tidebase 0.5.0

Python SDK for Tidebase — the open-source checkpoint layer for AI agents. Wrap your steps, and failed runs resume from the last safe point, in your own Postgres.

tidebase (Python SDK)

Python SDK for Tidebase — the open-source checkpoint layer for AI agents: wrap your steps, and failed runs resume from the last safe point — in your own Postgres, without moving execution into a new runtime.

Zero dependencies (stdlib only), Python 3.9+.

from tidebase import Tidebase

tide = Tidebase()  # reads TIDEBASE_URL (default http://localhost:7373) and TIDEBASE_API_KEY

def workflow(run, input):
    plan = run.step("plan", lambda: make_plan(input))
    sources = run.step("fetch-sources", lambda: fetch_sources(plan))

    run.state.set({"status": "writing", "progress": 0.7})

    decision = run.gate("approve-report", "Send the report to the customer?")
    if not decision.approved:
        raise RuntimeError("not approved")

    return run.step("write-report", lambda: write_report(sources))

tide.run("generate-report", workflow, run_id=run_id)

Re-invoke with the same run_id after a crash: completed steps return from their checkpoints instantly; only unfinished steps execute.

Surface

Call	Does
tide.run(name, workflow, run_id=…, input=…)	Create or resume a run
run.step(name, fn, side_effects=…, idempotency_key=…, retries=…)	Checkpoint a unit of work; replays from storage on resume
run.state.set / patch / save / versions	Live state + versioned history (snapshot = labeled version)
run.gate(name, prompt)	Durable human approval; resolves exactly once
run.child(...) / run.fanout(name, children)	Subagents as child runs, idempotent by edge name, durable join
run.usage.record(kind=…, input_tokens=…, cost_usd=…)	Per-run token/cost ledger, no LLM proxy
tide.runs.create / get / list / recover / subscribe	Run API + SSE event stream
tidebase.verify_webhook_signature(body, header, secret)	Verify signed recovery/channel webhooks

External writes should declare side_effects and an idempotency_key; otherwise a final failure is classified manual_review instead of silently retrying — that's the replay contract.

Tests

Integration tests assert the durability invariants against a real server:

docker compose up -d postgres && pnpm server   # in the repo root
python3 -m unittest discover sdk-python/tests -v

Status

Alpha, like the rest of Tidebase. The step input hash matches the TypeScript SDK for common JSON types, so both SDKs can drive the same run (caveat: floats like 1.0 hash differently between the two — avoid mixing SDKs on steps whose input contains them).