DOCUMENTATIONv2

POST

Issuer Launchpad

Request contractual subscription

/api/v2/launchpad/offerings/{offering_id}/subscriptions

AUTHENTICATIONBearer token · launchpad:subscribeAUTHORITATIVE OWNERlaunchpad-serviceCONTRACT AUTHORITYGenerated Rust OpenAPISTATUSSource ready · production listed

PURPOSE + BUSINESS CONTEXT

Verify the authenticated investor's Identity-issued agreement receipt against the current deal, then record exact requested units, selected enabled rail, and optional immutable first-touch attribution. This does not reserve or move funds, allocate, issue, admit, or trade the instrument.

WHEN THIS CALL IS USEFUL

Use immediately after Identity returns the signed acceptance receipt for the same authenticated investor, units, rail, and current deal.

OUTCOME · Create or advance

What changes

Creates a REQUESTED subscription intent and immutable optional first-touch attribution. It does not reserve funds, allocate units, issue an asset, admit a market, trade, or accrue commission.

WHY IT MATTERS

Gives people and agents a contract-backed way to advance contractual subscription.
Connects private issuer preparation to public, citation-bearing disclosure without exposing draft evidence or collapsing review, signature, finality, and availability into one state.

ISOLATION + AUTHORITY

Workspace, issuer, offering, security-class draft, Data Vault object version, requirement pack, diligence case, evidence view, reviewer decision, auditor attestation, release, signer, validator finality, replication, public index, and investor eligibility remain distinct. Launchpad cannot issue, mint, custody, sell, trade, match, settle, or authorize an investment, and its public routes expose only finalized disclosure evidence.

BEFORE YOU CALL

Authenticate at the documented boundary: bearer+scope.
Supply the required offering_id (path), requested_units (body), subscription_agreement_reference (body), selected_funding_rail_key (body) exactly as defined by the live contract.
Use one Idempotency-Key only for retries of the same byte-equivalent logical mutation.
Resolve the authenticated workspace and derived issuer, reviewer, auditor, signer, or publisher authority for this stage; use exact Data Vault versions and distinguish private preparation from finalized public disclosure.

WHAT TO DO NEXT

Re-read contractual subscription using the canonical identifier returned by this operation.
Reconcile an ambiguous response with the same idempotency key before attempting another mutation.
Follow returned canonical identifiers and commitments into the next explicit Launchpad stage, re-attesting protected evidence and re-reading release finality before public reliance.

AGENT GUIDANCE

Use contractual subscription only for the purpose and lifecycle stage described by this operation; do not treat it as authority for an adjacent action.
Supply the required offering_id (path), requested_units (body), subscription_agreement_reference (body), selected_funding_rail_key (body) exactly as defined by the live contract.
Keep draft creation, evidence linking, evidence-view pinning, review, attestation, release assembly, freeze, signature, submission, validator finality, replicated availability, indexing, and supersession as separate lifecycle facts.
After a timeout or conflict, read authoritative state before deciding whether an equivalent retry is safe.

MACHINE CONTRACT

The exact deployed parameters, schemas, responses, security requirements, and Hybrid-Chain agent metadata are authoritative at this operation's production OpenAPI JSON Pointer. The readable tables below add integration guidance; the deployed OpenAPI controls if guidance and the machine contract ever differ.

Open the authoritative production contract ↗

EXTENDED INTEGRATION GUIDANCE

Readable request and response reference

Examples illustrate integration intent; the referenced OpenAPI operation and component schemas define the executable shape.

PARAMETERS

Headers, path, query, and body

NAMELOCATIONPRESENCETYPE / RULES / PURPOSE

AuthorizationheaderRequired

Bearer tokenCredential containing launchpad:subscribe authority.EXAMPLEBearer hc_live_…

offering_idpathRequired

identifierStable offering id selecting the exact resource addressed by this route.EXAMPLEoffering-id-01

X-Request-IDheaderOptional

stringOptional caller correlation identifier. The gateway emits the effective value on the response.

Idempotency-KeyheaderRequired

ASCII string · 1–128Caller-generated stable key reused for retries of the same logical mutation.

referral_codebodyOptional

public referral identifier · 1–64 | nullOptional first-touch sales attribution from the public deal URL. It grants no authority and cannot be replaced after acceptance.EXAMPLEpartner-7

requested_unitsbodyRequired

integer · 1–9223372036854775807Exact number of units contractually requested; this is not an allocation.EXAMPLE125

selected_funding_rail_keybodyRequired

enabled funding-rail keyExact enabled rail returned by the public deal, such as crypto:usdc:ethereum. Selection moves no funds.EXAMPLEcrypto:usdc:ethereum

subscription_agreement_referencebodyRequired

Identity acceptance receipt · hcla_ + 32 lowercase hexImmutable signed acceptance receipt returned by Identity for these exact current deal facts.EXAMPLEhcla_0123456789abcdef0123456789abcdef

REQUEST

JSON body example

{
  "referral_code": "partner-7",
  "requested_units": 125,
  "selected_funding_rail_key": "crypto:usdc:ethereum",
  "subscription_agreement_reference": "hcla_0123456789abcdef0123456789abcdef"
}

RESPONSES

Status and payload examples

201Mutation accepted and canonical state returned.Mutation completed · JSON RESPONSE+

{}

INTEGRATION DECISION

CALLER ACTION: Accept the returned representation or receipt, then re-read contractual subscription using the canonical identifier returned by this operation.
RETRY SAFETY: Do not repeat a successful mutation merely to confirm it. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions.
STATE RECONCILIATION: Persist returned identifiers, versions, commitments, and receipts. Refresh the offering revision, evidence commitments, review and disclosure status, readiness milestone, issuer authority, and publication or finality receipt.

