Webhooks Glossary

Actors & Core Concepts

Defines the core roles and nouns in a webhook system: who emits, who receives, what URL is hit, and the edge entry point. This matters because a shared vocabulary makes responsibilities clear, keeps implementations consistent, and speeds debugging.

Endpoint

Property	Description
Definition	HTTP URL that receives webhooks. Example: `/webhooks/stripe` (POST).
Why it matters	Determines auth, timeout, concurrency, and routing targets.
Hookdeck	After consuming a webhook on your behalf, Hookdeck delivers the event to your endpoint. Learn more
Also called	listener, callback URL, webhook URL, destination URL, target URL, receiver URL, notification URL, callback endpoint, hook URL, push URL, event URL, subscriber URL, consumer endpoint, ingestion endpoint, reception point

Related terms: Forwarding · Signature (HMAC)

Webhook body

Property	Description
Definition	The HTTP request payload containing the event data, usually in JSON format.
Why it matters	The body holds the actual business event (e.g., `invoice.paid`, `user.created`) that your app consumes. Parsing and validating it correctly is essential for correctness and security.
Hookdeck	Hookdeck stores the raw body, exposes it in logs, and forwards it unchanged to your app unless transformations are applied.
Also called	payload, message body, event payload, data body, webhook payload

Related terms: Webhook header · Webhook event · Schema drift

Webhook consumer

Property	Description
Definition	System that receives/processes webhooks.
Why it matters	Owns retries, idempotency, and downstream effects.
Hookdeck	Hookdeck acts as the public-facing consumer; your app is the downstream destination. Use Hookdeck's URL instead of your endpoint.
Also called	destination, subscriber, receiver, listener, target system, recipient, handler, processor, event consumer, webhook receiver, ingestion system, sink, destination system

Related terms: Endpoint · Retry · Idempotency

Webhook event

Property	Description
Definition	Fact emitted by a provider at a point in time (immutable payload + metadata).
Why it matters	Basis for idempotency, ordering, and schema contracts.
Hookdeck	Hookdeck preserves event identity/metadata for tracing, dedupe, and replay. Learn more
Also called	webhook, event, message, notification, trigger, signal, action, occurrence, incident, activity, operation, transaction, state change, update, alert, notification trigger, event notification, business event, system event, domain event

Related terms: Idempotency · Correlation ID · Schema drift

Webhook gateway

Property	Description
Definition	Entry point that offers verification, middlewares and routing of webhooks.
Why it matters	Offloads edge complexity and centralizes control/visibility.
Hookdeck	Treat Hookdeck as your managed event gateway for webhooks. Learn more
Also called	broker, edge, API gateway, edge gateway, message broker, event broker, ingestion gateway

Related terms: Webhook proxy · Visibility layer · Routing

Webhook header

Property	Description
Definition	HTTP headers attached to a webhook request, carrying context such as event type, signature, delivery ID, and retry count.
Why it matters	Headers are critical for authentication, tracing, and interpreting the payload; missing or tampered headers can break verification or observability.
Hookdeck	Hookdeck preserves provider headers, adds delivery IDs and metadata, and makes them searchable in the dashboard.
Also called	request header, HTTP header, metadata header, webhook request header

Related terms: Webhook body · Signature (HMAC) · Correlation ID

Webhook metadata

Property	Description
Definition	Supplemental information attached to a webhook delivery that isn't part of the main event body (e.g., delivery ID, retry count, timestamp).
Why it matters	Metadata enables idempotency checks, observability, and replay; it's how you distinguish retries or trace an event across systems.
Hookdeck	Hookdeck enriches webhooks with delivery metadata (timestamps, status, attempt count) and makes it queryable for debugging or replay.
Also called	event metadata, delivery context, webhook context, delivery attributes

