DOCUMENTATIONv2

POST

Developer access

Create webhook

/api/v2/developer/webhooks

AUTHENTICATIONBearer token · developer:writeAUTHORITATIVE OWNERdeveloper-platformCONTRACT AUTHORITYCapability registry · plannedSTATUSPlanned · not executable

PLANNING CONTRACT · NOT CALLABLE

This page describes intended capability and integration boundaries so people and agents can prepare safely. Do not send this request or register it as an executable tool. Wait until the capability registry marks it implemented-contract, then re-fetch the deployed OpenAPI document and build the request from that machine contract.

PURPOSE + BUSINESS CONTEXT

Planned capability: register a signed webhook destination and subscribed event types.

WHEN THIS CALL IS USEFUL

Do not call or register this operation as an executable agent tool yet. Use this page to plan the future webhook workflow; enable it only after the status becomes implemented-contract and the exact operation appears in deployed OpenAPI.

OUTCOME · Planned · Create or advance

What changes

None today: this route is not executable. Its intended behavior is: no executable public webhook registry or delivery owner exists. A future promotion would register one callback, create one signing secret, verify destination safety, and return the secret exactly once without delivering historical events.

WHY IT MATTERS

Lets people and agents prepare for webhook without falsely presenting roadmap scope as a live capability.
Gives people and agents a contract-backed way to advance webhook.
Separates subject identity, consent, evidence, provider output, review, issuer credentials, and relying-party acceptance instead of collapsing them into a universal trust score.

ISOLATION + AUTHORITY

Bearer subject, tenant, purpose, policy version, role, issuer, reviewer, provider, and relying-party boundaries remain distinct. The response or transition grants no payment, custody, settlement, publisher, matching, or trading authority and must not expose regulated evidence beyond the live schema. This planning record grants no runtime authority, and only deployed OpenAPI can define an executable public contract.

BEFORE YOU CALL

First confirm that this operation is marked implemented-contract and exists in the currently deployed OpenAPI document; until then, no production request is valid.
Its capability-registry profile is provisional integration guidance, not an executable request schema.
Authenticate at the documented boundary: bearer+scope.
Treat the proposed name (body), url (body), event_types (body) as planning input only; re-generate the request from deployed OpenAPI before making a call.
Use one Idempotency-Key only for retries of the same byte-equivalent logical mutation.
Resolve the applicable purpose, policy version, consent or role basis, and required assurance before relying on this result.

WHAT TO DO NEXT

Keep this operation disabled in clients, agents, SDKs, and workflow automation while it remains planned-contract.
Use the stated owner, lifecycle, authority boundary, and provisional webhook profile to prepare requirements and conformance tests without sending a request.
Monitor the capability registry for implemented-contract, then re-fetch deployed OpenAPI and validate its exact security, parameters, schemas, responses, and agent metadata before enabling the integration.

AGENT GUIDANCE

Never call this planned contract, include it in an executable tool registry, or infer runtime availability from this readable page.
Its capability-registry profile is provisional integration guidance, not an executable request schema.
Use webhook only for the purpose and lifecycle stage described by this operation; do not treat it as authority for an adjacent action.
Treat the proposed name (body), url (body), event_types (body) as planning input only; re-generate the request from deployed OpenAPI before making a call.
Treat policy availability, consent, evidence capture, completed checks, review, decision, credential issuance, validity, and relying-party acceptance as separate facts.
After a timeout or conflict, read authoritative state before deciding whether an equivalent retry is safe.
When implementation lands, discard generated requests based on this planning record and rebuild them from the deployed OpenAPI operation.

MACHINE CONTRACT

This operation is a non-executable planning contract. Its capability-registry record defines the intended owner, parameters, responses, and integration boundary until an implemented Rust OpenAPI operation replaces it.

EXTENDED INTEGRATION GUIDANCE

Readable request and response reference

Examples describe the reviewed planning contract and remain non-executable until promoted into OpenAPI.