401Bearer credential is missing, expired, or invalid.Authentication required · JSON RESPONSE+

{
  "code": "invalid_credentials",
  "message": "the supplied Hybrid credential is invalid"
}

INTEGRATION DECISIONinvalid_credentials

CALLER ACTION: Discard the rejected credential, complete the documented authentication or reassertion flow, and rebuild any request signature with fresh timestamps and nonces.
RETRY SAFETY: Retry only with a newly valid credential and fresh replay-protection values. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions.
STATE RECONCILIATION: Assume the outcome is unknown only when the connection failed after transmission; otherwise authentication failed before domain work. Refresh the offering revision, evidence commitments, review and disclosure status, readiness milestone, issuer authority, and publication or finality receipt.
ESCALATE WHEN: Escalate when issuer authority, diligence evidence, disclosures, approvals, publication, or chain finality cannot be matched to one immutable revision.

403The principal lacks the required scope, role, tenant, or step-up authority.Authority or policy denied · JSON RESPONSE+

{
  "code": "invalid_credentials",
  "message": "the supplied Hybrid credential is invalid"
}

INTEGRATION DECISIONinvalid_credentials

CALLER ACTION: Verify the exact scope, tenant or workspace membership, owner boundary, step-up purpose, feature policy, and resource eligibility. Never broaden authority automatically.
RETRY SAFETY: Do not retry until the missing authority or policy condition has been deliberately resolved with least privilege.
STATE RECONCILIATION: Confirm the caller and resource resolve to the same authority boundary for issuer-private offerings, evidence, reviews, disclosures, readiness milestones, publication, and finality receipts.
ESCALATE WHEN: Escalate when issuer authority, diligence evidence, disclosures, approvals, publication, or chain finality cannot be matched to one immutable revision.

422Path, query, or body validation failed.Request must change · JSON RESPONSE+

{
  "code": "invalid_credentials",
  "message": "the supplied Hybrid credential is invalid"
}

INTEGRATION DECISIONinvalid_credentials

CALLER ACTION: Rebuild the request from the live OpenAPI operation and correct the rejected method, media type, header, parameter, or body field.
RETRY SAFETY: Do not retry the same invalid request. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions.
STATE RECONCILIATION: Compare the submitted values with the documented constraints before another call. Refresh the offering revision, evidence commitments, review and disclosure status, readiness milestone, issuer authority, and publication or finality receipt.
ESCALATE WHEN: Escalate when issuer authority, diligence evidence, disclosures, approvals, publication, or chain finality cannot be matched to one immutable revision.

503The authoritative service or read model is unavailable.Dependency unavailable or outcome uncertain · JSON RESPONSE+

{
  "code": "invalid_credentials",
  "message": "the supplied Hybrid credential is invalid"
}

INTEGRATION DECISIONinvalid_credentials

CALLER ACTION: Preserve the exact request and treat the outcome as uncertain until authoritative state proves whether it committed.
RETRY SAFETY: Reconcile before retrying. For one logical mutation, retain the same Idempotency-Key and byte-equivalent request. Never reuse that key for changed instructions. Use bounded backoff with jitter.
STATE RECONCILIATION: Refresh the offering revision, evidence commitments, review and disclosure status, readiness milestone, issuer authority, and publication or finality receipt.
ESCALATE WHEN: Escalate when issuer authority, diligence evidence, disclosures, approvals, publication, or chain finality cannot be matched to one immutable revision.

OPERATIONAL NOTES

Security and lifecycle guarantees

Verify the authenticated investor's Identity-issued agreement receipt against the current deal, then record exact requested units, selected enabled rail, and optional immutable first-touch attribution. This does not reserve or move funds, allocate, issue, admit, or trade the instrument.
The Rust gateway validates the public contract and routes only to the authoritative owner; clients never address internal services directly.
Mutations are retry-safe only when the same Idempotency-Key and canonical request body are reused.
The tables and examples are derived from the current gateway source OpenAPI. Re-fetch the deployed OpenAPI before execution; deployment status is shown separately on this page.
Only parameters present in the OpenAPI operation are accepted; undocumented query keys fail closed with HTTP 422.

DOCUMENTATION STATUS

This route is implemented in canonical gateway source and appears in the production OpenAPI snapshot observed 2026-09-11T06:35:11.572Z. Authentication, tenant, feature, venue, and market policy still apply.

Verify the exact production OpenAPI operation ↗Return to the V2 directory ↗