Related terms: Idempotency · Retry · Correlation ID

Webhook provider

Property	Description
Definition	System that emits webhook events. Example: Stripe publishes `invoice.paid`.
Why it matters	Clarifies who signs requests and defines payload schema.
Hookdeck	Hookdeck doesn't change your provider; it consumes their webhooks and normalizes intake. Learn more
Also called	source, publisher, sender, producer, emitter, originator, broadcaster, source system, event producer, notification source, event source, webhook sender, dispatcher, initiator

Related terms: Webhook consumer · Endpoint · Signature (HMAC)

Forwarding & Edge Proxy

Accepting webhooks at the edge and relaying them to internal destinations (including localhost during development). This matters because it hides internal surfaces, centralizes control and visibility, and reduces production risk.

Forwarding

Property	Description
Definition	Push received webhooks to another URL (localhost or multiple services).
Why it matters	Hides internal services; enables fan-out and env isolation.
Hookdeck	Forward from Hookdeck to one or many internal endpoints without exposing them.
Also called	relay, proxy, event relay, message forwarding, webhook relay, pass-through, re-routing

Related terms: Routing · Replay

Tunnel

Property	Description
Definition	Temporary public URL to localhost.
Why it matters	Enables local development/testing without exposing prod.
Hookdeck	Use tunnels for dev using the CLI. In prod terminate at Hookdeck, not localhost. Learn more
Also called	reverse tunnel, localhost tunnel, dev tunnel, HTTP tunnel, secure tunnel

Related terms: Sandbox · Forwarding

Webhook proxy

Property	Description
Definition	Component that terminates incoming HTTP then re-sends.
Why it matters	Adds visibility, control, and security at the edge.
Hookdeck	Hookdeck is your managed webhook proxy with logs and control.
Also called	gateway, edge proxy, webhook gateway, reverse proxy, middleware proxy, intermediary

Related terms: Visibility layer · Signature (HMAC)

Ingestion & Flow Control

Reliable intake and traffic shaping before processing—accept, buffer, queue/stream, and apply backpressure. This matters because it decouples providers from consumers, absorbs bursts, preserves durability, and keeps downstream systems stable.

Backpressure

Property	Description
Definition	Mechanism to slow producers when consumers lag.
Why it matters	Prevents overload and cascading failures.
Hookdeck	Use Hookdeck rate limits to push back safely.
Also called	flow control, rate control, congestion control, throttle feedback

Related terms: Rate limiting · Burst control

Buffer

Property	Description
Definition	Short-term storage before processing.
Why it matters	Smooths spikes; prevents loss on crashes.
Hookdeck	Hookdeck absorbs bursts and smooths delivery to protect services.
Also called	queue, staging area, cache, temporary storage, holding area, event buffer

Related terms: Queue · Burst control

Fan-in

Property	Description
Definition	Many providers into one ingress point.
Why it matters	Centralizes auth/verification and reduces operational sprawl.
Hookdeck	Receive from many providers in Hookdeck; normalize and forward internally.
Also called	aggregation, consolidation, many-to-one, collection point, convergence

Related terms: Ingestion · Routing

Ingestion

Property	Description
Definition	Reliable intake of inbound events (accept → buffer → persist → dispatch).
Why it matters	Absorbs spikes and decouples providers from consumers.
Hookdeck	Hookdeck is your ingress: receive, verify, buffer, then deliver.
Also called	intake, intake pipeline, event ingestion, data ingestion, collection, event collection

Related terms: Buffer · Queue

Partition

Property	Description
Definition	Subset/lane of an event stream.
Why it matters	Scales processing while preserving per-key order.
Hookdeck	Route by keys via Hookdeck to approximate partitions.
Also called	shard, segment, slice, channel, lane, sub-stream

Related terms: Stream · Ordering

Queue

Property	Description
Definition	FIFO structure for events awaiting processing. Careful not to confuse FIFO with ordering.
Why it matters	Controls concurrency and isolation.
Hookdeck	Deliveries queue at Hookdeck; control concurrency toward your app.
Also called	message queue, event queue, task queue, work queue, processing queue

Related terms: Retry · DLQ

Stream

Property	Description
Definition	Ordered partitioned log of events.
Why it matters	Supports high-throughput ingest with partitioned ordering.
Hookdeck	Forward from Hookdeck into your stream processor if needed.
Also called	log, topic, event stream, message stream, data stream, event log, commit log

Related terms: Partition · Routing

Routing & Transformation

Decide where each event goes and how its payload is shaped so consumers can act. This matters because it reduces noise and coupling, enables multiple consumers, and keeps data usable across services.

