Skip to main content
Apostra publishes bounded, versioned workflow skills that teach an AI agent how to complete a client job safely. The public catalog is the source of truth for the current workflow roster and immutable version URLs.

Workflow skill catalog

Read the machine-readable catalog of current and published workflow versions.

​
Workflow skills

Build with Apostra

Connect a repository and build a tested agent, data sender, or reporting pipeline. Start with the V3 quickstart.

Get an Account Ready to Buy

Resolve buyer identity, billing, and seller-connection readiness.

Set Up a Campaign

Turn a buyer brief into a grounded draft and staged media buy.

Manage a Campaign

Review delivery and safely change an existing campaign.

Set Up an Event Source

Configure or reuse conversion tracking for social platforms, direct feeds, and measurement partners.

Generate Campaign Creatives

Create, refine, approve, and finalise a Creative Session when the buyer is enrolled.

Buy from a Seller

Discover one seller’s verified AdCP endpoint and transact through it.

Publish an OpenAI App

Prepare a seller’s Apostra-powered app for OpenAI review.

Test a Sales Agent

Run evidence-oriented, no-spend validation through ordinary V3 buyer tools.

Inspect a Tag Sheet

Preview CSV, XLS, or XLSX parsing locally and report only a content-free receipt.
The stable URL for a skill resolves to its current version. The catalog also publishes immutable URLs such as /skills/set-up-a-campaign/1.2.0/SKILL.md for clients and evaluation runs that need to pin exact instructions.

​
Apostra workflow packages

Claude Code and Cowork users can add the public Apostra marketplace, then install only the workflow package that matches their job:
Buyer packages cover account setup, campaign management, creative management, and reporting. Storefront packages cover listing, merchandising, distribution, and seller-side campaign management. sales-agent-testing works with sales agents built by Apostra or by third parties. amc-self-serve-buyer combines the current buyer workflows for an Agentic Media Company’s own self-serve plugin. Some packages initially provide authenticated MCP access while their bounded workflow skill is still being authored. The marketplace README lists the exact canonical skill version included in every package. Installing a package never grants account access: Apostra OAuth, roles, capabilities, and entitlements still control every tool call. When a canonical skill advances, an automated source workflow composes a new content-derived package version and opens a review PR in the public marketplace. The update becomes public only after that mirror PR passes validation and is merged. The Inspect a Tag Sheet skill includes a self-contained local Node.js inspector. The workbook stays on the user’s machine: the inspector prints only parser and mapping-profile versions, a row count, canonical role and rule IDs, and closed diagnostic codes. It never prints or transmits filenames, worksheet names, headers, placement names, tags, URLs, formulas, or cell values. A host that cannot execute a local command can still present the exact command for the user to run, but must not claim it inspected the file.

​
How agents receive skills

The account-resolved V3 MCP endpoint advertises the io.modelcontextprotocol/skills extension and implements skills/list and skills/get. It also exposes eligible skills through MCP resources. Responses include a SHA-256 digest so a host can identify the exact bytes it retrieved. The ordinary V3 noun surface also supports search({kind: "skill", query: "test my agent"}) and get({kind: "skill", id: "test-sales-agent"}). Search returns only workflows applicable to the authenticated Buyer or Seller Account, its verified client channel, its server-authoritative V3 capabilities, any runtime feature entitlements explicitly required by the skill, and any required customer-scoped feature flags. It uses deterministic metadata matching—not a model call—and returns at most five candidates with the exact terms and match reason that selected each one. Get returns the exact current version, bundle digest, instructions, declared assets, required tools, documentation, and the evaluation contract when that version declares one. Declared JSON workflow assets such as scenarios and fixtures are also returned as parsed, digest-bound workflowAssets, so an agent can follow the workflow without permission to fetch an arbitrary server-supplied URL. These reads let Murph and external agents find a workflow from the user’s goal without a separate proprietary find_skill tool. Before an agent follows a workflow that can mutate account state, it must use get({kind: "skill", id}) for the active account and continue only when that account-filtered retrieval succeeds. Its returned version and bundle digest identify the exact eligible workflow. A public or installed bundle, skills/list, or an operation in tools/list is not account eligibility evidence; a workflow that is missing, inapplicable, unsupported, or unavailable stops before a mutation.

