo under --cwd. The file is created 0600 and its dir 0700. The README suggests adding .tinyagent/ to .gitignore.
• The trajectory JSON is still the resume format. The DB sits beside it and doesn't replace it.
• No tinyagent logs subcommand yet. The README shows how to query with sqlite3.
• The optional flag value has to be written --log-db=path, because Go's flag package can't take an optional value after a space.
• I didn't add per-request model events, so --json keeps its shape. Per-run tokens and cost go in runs. tool_calls.exit_code is reserved and currently NULL.
• Writes are batched on a background goroutine. If the process crashes, the last few events may not be written.

Testing

• New tests for: fresh schema and WAL, migrating forward, metadata storing no bodies, full storing bodies, redaction, retention by max_runs and max_days, a write failure warning once, 4 concurrent runs × 200 events, injection-like input, payload truncation, an unwritable path, JSONL↔DB mirror equality, off by default (no .tinyagent), the default path being created, config path relative to --cwd, and the retry observer.
• gofmt -l, go vet ./..., go test ./... all pass. The eventlog tests also pass with -race -count=5.
• CGO_ENABLED=0 builds succeed for linux/darwin/windows × amd64/arm64.

Binary size

linux/amd64, -trimpath -ldflags="-s -w": 9,506,976 → 13,738,144 bytes (+4,231,168, about +4.0 MiB / +44.5%). Other targets: 12.8–13.8 MB.

Closes #70

[vicgupta]

Rebased onto main by the hourly merge job (head now bcd69c5), which now includes #75 (format errors) and #76 (durable checkpoints, plan tool).

Rebase notes: all conflicts were additive (flag/config/docs/event-table rows, the OutputSchema + cur/Step() agent fields, and the Plan + LogDB config types). One fix beyond conflict resolution: the merged --help golden text in cmd/tinyagent/main_test.go had a stray blank line before Other:; removed so the golden matches the actual --help output (verified by the passing TestUsage). No behavior change.