Enrichment

Property	Description
Definition	Add data from other systems.
Why it matters	Provides context for smarter downstream decisions.
Hookdeck	Do enrichment in downstream services; Hookdeck focuses on transport/control.
Also called	hydration, augmentation, enhancement, data enrichment, context addition

Related terms: Transformation · Routing

Fan-out

Property	Description
Definition	Send one event to many endpoints.
Why it matters	Lets multiple teams/systems react to the same event.
Hookdeck	Fan-out from Hookdeck to billing, analytics, CRM, etc.
Also called	broadcast, multicast, one-to-many, distribution, replication, scatter

Related terms: Forwarding · Routing

Filtering

Property	Description
Definition	Include/exclude events via predicates.
Why it matters	Reduces noise and downstream cost.
Hookdeck	Filter at Hookdeck so your app only sees relevant events. Learn more
Also called	rules, selectors, event filtering, event selection, subscription filtering, event discrimination, topic filtering, event criteria

Related terms: Routing · Transformation

Routing

Property	Description
Definition	Send events to destinations based on rules (headers, type, body fields).
Why it matters	Ensures the right services receive relevant events.
Hookdeck	Route by headers/body rules in Hookdeck; target the right services.
Also called	dispatch, fan-out, event routing, message routing, distribution, directing

Related terms: Filtering · Forwarding

Transformation

Property	Description
Definition	Change payload shape.
Why it matters	Normalizes inputs across providers and versions.
Hookdeck	After consuming a webhook, modify payload using `Javascript` before delivery. Learn more
Also called	mapping, adapters, translation, conversion, reshaping, reformatting, normalization

Related terms: Enrichment · Schema drift

Delivery Semantics

The delivery contract: what “delivered” means and what guarantees exist (acknowledgement, ordering, idempotency). This matters because it sets correct expectations, drives handler design, and informs retry/redelivery behavior.

Acknowledgement

Property	Description
Definition	Endpoint's confirmation of receipt (e.g., 200/204).
Why it matters	Fast acks prevent provider retries/timeouts.
Hookdeck	Hookdeck acks providers quickly, then delivers to your app asynchronously.
Also called	ack, 2xx response, receipt confirmation, delivery confirmation, success response, webhook acknowledgment, reception confirmation, ACK

Related terms: Delivery · Timeout

At-least-once

Property	Description
Definition	Deliveries may be duplicated but not lost.
Why it matters	Default for most providers; requires idempotent consumers.
Hookdeck	Embraces at-least-once; pair with idempotency/deduping.
Also called	guaranteed delivery, reliable delivery

Related terms: Idempotency · Retry

At-most-once

Property	Description
Definition	No duplicates, but loss possible.
Why it matters	Not ideal for critical workloads.
Hookdeck	Prefer at-least-once + idempotency instead.
Also called	best-effort delivery, fire-and-forget

Related terms: Delivery

Deduplication

Property	Description
Definition	Detect and drop duplicates.
Why it matters	Prevents double-charging, double-sends, and data skew.
Hookdeck	Combine provider IDs with Hookdeck delivery IDs to drop duplicates.
Also called	de-dupe, duplicate detection, duplicate removal, duplicate filtering

