Pre-computed at merge time. Deduced at error time.
Déjà builds its causal map of your system before anything breaks — every merged pull request updates the Upstream Producer Graph. When an incident fires, the answer is a lookup, not an investigation: deterministic deduction, scored by a six-signal Causal Confidence Score (W1–W6), sealed as an Ed25519-signed DSR/1.0 receipt.
Not an LLM. No probabilistic guessing · zero instrumentation · zero code changes · no trace IDs required.
Continuously · at merge time
Every merge is analyzed and indexed into the graph — the causal map exists before the incident does.
then, when something breaks ↓
In seconds · at error time
No human deduction, no terminal opened — the receipt is signed while your team is still reading the alert.
Step 01 · org-level integrations
Connect your tools once, at the org level.
Monitoring, source control, delivery, and alert routing connect once for your entire organization. Every vault and Service Zone inherits them — no per-team re-wiring, no duplicate credentials. Connections are read-only and arrive by webhook subscription; Déjà never touches code contents.
Monitoring tools
When any of your services crashes, Déjà receives the signal automatically — with full stack trace and error context.
Source control
Déjà reads PR diffs at merge time to pre-compute the producer graph — so root cause is identified before the alert even fires.
Delivery channels
Every resolution generates a tamper-proof, cryptographically signed receipt — delivered where your evidence already lives.
Alert routing
When a prior fix is found, Déjà notifies your on-call with the causal PR and proven resolution — before they open a terminal.
Step 02 · vault & zones
One vault per org. A zone per service.
Your vault is your organization's evidence scope — created when your GitHub org connects, named after it, holding one append-only ledger. Inside it, you define a Service Zone for every service you want Déjà to watch. Receipts are signed against the zone topology, which is why zones lock after setup.
payments-checkout
payments-refunds
payments-webhooks
Name your Service Zone
Use the name your team already uses — payments-checkout. One service, one zone. The name becomes the forensic identifier on every incident and receipt.
Select the repository
Choose the repo this service lives in. The engine reads its PR history to pre-compute causal relationships with upstream services.
Pick the monitoring tool
Select which connected tool — Datadog, Sentry, New Relic — sends error signals for this zone, so Déjà knows exactly where to listen.
Provision. You're done.
Fingerprinting begins immediately. From this moment forward, every incident on payments-checkout is remembered — whether or not your team has ever seen it before.
Step 03 · fully automatic
When something crashes, Déjà handles the rest.
From the moment an alert fires to the moment a signed receipt lands in ServiceNow — typically under 60 seconds. No engineer typed anything.
! Illustrative example · payments-checkout · 02:47 UTCSignal received02:47:03
Datadog detected a KeyError on payments-checkout. The exception surfaced in production. The trace ID was gone — Kafka had stripped it at the service boundary. Every other tool stops here. Déjà kept going.
Fingerprinted deterministically02:47:04
The error was normalized, stripped of runtime noise, and fingerprinted with SHA-256. The fingerprint was checked against every prior incident in the vault — instantly.
The engine identified the cause02:47:05
The Schema Deduction Engine extracted the error's schema signature and queried the pre-built Upstream Producer Graph — constructed from every merged PR in your repos, at merge time. It found that three weeks ago, PR-4611 removed customer_tier from the upstream message schema. No trace ID needed. No human deduction.
Your on-call was notified — with the fix02:47:09
Slack, PagerDuty, ServiceNow, or email — whichever channel your team uses. Not just "something crashed," but: payments-checkout crashed, the causal PR is PR-4611, and here's what changed. Your engineer hadn't opened a terminal yet.
A signed DSR/1.0 receipt was issued02:47:41
A tamper-evident, chain-of-custody receipt was generated and delivered — structured to satisfy your SOC 2 Type II, ISO 27001, NYDFS Part 500, DORA, or SR 11-7 engagement. Your audit firm verifies it offline with dsr-verifier-cli — no Déjà account required.
"type": "R1",
"causal_pr": "PR-4611",
"ccs": 0.94 · six signals · W1–W6,
"trace_id_used": false,
"signature": "ed25519:…" · "spec": "DSR/1.0"
}
Proof of mechanism
What the engine actually does.
Deterministic · by construction
Déjà is not an LLM wrapper. It performs deterministic static analysis on every code change at merge time — extracting a Schema Error Tuple, indexing it into the Upstream Producer Graph. At error time it queries that graph and computes the Causal Confidence Score: six weighted signals (W1–W6) summing to 1.00 — field overlap, temporal proximity, blast radius, error-type match, author history, zone boundary. Output: an Ed25519-signed DSR/1.0 receipt written to an immutable, append-only, tamper-evident ledger. Same inputs, same answer, every time — mathematical certainty by construction, triggered by webhook subscription on every pull_request.merged event from your source control platform.
Measured, not estimated. Every number on this page is produced by the pipeline itself — if we can't sign it, it isn't here.
1.6s
median attribution — signal to causal PR identified
measured · production vaults
<60s
typical signal-to-signed-receipt, end to end
measured · production vaults
Zero-trust principle
Receipts are independently verifiable. No implicit trust is required between Déjà, you, and your audit firm — the signature is the contract; the verifier is the proof. If Déjà were compromised or shut down, your receipts continue to verify: the verification logic lives in your audit firm's own copy of dsr-verifier-cli, running offline. Trust nobody — verify everything.
Connect once. Remember forever.
Your team keeps shipping. Déjà keeps producing verifiable evidence — durable across audit cycles.
14-day trial · no card required · trial receipts watermarked