Syntax Cheatsheet

GCF has two encoding profiles that share the same grammar primitives (##, @, |, =).

Two profiles, one format

Graph profile (encode): code graph payloads with symbols, edges, and distance groups. For MCP tools returning code intelligence data.

Tabular profile (encodeGeneric): any structured data with arrays, nested objects, and primitives. For everything else.

---

Graph Profile

Header

GCF tool=<name> budget=<int> tokens=<int> symbols=<int> pack_root=<hex>

Only tool is required. All other fields are optional.

GCF tool=context_for_task
GCF tool=context_for_task budget=5000 tokens=1847 symbols=10
GCF tool=context_for_task budget=5000 tokens=1847 symbols=10 pack_root=a1b2c3d4
GCF tool=context_for_task tokens=800 symbols=5 session=true
GCF tool=context_for_task delta=true base_root=aaa111 new_root=bbb222 tokens=30 savings=81%

Symbol lines

@{id} {kind} {qualified_name} {score} {provenance}

@0 fn github.com/org/repo/pkg.AuthMiddleware 0.78 lsp_resolved
@1 type github.com/org/repo/pkg.Config 0.65 ast_inferred
@2 method github.com/org/repo/pkg.Server.Start 0.54 lsp_resolved
@3 iface github.com/org/repo/pkg.Handler 0.48 structural
@4 var github.com/org/repo/pkg.DefaultTimeout 0.32 ast_inferred

• id: zero-based integer, sequential
• kind: abbreviated (see table below)
• qualified_name: no whitespace allowed
• score: 2 decimal places (e.g., 0.78)
• provenance: no whitespace allowed

Edge lines

@{target}<@{source} {edge_type} [{status}]

@0<@2 calls              # @2 calls @0
@1<@0 references         # @0 references @1
@3<@2 implements         # @2 implements @3
@0<@4 calls added        # new edge (diff payload)
@1<@3 imports removed    # deleted edge (diff payload)

• < arrow points toward target
• Status is optional: added or removed (omit for normal payloads)

Distance groups

## targets       # distance 0 (direct matches)
## related       # distance 1 (one hop)
## extended      # distance 2 (broader context)
## distance_5    # explicit distance N
## edges         # relationship section

Kind abbreviations

Short	Full	Short	Full
fn	function	table	table
type	type	resource	resource
method	method	class	class
iface	interface	selector	selector
var	var	field	field
const	const	route	route_handler
file	file	ext	external
pkg	package	svc	service

Unknown kinds pass through verbatim.

Session bare references

@7  # previously transmitted

Two spaces before #. Used when session=true in header.

Delta payload

GCF tool=context_for_task delta=true base_root=aaa new_root=bbb tokens=30 savings=85%
## removed
fn pkg.OldFunc
method pkg.Server.Deprecated
## added
@0 fn pkg.NewFunc 0.85 rwr
@1 type pkg.NewConfig 0.72 ast_inferred
## edges_removed
pkg.Router -> pkg.OldFunc calls
## edges_added
pkg.Router -> pkg.NewFunc calls

• ## removed: kind + qname only (consumer has full declaration from prior response)
• ## added: full symbol lines with sequential IDs from 0
• ## edges_removed / ## edges_added: source -> target type format

Complete graph example

GCF tool=context_for_task budget=5000 tokens=1847 symbols=5 pack_root=a1b2c3d4
## targets
@0 fn github.com/org/repo/internal/auth.Middleware 0.78 lsp_resolved
@1 type github.com/org/repo/internal/auth.Config 0.71 ast_inferred
## related
@2 fn github.com/org/repo/internal/server.New 0.54 lsp_resolved
@3 method github.com/org/repo/internal/server.Server.Start 0.48 lsp_resolved
## extended
@4 iface github.com/org/repo/internal/handler.Handler 0.32 structural
## edges
@0<@2 calls
@1<@0 references
@4<@2 implements
@3<@2 calls

---

Tabular Profile

Tabular arrays

## {name} [{count}]{{field1},{field2},{field3}}
value1|value2|value3

## employees [3]{id,name,department,salary}
1|Alice Smith|Engineering|95000
2|Bob Jones|Sales|72000
3|Carol Wu|Marketing|85000

• One header declares field names; rows are positional values only
• Pipe | separator, no spaces
• No @id on flat rows (only when nested fields need cross-referencing)

Tabular with nested fields

## orders [2]{id,total,status}
@0 1001|249.99|shipped
  .customer
    name=Alice Smith
    tier=premium
@1 1002|89.50|pending
  .customer
    name=Bob Jones
    tier=standard

• @{id} prefix when rows have nested sub-objects
• .fieldname introduces an inline nested object
• Nested fields use key=value pairs, indented

Object encoding

config=production
version=2.1.0
## database
  host=db.example.com
  port=5432
  pool_size=10
## cache
  ttl=3600
  max_size=1000

• Primitives: key=value (no quotes for numbers/booleans)
• Nested objects: ## key section header + indented key=value
• Null/missing: -

Value formatting

Type	Format	Example
String	bare text	Alice Smith
Number	unquoted	95000
Boolean	lowercase	true / false
Null	dash	-
String with | or newline	quoted	"value|with|pipes"

Complete tabular example

name=Acme Corp
region=us-east-1
## employees [3]{id,name,department,salary,active}
1|Alice Smith|Engineering|95000|true
2|Bob Jones|Sales|72000|true
3|Carol Wu|Marketing|85000|false
## projects [2]{id,title,lead}
@0 101|Auth Rewrite|Alice Smith
  .tags
    priority=high
    deadline=2026-Q3
@1 102|Dashboard|Bob Jones
  .tags
    priority=medium
    deadline=2026-Q4

---

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