Related terms: Idempotency · Replay

Delivery

Property	Description
Definition	Act of sending an event to an endpoint; success = HTTP 2xx.
Why it matters	Drives retry/backoff policy and alerting.
Hookdeck	Hookdeck manages delivery with retries, backoff, and observability.
Also called	dispatch, push, transmission, send, event delivery, webhook delivery, notification delivery, message delivery

Related terms: Retry · Timeout · Latency

Exactly-once

Property	Description
Definition	No loss, no duplicates, ordered.
Why it matters	Hard to guarantee over HTTP; emulate at consumer.
Hookdeck	Achieve via idempotency + dedupe, not transport promises.
Also called	guaranteed unique delivery, perfect delivery

Related terms: Idempotency · Deduplication

Idempotency

Property	Description
Definition	Safe to process the same event more than once.
Why it matters	Enables safe retries/replays without double effects.
Hookdeck	Hookdeck exposes stable IDs so your app can record and skip duplicates.
Also called	deduplicated processing, idempotent processing, duplicate safety, re-delivery safety, multiple delivery handling, replay safety

Related terms: Retry · Replay · Correlation ID

Ordering

Property	Description
Definition	Sequence guarantees across deliveries.
Why it matters	Some workflows need per-key ordering; most webhooks don't guarantee it.
Hookdeck	Don't assume order; design consumers for out-of-order events.
Also called	in-order delivery, sequential delivery, event ordering, message ordering, FIFO guarantee

Related terms: Partition · Idempotency

Reliability & Recovery

Controls and patterns that keep deliveries working under failure (retry, backoff, timeouts, DLQ, replay, rate/burst limits, circuit breakers). This matters because they prevent loss, protect dependencies, and enable safe, targeted recovery.

Backoff

Property	Description
Definition	Increasing delay between retries.
Why it matters	Avoids thundering herds and contention.
Hookdeck	Hookdeck staggers retries with backoff and jitter.
Also called	exponential backoff, progressive delay, incremental retry, graduated retry, expanding intervals, geometric backoff, progressive backoff

Related terms: Retry · Rate limiting

Burst control

Property	Description
Definition	Smooth short spikes to a steady flow.
Why it matters	Prevents overload and keeps latency predictable.
Hookdeck	Hookdeck smooths spikes with buffering and controlled concurrency.
Also called	smoothing, traffic shaping, load leveling, spike dampening

Related terms: Rate limiting · Buffer

Circuit breaker

Property	Description
Definition	Temporarily stop calls to a failing endpoint.
Why it matters	Prevents cascading failures and protects upstreams.
Hookdeck	Pause or disable forwarding when an endpoint degrades. Learn more
Also called	failure protection, automatic cutoff, endpoint protection, overload protection, failure circuit

Related terms: Retry · Timeout

Dead Letter Queue (DLQ)

Property	Description
Definition	Holds permanently failed events.
Why it matters	Stops endless retries; enables safe manual review.
Hookdeck	Hookdeck isolates permanently failing deliveries for review and replay.
Also called	poison queue, failed message queue, error queue, undeliverable queue, failed webhook storage, retry exhaustion queue

Related terms: Retry · Replay

Rate limiting

Property	Description
Definition	Cap accepted requests per time unit.
Why it matters	Protects brittle or costly endpoints.
Hookdeck	Throttle at Hookdeck to shield downstream services. Learn more
Also called	throttling, request throttling, API throttling, rate control, request limiting

Related terms: Burst control · Backoff

Replay

Property	Description
Definition	Re-send historical event to an endpoint.
Why it matters	Fix bugs and recover without asking providers to resend.
Hookdeck	Replay single events or ranges from Hookdeck.
Also called	re-drive, reprocess, re-run, event replay, message replay, historical replay

Related terms: Idempotency · DLQ

Retry

Property	Description
Definition	Re-delivery attempts after failure.
Why it matters	Prevents loss from transient errors.
Hookdeck	Configure Hookdeck retries so transient failures don't drop events. Learn more
Also called	redelivery, retry attempt, retry logic, retry mechanism, resend, re-attempt, failure recovery