​
Correlate a skill run

Clients may send optional workflow identifiers on V2 REST requests: x-scope3-run-id, x-scope3-workflow-id, x-scope3-skill-id, x-scope3-scenario-id, and x-scope3-step-id. MCP clients can use _meta["scope3/run-id"], _meta["scope3/workflow-id"], _meta["scope3/skill-id"], _meta["scope3/scenario-id"], and _meta["scope3/step-id"]. The optional x-scope3-intent-hint header or _meta["scope3/intent-hint"] accepts a stable client-owned label of 1–64 characters: it must begin with a lowercase letter and then contain only lowercase letters, digits, or underscores, such as agent_testing. It is a correlation hint, not an authoritative Apostra intent taxonomy. Retrieve the skill in the same correlated workflow before sending its scenario step requests; operations observed before retrieval are not attributed to that skill. Existing V2 REST and V3 MCP calls behave the same when this metadata is omitted. Invalid workflow, skill, scenario, step, or intent values return REST 400 INVALID_CORRELATION_METADATA. Invalid run metadata returns 400 INVALID_RUN_METADATA. MCP returns JSON-RPC -32602 with the specific code in error.data.code. See Audit logs for a complete request example. These values help correlate a client’s run; they are not authorization and do not prove that the named skill was retrieved, followed, or completed. A search receipt records the applicable candidate versions. Attributing subsequent operations to one skill requires the server receipt returned by get({kind: "skill"}) for that exact version and digest. Workflow completion evidence comes only from server-observed operations, structured results, follow-up reads, cleanup, and the skill’s scenario assertions. If the server does not observe intent or completion evidence, those values remain absent. The Murph V2 insights response now provides nonEscalationRate and notEscalated for its support signal. Existing clients continue to receive taskSuccessRate and resolvedWithoutEscalation as deprecated aliases with identical values. Those aliases measure only the absence of escalation; they do not prove that a task completed successfully. Apostra does not copy skill search text, matched terms, retrieved instructions, prompts, credentials, signed URLs, briefs, creative bodies, or tool payloads into skill-learning analytics. For this analysis, Apostra stores only bounded identifiers, immutable digests, operation names and counts, outcome categories, and evidence references. Eligibility is contextual:
  • Buyer Accounts receive account readiness, campaign setup, and campaign management skills through generic MCP discovery and submission bundles.
  • Seller Accounts receive the OpenAI publication skill through generic MCP discovery. It is not included in the buyer submission bundle.
  • Buy-from-seller and Sales Agent testing are published over HTTP and are discoverable through the account-aware V3 Skill noun where applicable; they are not pushed through generic account-wide MCP skill distribution.
  • A public skill URL describes a workflow. It does not grant account access, tool entitlements, or permission to transact.
This filtering is especially important for white-label clients: an agent sees only the workflows applicable to the authenticated account and distribution channel, while the public catalog remains available for documentation and version pinning. Applicability never comes from a package-name guess. A complete version manifest declares separate Buyer and Seller audience rules and can require a named V3 capability or canonical runtime entitlement. Older manifests remain explicitly marked as legacy and use a reviewed compatibility entry until a new immutable version adopts the complete contract. The platform checks the applicable rules before advertising or returning the skill. If entitlement state cannot be verified, an entitlement-gated skill is withheld.

​
Skill format and versioning

Each workflow starts with YAML front matter containing its stable name and description, followed by the workflow, guardrails, required evidence, and failure behavior. Some skills also publish a version manifest and deterministic scenario or fixture assets; the version manifest declares those assets and the versioned routes serve them. Workflow versions use semantic versioning:
  • Patch versions clarify or safely correct an existing workflow.
  • Minor versions add compatible behavior, evidence, or scenarios.
  • Major versions change a contract in a way that can require client work.
Use the stable URL when you want improvements automatically. Pin an immutable version and digest for acceptance tests, canaries, or regulated workflows.

​
Role-wide API guides

Apostra also keeps two broader v2 role guides. These are API manuals rather than entries in the bounded workflow catalog:

Buyer API guide

Role-wide v2 buyer operations and presentation rules.

Storefront API guide

Role-wide v2 storefront operations and presentation rules.
Agents using those role-wide guides work through health, ask_about_capability, and api_call. New V3 integrations should prefer the typed V3 tools and bounded workflow skills above.