PARAMETERS

Headers, path, query, and body

NAMELOCATIONPRESENCETYPE / RULES / PURPOSE

AuthorizationheaderRequired

Bearer tokenCredential containing the developer:write scope.EXAMPLEBearer hc_live_…

Idempotency-KeyheaderRequired

ASCII string · 1–128Caller-generated key reused for every retry of the same logical mutation.EXAMPLEwebhook-treasury-evidence-20260901

Content-TypeheaderRequired

application/jsonSigned mutations accept canonical JSON only.EXAMPLEapplication/json

Content-DigestheaderRequired

RFC 9530 SHA-256 digestDigest of the exact transmitted body bytes.EXAMPLEsha-256=:47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=:

Signature-InputheaderRequired

RFC 9421 signature parametersCovers @method, @path, content-digest, content-type, and idempotency-key; includes keyid, nonce, created, and expires.EXAMPLEsig1=("@method" "@path" "content-digest" "content-type" "idempotency-key");created=1786582800;expires=1786583100;nonce="01J…";keyid="machine-prod"

SignatureheaderRequired

Ed25519 HTTP Message SignatureSignature made by an active public key registered to the authenticated client.EXAMPLEsig1=:base64-signature:

namebodyRequired

string · 2–120Owner-visible callback registration name.EXAMPLETreasury evidence updates

urlbodyRequired

public HTTPS URL · max 500Exact integrator-controlled destination. Private, loopback, link-local, metadata-service, credential-bearing, redirected, non-HTTPS, and rebinding targets fail closed.EXAMPLEhttps://integrator.example.com/hybrid-chain/events

event_typesbodyRequired

allowlisted event identifier[] · 1–100 uniqueExact public-safe event classes. Wildcards and internal event names are forbidden.EXAMPLE["billing.usage.updated","price_feed.health.changed"]

descriptionbodyOptional

string · max 320Optional operator context. Credentials, tokens, signing material, and other secrets are forbidden.EXAMPLEUpdates for the production reporting pipeline

REQUEST

JSON body example

{
  "name": "Treasury evidence updates",
  "url": "https://integrator.example.com/hybrid-chain/events",
  "event_types": [
    "billing.usage.updated",
    "price_feed.health.changed"
  ],
  "description": "Updates for the production reporting pipeline"
}

RESPONSES

Status and payload examples

501Profiled planning contract only; no public V2 webhook registry or delivery owner exists and the operation is absent from live OpenAPI.Not executable · JSON RESPONSE+

{
  "code": "planned_contract",
  "message": "Developer webhook registration is not available through V2."
}

INTEGRATION DECISIONplanned_contract

CALLER ACTION: Do not send this request or register it as an executable agent tool. Use the implemented alternatives linked by the module guide.
RETRY SAFETY: Do not retry on a timer. Re-fetch production OpenAPI and proceed only after this exact operation appears there.
STATE RECONCILIATION: No runtime state exists to reconcile for this planning contract. Continue from developer applications, credentials, signing keys, callbacks, scopes, secrets, and lifecycle receipts through an implemented operation.
ESCALATE WHEN: Escalate when a secret-bearing result was lost, key or callback state is ambiguous, or least-privilege scope cannot be established.

OPERATIONAL NOTES

Security and lifecycle guarantees

A future owner must resolve DNS and reject private, loopback, link-local, multicast, metadata-service, credential-bearing, non-HTTPS, redirected, and rebinding targets before registration and every delivery.
A promoted 201 response would return registration metadata, verification posture, and the signing secret exactly once under no-store. Put the secret directly into an approved secret manager; it cannot be caller-selected and must never enter prompts, logs, source control, URLs, analytics, or agent memory.
Consumers must verify the exact raw request bytes, timestamp, delivery ID, event ID, signature version, and HMAC before parsing; reject stale timestamps and atomically deduplicate event IDs. Return a bounded 2xx only after durable acceptance.
A callback reports committed domain state but is not that domain's authority. Re-read the referenced owning resource before consequential action. Promotion requires an authoritative registry and outbox, public event schemas, SSRF-safe delivery, encrypted secret custody, rotation, jittered retries, dead-letter evidence, and payload-safe observability.

DOCUMENTATION STATUS

This planned contract now defines its public parameters, authorization boundary, replay behavior, responses, and authoritative owner. It remains non-executable until its owner adapter and conformance tests are promoted into the Rust gateway.

Return to the V2 directory ↗