Related terms: Backoff · DLQ

Timeout

Property	Description
Definition	Max wait for endpoint to respond.
Why it matters	Balances provider SLAs with processing time.
Hookdeck	Hookdeck returns fast to providers and continues delivery to your app. Learn more
Also called	request timeout, connection timeout, response timeout, delivery timeout, time limit, maximum wait time, deadline

Related terms: Delivery · Latency

Security & Data Governance

Identity, transport security, access control, and data handling/retention for webhooks. This matters because it preserves integrity and confidentiality, limits blast radius, and satisfies compliance requirements.

Encryption at rest

Property	Description
Definition	Stored data encrypted on disk.
Why it matters	Compliance and risk reduction.
Hookdeck	Data is encrypted with AES-256. Retain only what you need; apply org data-at-rest policies.
Also called	data-at-rest encryption, storage encryption, disk encryption

Related terms: PII masking · Retention window

Encryption in transit

Property	Description
Definition	TLS for all network hops.
Why it matters	Prevents eavesdropping/tampering.
Hookdeck	Data is encrypted with TLS 1.2 or better. Terminate HTTPS at Hookdeck and forward over TLS.
Also called	HTTPS, transport encryption, wire encryption, data-in-transit encryption

Related terms: mTLS

IP allowlist

Property	Description
Definition	Only accept from trusted source IPs.
Why it matters	Hardens ingress; reduces attack surface.
Hookdeck	Allowlist Hookdeck egress IPs on your network; block everything else.
Also called	whitelist, allowlist, IP filtering, source IP restriction, network filtering, IP authorization, access control list (ACL)

Related terms: mTLS · Signature (HMAC)

mTLS

Property	Description
Definition	Mutual TLS between sender and receiver using client certs.
Why it matters	Stronger identity than shared secrets.
Hookdeck	Keep Hookdeck at the edge; use mTLS on internal hops where policy requires.
Also called	client cert auth, two-way SSL, bidirectional TLS, two-way TLS, certificate-based authentication

Related terms: Encryption in transit · Signature (HMAC)

OAuth (Webhook auth)

Property	Description
Definition	Token-based auth for receiving/forwarding requests.
Why it matters	Standardizes access; less common for inbound webhooks.
Hookdeck	Hookdeck forwards bearer headers if your app expects them. Learn more
Also called	bearer tokens, token authentication, API tokens, access tokens

Related terms: Signature (HMAC)

PII masking

Property	Description
Definition	Hide sensitive data at rest/in logs.
Why it matters	Compliance and least-privilege.
Hookdeck	Keep retention low; mask or avoid storing PII in downstream logs.
Also called	redaction, data masking, data obfuscation, anonymization, sensitive data removal

Related terms: Encryption at rest · Retention window

Retention window

Property	Description
Definition	How long events/logs are kept.
Why it matters	Impacts privacy, cost, and compliance.
Hookdeck	Set intentional retention; keep only what you need for replay/compliance.
Also called	TTL, retention period, data retention, storage duration, keep-alive period

Related terms: Replay · PII masking

Secret rotation

Property	Description
Definition	Regularly change signing/verifier keys.
Why it matters	Limits blast radius of leaked/old secrets.
Hookdeck	Rotate provider secrets in Hookdeck; overlap keys during cutovers.
Also called	key rotation, key refresh, secret refresh, key management

Related terms: Signature (HMAC)

Signature (HMAC)

Property	Description
Definition	Cryptographic proof event is from provider (verify signature header with shared secret).
Why it matters	Prevents spoofing; only trusted events reach systems.
Hookdeck	Verify provider signatures at Hookdeck; forward only if checks pass. Learn more
Also called	signing secret, hash signature, message authentication code, security signature, verification signature, authentication hash, request signature, payload signature

Related terms: IP allowlist · mTLS

Performance & SLAs

The metrics and targets for system behavior (HTTP codes, latency, throughput, SLOs/SLAs). This matters because they guide capacity planning, alerting, and performance tuning so the experience meets commitments.

