{"slug":"oip-vs-function-calling","title":"OIP vs LLM Function Calling","body":"## Introduction to OIP vs Function Calling\nOIP (Object Invocation Protocol) is a protocol standard that defines a mechanism for invoking objects, which are directory objects that contain a set of capabilities. A capability is a directory object that can be invoked using the `POST /api/dispatch` route or the `GET /api/dispatch?invoke=KEY&body=...` route, which appends to the ledger and returns a receipt at `/api/dispatch?receipt=inv_ID`.\n\n## Comparison to LLM Function Calling\nLLM (Large Language Model) function calling, such as OpenAI and Anthropic, uses a tool schema to define the structure of the input and output data. In contrast, OIP uses a directory row to define the capabilities of an object. The directory row contains a set of key-value pairs that define the object's properties and behavior.\n\n## Receipts in OIP\nOIP returns a receipt for every invocation, which proves that the invocation was successful and provides a record of the transaction. The receipt is stored in the ledger and can be retrieved using the `/api/dispatch?receipt=inv_ID` route. This provides a transparent and auditable record of all invocations, which is not typically available in LLM function calling.\n\n## Tool Schemas vs Directory Rows\nTool schemas in LLM function calling define the structure of the input and output data, whereas directory rows in OIP define the capabilities of an object. The directory row contains a set of key-value pairs that define the object's properties and behavior, which provides a more flexible and dynamic way of defining the object's capabilities.\n\n## Invocation Mechanism\nThe invocation mechanism in OIP is defined by the `POST /api/dispatch` route or the `GET /api/dispatch?invoke=KEY&body=...` route, which appends to the ledger and returns a receipt at `/api/dispatch?receipt=inv_ID`. This provides a standardized way of invoking objects, which is not typically available in LLM function calling.\n\n## Comparison to MCP\nMCP (Model Context Protocol) is a related standard that defines a mechanism for connecting models to servers that expose tools, resources, and prompts over a session. OIP and MCP are complementary protocols that provide a comprehensive framework for building and deploying models. While MCP defines the mechanism for connecting models to servers, OIP defines the mechanism for invoking objects and managing their capabilities.\n\n## Conclusion\nIn conclusion, OIP provides a more flexible and dynamic way of defining object capabilities, and returns a receipt for every invocation, which provides a transparent and auditable record of all invocations. The comparison to LLM function calling highlights the differences between tool schemas and directory rows, and the importance of receipts in OIP.","hero":null,"images":[],"style":{"accent":"#16324f","measure":860},"tags":["oip","object-invocation-protocol","protocol-specification","machine-native-json","dynamic"],"model":null,"ledger":null,"embeds":[],"widgets":[{"type":"stat","value":1,"label":"version"},{"type":"note","title":"Zero-context rule","text":"A reader should understand the protocol unit, object contract, invocation route, receipt schema, and repair path from this page plus its machine bundle."},{"type":"note","title":"Machine-native rule","text":"The JSON is the executable map: object, routes, inputs, proof loop, ledger, and next article to open."}],"home":false,"claims":[{"id":"oip-c1","tier":"system","text":"The OIP article layer is generated from live directory rows, so it documents the objects that actually run the reference implementation.","who_claims":"system/oip_articles","source_ids":["oip-s3","oip-s4"]},{"id":"oip-c2","tier":"system","text":"The OIP operating path is caller to directory object to dispatch runner to invocation ledger to receipt.","who_claims":"system/oip_articles","source_ids":["oip-s1"]},{"id":"oip-c3","tier":"system","text":"Every executable capability in the reference implementation is reachable as an OIP object with a human article, a machine document, invocation history, and receipt path.","who_claims":"system/oip_articles","source_ids":["oip-s2","oip-s3"]},{"id":"oip-c4","tier":"system","text":"Tap & Go is the copy primitive: one drop carries credential, protocol, tree, search, execute, and receipt instructions without a separate token-map-bundle assembly step.","who_claims":"system/oip_articles","source_ids":["oip-s2"]},{"id":"oip-c5","tier":"system","text":"OIP receipts are the proof object for actions: they record request, response, actor, links, replay, repair, and lineage.","who_claims":"system/oip_articles","source_ids":["oip-s2","oip-s5"]}],"sources":[{"id":"oip-s1","type":"protocol","title":"BUILD_SPEC object invocation path","url":"https://miscsubjects.com/api/file/docs/BUILD_SPEC.md","summary":"Defines directory rows, dispatch, ledger, and the escalation path for changing the build.","quote":"Run anything: POST https://miscsubjects.com/api/dispatch {key, body}","claim_ids":["oip-c2"],"link_status":"ok","hash":"oipbuildspec0001"},{"id":"oip-s2","type":"protocol","title":"Object Invocation Protocol spec","url":"https://miscsubjects.com/api/file/docs/OIP.md","summary":"Defines OIP surfaces, invariant loop, receipt/replay/repair, and invocation envelopes.","quote":"identify, explain, invoke, ledger, yield","claim_ids":["oip-c3","oip-c4","oip-c5"],"link_status":"ok","hash":"oipspec00000002"},{"id":"oip-s3","type":"protocol","title":"Live OIP capability tree","url":"https://miscsubjects.com/api/dispatch?map=1&format=markdown","summary":"Public recursive capability tree.","quote":"root > shelf > system article > capability article > receipt","claim_ids":["oip-c1","oip-c3"],"link_status":"ok","hash":"oipmap0000000002"},{"id":"oip-s4","type":"protocol","title":"Directory row documentation","url":"https://miscsubjects.com/api/dispatch?key=OIP_TREE&format=markdown","summary":"Capability articles are generated from live rows.","quote":"Machine Contract","claim_ids":["oip-c1"],"link_status":"ok","hash":"oiprow0000000003"},{"id":"oip-s5","type":"protocol","title":"Invocation ledger","url":"https://miscsubjects.com/api/invocations","summary":"Append-only invocation records and receipt links.","quote":"invocations","claim_ids":["oip-c5"],"link_status":"ok","hash":"oipinvocations0005"}],"reviews":[],"extra":{"oip_virtual":true,"oip_type":"dynamic","count":1,"metric":"version","version":1,"author_model":"@cf/meta/llama-3.3-70b-instruct-fp8-fast","revision_source":"manual"},"register":"oip_protocol","status":"published","revisions":0,"contributions":[],"provenance":[{"action":"generate","model":"system/oip_articles","ts":"2026-07-03T00:21:27-07:00","hash":"virtual-oip","tokens_in":0,"tokens_out":0}],"energy":{"passes":1,"tokens_in":0,"tokens_out":0,"tokens_total":0,"cost_usd":0,"models":{"system/oip_articles":1},"head":"virtual-oip"},"posted_at":"2026-07-02T00:00:00.000Z","created_at":"2026-07-02T00:00:00.000Z","updated_at":"2026-07-03T00:21:27-07:00"}