HTTP 2xx/4xx/5xx

Property	Description
Definition	Success (2xx), client error (4xx), server error (5xx).
Why it matters	4xx usually stop retries; 5xx/timeouts trigger retries.
Hookdeck	Configure per-route retry policy and alerting.
Also called	response codes, status responses, HTTP responses, result codes, return codes

Related terms: Retry · Timeout

Latency

Property	Description
Definition	Time from send to acknowledgement.
Why it matters	Impacts user experience and SLAs.
Hookdeck	Provider-facing latency minimized; internal delivery latency observable.
Also called	response time, delivery latency, processing time, round-trip time

Related terms: Timeout · Throughput

SLA / SLO

Property	Description
Definition	Availability/latency commitments and objectives.
Why it matters	Guides reliability budgets and alerts.
Hookdeck	Measure at Hookdeck routes and downstream endpoints.
Also called	Service Level Agreement, Service Level Objective, uptime guarantee, performance targets

Related terms: Latency · Retry

Throughput

Property	Description
Definition	Events processed per time unit.
Why it matters	Capacity planning and cost control.
Hookdeck	Buffering + rate limits let you right-size downstream capacity.
Also called	TPS, RPS, events per second, messages per second, processing rate, event rate

Related terms: Rate limiting · Burst control

Observability & Environments

Seeing what’s happening and testing changes safely through tracing/visibility and sandbox/staging/blue-green/mocks. This matters because it speeds debugging, makes regressions obvious, and lowers risk when shipping changes.

Blue/Green

Property	Description
Definition	Two prod environments for zero-downtime switch.
Why it matters	Reduces risk during deploys and migrations.
Hookdeck	Pause a route, then flip Hookdeck routing between blue and green during deploys.
Also called	blue-green deployment, zero-downtime deployment, rolling deployment

Related terms: Staging · Routing

Correlation ID

Property	Description
Definition	ID used to trace a single event end-to-end.
Why it matters	Links logs across hops for debugging.
Hookdeck	Complete logs and traceability within Hookdeck. Learn more
Also called	trace ID, request ID, message ID, event ID, webhook ID, transaction ID, unique identifier

Related terms: Visibility layer · Idempotency

Mock server

Property	Description
Definition	Simulates provider to test consumers.
Why it matters	Enables deterministic tests without external dependencies.
Hookdeck	Use provider fixtures/mocks; forward via Hookdeck for end-to-end tests.
Also called	stub, test server, simulator, fake server, test double

Related terms: Sandbox

Sandbox

Property	Description
Definition	Safe environment for testing webhooks.
Why it matters	Prevents test data from polluting production.
Hookdeck	Point provider test mode at Hookdeck sandbox project or routes; isolate from prod.
Also called	test mode, test environment, dev environment, staging sandbox

Related terms: Tunnel · Staging

Schema drift

Property	Description
Definition	Payload shape changes over time.
Why it matters	Breaks consumers silently; must detect early.
Hookdeck	Use Hookdeck logs to spot payload changes; alert via your observability stack.
Also called	contract drift, schema evolution, payload drift, format drift, API versioning issues

Related terms: Transformation · Filtering

Staging

Property	Description
Definition	Pre-prod environment mirroring prod.
Why it matters	Validate fixes before live traffic.
Hookdeck	Use separate Hookdeck project or routes per environment.
Also called	pre-prod, UAT, pre-production, test environment

Related terms: Blue/Green · Sandbox

Visibility layer

Property	Description
Definition	Central place to observe/trace webhooks.
Why it matters	Speeds debugging and incident response.
Hookdeck	Hookdeck centralizes logs, search, and alerts for every webhook.
Also called	observability gateway, monitoring layer, telemetry layer, insights platform

Related terms: Webhook proxy · Correlation ID

What's a Webhook